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Axkiker
10-15-2014, 09:16 PM
I have some chatter in my lathe and I believe part, if not all of the problem is in the compound and cross slide. I know they both have wear so it will only help to scrape them in. Neither surface should be hardened like the ways so this I think is a doable task.

I do not have a surface plate for reference and really dont want to get one. Any alternatives or ways around this ???


Thanks

J Tiers
10-15-2014, 10:07 PM
You have to have something seriously flat. And another something to reach into the dovetail ways that is also seriously flat. And some tools for scraping what is presumably cast iron. And some basic know-how on how to do the job, plus incidentals like marking material, etc.

The know how and practice is very important, or you are virtually guaranteed to make things worse than they were. Don't bother arguing about that, we've many of us thought the same thing, and learned better.

For this job, NONE of the "make-do" stuff that is "kinda pretty close to flat" will work at all.

But, luckily for you, a surface plate is not very helpful for a large part of the job. The bad news is that you still need some other flat reference, like a wide "straightedge" with an angle part on it.

Don't have one? Don't want one? Don't start.

Fasttrack
10-15-2014, 10:14 PM
... is this a "troll" post?

If this is a legitimate question then here are some general pieces of advice:

1)Before going through something as drastic as re-scraping your cross slide, make sure you fully understand what is causing the problem. You should be able to remove the chatter by adjusting a gib strip and/or locking the crossfeed while feeding in the longitudinal direction

2)Scraping any machine tool, even something as "minor" as the compound requires a fair amount of expertise. You first need to understand metrology and then build up a collection of measuring tools fit for the task. It is not something you approach willy-nilly.

3)There is no substitute for a flat reference. That said, you can generate your own reference from (3) blocks of cast iron. Again, this is something that should be attempted only after you have "mastered" more basic tasks involving precision measurement and layout. You will need high quality measurement tools - e.g. DTIs with 0.0001" graduations from a company like Interapid or Brown and Sharpe. Not "Fowler", "Econo", etc. If you have to ask about a surface plate, then you probably aren't ready to generate your own - and I truly mean no offense by that statement. We all have to start somewhere, but it sounds to me like you are jumping into something too quickly here.

Edit: As JT says, you don't need a "surface plate" per-se. You do need a flat reference, which you can generate yourself if you have the knowledge, patience and materials to do so. However, this is equivalent to running before you crawl. The reference is just that - the master by which everything else is judged. If it isn't "dead-nuts", then everything else you do will be suspect and your lathe will end up in worse condition than when you started.

PStechPaul
10-15-2014, 10:31 PM
I have ordered some optical flats from www.surplusshed.com. They had a 40% off sale that ended yesterday. They are used to check flatness to 1/4 to 1/20 wave, or nanometers. Cost is less than $10.

Some ideas:
http://www.surplusshed.com/pages/item/pm1250.html
http://www.surplusshed.com/pages/item/pm1126.html

Doozer
10-15-2014, 10:40 PM
I acquired a cast iron surface plate.
This was because it was lighter than granite for a given size.
A plus for me, as I had a basement shop at the time.
They are around, just have to look harder.

-D

dp
10-15-2014, 10:43 PM
Since you're not looking for perfection you can use granite floor tiles. They're much less expensive than surface places. Check them at the store for flatness with a laser pointer.

Paul Alciatore
10-15-2014, 11:03 PM
First, there are 6" x 6" plates advertised for well under $20. That size should provide about 8.4" on the diagonal which should be enough for the cross slide and compound on most home shop sized lathes. So it need not be a large expense or take up a lot of room in your shop.

But, as others have said, what you really need is small straight edges that will fit in the dovetails and a good right angle. On a limited budget I would go to the local stone cutters. A polished piece of marble is probably very flat and they can cut some scraps into suitable pieces. A good test of it's flatness is to view a reflection at a very shallow angle. If it is not distorted, then the surface is flat.

http://img.photobucket.com/albums/v55/EPAIII/Web%20Post%20Photos/FlatnessTest2_zpsa036a3e4.jpg (http://smg.photobucket.com/user/EPAIII/media/Web%20Post%20Photos/FlatnessTest2_zpsa036a3e4.jpg.html)

The reflected image should be viewed from two directions which are at right angles to each other (from adjacent sides). The reflected image should be the same size as the original and there should be no distortions or wiggles when it is moved around slightly by tilting the surface of moving your eye. This is not a perfect test, but it will quickly eliminate most non flat surfaces.

On the right angle, look up "cylindrical square". You can make one on your lathe, even if it is a bit sloppy.

PStechPaul
10-15-2014, 11:08 PM
A 9x12 0.0002 surface plate is only about $42: http://www.use-enco.com/1/1/1255-black-granite-inspection-surface-plates-640-0100.html

dp
10-15-2014, 11:28 PM
Here is Evan's brilliant solution using the laser:

http://bbs.homeshopmachinist.net/threads/30712-Measuring-Flatness?p=381028#post381028

Direct link: http://vts.bc.ca/metalshop/laser/flattest.htm

Home Depot 12"x12" granite tile - $5.00:

http://www.homedepot.com/p/MS-International-Absolute-Black-12-In-x-12-In-Polished-Granite-Floor-and-Wall-Tile-5-sq-ft-case-THDINDBLK1212/202194774

mike4
10-16-2014, 01:00 AM
As has already been mentioned , check the gibs , maybe one is worn , they are easy to make and then you will again have a wide range of adjustment , something to check before embarking on the scraping activities which can as others have stated cause much grief if not done correctly.

Michael

J Tiers
10-16-2014, 08:40 AM
Yes, look for every other possible cause before starting on scraping.

And practice on something other than the machine before starting. Once yo've scraped a few surfaces flat, THEN you can start with the machine.


Since you're not looking for perfection you can use granite floor tiles. They're much less expensive than surface places. Check them at the store for flatness with a laser pointer.

Sorry to burst THAT bubble.... but the floor tile is simply NOT GOING TO DO ANYTHING GOOD.

Scraping to a floor tile for flatness is likely to result in a cross-section of the Andes mountains being scraped-in to the surfaces. Flatness for slides and flatness for floor tiles are simply not in the same universe. The result may well be much worse than what you start with.

Then also, the dovetails will need to be scraped to something that fits into the dovetail. That, if scraped to a floor tile, will result in a negative image of the Andes.... Again not what you want, with the added "feature" that the two resulting "surfaces" may actually interlock.

oldtiffie
10-16-2014, 08:55 AM
Here is the OP's post.


I have some chatter in my lathe and I believe part, if not all of the problem is in the compound and cross slide. I know they both have wear so it will only help to scrape them in. Neither surface should be hardened like the ways so this I think is a doable task.

I do not have a surface plate for reference and really dont want to get one. Any alternatives or ways around this ???


Thanks

Why does everybody accept his diagnoses and not challenge the OP as regards other possible causes of his "chattering"?

Axkiker
10-16-2014, 09:16 AM
Thanks everyone who responded... Well everyone except the one who called me a troll. Anyways this was just my first initial thoughts. I plan to pull everything apart over the winter and check things out. Once I do that ill have a better understanding as to what I will do

Thanks

Fasttrack
10-16-2014, 10:03 AM
Thanks everyone who responded... Well everyone except the one who called me a troll. Anyways this was just my first initial thoughts. I plan to pull everything apart over the winter and check things out. Once I do that ill have a better understanding as to what I will do

Thanks

:)

I didn't call you a troll, I just asked if this was a troll post. It's kind of like getting on here and posting "I just bought an HLV but I don't want to buy way oil. Can I use barn and chain lube?". It's a loaded question and will likely result in controversy.

In seriousness, when it comes to scraping in a machine - as JT says - a floor tile is not the thing to use... at all. Believe it or not, that hard, rigid floor tile will actually deflect quite a bit depending on how it is supported. There is a reason why surface plates are made THICK and reside on specially engineered stands.


Why does everybody accept his diagnoses and not challenge the OP as regards other possible causes of his "chattering"?
I did not accept his diagnosis. I mentioned that the problem is probably with a gib strip or something else entirely. Hence my recommendation to *fully* understand the problem before starting in on scraping.

Axkiker - scraping is a fun and useful skill. But it isn't one you develop in a couple hours of internet surfing or even diligent studying. Like JT says, you need to spend a lot of time practicing and building up your arsenal of tools and know-how.

Re: optical flats - they may be flat but they don't spot well. It is difficult to get good transfer. (Incidentally, one of the biggest things you will have to practice is spotting the work and learning to read what you are seeing. It is not as straightforward as it seems initially).

Look for a pdf copy of the book "Machine Tool Reconditioning" by Connelly for a good place to start.

Mike279
10-16-2014, 10:58 AM
I have chatter in my lathe. Without telling us what kind of lathe, material, or cutter you are using. Let's jump to a conclusion that is probably the hardest to do, without exploring the usual problems first. Why don't you give us some background so, we can suggest the usually more simple and effective ways to turn materials on a lathe? Mike

Old Hat
10-16-2014, 11:59 AM
A lathe so loose you can move the components by pushing on them often will cut like dream.

Chatter is caused by a cutting edge being unable to hold a constant chip-load
(ie, take-on an amount of defection and sustain it) the cutting edge digs in untill it chops
becoming momentairilly free recoiling for the nect cycle of digging in.

You are looking at the least likely cause of chatter.

Run CW and bore/turn on the back side, with down faceing cutter, note results,
Run CCW and bore/turn on the back side, with up faceing cutter,note results.
Run CCW and bore/turn on the usual side, with down faceing cutter, note results,
Monitor the spindle behind the chuck, note results.
Tool-post? Type? Condition? well mounted?

Bit / Insert geometry?
See where I'm going with this?

dp
10-16-2014, 12:07 PM
Sorry to burst THAT bubble.... but the floor tile is simply NOT GOING TO DO ANYTHING GOOD.

The OP is not looking to do anything good else he would get a proper tool set so floor tiles are not going to hurt anything. Did you miss that?

Axkiker
10-16-2014, 02:27 PM
The OP is not looking to do anything good else he would get a proper tool set so floor tiles are not going to hurt anything. Did you miss that?

Hey guy... how about not guessing what I will or will not do. You, nor anyone else on here know what I WILL do. I asked a simple question about a surface plate alternative. If you have any advice around an alternative then suggest.

If not, don't reply and stay out of the thread. I don't mind the suggestions regarding why not to undertake the project, thats perfectly fine. If you are so full of yourself that you believe you know what I WILL eventually do then just save it. I don't need your arrogance or advice.

mikem
10-16-2014, 02:58 PM
DP offers some good advice, so I wouldn't be running him off, just yet. Jtiers offers lots of good advice. Paul took the time to make a drawing for you.

Here is the deal.....your question and comments have shown that you have some things to experience yet in machining. Don't be offended by someone that is trying to help you. You ask for help....you should be grateful, say thanks and try to understand what they are telling you.

Your chatter can be caused by a dozen different things, the least likely maybe be the flatness of the cross slide. More likely, the cause is too much flexibility between the cross slide and the cutting tip. Fixes might include shortening the overhang on your tool bit, sharpening your bit differently, less feed.....lots of things to try.

Axkiker
10-16-2014, 03:06 PM
DP offers some good advice, so I wouldn't be running him off, just yet. Jtiers offers lots of good advice. Paul took the time to make a drawing for you.

Here is the deal.....your question and comments have shown that you have some things to experience yet in machining. Don't be offended by someone that is trying to help you. You ask for help....you should be grateful, say thanks and try to understand what they are telling you.

Your chatter can be caused by a dozen different things, the least likely maybe be the flatness of the cross slide. More likely, the cause is too much flexibility between the cross slide and the cutting tip. Fixes might include shortening the overhang on your tool bit, sharpening your bit differently, less feed.....lots of things to try.


I thanked everyone for the advice and suggestions earlier. I also stated this was my initial thoughts and would be pulling everything apart in the winter for a closer inspection. Then I could decide what I would do.

DP states that I dont plan on doing anything good or I would buy the proper equipment. This is not trying to help and I do not want this type of arrogance in my thread. No matter how much he may or may not know.

QSIMDO
10-16-2014, 03:19 PM
I think what's most puzzling to responders is your aversion to obtaining an actual surface plate.
They are ubiquitous in shops everywhere and are the basis for so many operations it probably can be argued one should be in your shop before the machines.

For what you want to do a smaller, easily handled and inexpensive granite surface plate is the best way to go...not the ONLY way, mind, but at least you won't be wondering how accurate your surface is.

plunger
10-16-2014, 03:25 PM
I may be in the same boat .Maybe I can ask the forum if a granite cut out that comes from a sink top would work. They seem to be very flat and are 32mm in thickness. I also have a sheet of glass that is 500mm x 500mm by 25mm thick. You guys overseas are really spoilt for choice when it comes to buying stuff.

Axkiker
10-16-2014, 03:27 PM
I think what's most puzzling to responders is your aversion to obtaining an actual surface plate.
They are ubiquitous in shops everywhere and are the basis for so many operations it probably can be argued one should be in your shop before the machines.

For what you want to do a smaller, easily handled and inexpensive granite surface plate is the best way to go...not the ONLY way, mind, but at least you won't be wondering how accurate your surface is.

Im not... I just thought there may be a cheaper alternative. I really didnt know that the smaller plates could be had for so little. Now that I see this I kinda want to grab one just to try scraping some scrap iron. Would be fun just to try it out at first.

Fasttrack
10-16-2014, 03:44 PM
I may be in the same boat .Maybe I can ask the forum if a granite cut out that comes from a sink top would work. They seem to be very flat and are 32mm in thickness. I also have a sheet of glass that is 500mm x 500mm by 25mm thick. You guys overseas are really spoilt for choice when it comes to buying stuff.

Most things in machining are a case of "you get what you pay for". There is a reason why good granite surface plates are large and costly. Will a granite slab cutout or piece of glass work as a reasonably flat reference for use during setup/layout/inspection? Probably. Is it a substitute for the real thing? No. It just depends on what you want to do with it and how accurate you need to be.

Quality granite surface plates should be calibrated in-situ and be used in an environmentally controlled room. A little while ago, I quoted the cost to calibrate my 3' by 4' plate by an outfit I found through the Tektronix website. IIRC, it was about $1k, which I considered a bargain. The result was a certified, lab grade granite surface plate to be used in an environmental controlled room for QA on precision optical assemblies. If you just need something for general purpose, +/- a couple thousandths type work, then those substitutes are probably reasonably.

But if you want to scrape in a machine tool, you should start with an extremely accurate reference. You should pay attention to temperature during the process, even isolating your body heat from your spotting and measurement tools. You should approach it more like brain surgery than general machining or fabrication.

Axkiker - it is very fun. Buying a cheap Chinese "tombstone" and some scrap cast iron to practice with is a great way to learn. Also look for posts by Richard King and Forrest Addy on the subject. Again, the book I mentioned is invaluable for this learning process.

Axkiker
10-16-2014, 03:55 PM
So, is lapping a cross slide in an option? The reason I ask this is I saw one of Keith Fenner's videos where is did something similar. This is originally what got be to thinking about scraping in the slide. I kinda thought that if laping on a surface plate was a possibility that scraping could be a bit more accurate.

Fenner is definitely way above me in terms of skill. So I figure if it was acceptable for him it would probably be great for me.. Who knows just thinking out loud.

plunger
10-16-2014, 05:05 PM
I have three lathes. The one is in desperate need of a scrape. I would also need to make a new tapered gib.What I dont understand is that two of my lathes have no scraping at all. They seem to have been done with a fly cutter as it has mill marks like a fly cutter with fast feed.How accurately could slides be milled?

Fasttrack
10-16-2014, 06:29 PM
I have three lathes. The one is in desperate need of a scrape. I would also need to make a new tapered gib.What I dont understand is that two of my lathes have no scraping at all. They seem to have been done with a fly cutter as it has mill marks like a fly cutter with fast feed.How accurately could slides be milled?

Can you post a picture? Who is the manufacturer? Sounds like something a cheap Harbor Freight model would have...


So, is lapping a cross slide in an option?

It depends on what you are trying to accomplish. You shouldn't need to lap it. If it is worn enough to need work, then it should be machined (if necessary) followed by scraping. Lapping is typically used to generate very smooth and very flat surfaces. When it comes to machine ways, very smooth can result in stick-slip behavior and simply being very flat is not good enough. You also need the bearing surface to be in the correct geometry and have the correct geometrical relationship to each other.

oldtiffie
10-16-2014, 07:38 PM
Originally Posted by dp

The OP is not looking to do anything good else he would get a proper tool set so floor tiles are not going to hurt anything. Did you miss that?


Hey guy... how about not guessing what I will or will not do. You, nor anyone else on here know what I WILL do. I asked a simple question about a surface plate alternative. If you have any advice around an alternative then suggest.

If not, don't reply and stay out of the thread. I don't mind the suggestions regarding why not to undertake the project, thats perfectly fine. If you are so full of yourself that you believe you know what I WILL eventually do then just save it. I don't need your arrogance or advice.

For the OP:

While it is fact that you posted the original post, it is no longer exclusively yours as as soon as it was posted it was in the "public domain" which means that it can be read by anybody who logs on and can be replied to and commented upon by any member who wants to post a response to it.

BigSpike
10-16-2014, 08:14 PM
I saw in an old thread a recommendation to check Woodcraft stores for small granite surface plates. They have a 6" x 18" x 2" one for $43. There is a store near me & they have one in stock. The freight is what tends to make these too expensive for many hobbyists.

Also Grizzly has pretty good prices & freight rates.

Axkiker
10-16-2014, 08:47 PM
I saw in an old thread a recommendation to check Woodcraft stores for small granite surface plates. They have a 6" x 18" x 2" one for $43. There is a store near me & they have one in stock. The freight is what tends to make these too expensive for many hobbyists.

Also Grizzly has pretty good prices & freight rates.

Yeah freight is pretty high since these things are fairly heavy.

I wonder if ENCO excludes plates when they have free shipping. With Xmas coming up im sure they will be saving several sales.

Doc Nickel
10-16-2014, 08:48 PM
So, is lapping a cross slide in an option?

-Generally speaking, no. Lapping accurately takes a fairly specific setup as well as care and regular measurement. Typically it's only used for final finishing on certain parts and fits.

Also, it depends on what kind of 'lapping'. If you mean squirting abrasive between the cross slide and carriage and rubbing them back and forth 'til all the high spots go away, then the answer is definitely not. You'll basically just erode both parts into a sloppy fit- there's nothing to keep you from 'lapping' a warp, twist or sag into the ways.


The reason I ask this is I saw one of Keith Fenner's videos where is did something similar.

-While I like Keith's videos, there's more than a few times he's basically just throwing Band-aids and baling wire at a job. I haven't seen the lapping video you mention, but I suspect it was a case where he was trying to restore some use to an already-well-worn machine, not to properly refurbish it.

Scraping using proper techniques and a proper flat is the correct method. Yeah, it's not easy, but it's the right way.

Doc.

Axkiker
10-16-2014, 08:49 PM
It depends on what you are trying to accomplish. You shouldn't need to lap it. If it is worn enough to need work, then it should be machined (if necessary) followed by scraping. Lapping is typically used to generate very smooth and very flat surfaces. When it comes to machine ways, very smooth can result in stick-slip behavior and simply being very flat is not good enough. You also need the bearing surface to be in the correct geometry and have the correct geometrical relationship to each other.

Yeah I see what you mean. I guess you do need the highs and lows created from scraping to create that bearing kinda surface where the lows maintain oil.

Makes sense.

Thanks

SGW
10-16-2014, 09:38 PM
Looseness and/or lack of rigidity cause chatter. Non-flat surfaces probably don't, except to the extent they can contribute to lack of rigidity because of poor contact between mating surfaces. The simplest possibility: are you trying to take too big a cut for the size of your lathe? Is your toolbit truly sharp and possitioned correctly?

But as far as surface plates go, one of the old standbys is a slab of plate glass set into a wood frame/box with a layer of padding under it. These days though, cheap granite plates can be had so readily it's hardly worth looking for a substitute.

The workability of a substitute depends a lot on who is using it. My old mentor, Dan Fay, used a broken piece of granite storefront veneer for his surface plate. With it he worked wonders, but I doubt anyone else could have. Describing it one day, he said "It falls off about 5 thou as you get towards this corner, but I allow for that...." But even Dan eventually bought a proper granite plate when he came across a used one, really cheap. For us ordinary mortals, it's not worth the aggravation to try to make-do. Spend 50 bucks or whatever and get a decent surface plate.

schor
10-16-2014, 09:57 PM
Glass is not flat, and should not be used as a substitute for a surface plate.



I may be in the same boat .Maybe I can ask the forum if a granite cut out that comes from a sink top would work. They seem to be very flat and are 32mm in thickness. I also have a sheet of glass that is 500mm x 500mm by 25mm thick. You guys overseas are really spoilt for choice when it comes to buying stuff.

J Tiers
10-16-2014, 10:28 PM
First, the idea that something else might be the issue...

Sure, we already talked about that. It could be. Certainly SOME of it is something else because even a new good quality machine will chatter with some cuts that are technically within it's capability.

First answer the actual question.... which has been done. And it probably is done sufficiently to discourage taking that approach first.

That said, I have no doubt that virtually ANY manual lathe these days, new OR used, needs some scraping back to alignment. The chinese ones certainly often do, the way they, and chinese accessory stuff, such as levels, blue up is frequently disgraceful. Rocking chair levels, crosslides with a banana shape.... Maybe some old used stuff is better in alignment and way contact.

Before you howl at me, I am not talking about anything I have not personally seen. And in some cases returned to the vendor for full credit.


The OP is not looking to do anything good else he would get a proper tool set so floor tiles are not going to hurt anything. Did you miss that?

No I DID get that..... And I don't give a rat's hind end about it, frankly.... A floor tile "flat" WILL screw stuff up if used as suggested.... It wouldn't matter if the OP understood how bad an idea it is or not, it would still be a bad idea that screws up stuff. The NEXT owner will reap the problems, at least.

But I have a sneaking suspicion he really does "get it", after all.


Looseness and/or lack of rigidity cause chatter. Non-flat surfaces probably don't, except to the extent they can contribute to lack of rigidity because of poor contact between mating surfaces.



Which is precisely the point. Carriages wear to a "rocking horse" configuration because the cutting force puts pressure on the carriage wings that way, to take only one example. And, of course, if the carriage wears, there will be similar and opposite wear on the ways, just most likely a bit less deep, since it is usually distributed along the bed.

That rocking-horse wear lets the tool move in and out as the carriage twists and rocks on the ways in response to various forces of cutting. Perfect opportunity for chatter. There are plenty of other types of wear as well, each with its own type of problem and opportunity for chatter.

Is wear guaranteed to be the problem? Nope... re-read the other sections above.

Axkiker
10-16-2014, 10:53 PM
Which is precisely the point. Carriages wear to a "rocking horse" configuration because the cutting force puts pressure on the carriage wings that way, to take only one example. And, of course, if the carriage wears, there will be similar and opposite wear on the ways, just most likely a bit less deep, since it is usually distributed along the bed.

That rocking-horse wear lets the tool move in and out as the carriage twists and rocks on the ways in response to various forces of cutting. Perfect opportunity for chatter. There are plenty of other types of wear as well, each with its own type of problem and opportunity for chatter.

Is wear guaranteed to be the problem? Nope... re-read the other sections above.

You basically explained why my initial thoughts were to address the cross slide. I personally believe the wear has created this "rocking horse" scenario you mentioned. The tool tends to leave rings when turning. Its like the tool moves in and out at random places. Its very random, and very minor, but when trying to achieve a good finish in something harder than aluminum its a pain. It could coming from some other place, and most likely is to a certain degree. Its just my gut feeling that this is a part of whats contributing to the issue and may be the easiest to fix. I could be totally wrong but ill look into that this winter.

I was just thinking that a surface plate could be used to address this issue but that doesnt seem to be the case. Good to know but wow... I didn't think I would stir so much up.

J Tiers
10-16-2014, 11:05 PM
Well it's not that only one. The near end of the front way on the cross-slide also wears due to forces. That makes the characteristic symptom of the slide getting looser as you crank it back towards you.. the cranking gets easier and can feel "loose".

plunger
10-17-2014, 01:37 AM
Fast track two of my lathes have fly cutter marks. They are very accurate.I am wondering if they are not precision ground and then fly cut at great feed rate to break the smoothness to allow oil to do its thing.(emco austrian cost more than two bmws in 1978)

dp
10-17-2014, 02:19 AM
Hey guy... how about not guessing what I will or will not do. You, nor anyone else on here know what I WILL do. I asked a simple question about a surface plate alternative. If you have any advice around an alternative then suggest.

If not, don't reply and stay out of the thread. I don't mind the suggestions regarding why not to undertake the project, thats perfectly fine. If you are so full of yourself that you believe you know what I WILL eventually do then just save it. I don't need your arrogance or advice.

I think I'm the only one who did suggest an alternative. And as alternatives go it is actually quite valuable. I also provided a link to posts here to check your surface quality. Granite tiles have a lot of uses in the home shop (lapping, for example) and I currently have three of them. I also have an actual surface plate but for most purposes I'll use the tiles. If I'm doing something that actually requires surface place precision I have it and use it.

I presumed when you posted your original post you were aware of the consequences of your choices and were ok with them. I'm ok with them, too, btw, and are more common than a full machine audit and scraping kit, but they are not on the path to full precision. Your position has change since that post and that's fine - don't blame me, though, for responding to what you originally wrote. Now that you're better informed you are back on the path to better results and we can do a reset. If you can afford a surface plate and the other essentials needed (a brayer, best quality you can afford, India stones, dial test indicators, precision levels, a precision angle plate, and scraping tools, transfer inks) you can make excellent improvements to your machine.

dp
10-17-2014, 02:30 AM
No I DID get that..... And I don't give a rat's hind end about it, frankly.... A floor tile "flat" WILL screw stuff up if used as suggested....

Tell me you know this because you have analyzed first hand the quality and character of granite floor tiles that have been selected for the purpose. We can't both be right and I actually do have a lot of experience with tiles.

alanganes
10-17-2014, 07:32 AM
Yeah freight is pretty high since these things are fairly heavy.

I wonder if ENCO excludes plates when they have free shipping. With Xmas coming up im sure they will be saving several sales.

So far as understand, ENCO does not exclude granite plates when they do the free shipping offers, unless they have changed their policy. I recall several members on this board doing just that, waiting for a free shipping offer just to order a surface plate.

Fasttrack
10-17-2014, 08:32 AM
The tool tends to leave rings when turning. Its like the tool moves in and out at random places. Its very random, and very minor, but when trying to achieve a good finish in something harder than aluminum its a pain. It could coming from some other place, and most likely is to a certain degree. Its just my gut feeling that this is a part of whats contributing to the issue and may be the easiest to fix. I could be totally wrong but ill look into that this winter.



Out of curiosity, what kind of tool are you using? I suggest HSS with a slight radius and taking deeper cuts. I have found that this can produce great results in even very sloppy machines. There is no "creeping" up to a diameter using this method, but I would say most professionals don't creep up to diameters anyway. Takes too long ;)

As an example: if I need to take off .25" from the diameter, I would take the first pass at 0.15" off the diameter on my first pass and verify that I took the appropriate amount off and adjust the dial as necessary (always do this after the first cut). 2nd pass would be 0.05" off the diameter and (since this is now second to last) I would again check and make sure it was behaving as I expect. The final pass would be 0.05" off the diameter - the same DOC as the previous cut. This is important because changing the DOC on loose lathes can cause different cutting behavior as the compound, cross slide and carriage are loaded differently.

I can easily get to +/- 0.001" on diameters (measured with quality micrometers ;) ) using this method, even on some pretty worn out machines here at work. I used to creep up to the final diameter using finishing tools, but it takes too long when you are on the clock and can be really tough to get a good surface finish on old machines.

By the way, it is very difficult to get good surface finishes on crappy mild steel, even with huge, very rigid lathes. I have a number of American Pacemaker lathes and getting a good finish on mild steel with light DOCs requires tremendous effort. Again, I opt for a heavier DOC and lots of sulfurized cutting oil. So it may not be your machine at all! Try machining a leaded steel or even annealed 4140 and see what the results are.

http://www.lathes.co.uk/pacemaker/

http://www.practicalmachinist.com/vb/attachments/f39/52600d1337803045-american-tool-works-bulletin-25a-pace-000.jpg

(Just for giggles: Pacemakers are fantastic machines but they are the kind of machine that requires some serious muscle to move! Even non-structural parts that would be plastic or stamped metal on other machines are made from 1/4" or 3/8" cast iron).

J Tiers
10-17-2014, 08:46 AM
Tell me you know this because you have analyzed first hand the quality and character of granite floor tiles that have been selected for the purpose. We can't both be right and I actually do have a lot of experience with tiles.

Not necessary.....

Floor tiles are not made to be flat within any tolerance that is meaningful for precision measurement.... i.e. they don't care about that when making them. "Acceptably flat" is not going to be in the tenths without some help.

So..... What you are suggesting is that the output from a non-precision process, which was not created for the purpose of making perfectly flat things, will somehow manufacture perfectly flat surfaces on a regular enough basis that a person going into a random store and buying one will have any sensible chance of getting one?

You have said some "interesting" things before, but to be brutally frank, you are clearly arguing for a miracle here. The chances of there BEING any perfectly flat (within a barely usable tolerance of a few tenths) floor tiles, let alone a person randomly getting one, is likely to be on the order of the probability of your computer spontaneously jumping up off the table all by itself.

thaiguzzi
10-17-2014, 09:30 AM
I keep telling y'all... fine depth of cut on ANY steel with a SUPER finish = shear tool.

dian
10-17-2014, 09:53 AM
tiles, counter tops, float glass: they can be flatter than you think, if handled properly. but you have to be able to measure them, otherwise they are nearly useless. (usually you can find a line that is as flat as you can measure.)

schor, when did you last measure "glass" and how flat was it?

dp
10-17-2014, 01:44 PM
Not necessary.....

Floor tiles are not made to be flat within any tolerance that is meaningful for precision measurement.... i.e. they don't care about that when making them. "Acceptably flat" is not going to be in the tenths without some help.

So..... What you are suggesting is that the output from a non-precision process, which was not created for the purpose of making perfectly flat things, will somehow manufacture perfectly flat surfaces on a regular enough basis that a person going into a random store and buying one will have any sensible chance of getting one?

You have said some "interesting" things before, but to be brutally frank, you are clearly arguing for a miracle here. The chances of there BEING any perfectly flat (within a barely usable tolerance of a few tenths) floor tiles, let alone a person randomly getting one, is likely to be on the order of the probability of your computer spontaneously jumping up off the table all by itself.

Listen to you. At no point have I suggested you can use imperfect tools to create a perfect solution. The OP's question was regards alternatives to surface plates. There are no alternatives to surface places that do not result in loss of perfection and it is implied in the question that perfection is not what was sought. It is also absurd to suggest that excellent if imperfect results cannot be achieved using well-made and selected for purpose tiles. I even provided links to Evan's brilliant method of indicating surface quality. In cases (and there are many) where A grade surface plates are not needed. There are cases where B quality surface plates are not needed. There are cases where you just need a very flat and very smooth surface. You need to avoid leaping from being your usual curmudgeonly self to being stridently pedantic in areas where you have no specific experience.

Your homework assignment Mr. Smarty, is to find, select, and bring home a 12"x12" tile and audit it and then report your methods and the results.

Black_Moons
10-17-2014, 02:09 PM
You have to have something seriously flat. And another something to reach into the dovetail ways that is also seriously flat. And some tools for scraping what is presumably cast iron. And some basic know-how on how to do the job, plus incidentals like marking material, etc.

The know how and practice is very important, or you are virtually guaranteed to make things worse than they were. Don't bother arguing about that, we've many of us thought the same thing, and learned better.

For this job, NONE of the "make-do" stuff that is "kinda pretty close to flat" will work at all.

But, luckily for you, a surface plate is not very helpful for a large part of the job. The bad news is that you still need some other flat reference, like a wide "straightedge" with an angle part on it.

Don't have one? Don't want one? Don't start.

100% agreed.

Also, surface plates are cheap, You can get decent ones starting at $60

Scraping is also something that takes days of work for a single surface, after spending weeks of practice just to learn the absolute basics on blocks of iron and how to figure out what direction to actually scrape it to keep everything in line.

Trying to do it without the proper tools is like trying to bore out an engine with a file. Its really not going to happen and is not practical to do even if you could, even with the proper tools you need the proper skills to do it.

Axkiker
10-17-2014, 03:21 PM
Out of curiosity, what kind of tool are you using? I suggest HSS with a slight radius and taking deeper cuts. I have found that this can produce great results in even very sloppy machines. There is no "creeping" up to a diameter using this method, but I would say most professionals don't creep up to diameters anyway. Takes too long ;)

As an example: if I need to take off .25" from the diameter, I would take the first pass at 0.15" off the diameter on my first pass and verify that I took the appropriate amount off and adjust the dial as necessary (always do this after the first cut). 2nd pass would be 0.05" off the diameter and (since this is now second to last) I would again check and make sure it was behaving as I expect. The final pass would be 0.05" off the diameter - the same DOC as the previous cut. This is important because changing the DOC on loose lathes can cause different cutting behavior as the compound, cross slide and carriage are loaded differently.

I can easily get to +/- 0.001" on diameters (measured with quality micrometers ;) ) using this method, even on some pretty worn out machines here at work. I used to creep up to the final diameter using finishing tools, but it takes too long when you are on the clock and can be really tough to get a good surface finish on old machines.

By the way, it is very difficult to get good surface finishes on crappy mild steel, even with huge, very rigid lathes. I have a number of American Pacemaker lathes and getting a good finish on mild steel with light DOCs requires tremendous effort. Again, I opt for a heavier DOC and lots of sulfurized cutting oil. So it may not be your machine at all! Try machining a leaded steel or even annealed 4140 and see what the results are.

http://www.lathes.co.uk/pacemaker/

http://www.practicalmachinist.com/vb/attachments/f39/52600d1337803045-american-tool-works-bulletin-25a-pace-000.jpg

(Just for giggles: Pacemakers are fantastic machines but they are the kind of machine that requires some serious muscle to move! Even non-structural parts that would be plastic or stamped metal on other machines are made from 1/4" or 3/8" cast iron).

I have used freshly ground and honed hss as well as new carbide. I have not tried any of the other harder alloys you mentioned but I will do so as soon as I can get to the steel shop. Once i do I'll try to start another thread with pics and we can go from there.

mike4
10-17-2014, 07:18 PM
Why is there the constant bitter debate over surface plates , the original question was about alternatives.

As some people have mentioned there are times when any reasonably flat surface is good enough , like when assembling several machined parts .

I do not disagree that there are times when more precision is required and then pull out a surface plate and use it .

But when basic marking out or quick assembly of a few parts , to check it all fits before final machining of next pieces can often be carried out on a chunk of plate off the shop floor.

I dont always work to tenths as often a part has to fit not be made to an OEM drawing with close tolerances measured in tenths as some would like all of to do for every part that we make, I can hear customers screaming now that they wanted a new pin made that could be pushed in by habd out in the field , not requiring a clean room for assembly in a climate controlled factory.

When will people realize that high precision is MOT always required , eg making an idler roller for a screening plant , these work in a hostile enviroment , out in the open , so clearance is required otherwise they would seize in the first rotation .

Get out and look at heavy equipment that is required to work 24/7 without being pampered.

There are areas where close tolerances and precision are required , eg fuel pumps , hydraulic systems .
but not ripper pins.

Michael

CarlByrns
10-17-2014, 07:50 PM
The tool tends to leave rings when turning. Its like the tool moves in and out at random places. Its very random, and very minor, but when trying to achieve a good finish in something harder than aluminum its a pain. It could coming from some other place, and most likely is to a certain degree. Its just my gut feeling that this is a part of whats contributing to the issue and may be the easiest to fix. I could be totally wrong but ill look into that this winter.



Bingo! My 7 X 10 did the same thing and it was a combination of several small problems that had to be diagnosed logically. What's happening is the carriage or the cross slide has movement in two planes- the cutter is moving up-and-down and left-and-right. On my lathe the cause was loose gib screws in the compound, weak carriage clamps, and some play in the power feed leadscrew. I made new carriage clamps (see Machinist Workshop Aug/September for more) and took out all the slack everywhere else.

Clamp a long bar in the tool holder and try to wiggle it. I'll bet there is lots of play.

J Tiers
10-17-2014, 09:25 PM
Listen to you. At no point have I suggested you can use imperfect tools to create a perfect solution. The OP's question was regards alternatives to surface plates. There are no alternatives to surface places that do not result in loss of perfection and it is implied in the question that perfection is not what was sought. It is also absurd to suggest that excellent if imperfect results cannot be achieved using well-made and selected for purpose tiles. I even provided links to Evan's brilliant method of indicating surface quality. In cases (and there are many) where A grade surface plates are not needed. There are cases where B quality surface plates are not needed. There are cases where you just need a very flat and very smooth surface. You need to avoid leaping from being your usual curmudgeonly self to being stridently pedantic in areas where you have no specific experience.

Your homework assignment Mr. Smarty, is to find, select, and bring home a 12"x12" tile and audit it and then report your methods and the results.

And, there are cases where you want a good result. Scraping a machine would be one of them. Better to never start than to do a crap job with some floor tile.

The OP seems to know some things which you may have assumed he does not. He already called you out on that, and there you go again basically explaining how bad a job he will be happy with. Or perhaps what he SHOULD be happy with....

And, the "stridently pedantic in areas where you have no specific experience".... You seem to know a many details about the folks who post here, What they would be satisfied with, what they have experience with, etc. Perhaps you would explain what areas I do not have specific experience in.... Or perhaps that would not be worth looking at, so don't bother.

If you mean scraping something to a floor tile, well, NO I do not have any experience with that. I do not NEED any experience with that. I already know that a reasonable "chinese tombstone" can be expected to be much more accurate than a random floor tile. I have seen floor tile before, and have noted that it is not particularly flat, in general. Quite a lot is textured in one way or another.

Some of the ground surface stone pieces used in flooring are not so bad as tile, but still, nothing that it would be worth using in that way. I've seen some pretty flat pine boards too, but was never tempted to use one as a reference......

Old Hat
10-18-2014, 01:29 AM
The two best Tool Makers I ever knew argued constantly, about everything.
They worked very different ways, in just about everything but grinding.
They were both reasonably happy in their own skin.

The best Tool Room Machinist I ever worked with could do anything a Tool Maker could do.
He could never be asked a question he couldn't answer. But the answers were always
questions guiding the asker toward a generallity, where he would have to refine his
approach a little to zero in on the thing.

Is there another trade or field where there is less argue~ing?
I dout it, and if there is, I have no hankering to get involved in it.

dp
10-18-2014, 01:42 AM
And, there are cases where you want a good result. Scraping a machine would be one of them. Better to never start than to do a crap job with some floor tile.

The OP seems to know some things which you may have assumed he does not. He already called you out on that, and there you go again basically explaining how bad a job he will be happy with. Or perhaps what he SHOULD be happy with....

We both know that since his first post he's had a change in direction. A good change, I think we can all agree. Nothing I said in response to his first post is appropriate to his later posts. Even he must know that by now. We all recognize that except you. But - I stand solidly behind what I suggested based on his original post.


And, the "stridently pedantic in areas where you have no specific experience".... You seem to know a many details about the folks who post here, What they would be satisfied with, what they have experience with, etc. Perhaps you would explain what areas I do not have specific experience in.... Or perhaps that would not be worth looking at, so don't bother.

If you mean scraping something to a floor tile, well, NO I do not have any experience with that. I do not NEED any experience with that. I already know that a reasonable "chinese tombstone" can be expected to be much more accurate than a random floor tile. I have seen floor tile before, and have noted that it is not particularly flat, in general. Quite a lot is textured in one way or another.

Some of the ground surface stone pieces used in flooring are not so bad as tile, but still, nothing that it would be worth using in that way. I've seen some pretty flat pine boards too, but was never tempted to use one as a reference......

If this is your opinion then I accept it as said. All it means is we've not had the same experience. In fact by your claim you've not even tried what I have done and so your opinion is based on nothing and as such is without value. Thanks for being honest about that, BTW. A lot of people would try to bs their way out of a hole like this.

The good news is the OP is back on track and I think he's going to solve his problem.

mike4
10-18-2014, 01:50 AM
This site gets very heated every time surface plates and their use is enquired about , I personally think that its a subject that has been over debated .

With the high number of members over 50 I do think that the debate should be restricted for OH&S reasons , dont want some ones ticker to blow a fuse.

Michael

dp
10-18-2014, 02:28 AM
This site gets very heated every time surface plates and their use is enquired about , I personally think that its a subject that has been over debated .

With the high number of members over 50 I do think that the debate should be restricted for OH&S reasons , dont want some ones ticker to blow a fuse.

Michael

Yep - I don't get it. My heart meds are working well though - I'm good :)

Old Hat
10-18-2014, 02:44 AM
It's an effort to win an arguement decicively on a forum.
It's different in a shop, when you can demonstate to the point of having a pruvable result.

It's fun to sit back and watch the progress on a topic you don't care about like surface plates.
I can score each contestant on delivery and technique. I can try and predict who'll get hot,
and who won't because of the soundness of his case.

Fun.

Welders, real ones, don't argue that much.
I think because their work speaks for them.
And it's far more obvious who Rules in welding.

oldtiffie
10-18-2014, 03:40 AM
In many if not most cases a Grade 3/C or 4/D surface plate will do just as well as a 1/A or 2/B - same as slip gauges and A/B's are dearer than the C/D's.

http://www.starrett.com/metrology/metrology-products/precision-granite/surface-plates

http://www.starrett.com/metrology/metrology-products/precision-granite/surface-plates/superior-black

http://www.starrett.com/metrology/metrology-products/precision-granite/surface-plates/superior-black

https://www.google.com.au/?gws_rd=ssl#q=slip+gauges

http://en.wikipedia.org/wiki/Gauge_block

plunger
10-18-2014, 06:05 AM
I wonder how they grind the granite . Must be difficult to get something so hard so perfect

Old Hat
10-18-2014, 08:51 AM
Granite per say, is not all that hard, just incredibly stable, and consistent thru~out as rocks go.
And does not absorb water as some rocks do.

J Tiers
10-18-2014, 11:01 AM
I suspect the debates, so long as you agree the thing IS a debate, and not someone "doing a troll", are mostly from folks who insistently suggest off-the wall stuff like using a floor tile for a scraping reference, as in this case. The substitutes were needed when no better could be had, but make little sense these days.

Now if it was NOT for a scraping reference, but for rough assembly wanting a flattish surface, I would not bother to discuss it, because lots of jobs are fine with a 5 thou error. Scraping a machine, assuming you INTEND to do a good job, is not one of them. Might be fine as a kinda flat reference for some assembly type work.

The floor tile SHOULD be ridiculous for scraping, but somehow it gets actually said and repeated, and INSISTED ON as a serious suggestion, as if there was general merit in it.

Since I relatively routinely do scraping for alignment on machines here, and understand the problems, I would hate to have anyone use a crap reference. It would be a futile excercise, and likely would leave the machine worse than before, not to mention the "added wear" which all the material removal would amount to.

So it seems worthwhile to dump on the suggestion... if only to prevent anyone else from believing in it and actually trying to DO that.

Now, in another room, I have floor tile installed. I have NO experience using it as a scraping reference, and all of it is on the floor, grouted-in. But, I went over there with a 6" rule and a feeler gage. The rule's edge is flat against a real granite flat, and no feeler can be got under it, so it passes that test.

The first (and only) floor tile I tried is noticeably non-flat, and depending on where the rule is placed on the tile, anything from a 1 thou to a 5 thou feeler goes under the rule. These are nominally smooth tile, not the textured kind. The areas toward the edges are high, and the middle low. I expect it would be worse if the rule had spanned the entire tile.

This was not a surprise...... Nobody TRIES to make floor tile flat within the sort of tolerance we usually would want. Not grade "A", not "B", just forget the grades, floor tile is a "no grade" material as far as flatness is concerned.

Since 5 thou is quite noticeable slop, it seems unlikely that any serious improvement could be had with tools made using this floor tile as a scraping reference. You are likely to scrape-in a banana. It might be better described as a "scrapping reference". :D

I did not survey any others. It seemed unlikely that any further information would be had.... Do we suppose the "sample of one" is sufficient? I will not exclude the possibility that somewhere, there is one floor tile which is flat enough to be used as a reference, but the problem is to find it.

cameron
10-18-2014, 11:14 AM
Considering how little time it would have taken to check a couple more tiles, it might give rise to the suspicion that you lucked out on a bad tile and deliberately avoided gathering any further data that would weaken your case. Given that you are smart enough to realize that, my own suspicion is that you are deliberately fomenting further "debate".

Shame on you, Jerry.:p

dp
10-18-2014, 11:17 AM
Jerry - your post only demonstrates you are still uninformed and still opinionated about an experience you have not experienced. It is quite easy to select tiles for flatness. They wring. Go to a store and find three tiles from a stack that will wring in any combination and any relative orientation and you have a flat tile. If you don't find any then try another store. Not every store sells premium tiles.

Granite tiles that have been installed onto a floor would be very suspect to me. I have not tried the wring test on installed tiles though so will make no predictions as to what may come of it and it is not how I would select tiles for use in the shop.

I'm not sure I'm adequately motivated, but I will try to locate my granite surface plate and a couple of my tiles and do a test of a piece of iron I've scraped. Most of my stuff is still in boxes from moving so this may not happen depending on where the boxes are.

J Tiers
10-18-2014, 11:33 AM
Cameron.... I was accused of "knowing nothing" so I went and checked ONE TILE. I now have "experience" with tiles and flatness, but I see this was not enough to stop the "querulous caviling".

As for selecting ones that wring.... I have clearly NOT EXCLUDED the chance that there are flat ones. if there is one, there may be many.

There are likely also ones which are not flat, but wring somewhat against each other. Especially since it isn't "wringing", but the exclusion of air due to closeness of fit.... not very precise, but potentially adequate.

BUT

When a known decent granite flat can be had for pretty cheap, AND you wan the dumb thing for a scraping ref why SHOULD anyone go and try to wring one to another? By the time the gas and time is accounted for, especially for those living away from box stores, UPS and an order starts to look pretty good, price-wise, for a flat that is "intended to be flat", not "accidentally flat".

Done, folks.... this burger is burnt.

dp
10-18-2014, 12:12 PM
Querulous caviling is an excellent followup to a dish of red herring as it clears the mind and opens the senses. It is intellectual ambrosia.

BTW - I prefer to use my tiles for many operations because I treat my surface plate like it was a platinum standard. I can use the tiles like the box of rocks they are and even ruin one knowing I can have a replacement while out on a burnt burger run.

Old Hat
10-18-2014, 06:38 PM
Pretty much a draw right now, if the game was called for rain.

oldtiffie
10-18-2014, 07:22 PM
Sop far as I can see or recall the "surface plate" - that is to say the "job flat-face reference" is just a good surface plate as the be-all and end-all of all that is required to get all the flat faces needed for the OP's top slide and cross slide.

But perhaps not.

There are several "bevelled" surfaces to be considered and scraped.

What is the reference for these "bevelled surfaces".

I suspect that "bevelled" references (at least one - maybe two or more) are going to be needed and to be consistent with the discussion, they are going to be as accurate (perhaps one grade less) than the reference surface plate.

The bevelled surfaces will not only need to be accurate but will need to be accurately parallel.

J Tiers
10-18-2014, 07:49 PM
Sop far as I can see or recall the "surface plate" - that is to say the "job flat-face reference" is just a good surface plate as the be-all and end-all of all that is required to get all the flat faces needed for the OP's top slide and cross slide.

But perhaps not.

There are several "bevelled" surfaces to be considered and scraped.

What is the reference for these "bevelled surfaces".

I suspect that "bevelled" references (at least one - maybe two or more) are going to be needed and to be consistent with the discussion, they are going to be as accurate (perhaps one grade less) than the reference surface plate.

The bevelled surfaces will not only need to be accurate but will need to be accurately parallel.

Tiffie... that is of course, correct. Which is why I mentioned it in post #2 of this quagmire.

But, the reference for the dovetails can be simply flat, and capable of being put in contact with the dovetail (bevelled surfaces). So your straightedge should have a beveled side with an angle that fits into the dovetail nicely. The alignment is done most easily with two other devices which are used when scraping the parts.

1) an angle reference, which does not need to be big. Just big enough that you can scrape an area to it, or, that you can see the "blue-up" from it on the dovetail. You CAN actually use the scraped male dovetail as an angle reference for scraping the female dovetail. That means that so long as the male dovetail is scraped flat and parallel, the female dovetail can be matched to it without further tools. Tools may make it easier, with a better result.

2) mics and matched pins that fit into the dovetail. You measure across (or between) the pins as they sit in the dovetails, which gives you a consistent way to measure the parallelism of the two dovetails. It depends on where the gib is. Most often the gib is on the female dovetail, relieving you of the need to measure the ID "between" since the gib is adjustable. You just need to measure the OD over the two pins and dovetail.

The alignment to the rest of the machine you need to measure against the appropriate part of the machine with the ungibbed slideway surfaces in contact.

You bring up an excellent point, which is that a poor reference will have its errors reproduced in reverse on whatever reference tool is scraped to it. Then you have either double the error as a looseness, or, potentially, errors that complement, and can actually lock together in a bad case.

And there is a need for other tools, to clear out the "corner" of the dovetails so there is no interference, etc, etc.

oldtiffie
10-18-2014, 08:23 PM
That was an excellent and (very!!) informed post which I really did appreciate and enjoy JT - many thanks.

Reading between the lines - as it were - it is very obvious that you are "well into" this topic through hard won experience and informative reading and discussion.

Also for others - reading between the lines - is that a lot of measuring to scope the problems/jobs and the tooling and preparation before scraping even starts is one big job in itself.

Scraping is not one of my hobbies as I avoid it where and when I can - it is a "last resort" for me as I can still recall having to do it as an Apprentice and as a younger Tradesman. Further as it would take me at least a long time to do it, it would mean my one and only lathe not being available and I would not have the space to have the lathe in bits either as space is at a premium here.

And if I DID scrape it I'd go for a widely optioned mechanical scraper which I'd want to be new and well-optioned and that would be in excess of $4,000 (I think) here in OZ whereas given that all I need is a 10" or 12" lathe I could buy a new one for about or less that that and given my aversion to scraping it would be the way I'd go as I'd have a new lathe and have "dodged" the scraping" effort. I don't have the patience or perseverance that some here have - and which I do envy at times.

I know and freely admit that a "new lathe" is a "cop-out" from me but I'd like a good reason (excuse??) to buy a new lathe too and this might be it if I were in the position that the OP is in.

I've always read your posts and I've seen the scraping etc. that you've done - and I congratulate you on it.

Here are some lathes at my preferred supplier - assume that the OZ $ is the same as the $US for this purpose.

http://www.machineryhouse.com.au/Centre-Lathes

oldtiffie
10-18-2014, 09:49 PM
For JT:

What I forgot to mention is that the real reference surface is the lathe bed "vee"-ways to ensure that the cross-slide cuts are square to the lathe head-stock spindle axis/centre-line.

Further, the top and cross slide reference vee-way is that on which there is no gib.

And again, both sides of the dove-tails on each slide must have their base/reference surfaces in the same plane - not "in-between" twist or "relative" differential differences.

It would help no end if some one has the multi-post thread that "Michael Ward" - aka "McIver" here - that was posted some time ago had its link posted here for reference. It is the most detailed and instructive post on "scraping" per se that I can recall seeing.

I'd highly suggest that the OP read it to get an idea of the scope of his job.

Here is a sketch to determine if the cross-slide facing cut is flat and square to the head-stock spindle axis/centre line for reference:

http://i200.photobucket.com/albums/aa294/oldtiffie/Sketches/Face-platecheck1.jpg

J Tiers
10-18-2014, 10:12 PM
Actually, the reference is ultimately the spindle, which is normally aligned to the ways by scraping or adjusting the headstock. Which is used depends on the lathe design. All of mine would be aligned by scraping.

It is conventional to align the cross-slide so that it cuts anywhere from perfectly perpendicular, to a tiny angle which cuts a few tenths concave. You never want a facing cut to end up convex. So the cross-slide is aligned to a bar set perpendicular to the spindle.

Since I got the impression the OP was looking at the compound area , I wasn't extending the explanation to the bed, aside from a possible reference to "rocking horse wear".... I'd have to go back and look to see if that was in this thread or not.

But the bed is obviously important, and the alignment of the crosslide is important also. ALL the alignments are important, as far as that goes. Each part has its own set of problems for alignment.

To get the crosslide aligned you need to reference the spindle. If you scrape off much material you can get into problems with alignment of the halfnuts and feed pickoff to the leadscrew, alignment of the crosslide screw to its nut, and the like.

So there are a host of issues to be considered, beyond the mere provision of newly flattened surfaces on the slides.

And the most important issue to be considered is a complete survey of the machine to determine the causes of perceived problems. They are not always caused by the first things to come to mind.

Chatter in particular can be caused by looseness anywhere from the material flexing , through the grip of the chuck on the work, headstock issues, bed and carriage issues, crosslide and compound issues, and finally, toolpost and tool issues. Not to be forgotten is plain out "taking too big a bite", where the cut is excessive for the machine considered as a structure.

oldtiffie
10-19-2014, 01:03 AM
If I were the OP, I'd seriously get the whole saddle assembly (including cross and top slides and "bed ways")machined with a dove-tail and other cutters as required on universal machinelike this and then fine hand scrape the "ways" and "dove-tails" as required to suit.

http://www.machineryhouse.com.au/M637D

Axkiker
10-19-2014, 11:37 AM
If I were the OP, I'd seriously get the whole saddle assembly (including cross and top slides and "bed ways")machined with a dove-tail and other cutters as required on universal machinelike this and then fine hand scrape the "ways" and "dove-tails" as required to suit.

http://www.machineryhouse.com.au/M637D

The lathe just isnt worth that. Im looking to improve what I have to the best of my ability. If I ever pick up a Monarch or something along those lines I would consider doing that.

dp
10-19-2014, 02:29 PM
There is a lot that can be done to economically improve lathe performance. A simple step is to follow the vendor's setup process if that is available - if not then any general lathe setup you can find for a lathe similar to yours can be helpful. A reasonable effort to level the lathe then check for and remove warp in the bed, adjust the headstock if that is an option, same with the tail stock, and a complete cleanup and adjustment of gibs can help a lot. Pulling the carriage and cleaning out oil passages and oilers, replacing wipers, and replacing the cross-feed and compound nuts with Evanuts provide improvements where those original components show excessive wear. Sometimes it helps to use carriage and cross-feed locks, so explore features you may not have used before. Examine your chucks to see if they are bell-mouthed, check the tail stock quill to see if it is worn, and use a mild pry bar to see if your spindle bearings are wonky.

On my new then Grizzly lathe all the gibs on the carriage and cross-feed were badly made and a pain to adjust. Slop in the carriage feed and cross-slide feed made it impossible to get a good finish. It didn't help that I was not using way oil.

I recently purchased a 30+ year old Craftsman lathe from my neighbor's estate. I suspect it had less than 200 hours total time on it, but it did suffer some abuse. Grease and not oil was used in many parts and that had to be cleaned out before I could get oil to work its way to where it needed to be. It is now my primary lathe but it did require I do a lot of cleanup on those old bones.

Black_Moons
10-20-2014, 02:46 PM
There is a lot that can be done to economically improve lathe performance. A simple step is to follow the vendor's setup process if that is available - if not then any general lathe setup you can find for a lathe similar to yours can be helpful. A reasonable effort to level the lathe then check for and remove warp in the bed, adjust the headstock if that is an option, same with the tail stock, and a complete cleanup and adjustment of gibs can help a lot. Pulling the carriage and cleaning out oil passages and oilers, replacing wipers, and replacing the cross-feed and compound nuts with Evanuts provide improvements where those original components show excessive wear. Sometimes it helps to use carriage and cross-feed locks, so explore features you may not have used before. Examine your chucks to see if they are bell-mouthed, check the tail stock quill to see if it is worn, and use a mild pry bar to see if your spindle bearings are wonky.

On my new then Grizzly lathe all the gibs on the carriage and cross-feed were badly made and a pain to adjust. Slop in the carriage feed and cross-slide feed made it impossible to get a good finish. It didn't help that I was not using way oil.

I recently purchased a 30+ year old Craftsman lathe from my neighbor's estate. I suspect it had less than 200 hours total time on it, but it did suffer some abuse. Grease and not oil was used in many parts and that had to be cleaned out before I could get oil to work its way to where it needed to be. It is now my primary lathe but it did require I do a lot of cleanup on those old bones.

Finally someone with some sense telling OP how to fix his lathe!

Lots can and should be done before you ever think about scraping, by far that is the very LAST thing you ever do to a lathe after fixing every other problem and making all adjustments AND spending a couple 100 hours learning how to use the lathe.

Also, as for not getting a decent finish on 'harder then aluminum', most likely meaning mild steel or worse, mystery metal. Yes that is 100% common happens to EVERYONE.

Aluminum gives a good finish unless you try REALLY hard to make it ugly, anything steel looks like absolute crap even under good conditions unless its one of the *very* few alloys designed explicitly for machining (And those alloys generally can't be welded worth a damn).

Some steel alloys can give a good finish with much experience, the proper tools, the proper feed rates, depth of cut, alignment of the moon and stars, but generally one just sands/files the part afterwards if finish is important.

Most of the 'good finishes' you see on steel are grinding and/or buffing, or from cold rolling processes (or acid pickle baths after hot rolling)

I know you are likely thinking "Meh, they must just suck, Im sure I can get a good finish on steel no problem, if only my lathe was better", Nope, even highly experienced machinists jump for joy and try and record exactly what they did and with what tool when they get a decent finish on mild steel. For production machines it may take a few dozen parts before they figure out what settings get a decent finish, and then those settings won't work on the next part, or next batch of steel they get.

PS: removal of warp means just adjusting the feet of the lathe, Not doing any material removal or permanent bending.

Black_Moons
10-20-2014, 02:56 PM
Chatter in particular can be caused by looseness anywhere from the material flexing , through the grip of the chuck on the work, headstock issues, bed and carriage issues, crosslide and compound issues, and finally, toolpost and tool issues. Not to be forgotten is plain out "taking too big a bite", where the cut is excessive for the machine considered as a structure.

More good points. Many beginners may not realize that even with a 1000lb lathe, you really can't remove all that much metal at once. 0.03" is considered a deep cut in steel for a 1000lb lathe for example.

cameron
10-20-2014, 04:19 PM
If I were the OP, I'd seriously get the whole saddle assembly (including cross and top slides and "bed ways")machined with a dove-tail and other cutters as required on universal machinelike this and then fine hand scrape the "ways" and "dove-tails" as required to suit.

http://www.machineryhouse.com.au/M637D

No, you wouldn't Tiffie, you'd bin it, as you've told us so many times.

Axkiker
10-20-2014, 05:52 PM
Im going to just start a new thread with pics of a cut. Maybe it is just that and im getting a normal cut. I still feel like there is some give causing it to leave bands... we shall see.

I need to cut a shaft for some reloading thingy a guy wants me to make. So ill take a pic and hopefully post tonight.

oldtiffie
10-20-2014, 06:44 PM
Originally Posted by oldtiffie

If I were the OP, I'd seriously get the whole saddle assembly (including cross and top slides and "bed ways")machined with a dove-tail and other cutters as required on universal machinelike this and then fine hand scrape the "ways" and "dove-tails" as required to suit.

http://www.machineryhouse.com.au/M637D




No, you wouldn't Tiffie, you'd bin it, as you've told us so many times.

You are right Cameron - perhaps I was putting myself in the OP's shoes and being a bit facetious as well - as if I had to do the job as the OP wants to under take.

I did say in an earlier post of mine here that I don't like scraping in any of it manifestations - at all - particularly hand scraping.

I also said that if I was going to scrape it that I's want a new mechanical scraper and accessories - about US$3-4,000 here whereas a new lathe here is less than that here from my preferred supplier - I only need a good 10" or 12" lathe anyway.

http://www.machineryhouse.com.au/Centre-Lathes

And I can't find the space here for a long time dismantling the saddle (at least) and scraping it and having to do without my (only one) lathe either.

So, as you suggest and as I've said (too?) often enough, going for a new lathe and binning my existing is pretty well my only - and preferred - best value option for money space and time.

But having said all that I really do wish the OP all that he wishes for himself in his lathe restoration (hand scraping?) exercise and endeavour.

justanengineer
10-20-2014, 07:08 PM
More good points. Many beginners may not realize that even with a 1000lb lathe, you really can't remove all that much metal at once. 0.3" off the radius is considered a deep cut in steel for a 1000lb lathe for example.

Sorry for the fix but had to clarify a bit.

Willy
10-20-2014, 07:42 PM
Im going to just start a new thread with pics of a cut. Maybe it is just that and im getting a normal cut. I still feel like there is some give causing it to leave bands... we shall see.

I need to cut a shaft for some reloading thingy a guy wants me to make. So ill take a pic and hopefully post tonight.

Looking foreword to the pics and the new thread. I was thinking when you mentioned this earlier in this thread, this almost sounds like lead screw imprinting.

PStechPaul
10-20-2014, 07:43 PM
I was wondering about that as well. I have taken 0.03" cuts on my 200 lb 9x20, and perhaps as much as 0.05" or a little more, depending on diameter and material. IIRC I had to take only 0.02 to 0.01, or even less, when I was turning a 5" aluminum disk to 3.5". My lowest speed is 120 RPM, so that was 120*5/4 = 150 sfm. According a chart (http://www.littlemachineshop.com/Reference/CuttingSpeeds.php) I should have been able to use 500 sfm with feed of 0.004"/rev and 0.040" DOC for a mini-lathe, but I might not have had the tool properly sharpened or positioned, as this was back in March when I was still very much a newbie. Not that this has much to do with the surface plate...:rolleyes:

J Tiers
10-20-2014, 08:33 PM
More good points. Many beginners may not realize that even with a 1000lb lathe, you really can't remove all that much metal at once. 0.03" is considered a deep cut in steel for a 1000lb lathe for example.

maybe... I can take 0.187 off the *radius* with the 500lb Logan, though, in mild steel. It's all in the tool grind, and the material.

oldtiffie
10-20-2014, 09:04 PM
Originally Posted by Black_Moons View Post

More good points. Many beginners may not realize that even with a 1000lb lathe, you really can't remove all that much metal at once. 0.03" is considered a deep cut in steel for a 1000lb lathe for example.




maybe...

I can take 0.187 off the *radius* with the 500lb Logan, though, in mild steel. It's all in the tool grind, and the material.

And that is very good advice as it puts many such lathes more into the HSS and less in the insert/TC insert camps.

Of course there is a place on all lathes for both HSS and TC - just getting it right for the job is the trick.

Axkiker
10-20-2014, 09:25 PM
New thread posted.... have at it :)

Black_Moons
10-20-2014, 10:54 PM
Sorry for the fix but had to clarify a bit.
Actually. I meant 0.3" off the diameter is a deep cut in steel for a 1000lb lathe (0.15" DOC). 0.3" off the radius (0.6" diameter reduction) would be stalling my 2HP 1000lb lathe out with a decent feed rate.

thaiguzzi
10-20-2014, 11:06 PM
I'll say it again... a good finish on steel, even on an Atlas, Southbend etc = an easy to grind HSS Shear tool. And diameter will remain to within a couple of tenths for the whole length.

dp
10-20-2014, 11:13 PM
I put a link to a youtube video in the new thread that shows a shear cutter in action on a beat up lathe. Did a great job. I have one I made for my shaper that I use for lathe work from time to time. The finish on free cutting steel looks like glass.