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Fasttrack
03-31-2009, 02:01 PM
Well I've got a couple of threads I keep meaning to post about this shaper buisness. Anyway, I need to make a replacement gib and I thought now is as good a time as ever to start learning how to scrape. I've got a copy of "Machine Tool Reconditioning" to borrow. Enco has a "Inspection Grade A" surface plate on sale. (Unilateral accuracy of .0001") I'm thinking I'll get the largest one that they'll ship for free, which is a 18 by 12 I believe. Sure I'd like to have a huge one, but this will do for now.

Then there are the scrapers. Rather than investing in a diamond wheel and using carbide, I was thinking about going the HSS route. Since this is a gib for the tool slide on a shaper, I'm not overly concerned with accuracy, anyway. Anyhow, what are your thoughts on this:

http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=4839433&PMAKA=240-3363

It may just be a one time use deal, but that's ok. At least a steel scraper will be easier to sharpen. (And it will be used on mild steel)

So what do you guys think?

p.s. I downloaded that write-up from the Lawrence Livermore Laboratory on hand scraping.

BillH
03-31-2009, 03:04 PM
Well I've got a couple of threads I keep meaning to post about this shaper buisness. Anyway, I need to make a replacement gib and I thought now is as good a time as ever to start learning how to scrape. I've got a copy of "Machine Tool Reconditioning" to borrow. Enco has a "Inspection Grade A" surface plate on sale. (Unilateral accuracy of .0001") I'm thinking I'll get the largest one that they'll ship for free, which is a 18 by 12 I believe. Sure I'd like to have a huge one, but this will do for now.

Then there are the scrapers. Rather than investing in a diamond wheel and using carbide, I was thinking about going the HSS route. Since this is a gib for the tool slide on a shaper, I'm not overly concerned with accuracy, anyway. Anyhow, what are your thoughts on this:

http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=4839433&PMAKA=240-3363

It may just be a one time use deal, but that's ok. At least a steel scraper will be easier to sharpen. (And it will be used on mild steel)

So what do you guys think?

p.s. I downloaded that write-up from the Lawrence Livermore Laboratory on hand scraping.

I think you should search for all the posts made my Forest addy on scraping and go the carbide route and make your own scraper as Forrest does.

Fasttrack
03-31-2009, 03:11 PM
I think you should search for all the posts made my Forest addy on scraping and go the carbide route and make your own scraper as Forrest does.

But it seems like so much work :D

Actually I just read Forrest's response to your post back in 2003, Bill, about scrapers. I think I will go with a HSS or carbon steel scraper, for now. I don't mind touching up the scraper every couple of minutes. It's a small project and I don't have the money or time to shoot for the carbide scraper and proper tools for sharpening the carbide right now. Some day, but not yet! :) I can see carbide is a much better choice for "serious" work. I'll put it on my wishlist.

BadDog
03-31-2009, 04:23 PM
I bought one of those Enco scrapers quite a while back, just because I was already making and order, and it was cheap, so I figured I would see if it was worth anything at all. Frankly, I think it may be over priced. :o It does not hold up well at all. The edge just erodes away with very little accomplished. In my opinion, a good quality old file is better for any ferrous work.

I also picked up a Nicholson which does work pretty well, and I use it here and there. But it is VERY hard/brittle, so it won't take any abuse at all without fracturing the edge.

Fasttrack
03-31-2009, 04:43 PM
Alright, well that's a pretty convincing argument. I'll look for an old file or maybe I can braze a piece of tool steel to a steel shank?

Mcgyver
03-31-2009, 04:46 PM
I think I will go with a HSS or carbon steel scraper, for now.
.

i know the blades Anderson sells are HSS, but think there is no advantage to hss over carbon, unless you one really really fast scraper :D


It's a small project

whats a small project, that 36" (or what the monster is) shaper? you'll be sorry :)

BadDog
03-31-2009, 05:29 PM
I've been considered making an Anderson style scraper from conduit. You could do that, but with HSS parting blades mounted with silver solder on the business end.

Fasttrack
03-31-2009, 07:29 PM
I might have to try that ... I suppose Mcgyver is right, HSS isn't really neccessary. I got a whole bunch of it when I bought the shaper, though. I haven't been "in the buisness" long enough to acquire any dull files, on the other hand. Oh, I've got Rex 95, T15 and Tantung G. I think those all are harder than M2, but I could be wrong...

LOL - Yep it's for the 26" shaper. I need to make a new gib for that tool slide. I thought I'd try some scraping and see if I can scrape in a new gib. The gib only needs to be about 12" long, so an 18 by 12 flat doesn't seem too bad. Plus it's the largest with the free shipping :)

oldtiffie
03-31-2009, 08:08 PM
If it were me, I'd concentrate on the manufacture of the gib as that may be a sizable exercise in itself. It will or may have a 1/8" per foot (1:96) taper between the pressure faces. It will need to be made sufficiently accurately to be a good fit in the gib cavity (both faces) before scraping (if needed) is even considered let alone started.

I would bet that it will bend or bow under scraping unless very well balanced. A bent gib, if correct when straight can be inserted straight into the cavity and it will straighten as it goes in.

You seems to be assuming that the surfaces on which the gib contacts are straight and true - at least one may not be. If that is the case, scraping dead flat may be futile.

I would be more inclined to make the gib (milling and or hand-filing) such that equal gaps (feeler guages) are at each end when assembled. Even if the gib has adjusting screws (at least one - preferably two) on each end, and given that there will be wear on the ram dove-tails (both sides - the one one which rubs on the gib and the opposite/other one) as well as the mating bottom face of the ram and the flat face on which it slides.

I'd fit adjusting screws to the fixed dove-tail - just as there is on a lathe. They will adjust nicely (for) any irregularities so that you get an optimum (but never-the-less a compromise/d result) that WILL workas it does on many mills and lathe slide gibs.

I'd just scrape one face of the gib - the one that contacts the ram - for lubrication purposes - and even that is optional.

Optimally, ALL the rubbing and wearing surfaces on both the body of the shaper and the ram need to be scraped for it to be anywhere near perfect.

Unless it is for looks or appearance or for lubrication, scraping is pretty well an "all or bugger all" event.

I hope I have not rained on your parade.

Fasttrack
03-31-2009, 08:44 PM
It's not the ram gib, its the gib for the tool height adjustment. You've not rained on my parade at all. I've been thinking about how I was going to approach this for awhile.

The taper is actually, according to Forrest, usually .25" per 12". I've not verified that yet with the little stub of a gib I have remaining. Anyhow, the gib is flat on one side and tapered on the other. I intend to take a blank piece of steel and grind one face smooth on a surface grinder. Then it's over to a mill to machine the tapered face. Then it's back to the surface grinder to grind the taper.

Then it's time to scrape? I'm thinking of using the gib as a sort of master or straight-edge for the dovetail. I'm not sure yet ... I need to re-read Machine Tool Reconditioning :)

lazlo
03-31-2009, 08:53 PM
FT, I'd strongly suggest a carbide blade -- they last much longer than steel, and you can sharpen them with a cheap dipstick diamond hone.
All that scraping I did making the reference plane on my Millrite I did with a powerscraper and hand-sharpening the carbide.

You can use any cheap 1/8" x 3/4" carbide blank for the blade. MSC, ENCO et all carry them.

Herm Williams
03-31-2009, 09:58 PM
Has anyone tried TANTUNG? It works good on woodworking tools. Besides I recently got some at an estate auction for cheap.
re

lazlo
03-31-2009, 10:07 PM
Herm, Tantung (and Stellite) is a cobalt alloy. Cobalt adds high red hardness, and like McGyver says, red hardness isn't going to help, unless you're scraping really fast. :D

Fasttrack
03-31-2009, 10:59 PM
Herm, Tantung (and Stellite) is a cobalt alloy. Cobalt adds high red hardness, and like McGyver says, red hardness isn't going to help, unless you're scraping really fast. :D

I dunno, I'm pretty quick...

Rex 95 says the as-supplied hardness is 64-66 Rockwell C
The specs I could find on M2 tool blanks put it at 60-62 Rockwell C

Pretty big difference :D I'm going to snag a 1/2" wide carbide blank from Enco. That is the widest chunk of 1/8" carbide I can get in a short piece. I'm not saying I'll use it for sure, but for 4 bucks I'll toss it in the tool box!

lazlo
03-31-2009, 11:07 PM
IIRC, Rex95 is T-8, which is hard as hell. Might make a good scraper, but it's really expensive, unless you found a bunch on Ebay...

If you can wait 'till the morning, I think I might have some carbide blanks I can send you.

Fasttrack
03-31-2009, 11:13 PM
Oop! I just submitted my order. Thanks for the offer, though!

Yeah I'm not sure about the Rex 95. I didn't figure the 4 point difference was very much, to be honest. I think they put carbide at something like 80 on the Rockwell scale. I guess it can't be measured directly, they must have a conversion from Brinell scale.

Anyhow, I've got a pile of Rex 95 from when I bought the shaper. There was a box full of everything from Rex 95 to ordinary M2. The Rex 95 stuff was all pretty large pieces, though. In fact, one is a 1" by 1" by 6" piece! :eek:

Roy Andrews
04-01-2009, 01:31 AM
fastrack i have two of the scrapers with wood handles and replaceable blades one carbide, one hss. i would be willing to loan you either one if you would like.

doctor demo
04-01-2009, 01:33 AM
Fasttrack when that order comes in, or befor it gets there go to Your local horrar frieght and pick up the 4 piece heavy duty pry bar set for 8 bucks and braze the carbide on the larger ones . They have good handles on them and make better scrapers than pry bars. Or at least I think they work well.


Steve

Forrest Addy
04-01-2009, 03:54 AM
I advocate carbide for precision scraping for the reason that those who get into it wind up spending more time scraping than they anticipated. A carbide cutting edge does last about 50 times linger than HSS for scraping cast iron. Since carbide is far more productive as a scraping edge than second best, therefore I tend to push it possibly to the disadvantage of those with a limited need and limited funds.

However for a single project there's no need to equip more elaborately than actually needed. Refitting a gib on a single slide plus a little localized tune-up can be easily done with a modified file or a scraper tipped with HSS sharpened with a selection of oil stones. The one minute tool life can be a drag but arranging your sharpening equipment for quick access and a little practice will result in a tuned up edge is about thirty seconds.

The keenness of the scraping edge is quite important. For one thing a dead keen scraping edge is far more productive; you get so much more done per unit of sweat. For another, it leaves a clean satiny scraped finish. That said I strongly suggest you add a hard arkansas stone to the collection.

If you elect to silver braze HSS to a steel shank I strongly suggest you use a cobalt HSS over plain old M2. Brazing heat will draw the temper of M2 slighty and even a slight hardness reduction creatly shortens the edge life of a scraper.

As for carbide while very hard, it has a low energy of rupture; diamoind abrades it quickly even in a hand stoning milieu. Carbide sharpens quiclky using cleap diamond plated bench stones from Harbor Freight. A little diamong lapping compound applied to a flat piece of most any metal will provide the lapping capability you need for acheiving a keen edge.

You don't have to spend tons of money buying lots of carbide sharpening stuff. I think I spent about $300 on the powered wheels and grinders I take to my classes. You can get by lots cheaper than that if you don't mind a little work.

ckelloug
04-01-2009, 11:13 AM
I happened to have a 3 inch by 3/4 x 1/4 piece of Tantung left over from college. I sharpened the end on my grinder and then got out the diamond hand hones. It made a fine scraper even without a handle for a tiny scraping job I was doing. I am certain that somebody who knew what they were doing would have done a better job but tantung is very hard and can be sharpened to be very sharp.

lazlo
04-01-2009, 11:37 AM
go to Your local horrar frieght and pick up the 4 piece heavy duty pry bar set for 8 bucks and braze the carbide on the larger ones.

I've never be able to take Forrest's class (you should hold one in Dallas, dammit :)), but I've done a lot of scraping, and I personally don't like a rigid scraper shaft like that.

I have just about every style of hand scraper, and the Anderson tube-style scraper, which you can easily make out of 3/4" EMT conduit, is my favorite -- it has the perfect amount of flex.
My second favorite is the Anderson flat-beam style (that I bought from GMatov, actually) -- they're thin enough that they flex, and I prefer this style for roughing.
The cheapy Chinese Anderson flat-beam scrapers I bought from KBC tools are too thick, and very rigid.

The one's I dislike the most are the Sandvik scrapers, with the insertable carbide blades. They have a plastic handle, and are very stiff, and just generally not ergonomic to use.

When you start into power scraping, you find that a similar thing applies: most people like a thin, tapered blade that flexes a little. JR Thiele lent me a shop made Biax blade holder (thanks!), and it was very thick/rigid. I thinned it down on the milling machine (so it has a bit of flex) and it's a pleasure to use. The official Biax blade holders are even thinner...

Just my personal experience, YMMV...

Fasttrack
04-01-2009, 12:43 PM
Thanks guys - I'll take a look at Lowes and see if I can find a diamond hone. I should've ordered some lapping compound and a stone from Enco. I thought of that this morning when I woke up... oh well. Like I said, I may still use HSS. I'm trying to decide exactly how I'm going to approach the problem and how much time I want to spend on it. Got some paper out and have been taking note while reading Machine Tool Reconditioning. I haven't had a chance to thoroughly inspect the ways, so I'm not sure just how much "touch up" they need.

Roy - Thanks for the generous offer, but I'd rather tear up my own stuff while I'm first learning! :)

pcarpenter
04-01-2009, 04:45 PM
I will second the carbide thing. I was all set to make my own and will mail you a carbide chipbreaker I bought from a member here that was going to end up as a scraper blade. Chipbreaker inserts are fairly tough and should have worked well. I ended up with a pair of Anderson scrapers from George Matov. One was the standard model and the other tubular, with a shop-done crimp on the end so it would hold a blade from a Dapra scraper. That Dapra blade is tough as all get out. Its fairly narrow and each scraper has a very characteristic pattern it leaves, but I love them both.

I roughed my blades to shape on a diamond wheel here at work. In the absence of that, I probably could have used the cursed "green wheel" I own. They chip carbide and are not for finishing, but could have been used in a pinch for shaping...and they are cheap.

I use a diamond hand lap (Eeze lap brand?) for all my sharpening by hand. I have one of those magnifying lamps with a fluorescent ring light and it lets me see my work. "Medium" cuts things back to proper geometry and "fine" is all I need for most touch ups. They are maybe $7 each and are available everywhere....maybe even Wal-mart in the sporting goods section.

Sure....I'd love to own one of the Glendel Accu-sharps...but I don't and haven't needed it so far. A regular diamond wheel is in my future for my "carbide grinder", but that's way more material removal than makes sense for "sharpening".

The "pro" who tought me used shop made scrapers exclusively. His were about 1-1/8" wide at the face and were some springy steel maybe 24" long! Fine for machines, not so fine for bench work IMHO. He loaned me one for a while and I scraped the back of a gib....not the right tool for the job and also some way work where it did great. The spring made for some real ability to bear down and cut when needed. A big file handle or shop-turned handle works great. He had an Accu-sharp and its a fine piece of kit, but I am swiftly running out of room and don't plan on making a living scraping.

PM or email me (address is in my profile) if you want me to mail you one of those chipbreakers. You will probably get it in a day.

Paul

Teenage_Machinist
04-03-2009, 01:05 AM
A bernzomatic Mapp torch is capable (with difficulty) of bronze brazing carbide using Home Depot white flux coat rods. .

I scrape with: A scraper made of a bit of carbide from a dead parting blade brazed on the end of an old file.

A DMT diamond stone to sharpen it.

A green Silicon Carbide wheel on the bench grinder to shape. it.

It was pretty easy. :D

OTOH the file was used normally as a scraper at first. Would burr and dull in 3 seconds no exageration.

gmatov
04-03-2009, 04:14 AM
TM,

I think 3 seconds IS an exaggeration. Not that it might be much more, but that would be one stroke. If your edge is gone in 3 seconds, you have annealed the steel by overheating when you ground it.

Paul,

I have a couple diamond wheels I probably will never use. Aluminum disc with rubber diamond embed. I have no idea what they would be worth. Tomorrow I will take pics and post.

First and foremost, they are over 20 years old, not that they have 20 years of use. I do not know if the rubber carrier has that long a lifetime. Spin them up and they might go to hell. I don't think so but can't promise.

After picture, make offer. As said, will never use them. I don't do that stuff, anymore.

You have priority. You don't want, they will be available to the next person who wants to talk. NOT to dick around about price. I am not looking to make a fortune from stuff that I can no longer use.

My kids are going to have to get one of them full size dumpsters to clean my garage out. Maybe 2.

Cheers,

George

.RC.
04-03-2009, 05:29 AM
I have just about every style of hand scraper, and the Anderson tube-style scraper, which you can easily make out of 3/4" EMT conduit, is my favorite -- it has the perfect amount of flex.


Why do you want them to flex???? it seems to go against everything you learn in the machining trade where lack of rigidity is something to be avoided..

lazlo
04-03-2009, 09:27 AM
Why do you want them to flex???? it seems to go against everything you learn in the machining trade where lack of rigidity is something to be avoided..

It's a "feel" issue: a completely rigid scraper is like riding a hard tail -- it's really bone-jarring, especially on a power scraper.

Rich King mentions in his scraping video that the better the scraper you are, the thinner and "flexier" the power scraper blade you want. Newbies want/need a stiffer blade, because it's easier to control.

By the way, just about everyone I know likes the round conduit or Anderson tube-style scrapers best. That includes Mike Morgan and Rich King, both who talk about the tube scrapers on their respective scraping videos.

It takes 10 minutes to make one: partially flatten one end of the conduit and jam a scraping blade in the flattened section. Stick a file handle in the other end, and you have a great scraper. The tube-style scrapers have the perfect amount of flex.

Fasttrack
04-03-2009, 03:15 PM
I think I may just try making one out of conduit. I can see how flex would advantageous. Sort of like trying to scrape paint or adhesive off of a plaster wall - if you choose a stiff scraper (like the razor blade ones) it's tought to control and not gouge too deeply. It either gouges or it slides of the surface. One with a little flex lets you peel just what you want to peel ... (recently I've been "remodeling" a lounge for physics students in the physics building. It was in dire need of attention and I spent the last couple of weekends peeling wall base adhesive off :D)

Thanks Paul for your offer. It really is amazing to be able to "network" with so many generous, knowledgable and helpful people here!

pcarpenter
04-03-2009, 03:21 PM
You are certainly welcome.

I would offer that I find that my conventional Anderson scraper has lots of flex while the tubular one has none. In my case, the tubular scraper is also shorter which accounts for some additional rigidity, but the tubular design (by design) should be the less limber of the two.

Here are photos of the two. You will notice that the Anderson tubular model has been crimped at its mouth to grip a Dapra power scraper blade. That's not the standard blade type for that scraper.

Edit-- and by the way I agree. There are lots of generous souls here so giving you a carbide chip is a trivial gesture. Just to show that I don't forget a kindness, Steve Steven gave me a thrust bearing to use in making a 5C collet drawbar for my lathe. I have been gathering the other pieces including the 5MT to 5C adaptor, some tubing and an aluminum handwheel and I now have no excuse for not just getting it made. Likewise, I believe it was Darin (sp?) (aka Wierdscience) who sent me a bunch of carbide saw teeth from what must be some really big saws. Some of these will be used for shop made tooling and one of the wide pieces is going to be a shop made scraper (for gunk, not way surfaces). My giving you a carbide insert pales in comparison to these guys.

http://i108.photobucket.com/albums/n16/pfcarpenter/scraping/ScrapingToolsSmall.jpg

Rich Carlstedt
04-03-2009, 09:36 PM
I haven't heard Forrest comment on the material you selected.
I have always scraped cast Iron/Mehanite, and very little steel, except for small fittings. so lack experience here to comment accurately, but
I see much work for a steel gib, and possible warpage ?

just my thoughts
Rich

Fasttrack
04-04-2009, 04:06 AM
Well I'm certainly no authority on the matter, but according to Machine Tool Reconditioning, gibs may be made out of cast iron, steel or bronze. Also, the author claimed that steel was replacing cast iron because "more desirable wear characteristics" could be obtained with steel gibs running on hardened ways.