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rgsparber
05-01-2007, 12:06 AM
Apparently every professional machinist is well acquainted with soft jaws but I was somehow not in the room when the topic was being discussed until recently. If you are interested in the making and value of soft jaws, please see

http://rick.sparber.org/Articles/sj/sj.pdf

As always, comments and corrections are welcome. My hope is that those with experience will help me to enlarge this article to include more applications.

Rick Sparber
rgsparber@AOL.com
web site: http://rick.sparber.org

torker
05-01-2007, 12:23 AM
Rick...good article! Now you've got me thinking. I also have a crap parallel set. This looks like a better way.
Thanks!
Russ

slowtwitch
05-01-2007, 07:04 AM
I'm going to make a set this weekend.....Thanks for the post :D

pete

HTRN
05-01-2007, 07:15 AM
I love soft jaws. The first shop I worked in, used them almost exclusively - every 6 or 8 months, I'd find myself making up raw jaw blanks, for use in a variety of jobs, from a 12 foot lengths of 6061. We had an entire rollaway filled with them. As versatile as they are with a manual machine, with CNC they become a godsend - like for clamping round parts, just mill out to size..

You guys should also look at buying the Snapjaws screws (http://www.snapjaws.com/mntng.htm), and using their nifty quick change setup, just don't go throwing money away on the jaws themselves, they're easy enough to make.


HTRN

cmiller231
05-01-2007, 07:57 AM
I would add a relief in the corner of the steps.
chris

Evan
05-01-2007, 08:18 AM
I recently purchased a new vise for the corner of my lathe bench as I was moving vises around. The first thing I did was make aluminum soft jaws for it. Soft jaws are much more suitable for most machining uses.

http://vts.bc.ca/pics2/visejaws.jpg

LES A W HARRIS
05-01-2007, 08:47 AM
As always, comments and corrections are welcome. My hope is that those with experience will help me to enlarge this article to include more applications.

Rick Sparber
rgsparber@AOL.com
web site: http://rick.sparber.org

Drill & tap the ends for stop devices.

Parallel Vee groove version, with end stop above, for cylindrical work.

MikeHenry
05-01-2007, 09:57 AM
Thanks for posting that - soft jaws are just the ticket for a current job for which work holding was a problem.

BobWarfield
05-01-2007, 11:13 AM
Soft jaws are really nice. I've been using them since getting my first Kurt vise. I like the quick change setup, it'll make it more likely I pop them on and off and make up special purpose soft jaws. For example, how about some extra long ones to improve grip on long workpieces:

http://www.thewarfields.com/cnccookbook/img/OthersProjects/Widgit/WidgetViseJaws.JPG

I've seen examples of this where one set of soft jaws was used with two Kurt vises to make a really long clamping area.

Here's another soft jaw tip:

If you're in a hurry, you needn't tram the mill, just take a pass on the soft jaws. Whatever is gripped on that step is going to be aligned with the path the mill cut.

Best,

BW

PS Les, work stops are great time savers. I made mine to fit on the vise rather than the jaws:

http://www.thewarfields.com/cnccookbook/img/MillStuff/KurtViseStop/P7123547.JPG

lazlo
05-01-2007, 12:33 PM
If you are interested in the making and value of soft jaws, please see

Nice article Rick.

What are the dimensions of the step you milled in the jaws?

rgsparber
05-01-2007, 03:25 PM
I would add a relief in the corner of the steps.
chris

Chris, do you mean in the area of the vertical and horizontal surfaces? It makes a lot of sense

I guess it could be done with just a hack saw as long as it was deburred and cleaned. No precision needed.

Rick

rgsparber
05-01-2007, 04:17 PM
They were buried in the text: 0.1" x 0.1"

rgsparber
05-01-2007, 04:20 PM
Les,

Do I have your permission to add your ideas to the article and put your name into the acknolegement section?

Rick

lazlo
05-01-2007, 04:57 PM
They were buried in the text: 0.1" x 0.1"

Sorry Rich, I read that section where it said you took a finishing cut of 0.095 and then .005, and I thought you meant on the faces of the jaws themselves, but you were describing the step cuts.

LES A W HARRIS
05-01-2007, 04:57 PM
Les,

Do I have your permission to add your ideas to the article and put your name into the acknolegement section?

Rick

Sure they have been around thirty years as I know, Also Noted above, bore recesses for round parts, (two jaw chuck style) for flat gears, dog bone shaped parts and so on.

cmiller231
05-01-2007, 06:01 PM
rgsparber
Junior Member Join Date: Apr 2007
Posts: 14



--------------------------------------------------------------------------------

Quote:
Originally Posted by cmiller231
I would add a relief in the corner of the steps.
chris


Chris, do you mean in the area of the vertical and horizontal surfaces? It makes a lot of sense

I guess it could be done with just a hack saw as long as it was deburred and cleaned. No precision needed.

Rick


Yes , right in the corner ,just like it is done on machinst /grinding vices.You could use a slitting saw or, here i would use surface grinder with abrasive cut off wheel. And before some body corrects me on that. as i know that you are not susposed to use an abrasive cutoff wheel on aluminium. Dressing with a carborudum or norbide stick regular will take care of over loading the cut off wheel.This is a very small under cut., .030-.06 wide x .060 dp ought to be plenty. Chris

rgsparber
05-01-2007, 08:24 PM
Sorry Rich, I read that section where it said you took a finishing cut of 0.095 and then .005, and I thought you meant on the faces of the jaws themselves, but you were describing the step cuts.


Sorry for the confusion. I will add a small figure.

Rick

gellfex
05-01-2007, 09:36 PM
Reading the article and thread, it occurs to me another chronic problem may be solved inadvertently with softies: the moving jaw lifting the work with a non kurt style vise, like my Bridgeport. If you cut the lips with the jaws on a block as you have, the moving jaw is in it's lifted position, so when work is secured in it the work is lifted to perfectly level when the vise is tightened. I'm definitely going to try this out.

rgsparber
05-01-2007, 09:41 PM
Maybe this is the reason the experts told me to use a "jack block" about the same width as the block to be cut. One down side to having these steps in the side is that you can't reach under and see if they slide around. To get around this problem, I will mic the block to be cut, bed it down, and then use my DTI to see if I read the same thickness.

Rick

rgsparber
05-03-2007, 12:18 AM
Has anyone tried cutting the top lips of the soft jaws with a dove tail cutter? You would still have the horizontal surfaces but the angled side might help keep thin plate down. It would look sort of like this /_

Rick

rgsparber
05-03-2007, 06:12 PM
I'm having trouble with the movable soft jaw. The horizontal face of the step remains parallel to the table but rises up about 5 tenths when I tighten onto my test block. I tried placing the jack block near the top of the jaws before taking a light clean up cut and that did help. I also see maybe 1 or 2 tenths error due to tram. My best results come from just pressing down on the test cube with my thumb as I tighten the jaws. Tapping with a deal blow hammer makes things worse with errors up to 2 thou.

Any suggestions of what to try?

Rick

DaHui
05-03-2007, 11:13 PM
Here are some softjaws I made on a Haas VF0. Finished and trued on all sides, chamfered all around and with quick change slots. They are so nice I'm affraid to use them.


http://www.the-alchemist.com/Images/Shoptask/SoftJaws/jaws_2.jpg

Here is another set that I did manually on a BP, except for the holes that were drilled and reamed on the VF0. They were used to hold two parts at the same time through six operations, machining a square block on all six sides. I just swapped out the dowel pins to locate the parts for the different ops.

http://www.the-alchemist.com/Images/Shoptask/SoftJaws/jaws.jpg

rgsparber
05-03-2007, 11:55 PM
After a bit more study and thinking, I found out why the movable jaw is rising up. It is not! It is sort of like sitting in your car in the car wash and having the spray gantry move over your fixed postion. It appears that you are moving but you are not. Anyway, it turned out the movable jaw was fixed and the fixed jaw was moving. With the steps at the top of the jaws, the force on the fixed jaw is much larger than when I clamp lower down the face. This causes the bolts to stretch and pivot the jaw. I measured a 2 thou rise in the fixed jaw as I tightend the vise. Most of this error is canceled when I clamp my jack block in the vise and take light cuts on the steps but I'm still left with 5 tenths error. I will try using hold down clamps to help keep the fixed jaw down. I may also change to tougher steel in the bolts so they don't stretch so much. There is always more to learn!

Rick

rgsparber
05-03-2007, 11:58 PM
Dahui,

I had to laugh when I saw your "soft jaws". They look good enough to give as a wedding present.

Can you supply some pictures of how you used dowel pins to fixture a cube for machining on all 6 sides. It sounds very interesting.

Thanks,

Rick

rgsparber
05-04-2007, 03:02 PM
I've leaned a few things since my last post. First of all, my fixed jaw support was riding up due to the increase in force with the step at the top of the jaw. I added hold down clamps that press on the soft jaw and that problem was solved. I then used a dove tail cutter to lightly face the bottom of each step and also cut a relieve in the vertical face. It worked very well. Changing to an end mill, I raised up the cutter so it did not touch my horizontal surfaces. Then I side cut the vertical part of the step. All surfaces were cleaned with WD40 and a clean piece of toilet paper. I put my test block on the steps and used thumb pressure to set it as I gently tightened the vise. I am only taking a few thou so no need to crank down hard on the vise. It will only increase distortion. I have only cut my first dimension of my test cube. I mic'd each corner of the face plus in the middle. The result was a surface that varied by +/- 1 tenth. The left front and left back were both low compared to the right so there is still a little error to remove. However, this does demonstrate what a RF30 mill with an Enco copy of a Kurt vise can do. One thing for certain. It does take a lot of time and care to achieve a tolerance of +/- 1 tenth.

Rick

pcarpenter
05-04-2007, 05:30 PM
Rick-- a couple of things come to mind after reading your post. I don't know how big your cube is. In learning to scrape in my milling machine (a Bridgeport) I picked up a number of things...some from the bible on machine tool architecture and the scraping process "Machine Tool Reconditioning" and some from my mentor.

Its probably a reasonable expectation for a modern machine tool like a milling machine to be able to hold about .0005" per foot of travel with careful work and setup. The numbers are diffent for other sorts of machine tools. Some of this variability will already exist in your machine, so eliminating the other sources is helpful. You may want to extrapolate out what you got cutting the cube face and see what that works out to, but don't be too discouraged if it works out to more than that as there are plenty of well worn expensive machines that won't do it either. Enjoy whatever you have now as tolerances will likely only go up as the machine ages.

You already cut a clearance groove on the jaw steps to insure that the corners do not become the first point of contact on closure and that is a really good idea. I have a Bridgeport vise in addition to my Kurt and I found that a relief bevel was also needed on the inside corner of the jaw attached to the fixed face. That corner in the casting is just a bit round and will not let the jaw sit square otherwise. I don't think this is necessarily an issue with the Kurt vise, but I don't really recall.

There is also some advantage to maybe having a degree or so of bevel to the holding face of your jaw steps. This provides a similar function to the angular hold down force between the movable jaw and the vise base that is part of the Kurt design. This should help keep the part from being "squirted" upward as the jaws are closed....whether the jaws themselves move or not. This ought to be really subtle and I might tend to scrape it in as it shouldnt' take much. Go too far with it and you end up with a really narrow line contact at the top of the jaw holding your part.

Paul

rgsparber
05-05-2007, 09:47 PM
Paul,

It seems to me that having a small bevel is not always good. If the part being clamped is thinner than the bevel, then it makes sense. But if the part is taller, then the bevel will reduce the surface area able to clamp the block.

Rick

rgsparber
05-05-2007, 09:59 PM
I have now cut 2 out of the 3 dimensions of my test cube. The soft jaws really help a lot. I also have my largest hold down clamps on the fixed soft jaw because I found that it was tilting up and back about 5 tenths with rather light clamping pressure. My goal is to cut a .8200" cube. Here is what I have so far across each face (taken at 4 corners and center):

First dimension was .820,05 +/-.000,05" (beginner's luck?)
Second dimension was .820,25 +/- .000,15" (not at all sure why it is so bad)

Just to calibrate your mind, it took me 2 1/2 hours to cut the block from .86" down to .820,25". And I work fast too. There are just a lot of steps including using my DTI at each step to be sure everything is true and bedded property. It is also essential that all mating surfaces are kept spotless. I am using my DTI with a sine bar to set the final 3 cuts. My machine is a RF30 with an Enco copy of a Kurt vise.

Rick

BobC
05-05-2007, 11:12 PM
Rick,
An informative article and good comments by others. Thanks. I have seen references to soft jaws numerous times but never quite knew how they could be used to advantage. This is helpful.
Bob

BadDog
05-05-2007, 11:24 PM
How are you using the sine bar in this application?

rgsparber
05-06-2007, 06:31 PM
BadDog,

The short answer to how I use my sine bar is to look at

http://rick.sparber.org/Articles/sb2/sb2.pdf

This article has stirred up a huge amount of contraversy and I have learn a lot from the response. Before you get excited about seeing +/- 50 millionths of an inch, I want to be sure you understand that this equal +/- half a tenth. If I plan to cut 0.8200" and my mic says I got 0.8200", then the uncertaintly is +/- half a tenth.

Rick

rgsparber
05-06-2007, 09:41 PM
The square version of the step is about .1" x .1" but you will find more info in my next post (see below).

Rick

rgsparber
05-06-2007, 09:42 PM
Many generous and talented people sent me ideas on how to use soft jaws on a mill vise. These ideas are now in the latest version of the article.

If you are interested, please see

http://rick.sparber.org/Articles/sj/sj2.pdf

Comments and questions are welcome. I would be delighted to have to come out with version 3.

Rick

BadDog
05-06-2007, 09:48 PM
Oh, ok, I get it now. Never thought about using it that way. My first thought would be to use an Indicol with a 0.0005 or 0.001 DI. Then again, I've never put that much thought into getting more accurate than 0.001, and rarely even work that close. Generally, just using the dial on my knee is all I need.

Thanks for the education...

J. R. Williams
05-06-2007, 10:38 PM
Rick
Thank you for the very concise article on step jaws and associated problems. Many would take the fixed jaw as being solid. You have proved the fixed jaw could be a problem. Have you considered any axial movement of the spindle as the cutter engages the work? If the cutting edge has much of a radius, the cutter will skid on the surface until it finally starts the cutting action. This will change the force axially on the spindle until the cuttter starts making a chip. You may be trying to work to a smaller dimension than the edge on the end mill.
Keep the articles coming.
JRW

rgsparber
05-06-2007, 10:42 PM
Rick
Have you considered any axial movement of the spindle as the cutter engages the work? If the cutting edge has much of a radius, the cutter will skid on the surface until it finally starts the cutting action. This will change the force axially on the spindle until the cuttter starts making a chip. You may be trying to work to a smaller dimension than the edge on the end mill.
Keep the articles coming.
JRW

Can you say more? I'm having trouble envisioning the problem but it just the kind of error that I am trying to understand.

thanks,

Rick

Willy
05-06-2007, 10:49 PM
Rick thank you very much for going to the trouble of compiling these pdf's.I believe they have been very enlightening for everyone.Please keep up the good work, we all have much to learn from our collective wisdom.I am always grateful for all of the suggestions and knowledge that the members of this forum so freely give.I'll be saving your work for future reference.
Thanks Again, Willy

rgsparber
05-06-2007, 11:12 PM
Willy,

Thanks for the kind words. I too have been helped imensely over the years by the wisdom of others. The strength of our hobby is this free sharing of knowledge.

Rick

BigBoy1
05-07-2007, 10:35 AM
I was doing finishinng cuts on a lathe made part and needed soft jaws to hold the part. Clamping steel jaws on a finished aluminum surface in not good for the surface.

Since I had to make just a few cuts, I got by with using thin strips of wood to protect the finished surface. This worked this time but is not a good way to do it in my estimation. Has anyone have lathe soft jaw plans?

I'm thinking of something like an aluminum "shoe" that fits over the jaws. It would be much more accurate than wooden shims.

Bill

rgsparber
05-07-2007, 11:05 AM
I was doing finishinng cuts on a lathe made part and needed soft jaws to hold the part. Clamping steel jaws on a finished aluminum surface in not good for the surface.

Since I had to make just a few cuts, I got by with using thin strips of wood to protect the finished surface. This worked this time but is not a good way to do it in my estimation. Has anyone have lathe soft jaw plans?

I'm thinking of something like an aluminum "shoe" that fits over the jaws. It would be much more accurate than wooden shims.

Bill

Bill,

On my Bison lathe chuck, my jaws are in two parts. The bottom part engages the spiral and has a key sticking out the top. The top part has a mating key way and fits on with the steps facing in to the spindle centerline or facing out. It would be easy to measure this keyway and cut 3 blocks plus add a bolt hole. Any finishing of these blocks would be done in place.

If the chuck jaws are one piece, then something like a "shoe" would be a good idea. Another trick I have seen is to put the finished aluminum part in an aluminum holder that has a split in it. The force of the steel jaws on this outer surface of the holder causes it to tighten on the part being machined without maring the part. This is also a good way to hold square parts in a 3 jaw chuck if the outside of the holder is round and the inside is square. For maximum accuracy, put a mark on the chuck and on the holder. Then machine the holder in place with the marks adjacent. In use, be sure to keep the marks adjacent.

Rick

J.Ramsey
05-07-2007, 11:08 AM
BigBoy, get some .020-.040 soft copper sheet, it forms quite well by hand I use it to hold knurled aluminum parts, works great with no marking or marring.

BigBoy1
05-07-2007, 06:07 PM
The copper sheets sounds like a good idea. I'll have to get some for the next time I need them. After thinking more on the "shoe" idea, there would be very little chance for any errors in making as they would throw the part out of round if they were not all the exact same size.

Bill

rgsparber
05-07-2007, 08:24 PM
Those soft jaws really made a difference.

I have now cut all 3 dimensions of my test cube. Assuming these 3 thicknesses represent what I can expect from my RF30, then it looks like my best work is to cut a thickness within +/- 4 tenths with a surface variation of +/- 2 tenths. Placing the block on my surface plate and testing surface variation with my recently factory serviced Starrett Last Word showed less than 1 tenth total variation (I think I believe my mic on this one). I then held the test block against a 1-2-3 block on the surface plate to test how square the cube really is. It showed a worst case variation of 1 tenth.

My slowest time to cut a thickness was 3 hours and my fastest was 1 hour. I do a lot of cleaning, mic'ing, and verifying that the block is bedded with my DTI. I use as light a pressure in the vise as possible to minimize distortion.

When I was just measuring at a single point, my observed variation between expected and measured was less than a tenth. At this time I can't explain why the error went up to 4 tenths.

Rick

oldtiffie
05-21-2007, 08:42 AM
Rick,

thanks for having what it takes to actually:
- undertake the machining;
- achieve such excellence;
- invite comment, acknowlege it and use it;
- to record, publish, discuss, revise and publish it for our edification; and
- give so generously of your time.

I had a problem with my "Chinese" machine vyce - several problems actually - no surprise there to some I guess.

The ground hardened jaws were neither straight not square nor parallel. I solved this by surface grinding them. And while I was at it I countersunk the tapped holes to just greater than the screw diameters to stop any fouling that might be caused by burrs that might only show when in the tightened state (where I could'nt see them).

I pulled the vyce apart and did the same to the holes for the jaw screws as well while I was at it and gave it all a good clean up and check out and reassembled it.

Before I put and jaws in I trammed my mill, put in a new end mill (16mm - for parallelness and rigidity), ensured it was "true" and then took a skim cut over the vyce faces to which the jaws are attached - a few problems solved there too!!.

On the "usual" type of vyce there will always be a "jack-up" or "lift" when the jaws are closed on the work.

When I was an apprentice in the long-long ago an excellent milling machinist showed me what he did to at least minimise if not eliminate this "lift".

He had a series of - for want of a better word - horizontal "vees" machined into both jaws. He used to have a series of hardened strips about 1" x 1/12" to 1/16 to 1/4" thick with one of the narrow faces ground flat and square with reasonably sharp edges. The opposite face was ground with 2 "flat" bevels such that the "flat" between them was about 0.03" (say 1/32") to engage the "vees" in the moving chuck jaw.

He would put the job in the vyce and push the job up against the "fixed" jaw. He then put one of the blade-like strips against the centre of the face of the job that would normally be held by the vyce moving jaw and the other edge of the strip (the knife-like one) was engaged in one of the "vees" in the moving chuck jaw - but so that it "sloped down" toward the job. When he tightend the moving jaw, it lifted as expected but as it bore down on the "sloped" strip it also forced the job down on to the vyce base or parallel strip/s as the case may be. In other words he got a "Kurtz" "push/hold-down" effect from/with an ordinary vyce.

Needless to say had had to be carefull with his cutting load - but his work was superb. I saw grinding and milling machinists (mostly in the Tool Room) do the same thing but sometimes used 2 "strips" - one against each vyce jaw - and it worked treat there too.

Another point to consider is in regard to the vibration in the head of your mill.

I agree with all that you've done and say, but 2 things come to mind.

The first is whether the vee belt sheaves are true and dynamically balanced.

The second is that the "segmented" vee-belts that you use used to be known as "Braemar" belts (one for our Scottish friends there!!!). There is a "right" and a "wrong" way to use them as regards direction (can't remember which it is though). Have you considered the extra flexible A, B and C section belts that are used in automotive engines etc. - particularly the "segmented" ones? They have "sorted" a few "stiff" belt and "lumpy" belt problems for me.

The results I get are nowhere near as good as yours but they do the job - more in spite of me than because of me.

I have asked the local aluminium supplier to supply me with a catalogue and specifications as I'll make soft jaws for my chucks (lathe mill) and vyces (mill and grinders).

I apologise for my text not being as clear as yours (or at all??).

rgsparber
05-21-2007, 11:04 PM
oldtiffie,

Thanks for the kind words. My machining hobby has evolved into a hobby of machining, finding interesting things out, and sharing them. I'm glad it works for you.

My vise was made in India yet is a close relative of yours. I had to surface grind my jaws too. I too remachined the sufaces of the vise that contact the jaws. But first I had to indicate in the vise ways because the fixed jaw was not perpendicular to the ways.

With your permission, I would like to include your information about holding parts down in the vise. I will edit it and probably add a figure or two. If that is ok with you, please let me know how you want your name listed.

As to the balance of my mill's belt sheaves, I did run the motor by itself and saw very little vibration. I then added my idler sheave using a link belt and it too was quiet. Then I added the spindle with a second link belt and there was a little vibration. The major source of vibration came from the cutting action but I don't believe it is important. I do get a very nice surface finish. The important bit is that the vibration for a given cut depth in a given material is constant. I can take a 5 thou cut, zero my indicator, mic the thickness of the part (without removing it), and then make a second 5 thou cut. The mic tells me my cut is within a few tenths of 5 thou. So in this way I am able to cancel the vibration.

I do run my belts with the direction arrow facing the correct way. I have been told that they do run just as well in reverse but I never run my mill in reverse so it is not an issue for me.

Peace,

Rick

oldtiffie
05-22-2007, 05:20 AM
oldtiffie,

..........................

I would like to include your information about holding parts down in the vise. I will edit it and probably add a figure or two.

.........................

Rick

Thanks Rick - glad to be of help to one and all.

You decide what is done with it - with my blessing. Just don't bother about the credit - just (say) "it came to my notice that ........................."

On a similar vein I had a tramming problem on my surface grinder when I was "side-walling" a cavity/slot recently.

Didn't know it until I noticed that the "swirls" did not overlap and that the wheel engaged the slot at the top and worked down. Same on the other side of the slot.

So the slot was ground wider at the top than the bottom. And just as a check, I ran it round (?) the outside of the job while it was on the magnetic chuck. Same problem only reversed - as expected.

This was a classic "out of tram" item.

The "problem" wasn't a concern on this job and the tram is not out by much at all - but it could be depending on the job.

This is the only problem with my surface grinder as it works 100% as a surface grinder. The wheel-balancing systems is first class as well. Re-tramming it is a job for the future as I can "tram" my tool and cutter grinder relatively easily as well to do the job.

I have yet to see "tramming" relating to a surface grinder mentioned on this HSM BBS - but it does. It is just that it seems than a lot of people only associate it with a flat face parallel to the mill table - ie in the x-y plane.

In fact it relates to every "flat" surface that is to be cut with a peripheral cutter - bevels, S&F cutters, end mills, fly cutters - all of them. And this includes those faces that are cut on angle plates, tilting/angle plates - the lot.

For some reason a lot of people seem to insist on using their cutters at the largest size possible to get the surface cut in the least possible number of cuts or "passes". This requires slow cutter speed and consequent low feed rates and it maximises the errors caused by "tram error".

Using smaller cutters means higher revs, higher feed and over-lapped cuts.

The advantage is that the narrower overlapping cuts minimise the effects of "tram error" and allows a much better range of available speeds/revs and feeds (per tooth). And despite the cynics - it works and it looks good too.

All too often when using larger width cutters, the cutter speed is too high as the minimum revs on the machine (particularly a smaller one) are too high.

OK - "Use TC and bore it into 'er" I hear them say, but in my opinion, particularly for finishing cuts, I will always get a "sweeter" cut with a HSS cutter well within its rated speed and feed rates. I find that with a very sharp, and preferably honed cutter, I can "lift" the feed rate and get a very passable job.

I'd suggest that a lot of tramming could be eliminated if narrower width cuts were used. And the time saved by not always tramming could be better used for cutting.

I don't like "tear-ar**ing" at all let alone on a machine that I have a vested interest in keeping in as good a shape as I can for as long as I can. "Loading" the machine within reason is fine - within limits.

"Bashing" a machine is a recipe for disaster of one sort or another

"Making chips" is fine but that's what the wood-pile and the chainsaw are for.

"Haste makes waste" is as true now as ever it was.

Two things I remember vividly from when I was an apprentice or a younger Tradesman (55 years ago - just to set the scene).

One was being big-headed and a right "smart-ar*e" and telling someone - probably from the "office", "up there" or whatever - that "If you ain't done it you can't do it". I was stopped cold when the response was "Yeah, well how many Gynecologists have had a baby?". Not knowing what a Gynecologist at the time was bad enough, but not as bad as it was when I found out. My ego and self-esteem were crushed - as they deserved to be.

The second was in the machine shop where every person or a very small group of persons was allocated to each machine as the Foreman said that he would not have ANY machine that "everybody used" in his shop. He said that in his experience that "Everybody's machine is nobody's machine". And he was and still is proved to be 100% right in most cases.

It's too easy to thrash/flog someone else's (boss, neighbour, "relly") machine and leave the problem to "some one else". Not in my workshop thank you.

It is hard to decide if this has wandered "off topic" or not - but this thread seems to be getting a bit "longish"

Do you think you could or should start a new thread?

Well, I'd better do what I look forward to my Urologist doing - getting my finger out and getting on with and "looking into" something else. I'd like to say that I will keep it up - but that is a "Urology" problem and another story.

I hope this helps.

Your Old Dog
05-22-2007, 07:28 AM
Rick,
I've read most of this thread but not all. Someone may have mentioned this already.

On my vice, there is a small set screw underneath and parallel to the main vice screw. It rides on a 45 degree ramp and is used to reduce the amount of lift you get on the movable jaw. The big problem with my clone is that this ramp was not fully formed in the original casting so my adjustment set screw does not hit it just right. I've toyed with the idea of brazing on a piece of hard metal for the screw to rest on. I don't know if this is your lifting problem or not but you might want to look for this set screw. I had to take mine apart to see what was actually happening.

oldtiffie
05-23-2007, 03:02 AM
oldtiffie,

Thanks for the kind words. My machining hobby has evolved into a hobby of machining, finding interesting things out, and sharing them. I'm glad it works for you.

My vise was made in India yet is a close relative of yours. I had to surface grind my jaws too. I too re-machined the surfaces of the vise that contact the jaws. But first I had to indicate in the vise ways because the fixed jaw was not perpendicular to the ways.

With your permission, I would like to include your information about holding parts down in the vise. I will edit it and probably add a figure or two. If that is OK with you, please let me know how you want your name listed.

.............................

.......................
Peace,

Rick

Hi Rick,

just for the record, I thought I'd get as extreme a case as I could to demonstrate the "tilted clamping strip in a vyce" trick/method that I described in a previous post.

Use the info as you see fit with no credits to me thanks as it was passed to me in that sense and that I should pass it on.

See the following pics which should be relatively self explanatory.

This is to not only demonstrate that the system works but works very well under extreme conditions.

I used a terrible "Record" vyce that I use on my pedestal drill. I have (Note: only lightly) hand-tightened it with a bit of 1" x 1/2" cold rolled bright steel bar in it. I have used an old ruler as the "sloped hold-down strip" such that it engaged the existing "vee" in the movable jaw and the other end was engaged on the flat surface of the work-piece (takes a little bit of getting used to - but its worth it.

On reflection, a ground-off HSS (not bi-metal) 12" horizontal reciprocating hack-saw blade works very well.

The jaw "lifted" 0.037" (that's right "37 thou") as proven by the 3 feeler guages (0.012", 0.010" and 0.015" = 0.037" = 0.98mm).

And the work-piece? Hard down all over on the bottom of the vyce!!!

Did it grip hard enough - well see the pics where the whole shee-bang (vyce and all) is tilted on its edge and with the weight supported on the workpiece.

I could have easily tightened it up further.

A variation that I also use is to put a soft (aluminium preferred) spacer/packing strip between the sloped clamp and the job so as to not mark the job - but the strip MUST be clear of the bottom of the vyce. Ideally, the tilted strip should be as "flat" as reasonably possible (say 5 - 10 deg to the bottom of the vyce.

Does it work well - too damn right it does - try it for yourself.

Why did I do it?
- just to prove that it works;
- just to prove that something even worse that a "Chinese" vyce can do the job;
- it will make all vyces equal and work properly - even the "Non-Chinese" ones and "horror of horrors" - even the genuine "Kurt" - oh the shame of it all!!

In all of this, accepting for the sake of the discussion that the "sloped strip" works, it means that the only real requirement is that the base of the vyce be parallel to the milling machine table. The moving jaw is almost irrelevant as it is only used as a clamping device. The fixed jaw needs only to be as accurate as can be achieved.

Another variations is:
If the "sloped strip" cannot be used, a similar result can be achieved by finding the "jack/up-lift" in the moving jaw and put the equivalent amount of shim/packing under the job near the fixed jaw and let the movable jaw end of the job rest on the vyce base before engaging it with the moving jaw. The job will "lift" an amount equal to the "jack/up-lift". It works - try it.

One of the main problems with machine vyces is that some people will get more than just bit "heavy-handed" on/with the vyce handle and with "tapping" the work down.

The same Milling machinist that I referred to in my earlier posts also did the following to very good effect:
1.
finally and only close the vyce by hitting it with the heel of your hand - never a hammer (hard or soft); and
2.
tap the job down onto the vyce base or parallel strips with a lump of phosphor bronze or lead as they act as "soft" "dead hammers" with little or no "bounce". He always used a "cylinder-head" sequence when "tapping".

I was truly blessed as I had several such mentors. Their attitude as Tradesmen was that their job was to pass on information for the "learner" (me) and mine was to learn, practice and improve. Further, if any of us didn't do it we should either not be there in the first place or if we were there we should either "lift our game or leave"

The main reason that I got into this thread was to assist others.

If they are none the wiser for it then I can be assured that they are better informed.

It just seemed to me that all the discussion thus far more or less accepted that "vyce-jack" was inevitable, non-removable and could only be "worked around" and/or minimised.

I hope I helped dispel that myth.

Enjoy the pics.


http://i200.photobucket.com/albums/aa294/oldtiffie/Vyce_clamp6.jpg
http://i200.photobucket.com/albums/aa294/oldtiffie/Vyce_clamp5.jpg
http://i200.photobucket.com/albums/aa294/oldtiffie/Vyce_clamp2.jpg
http://i200.photobucket.com/albums/aa294/oldtiffie/Vyce_clamp1.jpg

pntrbl
05-23-2007, 10:14 AM
Good job on getting pics up Tiff. I still had to read the post twice but by doing that and correlating the pictures I finally understood.

Don't take that as anything negative regarding your ability to communicate in written English BTW. It's just that a pic is still worth a thousand words to a guy with little or no experience like myself.

Haven't milled anything yet but I'm gonna be ready when the time comes.

SP