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View Full Version : How do I make a machine vise better



Brett Hurt
01-30-2010, 11:47 PM
What I need is to is take my import machine vice and get it more accurate, ops hop I spelled that right . Where do I go on the web or with help from you guys. It came with my milling machine from grizzly, it is blue if that helps. The jaws are 6.250 wide, hope you can help me Brett

airsmith282
01-31-2010, 12:12 AM
well in my opnion you get what you pay for,to make it more accurate well i really dont know you cant reall shim it up they tend to up hill at bit but you can take a rubber mallet or hold it flate then tighten done your peice might help , you have not really explained the problem but , like i said you get waht you pay for , i got lucky on mine its great but i got mine from busy bee, but i also have cheaper vices that are better and i got one or 2 that costme some bucks and they are great and well built but not made in china, germans make great sutff so do the russians as well..

anyhow dont think i helped alot here sorry,

dp
01-31-2010, 12:38 AM
Check Doc Nickle's vise thread at http://bbs.homeshopmachinist.net/showthread.php?t=37741

PeteM
01-31-2010, 12:43 AM
You might start by gently putting it on a surface plate and mapping the defects. Does it sit perfectly flat? Is the bed of the vise parallel to the plane of the base? Are the vise jaws perpendicular to the bed?

Then on to a fix. For example, the base can be scraped or ground flat to the bed. I'd avoid shims if possible, because it will make it a pain to remove and reset the vise.

One common fault of the imports is that the angle lock part is rough and not properly adjusted. That's a pretty easy fix -- search the Web for disassembly and adjustment instructions. Another issue is that the casting isn't all that strong -- which of course gives an opportunity to buy a better vise should you bust it.

Consider also what accuracy you really need. Many of us worry about .0005 when the project will serve just fine with .005 accuracy.

oldtiffie
01-31-2010, 01:05 AM
What I need is to is take my import machine vice and get it more accurate, ops hop I spelled that right . Where do I go on the web or with help from you guys. It came with my milling machine from grizzly, it is blue if that helps. The jaws are 6.250 wide, hope you can help me Brett

First off all decide what level of accuracy you need (as opposed to want) and then check/measure the vise to the degree necessary. That should identify and errors outside the acceptable limits.

Then machine or correct those errors and do any "re-build" work.

Then re-check.

Its a bit of an iterative process.

The link that Dennis (dp) provided to Doc's site is as good as any and better than most as it is very detailed and instructive.

darryl
01-31-2010, 03:51 AM
I haven't looked at Doc's vise thread yet, though I will. I may have already read it- . Anyway, I just recently squared up some of the mill table mounting accessories I've made for it. One of them is a 1 inch sq bar that spans the width of the table, and is drilled to suit the t-slots. I chose one side to be the bottom, based on the finish I got by sanding it on a flat. What looked like good seating areas is what became the table side of it. Then I milled the top, working around the t-slot bolts and removing one of the three at a time to get the bolt head area cleaned up as well. In hindsight, I should have recessed all the holes and used socket head cap screws, trimmed to length, to secure the bar to the mill table. At any rate, I then raised the bar up off the table on some shims, squared the bar to the table, then milled the sides. After this I sanded it by rubbing it on sandpaper on a flat surface. I've used the surface plate for this, but I rather like to use some pieces of 1 inch thick stone countertop chunks which I have tested for flat on the surface plate.

Anyway, I ended up with something to mount to the mill table, and to subsequently mount something else to, knowing that it will not be tilted or something. And now, what all this was about- put your vise upside down on it and clamp the vise in place. I'm going to check out that link now-

Ok, that was an interesting read. So what I've said doesn't really help with that kind of vise, but for vises with a fixed jaw that's not removable, it gives you a way to machine the bottom of the vise to match the geometry of the jaws.

loose nut
01-31-2010, 10:40 AM
Soft jaws.

My vise is a cheapy too, hard to get square in all directions at once. Can't afford a better vise, it would cost almost as much as the mill.

Put in some home made soft jaws, adjust the vise as good as possible and take a skim off of them leaving a small lip that becomes a replacement for your parallels.

The vise face and lip should be exactly in line with the x axis and perpendicular to the spindle axis, within the limits of your machine. Repeat each time you set up the vise.

Best option for a home shop with limited or no budget and good enough for most jobs. If it isn't then you have to shell out for the better vise. See top of page!!

You can also mill in special shapes and parallels at different heights. Just replace them when they get to chewed up.

Cost is negligible.

JTToner
01-31-2010, 11:54 AM
I'm not out to bad mouth Asian vises, my own vise is a 6" made in Taiwan Wilton, but many import vises are somewhat less than ideal. One possible solution is to check eBay and Craig's List for a used Kurt in your area so you can avoid the substantial shipping charges. With your original vise, either put it on eBay or use it on your work bench. Its hard to do precision work with non-precise tools. Repeatability is another potential issue with imports. Replacing the vise may seem a bit extreme, but long term it will prove to be a wise decision.

Forrest Addy
01-31-2010, 12:22 PM
"Blue" vise? Doesn't narrow it down much. I assume you refer to a "lock down" style vise made the standard of the inustry by Kurt. These vises are made to be easily reconditioned. All you have to do is dismantle them and surface grind the wear out. You might have to do a little fitting too but it's a simple job. Old timey mill vises with the integral rased fixed jaw and the clamp screw boss can be recondtioned too but only with care and trepidation on the surface grinder.

The process is called "gold plating." That's when you spend hours and hours doctoring up cheap stuff to the point it's as accurate as the best on the market.

As it happens, a friend of mine asked me to work over three really cheap Asian import vises. I scraped the bottoms flat and made the bases and swivel plates parallel and the same thickness. I squared the fixed jaw and refitted the key. I matched the jaw tops and recut the keyways underneath oversize, parallel, and the same distance from the fixed jaw and made new hard keys for them.

In other words I matched the vices so you could place all three vises on a machine table in any order and they could be regarded as one vise with three movable jaws. I did it all with a scraper using technique that avoided the characteristic undulations of a scrape surface. After scraping I finished the scraped surfaces by abrasive sheet lapping and selective stoning so it appeared to be surface ground. When I was done the vise could be momentarly lifted then pushed across a surface plate and it would glide on a film of air to the opposite side.

I have one of the vises I gold plated. While it's very satisfactory, the work I did was pretty much wasted. The plan was to match a dozen or so vises and put them in service in a busy CNC shop with the object that all vises were universally interchangeble. The enterprise failed because the iron castings were so soft they quckly wore in service.

All that fancy work took hours and hours. If the initial flatness and references were acraped, the balance of the matching could be done on a surface grinder the job in 1/4 of the time. The key matchng etc would be a wash. It would take a full shift to match three 6" lock down vises.

All this is to say: yes a cheap vise can be made accurate using a scraper and a smallish surface plate (12 x 18") but if the castings are soft you may get unacceptable wear over time.

Here's how to rework Kurt (and most all other lockdown style) vises: http://www.kurtworkholding.com/downloads/guides/D-Series_Rework.pdf

lakeside53
01-31-2010, 12:51 PM
Kurt makes it sound so simple:D

Mcgyver
01-31-2010, 01:17 PM
The process is called "gold plating." That's when you spend hours and hours doctoring up cheap stuff to the point it's as accurate as the best on the market.


I do lots of gold plating, just didn't know it was called that.....well not to cheap stuff anyway, but to old stuff. fixin, scrapin, aligning etc.

The problem about gold plating a cheap vise doesn't stop them from snapping in two :)

its a good scraping project (given its not hardened steel) to get a vise's ways perfectly parallel and its fix jaw mount perfectly square....good because its not a big job and and there's some variety; need to work to flat, parallel & square

JoeFin
01-31-2010, 03:32 PM
"Blue" vise? Doesn't narrow it down much. I assume you refer to a "lock down" style vise made the standard of the inustry by Kurt. These vises are made to be easily reconditioned. All you have to do is dismantle them and surface grind the wear out. You might have to do a little fitting too but it's a simple job. Old timey mill vises with the integral rased fixed jaw and the clamp screw boss can be recondtioned too but only with care and trepidation on the surface grinder.

The process is called "gold plating." That's when you spend hours and hours doctoring up cheap stuff to the point it's as accurate as the best on the market.


Forest

Are the old Bridgeport Vises worth "Gold Plating"

I see them pretty often for less then $100

gnm109
01-31-2010, 03:53 PM
After reading Doc Nickel's article, I am glad I went for a Kurt. I suffered with a 6" mill vise for nearly ten years that I bought really, really cheap ($40) from H.F. because it was a floor model and somone had made off with the handle.

Now that I have the Kurt, one of my projects will be to tighten up the old 6" vise in my spare time. I tried to sell it on Craigslist and got no takers so I might as well try to see if I can make it better.

sch
01-31-2010, 06:16 PM
Re that Kurt rework ref, many import vises omit the #72 thrust bearing.
Adding that, while reworking the rest of the vise is a useful, inexpensive
improvement.

Paul Alciatore
01-31-2010, 07:16 PM
You can definitely improve less expensive vises. Here's some things I have done that have helped.

1. First thing is to insure that the bottom is fairly flat. You can check it on a surface plate, but it probably will show mostly no blue. I have used a glass flat and sandpaper to get them a lot better than when they arrived. It doesn't take a lot and you don't have to keep at it until it shows all blue on a surfact plate, just until it will sit on a milling table without rocking.

2. You can remove the movable jaw and mount it on the mill and refinish the top (between the jaws) where the parts rest and the fixed face. You need to align as best as possible on the fixed jaw first and use a milling cutter that can finish the whole fixed jaw in one pass.

3. I find that milling a flat on one side, adjacent to the table will aid in quickly aligning when mounting it. A square will quickly align it. I do this by mounting a 1-2-3 block on the table, running fore-aft: use studs through the holes and nuts on top (with soft washers). You can square it to the table, but it it not essential. Then clamp the vise on it, screw running left-right and one side up. Now take a facing cut on that side. This should make that side straight and square to the fixed jaw.

4. Finally, this drawing shows the origin of the "lifting" problem that is so common in cheap vises when short items are held.

http://img.photobucket.com/albums/v55/EPAIII/ViseLift.jpg

This problem is caused by a rotation of the movable jaw. There are some possible cures for this. First, that jaw is often held down by a sliding piece under the vise. This piece is often crudely made and it may be running on surfaces that are just cast, not machined. You can improve the finish of the surfaces it slides on, you can make it longer, and you can make the fit better - with less clearance. All of this will help. Some less expensive vises have a round guide (like 1/2" drill rod) running through a tight fitting hole in the movable jaw to keep it aligned. You may be able to add something like this if there is enough meat below the top (surface where the movable jaw rests) to allow this.