Hold parts in a vise by a thread

[rgsparber]

Especially when you are only able to hold onto a part with a small contact area, the grip can be greatly improved by placing a piece of paper between the part and the clamping surface. Think of this as a gasket that fills up microscopic surface irregularities.

One frustration is when the paper must be very small. At the moment I am holding a 1/2" x 1" x 2" block in my mill vise with only 0.050 to clamp. How do I ensure that the paper doesn't slip out? My solution is to use some self-stick labels. I stuck the label to the part, trimmed the excess, and clamped it into my vise. The paper can't slip around.

Of course, I'm still making rather light cuts but will have full access to almost the entire part.

Rick

[WmRMeyers]

Especially when you are only able to hold onto a part with a small contact area, the grip can be greatly improved by placing a piece of paper between the part and the clamping surface. Think of this as a gasket that fills up microscopic surface irregularities.

One frustration is when the paper must be very small. At the moment I am holding a 1/2" x 1" x 2" block in my mill vise with only 0.050 to clamp. How do I ensure that the paper doesn't slip out? My solution is to use some self-stick labels. I stuck the label to the part, trimmed the excess, and clamped it into my vise. The paper can't slip around.

Of course, I'm still making rather light cuts but will have full access to almost the entire part.

Rick

Rick, that is called "cheating." OTH, there is an old military maxim: If you ain't cheating, you ain't trying! I've got a couple of much smaller machines now than even the small desktop stuff I had (and mostly still have) before. I'm stealing this idea!

Bill

[mklotz]

For extreme cases you could use very fine self-stick sandpaper.

[WmRMeyers]

For extreme cases you could use very fine self-stick sandpaper.

YOU could buy it. I'm a cheap bastrich. I've got some gummed labels, and plenty of 20# bond printer paper. But a drop of CA glue, and then clamp... Should ought to work, don't you think? I'm sure there are a lot of ways to make some variant of this idea work.

Bill

[rgsparber]

Bill,

What is the CA glue for?

The glue on the label is just so the paper doesn't move around while the part is being placed in the vise. The huge PSI from the clamping action will ensure that that the paper doesn't move when in position.

Looking microscopically at the part's and vise's surfaces, there are hills and valleys. The thin layer of paper will compress more on the hills and compress less on the valleys. Yet, even in the valleys, there will be a lot of friction.


Marv,

As for using very fine sandpaper, I wonder if this might actually not hold as well since the grains will stand between the surfaces. On the one hand, the total contact area might be reduced. But, on the other hand, each grain will be bedded into the part's and vise's surfaces and can't move around. Now, this does assume the vise jaws are aluminum. If hardened steel, the grains might just slide across the surface.

The sheer force might have to be totally resisted by the grains and not by friction between the part and vise.

Depending on your definition of "very fine", I wonder if this would mar the surface.

I just finished a part that was 1/2" tall. It was clamped by the bottom 0.05" and I used this gummy label trick. Nothing shifted. Now, I did not try making the part without the paper nor did I try making more aggressive cuts to increase the sheer force. However, using paper is increase grip is a very old trick that doesn't need proving.

Rick