Here's a design of mine that I patterned after Lee Valley's rack stops.

This device is designed to help prevent racking when clamping work at one side of a vise. Simply stack up as many of the shims as you need to match the approximate thickness of your work and insert it into the vise opposite the work being clamped.

For thicker work, you can add a piece of scrap lumber to occupy the bulk of the space, and then use the rack stop to fill in the remainder. This keeps the jaws aligned as force is applied, eliminating potential for damaging the workpiece, the vise mechanism or both from racking.

They hook over one or both guide bars on my vise to stop racking. It depends where on your vise jaws you clamp your work.

Here's some of my work clamped.

Thanks for looking!

Cheers!

MrRick

Edited January 29Jan 29 by MrRick

I usually use a piece of scrap with a spring clamp. Quick and easy

That is quick and easy but not always convenient finding the right thickness of scrap to offset the racking. This this.

I made a piece with different thickness but it is a solid piece of wood. Like the idea of your feeler gauge .

I use them alot. All my vises are quick release Moxon style vises. They work very well with them.

Another slick idea!!!👍

Thanks Gunny!