I've been wanting one of these vises for a while, for holding things and such, but how to do it? I experimented with 1/2" threaded rod, but the execution was rather cumbersome. So I scrapped that idea and decided to go with an idea I've seen on here, two pipe clamps fashioned into a moxon vise. Implementing the two clamps into my workbench was easy enough, but unlatching the clutch on each clamp was cumbersome. With some help from a friend, a couple of beers and a healthy afternoon, we came up with a solution!
Step 1: Install the Two Clamps
I'm slightly ADD, so remembering to take pictures doesn't always happen. But getting the clamps installed is super easy, so don't fret about it too much. Basically, drill matching holes in your bench and a board the width of your bench. Make it bigger than your pipe diameter, you'll want some play for uneven clamping and such. Install your clamps with the tightening knobs on your board side, and your clutch under your bench, threading your pipe into the correct end nice and tight. Then screw your clutch side to your bench. You may have to drill holes in the clamp part as I did. Make sure to install your clamp so that, when working at your bench from the moxon vise, the part of the clutch that "pushes" from you is facing towards the center of your workbench. Check the pictures for reference.
(NOTE) The picture shows a 1/2" spade bit. Disregard, this picture is from when I tried using threaded rod and... well never mind, it failed Hahaha! Use an 1-1/8" spade bit.
Step 2: Work the Pedal
Now, onto the pedal.
Somewhere in the middle of the workbench, I cut a hole the size of a 2x4, plus some slack on the Z axis to allow it to lever up and down. The 2x4 I had handy wasn't the prettiest, so I planed it even(er) and drilled two counter bores with a 7/8" forstner bit halfway through my 2x4 foot pedal. These will be for my 1/2" EMT activation arms.
After the pedal is prepared, dry fit it through the opening so that the counter bores are clear of the back of the legs and mark where the front of the legs cross the pedal. At this mark, install one of the hinges on the bottom of the pedal, then install to the workbench.
Step 3: Mechanisms Mechanisms...
When I'm trying to work out a problem like this, I like to try and think of what mechanisms are involved, and then work from the end result back to my desired initiation. So, I'll describe my thought process here, that way you can build your mechanisms out of anything. This way, if you don't have what I have, you can still follow the principle of the mechanism and still have the same result, the difference of giving you a fish and teaching you how to fish:
The clutch needs to be pushed, so I used a hinge as a lever to push it for me. To actuate the lever, I used the angled part of the hinge as a wedge by wedging a piece of 1/2" EMT between the hinge and the workbench leg. To achieve the upward force necessary to actuate the lever, I secured the EMT to another lever, the foot pedal.
So! From theory to practice, I'll start with the class 3 lever. I mounted a hinge so that it can push on the clutch. My ADD engaged while I was preparing the EMT, so I don't have many pictures, apologies. I bent an offset in each EMT so that they would radiate from the pedal to just under the hinges. The length of these pieces are crucial, as the activation depth is minuscule. After getting the lengths right, I made guides out of wood by drilling a hole 2x the diameter of my EMT (ideally, 2x. my largest bit was not quite big enough) and cutting through the center of them, making guides to keep the EMT trained to the correct position. After placing the EMT in the counter bores, I trained the other ends underneath the hinges and screwed in my guides.
Step 4: Finishing Touches
So now the foot pedal should "work", but it's not perfect, as the EMT will most likely get stuck between the hinges and legs and need to be unstuck. To prevent that, the EMT needs to be secured to the pedal, and a counter force applied to the EMT.
I drilled a small hole the same diameter as a nail through the back of the pedal into each EMT, then hammered the nail into the EMT so it would stay put. Make sure the pedal is in the "unactivated" state when you do this to make sure it works correctly. For the counter force, I fashioned part of a discarded mag lock to the nails, so the weight of it would pull the EMT down when I'm not stepping on the pedal. And...
Done! So now, as long as you hold the foot pedal down you can freely move each side of the pipe vises in and out. And, if you let go, then the clutch will engage and will prevent the vise from being open, letting you tighten the knobs easier. And, after you are done clamping, all you need to do is press the foot pedal and pull, and your work piece is released!
I may not have explained everything clearly, so please, any questions or picture requests feel free to ask. Enjoy!