Low Profile Vise

A tipical problem: I need to mill a slightly long part, let’s say, a 10x10x130mm bar. Sure, you can use the good Sherline vise and clamp the part by the middle, but vibration at the ends of the part is a problem.  So after getting inspired by this and this , I decided to build my own wide low profile vise.

Start point

First, I bought a pair of used step jaws. They are really high precision, and include two stop options. As I understand this jaw types are for Kurt type vises, the big brand in professional vises (of course my vise will be a joke compared to one of this vises, but that’s not the point).

Design

Design specs were:

• Low profile
• 4″ wide
• Interchangeable jaws (must fit my Kurt 4″ jaws of course).
• Should have stops.
• Should be able to be used in the X or Y axis.
• Should not require clamps for installing.
• For light duty work (well, this cover Sherline use).
• And, of course, a simple design.

I choose 1/2″ tooling plate for the base and 1″ square bar stock for jaw supports. As always, after some draft drawings I began the building process.

Building

Main steps in building this thing were:

• Cutting to size and squaring the base plate
• Milling T slots (easier than what I expected).
• Cutting and squaring jaw supports.
• Drilling a lot of holes (harder than what I expected).

Some parts appears in previous posts. Here are some pics.

And here’s the assembled and installed vise.

Testing

After clamping an aluminum bar I found a problem: front and back supports lift about 0.5mm after tightening; it seems aluminum over aluminum lifts, but t-nuts remains fixed. So after that I add a key to the fixed jaw support (previous pics show that); at least this will allow to keep alignment.

Installing it’s a bit tricky, as two of the clamping screws go below the back jaw support.

How much clamping force? I don’t know, but at least I was able to raise the whole mill holding the clamped bar with both hands (I was not able to take a picture of this). That’s enought to me. Here are my vise and the Sherline one.

Tightening looks, at first, a bit troublesome, as this requires to tighten 8 screws, but anyway it’s a less than a minute process, so I can live with that.

Final Toughts

Sure, this is a light duty vise, but I love the step jaws, the stops and the fact it’s low profile.

I must admit I would have like a larger back for the movable jaw support, but space limitations led me to the actual design.

This vise can be used to clamp small flat plates, but a simpler solution for this are Dave Hylands Fly Cutting Clamps. They are the best practical design I’ve seen fot this type of clamps, so for sure I will anotate this in my long list of some-day-I-will-do projects.