I’ve used my little self centering vise for round stock which has been great. Now I want to get the same benefit of a repeatable center point on cubes instead of just round stock.
This presents a bit of a challenge, mostly because I’d like to support multiple sizes without switching jaws or moving a hard stop.
I only need to do minor cuts on the top side of the cube so that helps out a bit in that my cutting forces are low.
We use the 4 bolts in the vise jaws as self aligning turrets. If we use a shoulder bolt we can have the “jaws” of the turrets rotate freely. The vise itself can act as the parallel for the z axis.
The “jaws” in this case would be round stock with a tight tolerance through hole for the shoulder bolts (the shoulder bolts are locating bolts with precision ground diameters)
The round would then have a flat milled into it which mates with the stock.
Since each jaw can rotate individually and freely, it should do a pretty decent job averaging any small errors in the geometry of the cube while self centering.
It can also handle multiple sizes of cube without changing the X|Y zeros.
That’s the theory anyway, anyone think it’ll work
I took more than a little inspiration from the Saunders vise I recently got…if they’re doing it, surely it’s not a terrible approach
Let’s see how this goes.
I figured we might as well cover some other common use cases with the jaws, so I threw an arc on there for 40mm diameter and 1" diameter. Looks like a bird.
(I drew that sketch up before coffee this morning, so if it looks overly complicated…it is )
Cutting out of delrin first to ensure I didn’t mess up the geometry before committing to brass. If it works really well, I may commission some out of a real steel or something. They’re fairly small at ~20mm diameter and ~6mm height so getting a handful shouldn’t be too terrible. All doable in one setup as well so that helps.
Yeah metmo does some awesome stuff. Maybe I’ll grab one and try to convert it to be self centering
I hadn’t ever considered a fractal in a vertical configuration, that sounds super handy. sigh But how do I justify buying 3. One vertical, one horizontal, and one that I’ll end up destroying trying to convert it to self-centering
Good first:
The idea seems solid. Switching between different size rounds is wonderfully simple. This is going to be incredibly convenient, removing another hurdle for quick experiments.
I was a bit worried about jaw lift and had some ideas for fixing it. There’s no discernible lift though so I’ll leave the complexity out of it for now. (There is some in the photo but that’s because they weren’t tightened)
And the bad news:
I did my maths wrong and the diameter of the turrets is too small to hold my cubes
Notice how the corners aren’t over the lip of the vise jaw, it’s just too small to clamp before the jaws meet.
More bad news, the pieces aren’t symmetrical so there’s an apparent left and right side!
This doesn’t impact functionality but it does impact my sensibilities…so I’ll be mirroring the part next revision
And finally more good news:
I can just increase the diameter of the turret to fix the cube issue. This also gives me a bit more room to squeeze in support for additional diameters. Nice.
Doing the test in quick to machine delrin proved valuable here. It was probably quicker than 3d printing and certainly more fun than completely modeling the setup. (Though I should probably just suck it up and model it for v2)
Actually I have a design and material.
Hopefully this week I will start cutting parts .
I have my granddaughter next week, so that will slow me down. All good
Update: These things are awesome. I’ll likely mock up an entire SMW bed full of these vises with a few variations of the turret jaws, just to see how many stations I can fit comfortably.
I think my next workholding endevour will be a vac table, then a Longworth chuck, and eventually I want to get a tiny 4th axis. Maybe I’ll pick up a Carvera Air 4th axis and see if we can get it working without the carvera…surely it’s just a stepper and some homing sensors at the end of the day.
First things first though, let’s see how much these would cost in steel
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