A Split Collet Vise Stop

[BobWarfield]

I wanted to post one of my favorite projects. Although it isn't new, I thought it would be interesting and I wanted to give something back here as I've taken so may good reads away since joining recently.

First, split collets. These are gizmos I first read about in Guy Lautard's books. They're a handy way to clamp round stock. They take a bit more work than the usual job that involves slitting a bore and adding a setscrew, but in return, much less pressure applies a lot more clamping force. Once you get used ot making them, they're quite handy for various shop tooling. I'll start with how to make one here and then move on to the vise stop. All this is covered on my web site for reference:

http://www.thewarfields.com/cnccookbook/MTMillKurtViseStop.htm

Okay, first we start with a piece of round stock in the lathe. I like 12L14 as the leaded steel is super-easy to machine. Here is my drawing and notes on making a split collet clamp:

The flange OD and shoulder are turned. Center drill and then drill the two diameters:

Now we're ready to part off. That's an Aloris parting off tool that I really like:

 

[BobWarfield]

Here is the collet from both ends:

Note the holes differ in size:

Now we tap it:

I use 4 of these on my vise stop, so I just cranked out all four together as a little assembly line.

Next step is to make the blocks that the collets fit into. I started by squaring some stock with my flycutter in my Industrial Hobbies mill:

 

[BobWarfield]

Next, I layout the holes using machinist's dye (Dyechem) on the surface plate with a height gage:

Note: if you don't get the holes pretty close, you'll be scrapping some parts! In my case, each block has 2 split collets at right angles, so taking a little care in layout was worthwhile.

Now we bore 2 holes at right angles. One contains the split collet. The other is the one that the shaft being clamped goes in:

You can see I'm using a Kant-Twist as a vise stop. Stops are a real timesaver for doing symmetrical work and small multi-part runs.

Okay, with 2 holes bored, you can see how these work:

See the vague outline of the split collet at the bottom? As we tighten the clamp, the collet applies force to the shaft, which locks it.

 

[BobWarfield]

Another view with the collet removed:

Now here is what I have in mind for a vise stop:

And here is how it came out once finished:

It's been a real handy gadget. I love being able to tighten the split collets by hand easily and have to go find a wrench. Also note the softjaws in the Kurt vise, they're another real timesaver!

Happy New Year!

BW

 

[Powder keg]

Hey, That looks like a handy tool! I'm building a vice stop now. I'll post some pictures of it as soon as it's done. I'll be adding one of these to my small mill at home:O)

Wes

 

[cfellows]

Bob,

I like your vise jaws as well. Are those aluminum? Gotta have me some of those!

Chuck

 

[DICKEYBIRD]

DANGIT Bob, yet another must-do project! Great job.

 

[BobWarfield]

Yep, they're aluminum vise jaws. Extremely handy.

For example, if you cut the step after the vise is mounted, they're now guaranteed to be in tram (at least until you move your vise!). I find I use parallels a lot less with my aluminum jaws. It also leaves a little safety margin so I don't zap my vise!

Best,

BW