Taig CNC Vise/Clamp

The test part that you see in this report was started before I had an adequate way to hold the part to the Taig fixture plate I made. I broke several of 3/16 inch carbide end mills I was using before I admitted (to myself) that I took a shortcut along the way. I was not holding the part secure and deserved to break those tool bits. I decided to stop and build a suitable low profile "vice/clamp" for the Taig.

Here you will see the result of the 2:00 A.M., laying awake in bed, sudden burst of insight. This vice/clamp is similar to the one I made in steel to hold the A3 Locomotive drive wheels while I milled them. (That tool was a bit too small for this project)

This vice/clamp is made from 6061 T6 billet (I love that word) It is as large as I can go for the width on the Taig. I'll explain in the photo layout.

The two aluminum "billets" are 2" x 5.5" x 0.5" bar stock. The two long rods are 1/4" x 20 x 10" SS all thread. The four nuts are 1/4" x 20 SS. The four cap screws are 1/4" x 20 x 3/4" SS. The four washers are also stainless steel. Zinc plating against aluminum is verboten in my shop, especially since I use mist cooling.

The parts are assembled and placed on the home made fixture plate. The plate is the maximum width suitable for the Taig micro-mill. If I need to hold something longer, all I have to do is cut longer all thread rods.

This close-up shows why the bars are two inches wide. The holes in the fixture plate are spaced one inch apart and I want to be able to span two holes so not to have a "dead length" where I could not place a hold down screw. The narrow slot is milled 0.250" with an additional pass of an additional 0.020" to widen the slot. (0.27o" overall)

The hold down screws have nothing to do with clamping to the part. The long rods do all the clamping to the part. The hold down screws simply hold the clamp bodies (jaws) flat and secure to the table. The wide recess slots for the washers and bolt heads are 5/8" wide and 1/4" deep.

It is easy to square up one jaw to the table and the world as shown here. This is what is so great about the layout plate. Keep things square as you mount them to the plate and there is very little mental stress worrying about not making square parts.

This close-up reveals that I actually undercut the length of the aluminum bar so that I would not have interference here when I use the square as shown in the previous picture. I can clearly see and feel that I am against the table edge and not the end of the clamp.

This is the four inch square by one inch high test part clamped in place, ready for milling. Now it can't come loose. I am already thinking of other adapters I can add to this setup for micro-milling. A small strip with a Vee notch can be placed inside the clamp to hold round parts.

The heat sinks I am making require the outside edges to be milled to a depth of. 0.502". That allows the 0.500 high clamp get in the way. It is simple to add shims under the part in cases such as this. A small flat shim plate could also be used if it is more narrow than the part.

This is a peek level with the part. If you look close you can see the small step on the right corner of the test part, note the clamp jaw is well out of harms way. Paying attention to these details is important.

This is why the vice/clamp has to stay within the width limits (in the rear) of the fixture plate. Hitting the column limits the Y axis reach to the front. I designed the clamp to go under the Z axis guide. With some tall setups the Z axis screw can get in the way.

It pays to know the limitations of the machine. Most of the time the width of the part that can be milled is not the width of the table. Here the 1" high test part, if too far back, will hit the Z column guide way. Higher parts will hit the screw.

Here is the full set-up. There is plenty of room to mill the 4 inch wide part if kept centered. There are no clamp parts or bolts sticking up above the clamp/vise to get in the way of the the milling action. This is what I should have done the first time!
 

It took less than a day to make this clamp. It took much longer to get the parts. That is why I tend to put off doing things like this that I know I should be doing first. However, when it is all done it is well worth the effort. Taking the photos and this write-up are fun for me too, so I don't count that time. I hope this gives others ideas on how to do things.
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