Need advice on a new product I may make, wedge clamps.

I have been making my own for a few years now and just did two new fixtures where I made some more. I always change the design a bit to better suit the parts I need to hold so I have "prototyped" many new ideas. The latest "idea" works much better than I expected and I think it may be something others may want. The new "idea" is to make the shells out of steel with teeth to hold the parts for the first op to do a better job holding less part.

The main differences between my parts and what is currently available:
1) When clamped to the designed width the wedge is even with the top of the shell.
2) The shell is screwed to the fixture so it doesn't get chips under it.
3) The corners have a .067" radius so the fit in a pocket with .062" radiused corners.
4) I like longer clamps so mine are 1" long.
5) All of my parts are machined from stock, with tight tolerances. The base of the shell is held to +/-.0005", probably guarantee +/-.001" if I go into production.
6) I like 10 degrees per side on the shells, vs 20 degrees which is what the competition uses.
7) My clamps don't like to expand more than .02" so I will offer different widths in .005" or .01" increments.
8) Steel shells with serrated edges. At the moment they are not hard enough for steel parts.

Just wondering if this would be a viable product? I have already changed the shell design to make it more general porpose and am designing the production fixtures. I think I could sell the aluminum shell version for around $14 without anodizing and the steel shell version for around $20, assuming I am only doing smaller volumes with my current machines. If you need to buy new shells later without the wedges then that would not be an issue and the price would be fair. I am doing this post to see if someone can shoot the idea down before I make myself a lifetime supply of the things. I am simply looking to add to my own products that I make. The design patented but it looks like it expired in 2009 so I don't think it has any protection.

Here are some photos of my last parts, the production version of the steel shell would have different serrations to make it more general porpose. The pictured version is to hold onto .04" of the part for the first op roughing. The pockets have .005" of end clearance and .01" of side clearance which still allowes them to work without being chip traps.

I just got a batch back from the heat treater that to me looks oh so beautiful, 54 hrc! The aluminum shell is for 2nd ops and still needs to be tumbled. The shells moved a little when heat treating so I am going to try a better steel next time. These are all spoken for on a set of fixtures but at least I am set up to make them in production now.

To be continued...

I just almost finished my first set of fixtures using my newest clamps and stops. Of course the fixtures are double sided holding 4 or 8 parts each so they took quite a few clamps and stops. 1st op uses the hardend steel with teeth to hold the parts better with far less clamping force, the difference must be experienced to be appreciated. The second op uses raw aluminum shells so they don't mark the parts. The idea of anodizing the shells in NUTS!!! It drops the coefient of friction by a factor of 3, bad idea for a clamping surface. I have .003" of clearance in the pockets for the ends of the clamps and .012" on the sides so chips don't have anywhere to get trapped. Again, this must be used first hand to really appreciate.



To be continued...

No offense intended but you know this has already been done, right? Maybe I am missing something.

Uniforce(R) Clamps | Mitee-Bite Products LLC.

Significant differences! Read the first post.

I made a video of running the first parts in the first fixtures using my newest version of these clamps and stops. I haven't really optimized the program and I have to be real gentle not to pull a part since I am not using my serrated steel clamps. Turns out they are too hard and I broke a few, but damn they hold the parts! They went back to the heat treater yesterday to be tempered a little more. I think I will try an air hardening tool steel for the next batch of shells, it should work a lot better than the cheap steel I used for the first batch. Each pair of parts is held with 2 aluminum shell wedge clamps with an 8-32 screw torqued to around 18 in-lbs. Around 130 parts so far and nothing has moved.

Spindle load hits 160% at times on the first pass of op2.

I will update this video after I have done a few batches of parts and have it running as fast as possible. I figure I have at least 2 minutes of fat in it now.

Just a thought. Maybe use S7 steel for it's shock resistance. Also, I think 48-52Rc would be plenty hard for most applications. 4140 Prehard is only 30-32(?) Rc so you are up on that a good 15+ points. I think your idea is sound!

That's one of the steels on my list to try, and I think it would work in the high 50s with the right steel. I have them working with a bit better than the cheapest steel at 54Rc, about 300 production cycles per clamp so far in another fixture for another part without any problems.

DavidScott said:

That's one of the steels on my list to try, and I think it would work in the high 50s with the right steel. I have them working with a bit better than the cheapest steel at 54Rc, about 300 production cycles per clamp so far in another fixture for another part without any problems.

Click to expand...

Heck, if you are really going after this, maybe offer 4140ph as "aluminum only" clamps for a slightly lower price point (no heat treat involved). Then offer "high strength" (heat treated S7/A2/O1 etc) for tough to machine or exotic alloys.

Cheap, easier to machine steel and heat treat makes a better part and is cheaper, but yeah I am thinking both high end and cheap offerings. Works well with plastic too. No O1 as I want an air quench for least movement. The last ones bowed a few thou. Not enough to keep them from working but enough that I want to avoid it in the future.

Oh, and yeah I am really going to do this. I need several hundred more of these just for myself this year so making extras to sell is not much more work.