Here we go again . . . MK4

[Lee Roberts]

Nice work on the clamps, always handy to have.

Anyone else made their own clamps for machining, especially if they have any extra / time saving / novel features ?

These always stick out in my mind:

http://www.mycncuk.com/threads/4420-...hat-do-you-use

Some solid blocks from the side may come in handy for you, seen in this video:

https://youtu.be/MF4SK3ZIXGw

.Me

[routercnc]

OK, to conclude making the precision vice clamps.

Here is the first one set up against a backstop datum (a parallel), with the top surface flush with the jaw (using another parallel to get it level - not in photo). This is so I could batch machine the 4 parts without having to zero and set each one up:



By chance the long clamps I'd just made fitted into the slots on the side of the vice so I could hold it down to make the proper parts. For info the slots in the vice are 10mm wide.

I profiled the counterbores rather than using the drill press:


Then the clearance hole. I don't like drilling deep holes with an end mill as they can jam up, but because of the counterbore they were quite shallow and there was no problem:


Because of the datum plate on the vice each one took moments to set up, then a few minutes on the counterbore and hole and job done. Cleaned up the holes and finished:


Works well:


OK, now back to the main project. I dialled in the fixed jaw of the vice:


I needed to drill holes in the edge of the plate so I used the back face of the fixed jaw to clamp to:




Here is the backstop datum so the second plate would drop in without having to zero:


Then I offered up the parts and the holes were in perfect alignment (lower 5 holes in the plate). All was going well and I was really beginning to like this new vice! :


Then I noticed a problem. The outer plate is clearance for an M8, and the end plate I'd just drilled/milled should be M8 tapped which is dia6.8. Clearly they were the same size.


I checked the CAM and realised I'd picked the outer dia for the M8 tapped hole, which is 8mm. The inner circle, then one I wanted, is 6.8mm. This is because originally they were CAMmed for drill holes (so it doesn't matter which circle you pick), but at the last minute I decided to mill with a 6mm carbide to 6.8mm to save drilling out. But I didn't change the geometry so they were milled to 8mm. Aargh!!

OK, what to do!! M10 x 1.5 takes an 8.5mm pilot so I've ordered M10 button head bolts and will tap to M10 instead of M8. My M10 tap was from a car boot sale and did not want to cut so I've ordered an M10 tap from the same place I bought the M8. It is a spiral fluted tap and the last one I bought from them cuts really well and is good quality.

So I need to wait before I can assemble the end plates.

The other problem I had today was going too deep with a 6mm spot drill which clogged it up and jammed, then snapped it off in the part ! My fault for pushing it too far. Now I need to get a carbide cutting removal tool as someone posted in my thread a while back when I broke a tap.