A way not to do T-nuts and a clamp for a milling vice

[PekkaNF]

Hi all!

Is it ok to post here something that didn't go very smoothly?

I have a good sturdy Russian made milling vice. It has been located to the T-slot with a key and hold downs. Works well. However my milling machine is ex school and the last T-slot is not very straight where I want to place this vice.

I thought that few small/low profile clamps would be a nice side show. Got an brilliant idea: Make it from OD32mm mystery rod, cut it accurate length and mill flat to index it, and rest will be milling and sawing against stops. Good plan. The great plan was to clamp it well, set it up and do each feature with one "run". Push the piece against stop, locate and clamp, then one X or Y short feed with a milling machine and repeat with another piece.

Start went fast and as planned. I even didn't bother to skim outside of the bar, should done it to make them look nicer.

Flats were milled on one go. Removed 4,5 mm out of thickness on one go.

I made following mistakes:
* Tried to make them too close tolerance...Some groves were tighter than the one I made them. Had to take 0.1 mm all over.
* Got derailled and experimented with alternative methods. Tried slotdrill, should have sticked to plan to use 10 mm slitting saw to make 100 wide grove.
* Should have planned a little bit longer....Made in the end extra operations, that could have been omitted with petter planning.

My mill and vice is pretty strong those setups might not work on smaller machines.

And when I was sawing the spacer block in half I didn't cut it all the way. If the sawi cuts the alltread often bad things happens. Cut to the alltread from both sides and then finished them off manually.

[PekkaNF]

Then a I treaded T-nuts. The spacers had a clearance hole drilled at the lathe before. In retrospect I thought that it would save time to drill taping hole at very beginning...it didn't. I started with something like 66mm long stock and the lathe is capable of drilling about 35 mm on one go. Lame. Even more serious is that I could have saved one milling operation drilling the spacer block hole excentric and got better geometry for clamping as well. Next time.

This is what I aimed for:
* Need to save some place
* Spacer is pushed hard against the vice to locate it laterally.
* Bolt can't go trough the T-nut


Pekka

[Bernd]

Hi all!

Is it ok to post here something that didn't go very smoothly?

But of course you may. This helps us in our learning curve. Don't want to reinvent the wheel.

Bernd

[PekkaNF]

Thanks, It all seems to be smooth sailing (most of the time). I thought I had a clever plan to produce few parts quickly. I still think idea was right, should just have planned a little longer, like draw it to scale and just not dodle on the paper. It started out fast and as planned. There were no trouble before I tried few new ideas and tried to overbuild it.

Hope someone is inspired. I learned something I allready knew!

Pekka