So to those of you who use R8 - ER collets, how do you torque them down?
I can always just use the old TAF torque spec, but how would I do it properly?
Chasing tenths is hard...
Rigo fix collets are by far the best, they come with a torque spec sheet. Different torque for different size collets. They have a crows foot style wrench and a very expensive torque wrench made for it. Just FYI.
I made an 11 tpi one out of a broken 5/8 x 11 HSS tap. Cut the broken end off with an abrasive chop saw leaving about 12 cutting edges and ground off two of the three flutes. It worked well except the remaining fluted threads were about 1/4 inch long and the pitch angle left a slightly wide cut thread. Ground off about 1/8 inch of the trailing edge of the flute and thinned the trailing end of the cutting surfaces with a Dremmel with a 1 inch thin abrasive wheel. It now works great. I use it on 1 inch diameter mild steel shafts and matching 1 inch aluminum holes.
I have a Centroid CNC mill and thread milling is built into the conversational programing.
I also have made a single point thread mill by milling a 3/8 inch flat on a 4 inch long piece of 3/4 inch diameter drill rod. Milled a triangular pocket into the flat the same shape and depth as the 60 degree carbide inserts that came with some Enco lathe bits. The tip of the insert sticks out about 1/8 inch. Brazed the insert into the pocket. When it breaks off or wears down, I'll just heat it, rotate it 60 degrees and braze it back on. I single point 6 TPI male and female threads on two inch shafts and pulleys with it. Again, the Centroid system includes single point thread milling with multiple passes.
It took about 15 minutes to grind down the 5/8 inch tap and probably 45 minutes to make the single point one.
Dennis
With my 704, I just hold the spindle in place, and tighten with the spanner wrench. Seriously, you don't need a huge amount of torque if you are using stuff that is within the correct dimensional range.
With the bridgeport, I just stick it in back, and torque away...
That said, since I mostly am doing small cutter stuff, I've been using DA300 collets - Just stick the holders in a high quality/low TIR 1/2" R8 holder, and go for it... Main reason for that is that I can get a LOT closer to the workholding while still keeping a lot of tool shank in the collet.
Well, I got the bearing nut and a wrench for my ER40 chuck from Maritool. I like it, it definitely feels like I can torque it down better.
I also finished my spindle lock project. I am sharing a few pics of the complete work, but I admit, there's not a lot to see. I basically copied the idea from Fignoogle's product. I made mine from 1" steel plate though, (just because I had some lying around) and I think mine might be just a little bit stronger...
Overkill is my specialty
I have a nice knob on order, it should arrive within the week, but even without it, the spindle lock functions fine.
Right now I'm trying to decide if it's ok to tighten my ER40 chuck with the spindle lock, or if I should clamp it in a vice. I think the spindle bearings can easily take the strain, and I know my lock can. So I think tightening in the spindle should be just fine... Opinions?
Chasing tenths is hard...