[colby2000]

Hey everyone, I posted this earlier reposted because I wanted wanted to add a better drawing and some more info. Material is 17-4 ph. Would be running this on "Citizen L20-VIII" cnc swiss.
The maximum machine stroke is 8 inches, so with overall of 12.553, rechucking would be required. I have ability to eject through sub but not sure how to deal with .449 dia. on end of part. If I can figure out a way it would be roughly 800 - 1200 pcs. monthly.

Wanted to add 2 sites where I seen similar work performed.

CNC Swiss Machining, CNC Swiss Medical Machining, Pompano Precision

Swiss Screw Machining | Screw Machine Products | Alpha Omega Swiss



Attachment 188900

[MCImes]

Im having a hard time coming up with a good way to make this. This part is not well suited for a L series machine in my opinion. As you say, there is only 7 or 8" between the sub and main. This makes unloading really dificult.

Setup:
Normal cutoff
Front turn
.449 extended nose pickoff collet
a piece of bar/slug in one of the drill tools acting as a material stop

My (hair brained) process:
-Machine it small end first.
-Turn 6 or 7" like normal.
-Get your turn tool out of the way (above the stock)
-Stop the spindle
-Move the sub over to one of the ID tools. In that tool station just install a slug of material to act as a stop.
-Set the material out enough that the sub collet will still clear when it moves back inline with the main.
-So, with the main spindle stopped, move the sub to your stop.
-advance the sub forward so the stop is .001-.003 away from the tip of your part. Your part is sticking out of the GB 6 or 7"
-do your regrip. You will probably loose .001-.005 on your Z position
-retract your sub and move the Sub inline with the main
-turn the rest of your part (retract Z .030 or something and ramp back into your cut)
-Cutoff like normal, picking off on the big head. Do your cutoff at low RPMs to reduce the chance of the part whipping in the sub tube.

Push the part out the back of the machine by hand or pull it out with a magnet. I think these will have to be unloaded manually after each cycle, making this a 1:1 job most likely.
I dont see an automated way to unload this part in an L series. Have any M's available?

I have done a ghetto regrip similar to this and it held Z position +-.002 or so and it looks like on your print you have .015 total tolerance on your Z lengths? It will definitely hold tighter than that. You will get a small bump where you ramp back into your material after the regrip, but it should be <.001 in my experience.