citizen cincom C16

Does the C16 have a turret? If so could you not place a threading tool on the turret, turn the length to diameter and then thread-cut with the turret tool and the material stopped out? I can't see the suggested method working, how will the thread match up? although on second thoughts you may be able to get away with it as long as the customer does not mind a slight mis-match. Are you able to turn the part from the opposite end and cut the thread on the sub-spindle? similar to what I have suggested above?

I've done this by pressing a plug into the back of the guide bushing. Drill and bore the plug just slightly above the diameter of the raw material. When the bar retracts it won't drop a lot and it won't need to bounce into the bore of the bushing. We make two inch long, double entry thread on a Star SR-32 this way. Works like a charm.

We also produce a four inch long screw with a 1/2-13 thread. The largest dia. on the part is the major dia. of the thread. For this I just use full form, topping inserts. The part isn't turned down to it's finished size until the final pass of the threading insert. Does a very nice job

Gerry

vic cantu wrote:

We often thread parts longer than the guide bushing throat - Turn less than 3/4", thread, turn more & thread again until you reach the length you need. I "loop" my programs to repeat until we reach the desired length. Just be sure to enter & exit in lead - start your "Z" in increments of the thread pitch, come in at an angle, & thread out in pitch.

We often thread parts longer than the guide bushing throat - Turn less than 3/4", thread, turn more & thread again until you reach the length you need. I "loop" my programs to repeat until we reach the desired length. Just be sure to enter & exit in lead - start your "Z" in increments of the thread pitch, come in at an angle, & thread out in pitch.

would you provide an example of your method? I quite like this idea and could be useful where I work.

This is quick & dirty - I tried to write an example - one of my bone screw programs is complex (& proprietary!) - I haven't proofread, but it should get the genral meaning across. I use looping & macro "B" on the swiss -

Long thread example - #100 = 2.0 (length of thread) #101 = .75 (thread segment length) #102 = -.2 (thread start) #103 = .375 (thread major) #104 = .298 (thread minor) #105= .75 (LENGTH OF TURN/THREAD INCREMENT) #106 = [1/24] (PITCH) WHILE[#102GE#101] DO1 (turn operation) T1212(TURN TOOL) G0Z[#102-.01] X[#103+.01] (POSITION FOR TURN OP) G1 X#103 Z#102 F.002 G1Z[#101+.05] (TURN FURTHER THAN THREAD) X[#103+.05] T0 (CLEAR MATERIAL & OFFSET) T1414(THREAD TOOL) G0 Z#102 X[#103+.1] WHILE[#103GE#104] DO2 G32 X#103 Z[#102+.1] F#106 ('Z' TRAVEL MUST BE MORE THAN 'X'] G32 Z#101 X[#103+.1] Z [#101+.1] G0 Z#102 #103=[#103-.010] (.010 = DEPTH OF THREAD PASS) END2 #102=[#102+#105] (Next 'z' start pos - must be in increment of pitch) #101=[#101+#105] (next 'z' end position) END1

Sorry, A quick re-read & I noticed that first WHILE statement should have been -

WHILE{#101LE#100] -

Otis

What's that Lassie? You say that vic cantu fell down the old alt.machines.cnc mine and will die if we don't mount a rescue by Wed,

If the thread is the largest diameter of the part, you can have the stock ground to the major diameter. You will need a custom bushing and collet.

Or

You could try using a LH threading tool holder. That will get you one tool shank more in length. You may still have taper problems though.

I'm not familiar with the C16, but with an L25, I have turned a small diameter to hold with the sub spindle or sub spindle tooling. After the thread is cut, the front of the part is cut off.

Good luck

Dan H.

Thanks for that code, I'll have a look some time and see where I can use it.

Cheers

Thanks for your comments all. Sorry I didn't get back sooner. I will start the part Wednesday and will fill you all in on my progress. Vic