variable pitch threading with fusion 640?

is it possible to use veriable lead threading on a mazak quick turn with fusion 640? our control doesnt support iso,eai and i have some threads to cut that change by .00015 per revolution. the only way i think this is possible is to ad a g34 command in the mazatrol side of the control. im not a mazak programer by any means so the fuzion is all greek to me and mazak says 4-6 weeks to turn on the iso,eai format. any help here would be greatly appreciated.

I've never had to try it before. The G34 in the Manual Program Unit is for a variable thread, so I'd start there and what info it's looking for. I imagine I'd probably start with a G34 at the 1st feedrate to the 1st Z position and perhaps try the next line with the with the second Z position at the 2nd feedrate and work from there. Again, never had the luxary of needing to try it.

Thanks, ill give it a try. going from fanuc to fusion is like trying to learn cnc all over again.

I looked through the manual and am trying a couple things on my Mazacam CadCam. I think I have an idea how it works. For the thread line, try the G34 with your Z position move. Use the FEEDRATE to enter your starting pitch (ie: 20TPI + .050 IPR). Under the RADIUS/VARIABLE value, enter the amount the pitch will increase or decrease ( + or - respectively, +.00015 if thats how much you want it to increase per rev). That might work, I want to load this and try it, but my machine is running a job.

The only other question I'd have is what to do for multiple passes. It may be that if you start at the same Z position, the G34 (like the G32) will synch the feed and the spindle. You may be able to do the math using the depth of each pass and the angles on each side of the 1st thread which could create the alternating "zigzag" style of thread passes.

At this point I'd just be curious to see if the variable pitch thing worked out.

when i get the first pc off ill let you know. thanks for the info.

well i couldnt get it to sinc with the theads from fusion so i broke down and payed the $3300 for the iso option g32 combined with g34 worked great.

were you doing a standard thread for a certain distance and then varying the thread for the remainer and not having luck synching to the standard thr'd... or were you not having any luck synching the multiple passes for just a variable thr'd? I'm curious now.

the threads where 2.5-8 3" long standard then i had to go back and make a decremental cut (k-.00015 per revolution. then i tried using a g76 canned then followed by g34 and that split the threds. what i wound up doing was using g32 with a Q0 at the end of each line then a g34 with a Q0 that worked great. i know this is not somthing that has to be done offten but the nuclear industry came up with this idea for there hi pressure steam chest so that the thermal growth will give them a better contact on the thread.

i talked to mazak and they said it was impossible to do but i guess it just takes a liitle more creative thinking!!!