[tazman2221]

i want to know if there is a way to pick-up and chase a thread on my mazak slantbed? it has spindle orient. thanks

[chippy1]

Which Mazak CNC do you have. Usually there is a switch on the OP panel which will allow you to do this while in Auto mode.

Regards,

Chippy

[jimiscnc]

There is an obscure software option on at least Fusion and Matrix Controls: It's called "rethreading".

It will allow you to pick up on an existing thread and rethread right through the so called 'passing point'. It is a 'teach window' and you simply steer the tool point in to the center of the thred form and hit 'teach'. this records both the Z axis position and the spindle angular rotary position. (Z### and C##, but not really full blown contour milling C, just threading encoder C)

When you thread this part, your tool will pick up the lead and recut magnificently!

You also have to shut this off when done, or the machine will try to cut this part over and over again forever.

I would guess only maybe 2% of modern Mazak lathes even have it. Very obscure, but described in the books and very field retrofitable. And well under five figures in cost!

-jim

[jimiscnc]

there is also 'thread start point compensation'. this allows you to change the RPM and continue to pick up the thread lead already there, instead of cross threading a whole new thread that has a new angular start point by virtue of the changed RPM.

This one will not pick up the leads of existing parts for rework - thats what rethreading as described before does.

jim

[vwilmot]

I used to leave out the "M3" command, single block down the program. On a Fanuc it would position the tool at the exact starting point, then by turning the chuck by hand, this would start the tool down the thread. At this point, its a simple Z adjustment to put the tool in the right spot. Not sure if this would work with conversational or not. Hope I didn't make this sound too confuseing, because it really isn't. Hope this helps.

[jimiscnc]

vwil:

I never tried that on a modern mazak, or any other machine, for that matter. I think your suggest has a lot of merit and is a worthwhile thing to try, but your method is G code only.

This would not work in Mazatrol, unless you were willing to do a hell of a lot of research and experimentations. Even then, maybe no good results.

Mazatrol in concept is a post processor that feeds G code direct to the buffers driving the machine, instead of to a program G code text file. You could concievably single block and write down the buffer and next block info and end up with a labor intensively produced G code program from Mazatrol source.

I am not a computer expert, but it seems like this task could be done with some damn good computer programming. I have never heard of anybody anywhere ever actually doing it, though.

vwil, once again, my compliments on your constructive info!

-90% jimmy