INCREMENTAL THREAD

HI,
I NEED TO PERFORM A INCREMENTAL THREAD. NOW I'M PLANNING TO RETROFIT A CNC MILL (HEIDENHAIN TNC155) TO LINUXCNC. WILL BE POSSIBLE TO DO THIS WORK?.
ALSO, I HAVE ANOTHER MACHINE WITH A HEIDENHAIN TNC360, SO IT CAN CONTROL A FOURTH ROTATIONAL AXIS, BUT DON'T KNOW A WAY TO PERFORM THIS TASK.
HAVE ANYBODY EXPERIENCE ABOUT THAT?
THANKS IN ADVANCE, MARIO (AND SORRY FOR THE "WEIRD QUESTIONS" )
PD: NOTE THAT IN THE THREAD, THE NOTCH WIDTH IS ALWAYS THE SAME, BUT THE CREST WIDTH IS DECREMENTING.

Hi

Can you explain the thread you need in terms of this diagram
notch and crest width are a bit vague



As far as the controls go, Linuxcnc can control the machines in the same way that the Heidenhain controls do, albeit you may have to use some extra interface boards

regards

hi, sorry but i tryed to attach a picture and it didn't work.

Should be OK using jpg png or gif under 500K

Give it another try

ok thanks i didn't know about exact limit in attachements, there is a trim... not a complete picture. But in essence, this is a polycarbonathe cylinder with a thread "incremental pitch" milled on it. The aim is to feed bottles in a filling machine so that arrive at a variable speed, but regard to incremental spiral geometry, at the end of the thread, the bottle speed and position is syncronized with the whole filling machine.
Very thanks in advance, Mario.

I see!

It is a bit of a cross between an archimedes screw and a barley twist chair leg. :laugh:

So long as you can accomodate it on your machine, I would imagine it could be cut quite well using a mill with a 4th axis, the main problem would probably be flexing of the material away from the cutter, it would need supporting throughout its length.

What you need however is the G Code to cut the 'thread'

Although you could code it by hand I suspect a CAD / CAM route would be easier.