Lathe Rigid tapping G33.1 with tailstock as W axis

In general, this sounds like a good idea, though it looks like you've run aground on some of the TP's assumptions about rigid tapping. I agree with Andy that extending G33 / G33.1 to use all axes makes more sense than a separate command.

There's no fundamental reason we can't do threading with the W axis, thought the aging TP architecture makes it difficult. As you've probably found, the rigid tapping data structures assume only XYZ motion, and there are checks sprinkled in the TP in a few places that check for ABC / UVW motion during tapping and throw errors.

Fixing this is difficult (at least with the version of the TP in master) because the TP does some weird stuff to compute distance along a path. For example, a linear move that has motion in XYZ and UVW: the TP just looks at the XYZ portion, and then figures out what the UVW motion is at the very end. If you want to synchronize distance along the W axis with the spindle, then the UVW motion has to be part of the path distance calculation in TP.

I've got an experimental branch that does the latter, though it doesn't merge with master cleanly yet.

Hi thanks for your message, i have little checked tour github account it look to be more difficult than i hope for include the UVW to TP.

I have start to check the linuxcnc turning and also milling post process from fusion360, i see nothing about UVW another big job if we want to use this way

For now try to add cycle with Y inside the turning version (not really cool that need to deal with setup coordinate inside fusion 360 manufacturing mode but maybee some trick are possible inside the postpro)

Br

Hi

I have change the postppro from fusion360 linuxcnc turning for adding cycle G33.1 G73 G81 G82 G83 using the Y axis for motorised tailstock without need to change nothing in the setup process the only things needed is naming the tool "8" for all tool used in the tailstock with manual change stuff ticked.
The postpro change automatically Z value from fusion360 setup to Y if you ask managed cycle, for unmanaged cycle i have add a error comment.

I attach both original and patched + one gcode for reference if this can be usefull for someone.

Off course i'm sure this is not perfectly done but the original is i think not really better...

Br

Hi

I have do a little update for postpro, and the most important i have do test on a real machine with success.

Rigid tapping not good success for now because my motor have too less power at low speed i'm saad, but drilling cycle are really cool !

Thanks for helping, i really hope that is possible later to add UVW to TP.

Br

alkabal wrote: Rigid tapping not good success for now because my motor have too less power at low speed

You could try it at high speed. But try some air-cuts first to see how long it takes the spindle to reverse as you are likely to see overshoot at the bottom of the hole.

Thanks for suggestion.

IMO i can't try with higher speed without following error on the tailstock axis.
In all way i can retry because i have now a better tunned PID.

Br