Hello, my name is Dominik,
I hope it´s ok to start my participation to this forum with a feature request.
Short introduction on my situation: In the last years I built several CNC machines controlled by various software and
controller configuations, mostly cartesian but also some parallel kinematic machines.
One of my first CNC projects was a lathe conversion to stepper motors and mach3.
Because of the compact size and therefore minimal rotating masses it turned out not that perfect because
of the mach3 single index pulse issue treading with reasonable/reliable passes was impossible and so the
project was abandoned for several years.
A few weeks ago I switched my larger router to UCCNC and recognized the sync modes with encoder support.
So I picked up the project again, made some more improvements to the lathe and first steps with UCCNC and turning.
Even there is no real lathe support, yet, I´m very happy with the first results.
Here´s a full time video of one of the first sample parts (I hope posting links is allowed):
https://www.youtube.com/watch?v=jWzxNC5xbAc&t=3s
The video is very long, if interested G33 thread cutting starts at Minute 4, but my problem and feature
request comes at the end around minute 8.
I also use the G33 for parting off here, which othervise is the most difficult operation, and normally on such a small
machine ends up with tool parted off, not part parted off because the circle of death then starts with slowing down spindel
upon tool contact, less speed same feed again lowering spindel speed... etc.
With G33 I have a constant cut depth and this works really well if spindle speed is increased in relation to the diameter decrease
(constant cutting speed). Doing this manually is possible but not very nice on a CNC.
So finally the question: Will there be a sync mode command similar to G33 but with two (or one) more parameters, lets name them SpeedStart
and (more important) SpeedEnd?
Sorry for the long post.
Best regards
Dominik
P.S.:
Othervise I currently see three possible workarounds:
1.) Splitting the cut off in several smaller segments with new Speed Commands in between.
This will result in an intermittent cut which is for some materials (some sorts of aluminium or steel)
no ideal but will be very easy by just using modified G-Code.
2.) Picking up the step and encoder signals with a custom made PCB and overwriting the speed output
of the controller, this seems to be a hazzle to set up between cuts and most likely will result in a
custom modbus spindle controller.
3.) Maybe a more or less simple macro is possible? Not sure if the the spindle speed can be maniplulated during a running sync
motion? Would it be possible to read the X Axis field and write/validate the Spindle Speed Field during a sync motion?
(Have not played with the macros, yet)