After some distinct buggerage with the lathe cycle graphics, let's do some actual testing of the cycles on a live machine. Of course, I can start by checking what commands the macros are sending to the machine controller but ultimately I need to see what happens when I run the machine.
The more conventional "turning" and "facing" operations are prett straightforward and although I can't pretend I've done any seriously thorough testing at this stage, they seem to work largely as expected. I'm sure I can finesse the instructions a bit but initially I need to know if the toolpaths are almost sensible looking.
The "chamfer" toolpaths don't seem to be working quite as expected. There are 3 "corner types" on offer, depending on which of the3 possible chamfers you want to machine.
External chamfer (Front Outside"):
Here's the dummy setup I'm planning to run. It's air cutting at this stage but the tool starting position and chamfer parameters are hopefully good starting points.
And here's the displayed toolpath trace ie where the tool actually went, as reported in the backplot panel within the main screen:
Ooof. What's happening here?
- The backplot trace is all over the shop. This is due to the graphics freezing up, then waking up again and jumping to the current position. So parts of the toolpath are missing, with rogue traces where the jumps happened. The machine itself was working as expecting, so this seems to be a graphics problem.
- The starting coordinates are inappropriate. The macros start by acquiring and storing the current machine coordinates under the active WCS. This position is then used as the retract position (G30 perhaps?), so ideally you'd get them right. In my case, I seem to have positioned the tool miles away from the stock. It's a learning process, I guess.
- But more worryingly, the toolpath seems to be making rapid moves within the stock. For an external "Front Outside" chamfer, the tool should be clearing the work to the right and bottom of the screen for a front toolholder. The cause is actually quite visible - for this type of chamfer, the "chamfer distance" argument (5mm here) should immediately follow the feed argument (0.15mm) - check out the orange "call" script at the bottom of the setup panel). So, by sending the distance parameter as the 8th argument rather than the 7th argument, the GUI is accidentally specifying a "rear outside" chamfer. This turned out to be fairly simple to fix.
Here's the chamfer.ngc file:
chamfer
o<chamfer> sub
o<backup_status> call
#<chamfer_x> = #1
#<chamfer_ss> = #2
#<chamfer_doc> = #3 ;depth of cut
#<chamfer_z> = #4
#<chamfer_tool> = #5
#<chamfer_feed> = #6
#<chamfer_exterior_front> = #7 ;will be cut if > 0
#<chamfer_interior> = #8 ;will be cut if > 0
#<chamfer_exterior_rear> = #9 ;will be cut if > 0
#<chamfer_coolant> = #10
#<chamfer_maxrpm> = #11
#<chamfer_units> = #12 (=21) (20=inch, 21=mm)
o100 if [#<chamfer_tool> NE #<_current_tool>]
(MSG,ERROR : Set tool before use macro)
o100 return [-2]
o100 endif
o105 if [#<chamfer_doc> LE 0]
(MSG,ERROR: Depth of cut must be greater than zero)
o105 return [-2]
o105 endif
G8 ; Lathe radius Mode
G18 ; XZ Plane
G90 ; Absolute Distance
G21 ; Metric
#<chamfer_x> = [#<chamfer_x> / 2] ; because of radius mode
#<starting_X> = #<_x> (starting X)
#<starting_Z> = #<_z> (starting Z)
G96 D#<chamfer_maxrpm> S#<chamfer_ss> ; Constant Surface Speed Mode
M3 ; Start Spindle
G95 F#<chamfer_feed> ; Feed-Per-Rev Mode
G4P1 ; Wait to reach speed
o110 if [#<chamfer_coolant>]
M8
o110 endif
#<temp> = 0
o200 if [#<chamfer_exterior_front> GT 0] ; front outside
o201 while [[#<temp> + #<chamfer_doc> ] lt #<chamfer_exterior_front> ]
#<temp> = [#<temp> + #<chamfer_doc> ]
G0 x[#<chamfer_x> - #<temp>] z#<starting_Z>
G1 z#<chamfer_z>
G1 x#<chamfer_x> z[#<chamfer_z> - #<temp>]
G1 x#<starting_X>
G0 z#<starting_Z>
o201 endwhile
G0 x#<starting_X> z#<starting_Z>
G0 x[#<chamfer_x> - #<chamfer_exterior_front> ]
G1 z#<chamfer_z>
G1 x#<chamfer_x> z[#<chamfer_z> - #<chamfer_exterior_front> ]
G1 x#<starting_X>
G0 z#<starting_Z>
o200 elseif [#<chamfer_interior> GT 0] ; front inside
o202 while [[#<temp> + #<chamfer_doc> ] lt #<chamfer_interior> ]
#<temp> = [#<temp> + #<chamfer_doc> ]
G0 x[#<chamfer_x> + #<temp>] z#<starting_Z>
G1 z#<chamfer_z>
G1 x#<chamfer_x> z[#<chamfer_z> - #<temp>]
G1 x#<starting_X>
G0 z#<starting_Z>
o202 endwhile
G0 x#<starting_X> z#<starting_Z>
G0 x[#<chamfer_x> + #<chamfer_interior> ]
G1 z#<chamfer_z>
G1 x#<chamfer_x> z[#<chamfer_z> - #<chamfer_interior> ]
G1 x#<starting_X>
G0 z#<starting_Z>
o200 elseif [#<chamfer_exterior_rear> GT 0] ; back outside
o203 while [[#<temp> + #<chamfer_doc> ] lt #<chamfer_exterior_rear>]
#<temp> = [#<temp> + #<chamfer_doc> ]
G0 x[#<chamfer_x> - #<temp>] z#<starting_Z>
G1 z#<chamfer_z>
G1 x#<chamfer_x> z[#<chamfer_z> + #<temp>]
G1 x#<starting_X>
G0 z#<starting_Z>
o203 endwhile
G0 x#<starting_X> z#<starting_Z>
G0 x[#<chamfer_x> - #<chamfer_exterior_rear>]
G1 z#<chamfer_z>
G1 x#<chamfer_x> z[#<chamfer_z> + #<chamfer_exterior_rear>]
G1 x#<starting_X>
G0 z#<starting_Z>
o200 endif
M5
M9
o<backup_restore> call ; restore g20/21, g90/g91, feedrate cuter-comp and other using now global _backup_var
o<chamfer> endsub
M2
%
By placing the chamfer distance in argument #7 instead of #8, the cycle will select the correct section of code to execute("if [#<chamfer_exterior_front> GT 0] ; front outside" etc).
This looks almost credible, with the caveat that again, I seem to have positioned the virtual tool miles from the actual stock. And again, the graphics is sorely messed up due to the freezing / jumping behaviour:
Internal Chamfer ("Front Inside"):
Ditto, the freezing graphics issue and starting position have made a mess of things but otherwise it's actually looking OK:
There then followed a session where Claude buggered about with the Python code that generates these calls. This fixed the front / rear chamfer mixup.
Graphics problems:
As for the freezing graphics, "we" ended up changing "wake states" in the BIOS (no, me neither), which then highlighted an apparent "bug" (hate that word) in the rendering of the backplot. This resulted in the backplot completely vanishing for most of the rest of the day. I was able to monitor the PC between real life tasks elsewhere using the GL-iNet KVM (remote KVM over the network) as Claude beasted away trying (mostly in vain) to identify and fix the problem - and finally we got our backplot back by the end of play yesterday.
There's still the graphic problem causing the freezing / stuttering / jumping issue. I guess that's the next thing to focus on.
