While trying to cut some washers the centre hole seems to be shifted to the right and maybe a bit up. Hope the picture explains what I mean.
I drilled some marker holes in my bed at 60cm from zero and measured with a measuring tape. The Y axis seemed ok, but the X was 1mm less than 60cm. Would this cause this misalignment of holes?
Is there anything else that would cause this? Or is there a way of calibrating the machine?
Its strange that the centre holes are offset for all the washers considering they were cut one after the other.
I doubt it. But that’s odd. Try it at 30mm. If it’s down to 0.5mm error from 1mm then it’s linear, and wouldn’t have that big of an effect on the washers.
But the machine should move 60mm with less than 0.1mm error. See if you can measure the movements without cutting anything. If it’s not right on by the tape measure, then something is wrong (installed wrong, or loose or wrong parts somewhere).
W.r.t. the washers. If you’ve eliminated the obvious things, like making sure your CAD and CAM are actually in the right place, I would guess things are flexing a bit under the pressure of the cutting. You could try:
Cutting the middle with a helical drill instead of a hole operation. Those are EstlCAM terms.
Test in high density foam because the resistance goes away.
I can not think of a way it could do that other than CAM. If you cut the outside of one then the inside, then moved to the next it doesn’t make sense to be a machine issue. The outsides seem to be aligned correctly.
How fast and deep were you cutting with what diameter, and how long is your Z axis?
I see what happened there is no way to diagnose this. You missed a single step somewhere.
Next time do each full part at once. Inside, outside, then next one, the last thing is cut out the whole thing. You cut out all the outsides somewhere in the middle you cut out the entire piece, them some more outsides, then the insides. This results in all the pieces not working.
If you do the sequentially, you will see where it went wrong, and always do the outer biggest cut last in case it breaks free or the comes loose.
Ryan, ok that went better. Cutting the whole part at a time seems to have made a difference. Although on the first pass of the large outside cut it paused for a split second which made it cut the box wrong. You should be able to see from the picture.
So so does that mean I’m still going too fast, or too deep?
Is that aluminum? Do a test in something softer to make sure the Gcode is good. Check your pulleys, almost looks like one might be loose. (that would explain a momentary pause)
It should never pause, you can look at the gcode to see if there is any weird happening right at that point.
In aluminum fine tuning comes down to you ear for the most part. Too fast or too slow and the bit breaks, anything in between should sound good, as it cuts you should be able to hear parts where it obviously is under more load (90 degree corners). Skipped steps are usually a sign of other issues. The CNC is strong enough now to never skips steps it should always break a bit before it skips now. I originally designed it with weaker steppers and it would skips steps if your gcode was too far off. Now it is just a monster.
No, its HDPE 10mm thick.
When I say pause it was as if it struggled to cut and skipped steps.
Interesting that you say it shouldn’t do this. My steppers are 82gcm2, are they strong enough?
How can I make it a monster
Everything looks good, the gcode you sent was not from the previous pic?
There is a ton of moves in that file, try turning on arcs that is going to cut that code down significantly. Another option is slow down to 8mm/s and if that works make deeper cuts instead of faster.
You don’t have a 660 on there, so I can’t give specific suggestions, and I have no idea how long your z axis is. no matter what arcs should be on for circles larger than 6mm or so and go slower since you don’t have the power of the 660. If it is really tall you might need to go even slower.
I turned on arcs and reduced speed to 8mm/s. All went well until the last circle that totally went wrong. Its as if the bit hits denser material that’s harder to get through, which then throws off the rest of the cut.
I will try cutting shallower.
I was also playing around with tool change code. For some reason this code restarts the ramps board. Can you tel;l me why?
G0 X0 Y0 F2100 ; move head to safe area
G0 Z45 ; Raise spindle for tool change
M84 S999 ; keep motors on forever
M18 Z ; release Z
M05
M107
M000 ; pause for user
;Change tool: <n>
G28 Z ; Home Z axis to touch plate
G1 Z2 F150 ; Raise Z axis 2mm
M000 ; pause for user
G0 X0 Y0 Z0 F2100 ; move head to safe area
G0 Z45
M03
M106
Have you tried using Repetier to enter the sequence manually to see which line causes it to reset? Did it occur before or after the pause (M000)? If it was after, then it could be either of the first two lines following M000 because one of them has a speed greater than 8 mm/s (F2100) and the other has no speed. Note, I’m making the assumption that you are using the threaded rod and not the leadscrew, because the same issue happened to me until I limited the Z speed to below 480 mm/min.
