Speeds and feeds limits

Is there a limit on how fast the shapeoko can go.
for PVC im at 180 ipm but it seems like i can go faster for adaptive cuts

Depends on your GRBL settings. If you are using a recent version of CM and used that to configure your shapeoko, the max feedrate is now set to 10.000mm/min so 393ipm
BUT, this is mostly useful for rapids (outside the material). There are not a lot of actual cutting usecases (I did not say it never happened) where you would need from than ~200ipm


There are setting in GRBL that limit the travel speed, You can change these limits if you want to, and some on here have done just that. Be advised though, even in PVC there comes a point where too much speed isn’t a good thing. My understanding is that in adaptive, or HSM, the goal is to take deep cuts with a small tool engagement. This usually results in short moves especially when nearing corners or other geometry. If the length of the cut is short enough the additional speed won’t help. In fact the machine may never have time to reach the speed. this can result in jerky motion and poor cutting in corners.

@Julien beat me to it… internet must be faster over there… or maybe I’m just slower.


im still on 4.0.414 CM
for adaptive cuts im running .25 end mill o flute .39 doc 12000rpm and 180 ipm cuts like butter
i played wilth increasing by 20% while running and it still runs smooth

Yes, PVC likes speed, and is forgiving. But if you are going super fast, as @TheSilentEngineer said the problem may become to handle accelerations. Really depends on whether you’re shooting for max MRR, or optimal finish.

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my adaptive leaves stock and finishing passes are not as fast.
making face shields so im looking at speed mostly

There is also acceleration involved too. If the movements are short and lots of linking, then the motion could not even be reaching full speed either. Adaptive paths can cause lots of short movements and linking (especially in tight corridors), tuning the op can also help to reach those full speeds (decreasing time) by adjusting stock contours and enabling smoothing. Then there is retract heights, feed height, keep tool down, etc.


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