Moving axis at different speeds at the same time

Aurimas

Hi,
not sure if it is correct group for this topic - advice if not or move it.

So I have a system with 8 different independent axis. I want to be able to move them at the same time, but at different speeds, i.e. selecting different feed rate in the gcode for each particular axis.
at the end of the move all stop until the slowest one will finish action and then proceed to the next step
any ideas how to configure it and how would the gcode look like?

OwenD

@Aurimas
As standard all axis will arrive at the commanded positions at the same time.

I think you're after multiple motion streams.
See the docs here
https://docs.duet3d.com/User_manual/RepRapFirmware/Multiple_motion_systems

o_lampe

@Aurimas There once was a difference between G0 and G1 moves, but RRF treats both the same now.
But even if they were still different, it's the opposite effect of what you are looking for:

all axes run with the same speed, no matter when they arrive at their target. (unsynchronized move)

AFAIK, with multi-gcode stream you could run two streams independently but not 8.
I could imagine a setup with several independent duet mainboards, synchronizing their motions by external triggers.
But that would be experimental at best.

droftarts

@Aurimas

@o_lampe said in Moving axis at different speeds at the same time:

There once was a difference between G0 and G1 moves, but RRF treats both the same now.

In CNC mode, G0 does work differently, ie as per the NIST spec:

G0: Rapid move

Same as G1 except when in Laser and CNC mode, where moves are executed at the maximum feedrate available. See 'G1: Controlled linear' move for usage.

So if you can use CNC mode, set all axes speed limits separately, then command a move of all axes. I think that should work.

Ian

Aurimas

@droftarts it doesn't really matter what mode it is