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Stepper motor controller which is not CNC?

Posted by Elm999 
Stepper motor controller which is not CNC?
April 13, 2018 01:37AM
Hi,

I know about GRBL and similar Arduino firmware which does fancy CNC operations (means which have three axes X, Y and Z and user sends coordinate information to them in order to "draw" e.g. a line from the current coordinate position to the next one).

What I'm looking for is much simpler, a possibility to control several stepper motor axes (preferredly out of an Arduino too) which are completely independent from each other. Means I can start motion operation on these axes and they are performed straight forward, they just move until they have arrived at the target position and do not take care of the other axes, means they do not work like a CNC controller.

So: has anybody an idea if something like this exists?

Thanks!
Re: Stepper motor controller which is not CNC?
April 13, 2018 02:09AM
Independend moves was the basic idea behind G0, but in some firmware versions there seems to be no difference between G1 and G0.
You might get away with sending independend commands
G1 X## F## 
G1 Y## F##
G1 Z## F##
Re: Stepper motor controller which is not CNC?
April 13, 2018 04:21AM
OK, but when I send this sequence, do the axes perform a parallel movement or do they work sequentially, means does axis Y wait until X has finished and Z until Y has finished its motion completely?
VDX
Re: Stepper motor controller which is not CNC?
April 13, 2018 04:53AM
... with look-ahead "G1 X100; G1 Y100" may result in a diagonal (synchronized) move.

But "G1 X100 Y0; G1 X100 Y100" should give the "sequentiel" result ...


Viktor
Re: Stepper motor controller which is not CNC?
April 13, 2018 05:16AM
Hm, what I'm looking for ins neither a synchonised nor a sequential move, axes should be accessible independent from each other - but also should be able to move parallel...
VDX
Re: Stepper motor controller which is not CNC?
April 13, 2018 06:16AM
... you can simply use the G-Code-Syntax in a program, which will send the strings over the serial port, one by one, when pressing a button ...


Viktor
Re: Stepper motor controller which is not CNC?
April 14, 2018 03:19AM
Quote
Elm999
Hm, what I'm looking for ins neither a synchonised nor a sequential move, axes should be accessible independent from each other - but also should be able to move parallel...

Did you try G0? As I said, in some (older? ) firmware versions it works as intended, unsynced but simultaneous. For 3D printers there is no use for real G0 behaviour, so the programmers linked it to G1. ( saving some bytes on 8bit CPUs )
Re: Stepper motor controller which is not CNC?
April 16, 2018 01:28AM
OK, G0 seems to work...but seems to be software version dependent. Means there is some more to test...

But next problem: the manual talks about referencing but not about the referencing pins. Only thing I can see is one (!!) limit switch per axis. So is this single pin used for all tasks, upper and lower limit as well as referencing? Or is there an other pin used for referencing which is not shown on normal Arduino pinouts?
Re: Stepper motor controller which is not CNC?
April 16, 2018 03:16AM
Usually you only use one endstop per axis and tell the firmware which is it ( min/max) and also specify the boundaries of the movement.
EG. use it as min-endstop and specify it as -100 and max value as 100, your axis has a travel of 200, with the center being at 0.
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