Control robot arm with Marlin

Hello,

I'm just curious if somebody else tried this already before

I'm creating a robot arm with 6 stepper motors. Of course, I can wire everything to an Arduino Mega or so, but I thought it would probably more fun to wire it to a CNC board that supports 6 stepper motors.
If that is possible, then I can control my robot arm using regular gcode commands.

The general question might be: has anyone already experience with something similar?
And how can I control the remaining steppers, apart from X/Y/Z?


I hope somebody can give some tips / advice,
Roy de Kleijn

... you can search github for the various "robot-arm" or "6DOF-robot" projects ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks for your answer!

I did that, most firmware was custom made. I was wondering if firmware like Marlin can help too.

marlin is 3 axis. + tools, not suitable for 6 axis device

... there are some "3+2" roboter types, where have to reorient the "world-coordinates" with the "+2"-axes, then it's like common 3-axis control.

So it's more a task for the PC-software to generate the G-code, than for the firmware itself

Edited 1 time(s). Last edit at 07/29/2020 02:17AM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

@VDX exactly, I thought the same.

My remaining question is, can you control the extruders the same way as X/Y/Z ? how does the gcode look like for the extruders ?


If, I'm able to use a CNC board for this, then it would probably save a lot of time in regards to wiring / soldering.

... the G-code for the extruder (or dispenser or laser) looks like "G1 Xxx Yyy Zzz Eee Fff", where "ee" ist the amount of pulses, the extruder-stepper will receive (evenly distributed) along the moved distance.

To simplify the pulses/mm ratio, I'm setting the "Pulses per Millimeter" parameter in the configuration to 1 -- then I'm multiplying the E-value for the G-code with the needed p/mm number.

E.g. - for 100 laser-pulses per mm its like (laser get's the E-pulses instead of constant PWM):

"G0 X0.0 Y0.0"
"G1 X60.0 Y0.0 Z0.0 E6000 F2000" <-- this will move 60mm to the right and place 100 laser-pulses per mm -- so a pulse every 0.01mm, regardless, how fast/slow it moves

Edited 1 time(s). Last edit at 07/29/2020 03:37AM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

E moves like x,y,z but if it is E0 or E1 is set with the Tool command
feedrate of X,Y and Z is also limited to max feedrate of E, Its not completely independent.

... my E feedrate for pastedispensing or laserengraving is set to max. 100000mm/min and the acceleration too "totally overdimensioned", so not really limiting

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Ok, firmware-wise it's probably not so easy

Maybe I will buy a CNC board and write my own firmware. Atleast it saves me a lot of soldering