Increase maximum number of axii to 30?

o_lampe

@deckingman said in Increase maximum number of axii to 30?:

I thought we were talking about tools with multiple extruders but a single nozzle.

Until now, we don't know what the thread starter is planning to do. But I doubt, he needs a motion system with 25? axes to move only one nozzle?

Thorpydo

@o_lampe
I might not have made it clear before:
All motion systems and all extruders moving at the same time. Multiple extruders, moving independently, extruding at the same time. Four heaters, four extruders, four filaments being driven, etc. (all at the same time)
I understand there is currently no slicer available to be able to control what I am asking.
Writing the slicer is part of my scope of work. I am writing the slicer and that's why I need to understand explicitly the proper way to communicate with RRF and command with Gcode, all four extruders, and all motion axes, simultaneously.

It's still not clear to me if format should be:
G1 Xn Yn En0:En1:En2:En3
Or:
G1 Xn Yn En0:n1:n2:n3
(where n0, n1, n2, n3 represent feeding material in mm/s)

Based on your input, it sounds like the later?
G1 Xn Yn En0:n1:n2:n3

droftarts

@Thorpydo See https://docs.duet3d.com/en/User_manual/Reference/Gcodes#examples
Example there is:

G1 E10:10:5:0:0 F300 ; with a tool that has 5 extruder drives, extrude 10mm on drive 0, 10mm on drive 1, 5mm on drive 2 and 0mm on drive 3 and 4.

Ian

Thorpydo

@droftarts
Perfect, that jives with above. Thank you!

o_lampe

@Thorpydo I'm glad this concept already exists. I'm not at all an expert in the latest gcode implementations...
Just for clarity, the line should look like:

G1 Xn Yn Un Vn Wn {...etc. all axes receive their data at once followed by} En0:n1:n2:n3

Let's hope the line length doesn't exceed the planner buffer, ~~but @dc42 will surely find a way to help out.~~
//edit there's M595 command whichs allows setting the look ahead buffer for both queues. I thought, it was only for the second queue

Thorpydo

@o_lampe
Thanks!
I might have to clarify how to use the M595/look ahead buffer when I'm ready for that.

Currently, the slicer outputs extrusion in absolute mode but I would like to change to relative extrusion mode. It looks like that will be no problem and I can use M83 in start Gcode to do so.

Here's a single line gcode output; I believe this matches what has been discussed and aligned on in this thread:

G1 X556.90665 Y559.4645 Z559.4645 U556.90665 V564.15183 W564.15183 a556.90665 b559.4645 c559.4645 d556.90665 e564.15183 f564.15183 g556.90665 h559.4645 i559.4645 j556.90665 k564.15183 l564.15183 m111.49454 n113.41718 o113.41718 p111.49454 q111.36289 r111.36289 t-14886 E0:2712.35717:1611.15904:25136.476 F250

Thank you all for guiding me here!

o_lampe

@Thorpydo The lower letters will still need a single quote to mark them as axis.
I'm also not sure if the motion planner can handle coordinates with 5 digits behind the colon? Maybe it ignores the least significant digits?

Thorpydo

@dc42 said in Increase maximum number of axii to 30?:

When a 6HC is used as an expansion board, a single CAN message contains the movement information for all 6 drivers. So only 5 CAN messages would be needed per move even if all 29 motors move at once.

After reviewing the hardware configuration documentation and CAN bus interconnects, I was thinking that it would be easier to use x1 mainboard 6HC and 8x expansion board 3HC's because each expansion board comes with 2x RJ11 connectors and termination resistor is straight forward.

However, after re-reviewing this thread and DC42's comment above, it sounds like it I should optimize from a bus loading perspective and keep the number of boards to a minimum, thus 5x mainboard 6HC's, using both CANFD-0 and CANFD-1 connectors, and bypass the termination resistor on the middle 3 mainboards; first and last mainboards using CANFD-1 connector.

I see in the revision notes for mainboard 6HC v1.02a:
"improved the CAN-FD termination resistor bypass solder jumper design to make it easier to use the 6HC as an expansion board."

Where do I find documentation or detail on bypassing termination resistor for the mainboard 6HC v1.02a?
Does this all sound appropriate?

DIY-O-Sphere

@Thorpydo
https://forum.duet3d.com/post/312085

Thorpydo

@DIY-O-Sphere
Perfect, that's really helpful.

It looks like my understanding of the CAN connection was incorrect (two separate buses vs two connections for one bus).
I've created a diagram to make sure I understand how to correctly wire.

https://imgur.com/a/CbCiCU1
Is it correct?

Thanks for the help here!

Thorpydo

@Thorpydo
Hmmm, the RJ11 connector is made to accept one wire per pin, and it gets inserted instead of crimped.
How best to handle the junction here?