Z axis build question - dual instead of quad?

[chaosmstr]

First time building a Voron design, not my first build though.

2.4 uses a quad drive belt leveling system.
I want to build a multi-head system, and have a BTT M8P.
The current setup would only allow me to have two print heads when I could possibly have 4.

I was wondering if it would work with a two drive system instead.
Have the belts run in an inverted U config, with the gantry attached on the inside of the belt on the front, and outside of the belt on the back.
That way the gantry moves in the same direction.. of course.

I understand that front to back leveling would be a manual affair, but would it stay? And is there a Dual gantry leveling flag in Klipper that would work for left/right leveling?
I don't know how much belts would stretch or need to be re-tensioned, and I'm not sure how easily 2 nema 17 motors would actually hold the weight of the gantry.

I am still getting the parts together, so I thought I would put it out to the hive mind.

Thoughts?

 

[shiftingtech]

just get another mcu, so you can have more motors. crippling the leveling system is 100% not worth it.

 

[chaosmstr]

*sigh* I suppose you're right.
Now to find documentation on how to run two separate MCU's for one printer.

 

[chaosmstr]

Actually, I can use can bus for multiple heads. The M8P has a CAN interface, so i can leverage that and not have to worry about a second MCU.
Dunno why I didn't think of that first... must need more coffee.

 

[endstop]

>> Now to find documentation on how to run two separate MCU's for one printer.
Is this maybe very straightforward? What I see from my own (USB-based!) printer is that adding any number of microcontroller boards ("mcu") seems a defining feature of the Klipper architecture and routine. For example, I've got the four heads on individual MCU boards (Stealthchanger), plus Cartographer that is another MCU without stepper.
I have never tried it but I could see the same approach working with Z steppers as well, just configure it via a different "mcu" than that on the main board. I guess that's what was meant above.

 

[shiftingtech]

Actually, I can use can bus for multiple heads. The M8P has a CAN interface, so i can leverage that and not have to worry about a second MCU.
Dunno why I didn't think of that first... must need more coffee.

guess what? that canbus toolhead IS a second (or third, or whatever) mcu !

 

[chaosmstr]

guess what? that canbus toolhead IS a second (or third, or whatever) mcu !

Yup.. figured that out.
However, it's a much cleaner design wiring-wise... so I'm running with it.