any CAN board suggestions for the 3MS?

[bsafh]

Hi,

I run two Klipper printers which both use mainboard acting as a CAN bridge (Mellow Fly DP5, BTT Octopus Pro) and I already connect my toolhead over CAN. If I decide to use 3MS (most probably two in parallel in one printer), which MCU board that connect to the mainboard via CAN and not USB would be recommended?
2x BTT MMB v2? Or is there any board out there that can connect all 8 steppers, is adressable via CAN and is affordable?

[3DCoded]

Hi @bsafh ,

I've only ever used USB, but you should be fine using 2x BTT MMB boards. A quick cost analysis:

• 2x BTT MMB CAN + 8x EZ2209 = ~$95
• 1x BTT Octopus + 8x TMC2209 = ~$70

So using one board is probably the cheaper route. It looks like you should be able to use the Octopus as a CAN device (not host), but I would double-check before purchasing it.

[carmatas]

But you already have a klipper host right? just connect the mcu required for 3ms on the host with usb , you dont have to connect it on the printer board

[bsafh]

yes... but SBCs typically have very few USB ports (USB cameras, USB connection to touch screen, printer MCU, ...) so this might force a USB hub ... - well, USB over hubs is definitely not the most stable connection, and having touchscreens and cameras on the bus often introduces "noise", latency, timing problems, timeouts etc etc. THerefore I tend to separate the hardware control from all the peripherical systems. And using CANBUS for the machine related communication is one way of doing that. Of cource that could be done using a U2C, UCAN, Canable etc adapter, but those typically only run on 500k and not 1M bit CANBUS speed.