Can you send pictures of how you’ve wired your EBB to Octopus?
How long is the wiring? How have you connected power to the EBB (and what gauge wiring have you used)?
I can describe it 
So RJ11 with the Cable and used the 2 middle wires for high and low. (0.2 Cables)
AWG 20 from PSU directly to the Board
So i think i will order IGUS Can Bus Cables (Twisted and 0.5 Diameter) and try that again
That should probably be fine. I use:
and clip off the connector at one end along with 18 AWG stranded. The distance from the opened end of the cable to the Molex connector is 20mm. I did a back of the envelope calculation and came up with a characteristic impedance of 112 Ohms which is pretty good.
I guess you’re looking at:
https://www.igus.com/product/1109?artNr=CFBUS-PVC-021
They claim 120 Ohm characteristic impedance (at least I think that’s what they call “Wave impedance”) so you’re getting a bit of an improvement with this but not enough that would significantly change things.
Personally, I suspect your wiring and that you may have an internal break in one of the two CAN bus conductors that opens periodically. The 20 gauge wiring is a bit smaller than optimum for the nozzle heater current, but you should be okay.
Before you invest in the Igus, could I suggest that you make up another cable (say with all 18 or 20 gauge stranded wiring for all four conductors)? Don’t worry about twisting pairs and don’t put it in your drag chains (if you’re using them) and see if you get any change in operation. It will at least give you another data point. Chances are you won’t have any signal integrity issues (I presume you’re like me and your cables are around 1.2 metres long which shouldn’t be a problem for the Octopus CAN bus drivers to overcome).
Good luck!
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Hi,
so i did nothing you advised me but:
I have installed a CanHat to the Pi, reflashed my Boards (EBB using CAN, Octopus using USB) and guess what ? It works !
So there must be somethign faulty either with my Board or the Software.
Now i am Happy and it only cost me 13 Bucks more
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I don’t know how it applies to others in this thread, but I believe it tracked my issue down to a failing 5v regulator on my toolboard causing the MCU to mess up can signalling if too many fans are turned on. I’m waiting for 24v fans to come in to test it. I’ll report back if it solves my problem.
EDIT: I got the 24v fans in, the printer is now working as expected, no more timeouts. Just errors caused by faulty components.
Can you provide an update on this? I am experiencing the same issue with bytes_retransmit being at 0 all the time, then climbing to 500 and erroring out hours into a print in a matter of seconds. I have a single 5V fan 30x10 20mA to cool the Mellow FLY SB2040-V2 and I doubt that it messes with the 5V regulator too much. Maybe the LEDs do aswell?
No more issues for you still?
klippy (3).log (408.0 KB)
Hello @VoltexRB !
You noticed that all these informations are over a year old?
New versions of Klipper have been out since then.
I recommend to open a new thread on your issue.
Hello, I put a heat-sink on the mcu of the EBB 42. Make a special cable that have separated shield from VCC. It has no problem now. I think it just bad design
hardware. I don’t know how the Klipper handle real time control to synchronize on separated mcus. That could be a problem too if you are getting to high speed printing. And Oh if you try this with extremely high speed printing, you will like to be over load the can bus again. My setting is only 128000 for speed and 128 for buffer.
I was hoping to see a more in dept information, but I guest not.
What is your current setting for the TMC2209 on the EBB42?
If you are passing too much current through it and you have it attached to the back of a NEMA 17 stepper, you will find that the MCU overheats.
Questions back:
- Do you monitor the temperature of the EBB42’s MCU (STM32G0B1)? If not, you should add something like:
[temperature_sensor toolhead_temp]
sensor_type: temperature_mcu
sensor_mcu: toolhead
- What is you current setting for the EBB42’s TMC2209? I run mine at 0.4 to 0.6A
As Myke mentioned, you should heatsink the mcu AND the stepper driver if possible. Mine can get up to 50-60c WITH a heatsink on both.
Cooling the steppers is very much recommended.