IDEX: "extruder" no longer works after defining "extruder1"

Basic Information:

Printer Model: Custom large scale IDEX
MCU / Printerboard: BTT Octopus Pro + BTT EXP MOT
klippy290823.log (31.0 KB)

Hi, I’ve been having issues getting IDEX to work on my printer.
Whenever I uncomment [extruder1], the extruder-motor of [extruder] no longer gets powered. Even a FORCE_MOVE command won’t do anything at this point. However, when I include the (here commented out) toolchange macro’s, and change to T1, and then back to T0, it dóes work, somehow.

To be clear, I did have the tmc of [extruder1] uncommented, aswell as the IDEX macro’s, but to narrow it down I started commenting out stuff. This is how far I have been able to get.

I’m 99% sure that it is some dumb error I made, but I just can’t find it, so please point me the right way…
Thanks in advance, a very novice klipper user :slight_smile:

I do not understand what you are trying to achieve in your config:

step_pin = EXP2_6
dir_pin = !EXP2_5
enable_pin = !EXP2_7

step_pin = EXP2_3
dir_pin = EXP2_4
enable_pin = !EXP1_8

[tmc2209 extruder]
uart_pin = EXP1_6

aliases = 
	EXP1_1=PE8, EXP1_2=PE7,
	EXP1_3=PE9, EXP1_4=PE10,
	EXP1_5=PE12, EXP1_6=PE13,
	EXP1_7=PE14, EXP1_8=PE15,
	EXP1_9=<GND>, EXP1_10=<5V>,
	EXP2_1=PA6, EXP2_2=PA5,
	EXP2_3=PB1, EXP2_4=PA4,
	EXP2_5=PB2, EXP2_6=PA7,
	EXP2_7=PC15, EXP2_8=<RST>,
	EXP2_9=<GND>, EXP2_10=PC5

You are assigning your stepper pins to the expansion header for the display

Refer to


to correct your pins

Most likely it makes sense to really carefully check your entire config.

Hi, thanks for replying so quickly!

I am using the EXP slots to connect to a BTT EXP MOT board, which adds three more stepper drivers to the board. The renaming just makes it so that I can use the names that are on the pin map of the EXP MOT module.
I am aware that with klipper I could’ve just used a different board to get more motors, but at the time I wasn’t aware of klipper yet.

It might still very well be a sloppy mistake somewhere, I’m sure you noticed all the bits and bops everywhere scrounged together…

It seems very odd to me that this would only show up when I add another extruder, whilst I have already successfully printed with this when I hadn’t defined the second extruder yet.

EDIT: link to the exp mot, maybe it makes more sense then :slight_smile:

Ah sorry, missed the bit about the BTT EXP MOT.

Unfortunately, I have no experience with it.
What I noticed is that this board does not seem to have a way to disable the stallguard / diag pin. This typically is needed when not using this feature. Most of the modern boards have jumpers to do so.

Not sure if it would make any difference, though.

I guess you have verified that the rest of the jumpers do match the UART config.

Okay, I’m gonna have to do the walk of shame here, I think… I hád checked the jumper pins that the drivers sit on top of thrice by now, but now having the diagram back up, I noticed that the M2EN and M3EN jumpers were on (just to the right of the EXP ports, as oriented in the user guide). These aren’t supposed to be there in UART… So yeah, sorry to have you spend time on this, thanks for thinking along though, because that is what made me check again.

So yeah, apologies but also huge thanks :slight_smile: