Sensorless Homing Not Working on Voron Trident w/ FYSETC Spider V3.0 + TMC2209

[Azazel]

Hi all,

I'm building a Voron Trident 350, and have been slowly assembling it over the past six months. At this point, I’ve wired up enough to start testing motion — but I’ve hit a wall right away with sensorless homing for X and Y (Z will eventually use Tap). Either the axes don’t move at all, or they move but never stop, crashing into the frame.

What I'm using:​

• FYSETC Spider V3.0
• TMC2209 stepper drivers (included in the Spider kit)
• CoreXY setup — currently only A and B motors connected (i.e. X and Y)
• No endstop switches installed — I’m aiming to get sensorless working first
• Z motors are not connected yet

What I’ve tried / setup so far:​

• I’ve read multiple guides (like theforgetful.dev and clee and including the Voron docs and Klipper sensorless homing documentation) and watched a YouTube tutorial on sensorless setup.
• I created a sensorless.cfg file (attached), and included it into my printer.cfg (also attached).
• For DIAG pins, I originally set:
  

  stepper_x → diag_pin: ^PA1
  stepper_y → diag_pin: ^PA2

  ...based on some guesswork and diagrams, but I haven’t found definitive information on which DIAG pins are correct for the Spider V3.
• On the board, I have jumpered:
  • X-MOT: PDN → PE7
  • X-MOT: DIAG pins bridged
  • Y-MOT: PDN → PE15
  • Y-MOT: DIAG pins bridged
• I ran the common tuning sequence like this:
  

  SET_TMC_FIELD FIELD=SGTHRS STEPPER=stepper_x VALUE=255
  G28 X

  Then I gradually lowered the SGTHRS value to try to tune it. The result was that the carriage would always move a bit and “bounce,” but would never stop when hitting the rail. In other cases, it wouldn’t move at all.
• Current behavior:
  • Even with driver_SGTHRS: 255, it just slams into the rail and keeps going — no stall detected.
  • Endstop status shows triggered most of the time, even when the carriage is not near any rail. Occasionally after config changes, the endstops report as open, but it still doesn’t stop on contact.
  • I’ve tried increasing motor current and confirming stealthchop_threshold: 0 is set.

Questions:​

1. Does anyone know the correct diag_pin values for X and Y on the Spider V3.0 using onboard jumpers (no external wiring)?
2. Any advice on how to verify stallguard is actually working?
3. At this point, I’m wondering if I should just switch to simple microswitches to get motion working reliably — is that the best way forward for now?

Thanks in advance for any help or insight — I’m totally open to feedback or trying fresh config ideas.

 

[NoGuru]

I have no idea if you have the right pins for your board or not but I would assume you have them right.
And you started with SET_TMC_FIELD FIELD=SGTHRS STEPPER=stepper_x VALUE=255<br>G28 X and it doesn't move so you did SET_TMC_FIELD FIELD=SGTHRS STEPPER=stepper_x VALUE=245<br>G28 X working your way to 0?

So I would skip the macro for sensorless for now, its more suited from other drivers like 5160's since it drops the run current.
I have not run 2209's in a long time but I think you SGTHR is gong to be close to 0 or 10 if I remember correctly.

 

[Azazel]

I have no idea if you have the right pins for your board or not but I would assume you have them right.
And you started with SET_TMC_FIELD FIELD=SGTHRS STEPPER=stepper_x VALUE=255<br>G28 X and it doesn't move so you did SET_TMC_FIELD FIELD=SGTHRS STEPPER=stepper_x VALUE=245<br>G28 X working your way to 0?

So I would skip the macro for sensorless for now, its more suited from other drivers like 5160's since it drops the run current.
I have not run 2209's in a long time but I think you SGTHR is gong to be close to 0 or 10 if I remember correctly.

Well my issues have normaly been that either it moves a little and stopps each time all the way from 255 to 0, or it never moves.
After my last time around, playing around with settings it started moving all the way to the rail and tries to continue - which makes it jump and bounce against the rail without detecting a stall.

I think in my current standing values X never stops it goes to rail and start bouncing, while Y just moves a little and stops.

But i can't really figure out the right approach to configure the printer correctly.

 

[NoGuru]

Sometimes you have to be very precise with the number so I make jumps of 10 then 5 then 1's when you are getting close.
The other two factors are run current and speed. You can try and run a little faster which seems counter intuitive but it works.

 

[Azazel]

Sometimes you have to be very precise with the number so I make jumps of 10 then 5 then 1's when you are getting close.
The other two factors are run current and speed. You can try and run a little faster which seems counter intuitive but it works.

Either it was always moving a bit and didn't stall when hitting a rail or it never moved att all even when getting to 0 from 255.
But right now i picked up two micro switches i will try using for X & Y endstops to see if i can proceed like that - maybe i go back to attempt sensorless again later.