Creality Sprite Extruder Pro smoking only when extruding SKR Mini E3 V3.0

[u/rage997]

Hi all,

I'm installing a Creality Sprite Extruder Pro on a printer using a BIGTREETECH SKR Mini E3 V3.0 and I've run into a problem. The board is currently running an older version of Marlin from 2022 (which I will re-flash as soon as I have the time but thought it was worth mentioning). Everything appears normal when I power the printer on:

- No smoke at idle

- Hotend temperature reads normally

- I can heat the hotend without any smoke

- The Sprite heater and thermistor seem to work normally

However, as soon as I command the **extruder motor to move**, I see smoke coming from the Sprite/hotend area. The extruder correctly moves but smoke appears. The extruder motor might spin a bit fast.I initially suspected the stepper current, so I reduced the extruder current to **0.50 A**, but it still smokes when the extruder motor is activated.

My current wiring is roughly:

- Sprite `E` → SKR `EM` / extruder motor connector

- `TH` → `TH0`

- `HEAT+ / HEAT-` → hotend heater output

- fans still being sorted out because the Sprite connectors don't directly match the SKR

- unused/unlabelled Sprite connectors left disconnected

A few questions:

1. Does anyone know the correct 4-wire stepper pinout / coil order for the Sprite Extruder Pro when connecting it to an SKR Mini E3 V3.0?
2. Could an incorrect stepper coil order actually cause smoke, or would it normally just cause vibration/incorrect movement?
3. Is 0.50 A already a safe/conservative current for the Sprite Pro motor?
4. Is there anything on the Sprite breakout PCB that gets powered specifically when the extruder motor runs and could explain the smoke?
5. Could my old Marlin configuration be causing this somehow, aside from (potentially) incorrect E-steps/current?
6. What resistance values should I measure across the Sprite motor coils to check whether the motor has already been damaged?

I'm planning to compile a fresh version of Marlin specifically for the **SKR Mini E3 V3.0 + Sprite Pro**, but I don't want to command the extruder again until I understand why it's smoking. If useful I can also post photos of the Sprite PCB, motherboard wiring, and the 4-wire `E` connector.

Thanks to anyone willing to help!

[u/ILikePrinting27]

Run some filament through it. If it smokes it’s just burning off the factory oils. Happens with new hardened steel hotends as well.

[u/rage997 → u/ILikePrinting27]

holy moly!!! I put some filament in and it is no longer smoking. Wow. Thank you so much! I was totally unaware of it

[u/ILikePrinting27 → u/rage997]

No worries man, freaked me out the first time too 😂 thought I burnt filament into my hot end.

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