BIQU H2 suddenly needs higher value for E-steps

A few years ago I upgraded a Tronxy X5S to a Bigtree SKR v1.3 board and a BIQU H2 extruder.

Up until recently it had been working fine. Then one day it started under extruding.

Initially I thought this was a slicer setting issue, but I confirmed that a known good previous g-code file also under extruded.

Next I removed the BIQU unit and disassembled/reassembled to make sure there was nothing wrong with it.

Then I checked the wiring to the motor and confirmed that each phase wire was making it from the motor to the controller.

I thought perhaps this was a stepper driver issue. So I swapped the extruder driver with one from the Z axis. No improvement.

Fearing that perhaps there was a problem with the stepper motor on the extruder I decided to purchase a newer BIQU H2 V2 for $40 from aliexpress.

I installed the new extruder today and it was still under extruding. FWIW the E-steps recommended for the BIQU extruders is 932 and this is what I had set previously

I decided to re-calib the E-steps. When told to extrude 100mm it would only extrude about 40mm.

So now I have e-steps set to 2330 and the printer is now extruding properly.
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So, why suddenly does the extruder need so much more e-steps?

When it changes by a factor of two like that (almost is)

Check your microsteping.

How this is set is changes depending on your stepper driver type

Some are just jumpers under the stepper driver

Edited 1 time(s). Last edit at 04/03/2025 06:33AM by Dust.

Odd that it is a factor of 2.5 though. Micro stepping changes would be a factor of 2 or 4. Seems more like a change of filament diameter from 2.77mm to 1.75mm.

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[www.hydraraptor.blogspot.com]

Yeah, It's weird. The stepper drivers are 2130's

I will check the jumpers associated with the extruder. Reseat them. Maybe one came loose.

You got me thinking. I'm also going to check what the motor current is set to for the extruder. Maybe that somehow got changed. As I recall that can be changed through the menu.

Firmware is Marlin BTW. Marlin-bugfix-2.1.x

Changing the current won't change the extrusion rate. If it is too low the motor will stall and too high it will get hot.

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[www.hydraraptor.blogspot.com]

In Marlin menu - Extruder current is set to 800ma which is correct.

I have Stealthchop turned off on the extruder. It has always been this way. I figured no fancy modes needed for the extruder when I built the firmware a few years ago,

Stealthchop is on for all the axis drivers.

My Jumpers for the extruder are set like this guy's
[medium.com]

In any case, I pulled the jumpers and installed new fresh jumpers.

No change - doing test print now still with e-steps set to 2330.

Turned on StealthChop on the extruder. Extruder is now a bit more quiet. I'll think I will leave it on that way..

But still no understanding regarding the mystery of the E-steps.