SV04 leveling T1 issue - z goes lower than T0

Hello!
I have been searching my issues for the past 2 weeks on and off but could not find a solution. I am hoping someone here could help. I’ve own the SV04 for around 3 months and it was printing just fine in dual mode. One day, the T1 decided to crash into the print, lowering itself using a different z offset value than the T0… First thing I thought was that the leveling was off so I tried was bed leveling. T0 was good on all 5 spots but when it came to the T1 the Z drops few millimeters and dragged on the bed to the center. Then lowered even more which results in crashing onto the bed and then some. So the next step I thought was to auto Z-align and auto level. Even after this, T1 still drops and hits the bed when bed leveling… Next was to update the firmware to JohnCarlson V2.1.3.1b3. After doing so, still the same results, T1 still lowers some when bed leveling. I’m not sure what changed or made this change. I ran pronterface when leveling but I didn’t see any commands coming up to lower the T1 when bed leveling… I have the T1 adjustment screw all the way up also. Anyone else having this issue? And a solution?

This seems to be no firmware issue. You may want to check that:

  • all four side screws of the right print head are tight;
  • all eccentric roller bearings of both print heads located on the Y-axis are fitting without play;
  • the travel paths of the rollers on the v-slot profile are free of dirt on top & bottom side;
  • all roller treads are free of dirt;
  • the tension of both Y-axis timing belts is equal;
  • both print heads are moveable with the same slight resistance when the motors are powered off.

If all bullets above have been checked & the issue is still present you may need to change the right nozzle height by screwing it more into the heatblock (after turning out the right heat break a bit). Ensure that nozzle & heatbreak are screwed together tightly when heatblock is above 220°C - otherwise molten filament might spill out of the heatblock thread. Nozzle adjustment & calibration need to be done again afterwards.

Good luck
Björn

Hi Bjoern,
Thank you for your reply! I checked everything you noted and seems all clean, tight, and inline. The only reason I believe it is something in the firmware is because I can physically see the Z motor lower the T1 axis when leveling. When leveling T0, the Z goes up some then to center and then down to 0. Once selected T1, the Z goes down first and then goes even lower to what it believe its zero (the T1 is set 1.5mm lower than T0 for some reason). Is there any other tips? I’m super stuck right now…

Thank you

Dash

There is no Z difference between left and right nozzle in the firmware. Conceptually both nozzles of the SV04 share the same axis, therefore both nozzles have to be at same height which is adjusted mechanically. Page 6 of the “SV04 operating instruction” describes how to do that using the aux levelling function.
/R
Björn