Vent gcode not working correctly - Hardware, firmware and software help

RE: Vent gcode not working correctly

Conrad — Sat, 28 Mar 2026 00:30:07 +0000

I found almost all instructions on putting the vent together to be ambiguous. Only after watching a video and then double checking with the gcode did I have any confidence that I got it right.

RE: Vent gcode not working correctly

Steve — Fri, 27 Mar 2026 21:40:15 +0000

I got it to correctly open and close with the test code you sent me. Thanks!

RE: Vent gcode not working correctly

Steve — Fri, 27 Mar 2026 21:21:40 +0000

I rotated it around the z axis.

RE: Vent gcode not working correctly

hyiger — Fri, 27 Mar 2026 21:19:23 +0000

Posted by: @steve-36
It missed on the open, but then opened it when it was supposed to close...

Yes, it means it's installed upside-down

RE: Vent gcode not working correctly

Steve — Fri, 27 Mar 2026 21:17:03 +0000

It missed on the open, but then opened it when it was supposed to close...

RE: Vent gcode not working correctly

miroslav.h4 — Fri, 27 Mar 2026 21:14:08 +0000

Posted by: @steve-36
I rotated 180 degrees and it made no difference. The previous configuration had the lever between the 3rd and 4th vents, and when rotated 180 it is now blocking the 4th vent. The build guide states it should be between the 3rd and 4th and not blocking a vent.

Rotate 180° but along the transverse axis, not along the longitudinal one!

RE: Vent gcode not working correctly

hyiger — Fri, 27 Mar 2026 20:59:59 +0000

I wrote some g-code for you to test. Save this to a file and upload it to the printer via PrusaConnect or just copy on to the USB. Next print it. Ignore the warning about incompatible g-code and hit print. Then follow the on screen prompts. It should open the vent, wait 2 seconds then close the vent.

; Prusa CORE One vent test 
G28 ; home / initialize 
M0 Manually Close the Vent, then press Resume 
M117 Opening Vent 
M870 O 
G4 P2000 ; wait 2 seconds 
M117 Closing Vent 
M870 C 
M117 Done

Posted by: @steve-36
I must be thick. It looks like the diagrams in the install guide to me. But I'll try it and you'll probably be right. LOL.
Thanks for the reply.

RE: Vent gcode not working correctly

Steve — Fri, 27 Mar 2026 20:57:53 +0000

I rotated 180 degrees and it made no difference. The previous configuration had the lever between the 3rd and 4th vents, and when rotated 180 it is now blocking the 4th vent. The build guide states it should be between the 3rd and 4th and not blocking a vent.

RE: Vent gcode not working correctly

Steve — Fri, 27 Mar 2026 20:48:43 +0000

I must be thick. It looks like the diagrams in the install guide to me. But I'll try it and you'll probably be right. LOL.

Thanks for the reply.

RE: Vent gcode not working correctly

hyiger — Fri, 27 Mar 2026 20:46:32 +0000

Posted by: @steve-36
I tried to search, but couldn't really find anything on this issue. I've upgraded from the CoreOne to the CoreOne+. I printed my own components from printables. I've followed the upgrade instructions (and triple checked the correct orientation and location of the lever on the vent).
When I start a print, the head moves over like it supposed to for opening the vent, but it doesn't travel far enough. It executes the movement just to the right of the arm on the vent. Has anyone else seen this?
7796d0c0-prusa.mp4

You didn't flip the vent around when you reinstalled it.