Exception fan

My first run of the day keeps giving an !! Exception in fan message after printing the first layer. Any ideas on how to diagnose/resolve the issue? Using orca slicer with standard settings. Runs fine on subsequent runs.

Maybe a stupid question, have you checked if the fan is running normally, with no particular resistance?

Very valid question, both fans move fine. Also just finished a print and can cycle the fan 0-100% no issue.

The fans have a tachometer and send a signal back to the board so that the board can monitor the speed. Even if the fan is spinning, the board may not receive a message and display an error.

If you have already updated to the newest firmware to fix this issue…
You can comments these lines to turn it off:

224 #
225 #
226 #

Same issue here. Can’t print anything.
Already updated via OTA and checked all fan cables.

starting the fan by hand via the web interface works. Just when it starts after the first layer → exception.

Any idea how to fix this without deactivating the tachometer checks?

You can send an e-mail to info@sovol3d.com. Please enclose the problem pictures

If the fans are running fine, you can edit printer.cfg (via web interface) and comment out the tachometer_pin. That will disable the check.

Sovol did an awful job implementing the fan check. Fan commands are scheduled, together with all mcu commands. But they check immediately after scheduling. They should check only after the command was executed. If the schedule is long, the check gives false positives.

I’m also having this issue, first 10-15 prints worked fine, now “!! Exception fan” after the first layer about 70% of the time.

@sovol3d

This seems to be sudden issue.

Thanks for the extra info that makes sense. I’d rather not drop the checks, would be good if there was a way to delay the check if it’s a timing issue. I’ve messaged Sovol info, I’ll see what they say.

I ended up changing the setting in orca to use the part cooling fan from the beginning of the print, and turned the bed temperature up by about ten degrees for the first layer. Not ideal but so far so good.

Update to latest firmware version seems to have fixed the issue.

1 Like

So far in hours of trying to print only one 1.5-hour print succeeded.

I am on update 19 and the printer still gets the “Exception in Fan” for every print. The fans all work, can turn on/off and can be adjusted in through the web interface.

I have tried:
Using the USB instead of printing over air; neither has worked.
Resetting the printer through the screen.
Using 100% fan from layer 0

I also ran into this error, even after updating to version 19. To work around this issue, I used the advice given above. I modified the printer.cfg file to disable the fan tachometer for [fan], not ideal but better than no print.

This file can be access through the web portal (found by going to the printer’s IP address in a web browser) or by access through the Device page in Orcaslicer. Go to Device → Machine and scroll to the printer.cfg file. In here you will be able to comment out the lines shown in the image above.