How to Switch Back to Original Toolhead After Auto-Refill?

U1 Toolchanger U1 Troubleshooting guides
1

I ran into an issue with the U1’s auto-refill feature with 4 color print.

I had auto-refill enabled with a different color. During a print, the filament on T0 ran out, so the printer automatically switched to another toolhead that had the same material but a different color.

I noticed it pretty quickly and loaded the original color back onto T0, but the printer continued using the other toolhead.

Is there a way to tell the printer to switch back to the original toolhead after I’ve reloaded the correct filament? Or is the toolhead assignment locked for the remainder of the print once auto-refill has triggered?

IMO, this auto refill should only kick in when the “refill” toolhead is not in use or assigned to some part of the print, in this case it started using same toolhead for two different parts of print. Think about it, if i have extra same filament that i want to use as refill why would i have even assigned it to different part of the print in first place.

Lesson learned turned freaking use different color as refill off by default and turn on when you know it will be needed.

2

There is no point in having auto-refill enabled unless you are prepared for that eventuality. If I know a reel is likely to run out, I have another reel of the same filament on standby if I have a spare tool-head.

If you are going to need to flip in a new reel manually, don’t have auto-refil enabled. It’s just a case of the user using the various facilities appropriately, with knowledge of what they do.

Be aware that allowing a reel to run out (rather than being unloaded) leaves a stub of filament in the toolhead. I’ve found this to be the most significant contributor to nozzle jams.

3

I turned it off, I guess I didn’t bother turning it off or something.

But Snapmaker should look into not letting auto refill happen on already assigned toolhead,

4

Your correct allowing auto refill to use a tool head that is in use is a BAD idea. It should only switch to an unused tool head if available or pause with an error code

5

I think there might be a misunderstanding here.

Auto-refill is only for situations where the most important thing is to keep the print going, and you don’t care what with (unless you’ve planned for it). Pausing is what you get if you don’t turn auto-refill on.

6

I use this feature regularly and have never experienced clogs…

7

Interesting. My experience (and that is only a few times) is that when the extruder pushes the new filament in behind the run-out one, the ends are not necessarily aligned properly and perhaps the cut end on the old filament isn’t square, so the new end “slips off” as it were and can’t push the old end through the nozzle.

8

So people are unhappy that a filament function works as described? :person_facepalming:

9

It does not. It’s using already assigned toolhead. I don’t think that it should use any of the toolhead that already in use.

10

But then other people would complain that their print had paused when they had asked for auto-refill. Just don’t ask for auto-refill!

11

YOU don’t, but it wasn’t designed for you and your situation - you are trying to bend it to your specs

12

Thanks for such a helpful input, that was anyway side note, ask was if there is a way to switch.

13

I think this is more complex as we could expect.
Maybe open a feature request?
BTW what happens if you trigger another runout?-Does it switch back?
I understand your described situation, this would probably mean that the other colours toolhead could not print anymore but maybe you could get it done by smart filament switching (while printing the specific object)..

14

I tried that too, i cut the filament that it was using to trigger run out on that, but in that case it paused, and after i loaded that filament again it kept using same filament/toolhead for both colors.