Color change retract amount  

Re: Color change retract amount

Bump!

I'm also curious about this. I'm printing with HIPS for support material and if I switch between filaments (MH Ryno) too often the HIPS often doesn't retract enough to clear the metal tube in the Y. This jams the next material going in and effectively makes the print fail.

Re: Color change retract amount

Hello devon!

That is exactly my intension.
Would be optimal to have a certain additional retract on just one extruder

Re: Color change retract amount

It is on the "printer" tab under extruder

Re: Color change retract amount

@tim.t8 yeah I see the retraction option in Slic3r but it seems to be overwritten by the printer upon running the gcode. I've read that the value shouldn't be set much more than 4mm but as I mentioned before i'm getting this weird mushrooming that jams the multiplexer below the cooling tube but above the PTFE at the heatbreak. I think it may be related to the HIPS not being retracted all the way into the cooling tube.

Re: Color change retract amount

And these 4mm are way too few to retract the filament from the hotend into the joiner. This must be about 55 mm or so.

Re: Color change retract amount

I think it's hardcoded right now. A work is in progress to make the thing configurable.

Re: Color change retract amount

i'm getting this weird mushrooming that jams the multiplexer below the cooling tube but above the PTFE at the heatbreak.

I have had two successful multi color prints and several single extruder prints. My printer then sat idle for a month or so. Now I seem to be having this exact same problem on multiple extruders even when just running a single extruder.

At first, I thought it might be a problem with my filament as it is not on the "tested" list. But I tried a single extruder print with Prusa filament (what came with my printer) and it jammed again. The filament seems to be jamming right at the bottom end of the steel tubing. It jams so hard that the extruder can't move the filament forward or backward.

If adjusting a retraction setting would correct this, I think we really need to get that feature. It seems like just 2 or 3mm more should do it.

Joe

Re: Color change retract amount

I just had another thought about this. What if it isn't a distance setting but a retraction speed setting that needs to change? What if the material cools faster than the retraction can get it into the cooling tube and the material hardens before it gets to the bottom end of the tube? That would jam it up good.

Could it be that the extruder doesn't need to retract more distance but the same distance just faster?

Joe

Re: Color change retract amount

Hello Joe!

I don't think that could be the cure because of the non existence stiffness of flexible filament, it curls up in the bowden tube,
so even fast retraction would not pull back all of it away from the joining point, so that other filaments get stuck

Ewald