Object with a lot of retractions causing E overheat
Trying to print out an object with a lot of retractions (textured floor for a diorama piece). The print always fails at this layer (the textured floor) and it seems like the amount of retractions being performed is causing either A) the extruder to overheat and jam in the extruder or B) my nozzle to jam.
Steps I've taken so far:
-Decreased retraction length from .8 to .4
-Increased temps to encourage flow (less resistance for E motor)
-Added a heat sink to the back of the E.motor
-Increased Min Retraction Travel Distance from 1 to 5.
With these new settings I was able to print out another piece (30+ hour print) without any problems but I still can't print out this other diorama piece.
What can I do to help this situation?
Suggest you slice the model, then file/save project - then zip that file and post it here with Attach File
Hard to interpret that colorful jpeg you posted. Looks like a nightmare. If you post your sliced model we can see your settings and make suggestions.
RE:
Sorry, I was just showing all of the retraction movements on the piece. Just an image of the piece itself would be helpful?
Edit: NVM I see I overlooked your first comment. Will get the zip uploaded today
Reduce the need for retraction and other workarounds
Here's how I approached this problem. Retraction is one of many workarounds to deal with stringing. Others include wiping, coasting (Cura), and z-lift/z-hop. In a perfect world, our extruder would put out exactly as much filament as needed and no excess. Unfortunately, a bit of over extrusion can contribute to a lot of stringing. By reducing over extrusion, the need for these workarounds is greatly reduced, which reduces the amount of extruder motor actions, which reduces heat.
Early on, I was determined to figure out the fine stringing I was getting. I decided to start by calibrating my filament settings before tackling the testing. Much to my surprise, calibrating my slicer filament settings resolved most of the problems. (I've got detailed notes here if you're interested). In hindsight, it makes sense: If my slicer settings don't match my real-world filament, the generated gcode will under or over extrude slightly. If it over extrudes even a bit, I'm more likely to get stringing. If I attempt to deal with stringing with workarounds, I'm making the printer work to counter settings problems. This can run into the rapid-fire machinegun retraction situation which sounds like your problem.
After calibrating my slicer filament settings (filament diameter, extrusion multiplier, maybe linear advance), I find I can work with slicer settings that require far less work from the extruder motor:
- Retraction 0.4mm.
- Z-lift 0.4mm
- No wiping
- 50mm/s retraction speed
- 25mm/s deretraction speed (note: this avoids hammering molten filament back into the extruder. Non-Newtonian fluid and all that.)
I would not increase temperatures, as that is going to contribute to stringing, which is presumably why you're doing retractions. In fact, I try to reduce temperatures for PLA as much as possible.
tl;dr - Calibrate your filament settings to match your real-world printer and filament characteristics, then adjust your slicer retraction settings to minimize unnecessary work by the printer and extruder motor to compensate.
I've got some general notes on extruder troubleshooting and heat problems here that might be useful.
RE: Object with a lot of retractions causing E overheat
Thanks for the thoughtful reply! I was actually using your blog beforehand with the article about extruder problems. All of the recommendations I used so far came from that/your article as well as the volumetric load (tuned it down to 11).