Snapmaker 2 Dual Extruder Issues

I’ve had my dual extruder module for about 2 weeks now and I haven’t had a successful print yet and I can’t seem to figure out why they keep failing. They print fine to start but they keep under extruding at random parts of the print. I’ve played with the temperature, I’ve messed around with bed leveling, tried with each of the nozzles, I’ve removed the tubes, I’ve changed how the filament is hung while it’s feeding, I can’t seem to pin point the issue. If anyone has any suggestions I would love to hear them!

all of my extrusion issues that look like this were about the heat control in the nozzle cooling areas. if they get to warm they extrude like this. however, i have never had a case when the toolhead gets swamped with heat like that where the top layers get better. the pictures looks like there are top layers that are more substantial then the strings underneath.

Yeah I’ve had prints where this happens about 3 times before one of the segments detaches and I start printing plastic spaghetti. Other times it does this and then just clogs and stops printing so I’m not entirely sure what’s going on.

The wedge did it for me.
I printed it with Z +10%.

Thank you, I’ll give this a try when I get home and let you know how it goes!

Hi there xchrisd;
I’m having issues with the dual extruder as well and I’m relatively new to this, with only about a dozen print in my belt. When you say you printed it with a Z +10% I assume you refer to the distance between the print head and the bed. That calibration is done with the calibration card or automatic (my issue). How would you set Z+10%?

The issue I ended up having was with the fans and something called heat creep and not feeder at the top being loose. Essentially the fans weren’t dispersing the heat enough which causes the filament to overheat and actually expand. When the filament expands it can’t be pushed through the nozzle as effectively or at all which results in the under extrusion (the separating layers) or full on clogs. So I bought a tiny little fan to add some additional cooling while I’m printing and my prints have been working fine ever since. I know this doesn’t really answer your question but I hope this helps you with your prints!

do you have a dry box and bowden tubes from it to the extruder?

If so Dual Extruder design / Dry box setups explains some issues i had with it at first.

I printed the wedge with +10% dimension offset, this means you would have to expand the part by about 0.4mm in the height.

This has to be done in your prefered slicer (probably luban or cura) , in the object settings like movement on the build plate.

Maybe the wedge is good for you, mine was way too small.

myA350dualblock.stl (1.3 KB)
here is a new block for those that want one. i found that the hard rubber blocks have been really good as well.

front plate to print plas
myA350dxfrontplate.stl (239.5 KB)
Screenshot 2023-06-29 at 9.37.57 AM

this addresses a lot of the heat creep issues. if you have an enclosure this will print with front door open and no fan, using plas and long(8+ hours) prints

also some notes. the print head and the x module trade heat back and forth. at first the x module is a heat sink but as it heats past critical it becomes a heat source. this means that the left extruder wont be cooled like the right extruder because it is closer to the module mount. in fact my first success was setting the enclosure in a way that the enclosure fan would pull air across the head AND x module.

this suggests that if you are using two different print temps. then the warmest print temp should be on the left.

so any temp issues that you are fighting may be alleviated by a small fan blowing across the x module from the front of the enclosure

i also had issues with the left feeder mechanically. the feed tube below the gears was loose and slid up and down. during the print it would slide down leaving me with this…

this sent me down a rabbit hole because the feeder fail was greatly influenced by heat

on the right you can see the yellow feed into the tube and how high the tube should be