Dual Extruder - Right Extruder Height and Auto Z Height Calibration problems

Snapmaker 2.0
1

I have had the dual extruder on my A350 for a couple of months now. Initially all has been going well, but I was only doing prints that required a single filament color. So basically, just like using the original extruder.

Lately I have been experimenting with two color prints and two problems have cropped up.

  1. After experimenting with a two color print (a name plate with background of one color and text in another color), I was printing a “normal”, one color object and found that the right extruder was not high enough to keep out of the way of the filament the left extruder was laying down. This causes the right extruder nozzle to drag the laid down filament over the work surface, obviously ruining the print.

Normally, it’s easy to see that the right extruder is several mm higher than the left one. When this is the case the print works fine. I have had to resort to re-running the Auto Leveling process or the Auto Z Height calibration to get the right extruder back to a “safe” position.

I have had the experience where I set up a single color print which I transferred from Luban to the SM and it worked fine. But when I print this same object from the “files” menu to make the same object again, I occasionally have the problem where the right extruder is not in a safe position and the print is ruined.

I am wondering if by trying out some two color prints, I had inadvertently set some parameter that is causing this problem.

After another ruined print last night, today I tried running the Auto Z Height calibration and this leads to the second issue:

  1. Auto Z Height Is Stuck

I tried to run the Auto Z Height calibration and the print head moved down to the print surface, but the right extruder was slightly lower than the left and contacted the print surface. The display shows “Running Calibration” but didn’t do anything after more than 10 minutes.

So I powered off the SM and tried this again. This time it went to the home position and when I tried to run the Auto Z Height process it showed “Running Calibration” but just sat in the Home position and never moved.

I again powered down the SM and then ran the Auto Leveling calibration process which worked fine. Then tried the Auto Z Height process and again the machine was stuck. Could not back out of this process, so had to power down the SM again.

As I am writing this I am running a single color print and checked to see that the right extruder is in a safe position. So far so good.

At this point I don’t know if I will be able to run the Auto Z Height process without the SM getting stuck.

Rick

2

To me it sounds as if the right-nozzle-movement-mechanism is jammed or broken… I’d reach out to Snapmaker support in your case. Perhaps before that I’d unscrew the head and see if perchance a bit of filament got stuck in the lead screw of the head movement mechanism.

3

I will take your advice to remove the dual extruder head and check for anything that might be lodged in there and that might be preventing the right nozzle from moving.

It’s not that the right extruder won’t move - it does. It just doesn’t seem consistent from the perspective of keeping the right extruder in a position that doesn’t interfere with the filament that the left extruder is putting down.

Rick

1 Like
4

OK, interesting… I’m curious what your investigation will yield. Is it that the right head is sometimes not moving up or not moving up enough, or does it slide down on its own after being moved up?

Just a side remark: I yesterday was chasing a Z-height problem with my DX, the nozzle being way too high, when I suddenly realized that the hot end module had slightly dislodged. After re-inserting it properly I was back in working order. The dislocation most likely happened when I put in new filament - the first try was not successful, and I suppose that the pressure from that caused the misalignment.

5

Any update on your problem? I just installed new board and started calibration. Same thing happens to me. I am fairly certain I was correct putting everything back together correctly. I am losing all hope for this head.

6

I went through support. They sent some replacement parts, the lifting motor, the brass nut, and linear sensor. Worked better for a few minutes then went back to not working. I just received the replacement DX yesterday haven’t had a change to run out yet though. Note: My DX never worked properly.