I posted a while back that I made a second MP3DP to allow me to have a 330x330 build platform. Since doing this I have struggled with the nozzle hitting/dragging/snagging on the previous layers. In an effort to help reduce the weight/load on the X and the two X rails I removed the Mk8 extruder and went with a Bowden type hotend. With about 15 oz less weight I am still having the same issue.
I think the issue is my Cura settings so I am reaching out to see if anyone would share there Cura settings with me to see if it will help my issue.
If anyone has any better ideas, I am willing to hear them all.
The previous layer should be below the nozzle, since it put it there. If it is higher than the nozzle, then it probably means you are over extruding, or the print is warping, and lifting.
If you have a big aluminum bed, then maybe it isn’t really heated up when you start the print, and then once you start printing, it heats up, expands, and raises the print into the nozzle? You can add a pause or just preheat the bed for a few minutes before starting your print.
I add a large bed heater and the bed feels plenty warm, but I will try a few things. I think you are on to something in regards to over extruding. I will load up some light colored PLA to run 100mm which should be a good test
If it is a new printer, have you verified steps/mm is dialed-in? Could acceleration and/or velocity settings be causing missed steps when raising Z?
I calibrated my extruder which was only slightly off but I realized I had a bunch of play on my z axis lead screws. Time to order replacement nuts
So I think I figured it out. This all started when I installed a 1.0 nozzle. So I am assuming the nozzle is something smaller than 1.0 and when extruding things are a mess.
I swapped out the 1.0 nozzle with a 0.6 nozzle and the problem went away.
That would do it too.
How do you manage your Z homing? On my Prusa clone I’ve got a differential IR board in place of the PINDA probe, so the “homing” is independent of the actual nozzle height. If the 1.0mm nozzle is just a tad longer, that would account for the issue you’re seeing. I’d need to tweak the Z offset each time I changed the nozzle.
I use BL Touch on both my MP3DP’s.
The problem is not the length of the nozzle (which I would have to account for) but more likely that the nozzle is undersized or damaged and does not extrude properly. After changing nozzles and resetting the Z height, my MMP3DP is working like a dream again.
Glad to hear it.