Stringing, blobbing, zitting, I got it all!
I'm having a major bad time with my MK3S+. I know it can print well, because it used to, but I've been trying to print a particularly difficult part and having no success. It started out that I wanted to build a clock. Ok, gears are no problem, they print well, but I'm trying to print the escapment wheel, about 40mm diameter, with teeth like the suns rays. I printed it a couple of times, and got bad stringing, so i dried my filament in the oven, kept it in a ziplock bag for days with some water absorbing stuff and tried again. No better, but it seemed that the filament was dribbling out all the time during loading/heating, so I dried it some more....no difference. Next, I calibrated the printer. No change. I then noticed it was getting a bit dirty around the hot end and extruder, so I stripped and cleaned it up, changed the ptfe tube (genuine replacement from Prusa), and put a new nozzle (not Prusa, but a known good make) on for good measure. No difference. Still stringing. This was getting personal, and so I watched what was happening to get more clues. The weird thing is, I could see the nozzle go out from the wheel hub to print a "sun ray" then back in to the hub, then round the hub, then out and back on the next sun ray, but the stringing was happening between the tips of the sun ray's. How can that be? So anyway, I tried tweaking retraction....not much, from 0.8 to 1.0 and upped the retraction speed a bit. I also set the slicer to "not cross boundaries" . No change....
In addition, there is something wrong with the first layer on a real print...first layer calibrations look fine, but as soon as I go to the thing I want to print, I get blobbing, zitting, and often as not, the print gets ripped off the (smooth, clean!) Sheet
This has taken weeks of organised experimentation (yeah, and some spur of the moment fiddling, I admit it!) but I'm no further forward. I was thinking of trying a different slicer software, 'cos that and firmware are the only things that changed since it was printing OK, but thought I'd ask here before I go to the lengths of learning another slicer. What am I doing wrong???
Thanks for any/all/some suggestions
Jim
RE: Stringing, blobbing, zitting, I got it all!
Well, here's the report I did not want to post...I've always thought Prusa had the 3D consumer market pretty well supported, but I'm faced with something I did not expect that calls my trust into question. The report above was accurate, I was pulling what little hair I have left out, and could not adjust my way out of trouble. So....desperate times call for desperate measures, so I loaded Ultimaker Cura. Never tried it before, never seen it. I installed it completely vanilla, then loaded my difficult "Sunray" wheel into it and sliced it with default everything - thought "I've got to start learning, so lets try baby steps". Put the resultant file on my S3+ and printed. Well, here's the shocker: it printed the wheel, no stringing, no faults PERFECT.....and in half the time.
C'mon Josep, get yer software sorted, Slicer has cost me hours of calibration and pounds in new parts....OK, so I now have the tightest setup of any printer in the world, but it shouldn't be this hard!
Thanks and good luck
Jim
RE: Stringing, blobbing, zitting, I got it all!
Hello Jimbo,
What you are describing is very much like the problem I am having as of yesterday. A bunch of prints were almost 100% and then things started to go bad. I thought it was the filament being wet and when I tried today, the filament that worked great yesterday was blobing and smoking. My print head is much to hot for the displayed settings. You can see my post in the hardware section.
Are you using the default Arachne perimeter generator? You may do better switching to Classic for fine gear teeth...
Print Settings > Layers and perimeters > Advanced > Perimeter generator
Cheerio,