Assembling, caibrating, all appears ok. But printing gives "a bit of a mess"
Hi, hope you can help another noob with his printing problems.
I received the MK3s as kit, took the time to assemble it, did have some small errors (like keeping the X-axis motor wire a bit to short so it could not reach the top level at first) but I think I learned a lot about the extruder mechanism and the possibilities what one can do with printed parts in the future. So far, so god. Had myself scratching my head why the holes on the Heatbed steel sheet did not match the two screws at the top of the headbed but the Prusa FAQ showed me they where there to hang the sheet to dry in production and rotating the sheet 180 degrees fixed that too.
The "first layer calibration" for a first starter, leaves some questions about what is the exactly right value, but someone did send me an 20x20x3 mm print example which I printed and send the pictures of the bottom. I even printed the logo twice, the first one with quite some ribbing at the bottom, the second one, after adjusting Z a bit was quite smooth.
However, when I want to print something, often a strange thing happens. Printer heats, calibrates, goes to start, cleans its nose....
Then the printing starts, but sometimes the nozzle "drops" a bit of filament on a strange place, which gets hard, which get touched by either the nozzle point or the Fan holder, and destroys the complete object, sometimes the object got moved from the heat bed, mostly when the printing had just started.
After this test print I cleaned the bed , removed the filament, places it back and printed the same part again which to me looks all ok now.
During one print in the testing phase the printed object got attached to the nozzle, so it might be that there has been some remains of the PLA on the extruder which dropped down when hot enough ?
Could one think of other reasons why the extruder would "blob" on my bed ?
Thanks for your advices,
Ben from the Netherlands
RE: Assembling, caibrating, all appears ok. But printing gives "a bit of a mess"
This may be what some people call 'boogers' clinging to the nozzle and/or the underside of the extruder assembly which will dislodge and drop to the print bed when the system gets warm enough. I (try to) do a quick inspection of the nozzle and extruder before each print and use a wire brush to carefully to remove any plastic blobs that aren't supposed to be there.
RE: Assembling, caibrating, all appears ok. But printing gives "a bit of a mess"
[...] Then the printing starts, but sometimes the nozzle "drops" a bit of filament on a strange place, which gets hard, which get touched by either the nozzle point or the Fan holder, and destroys the complete object, sometimes the object got moved from the heat bed, mostly when the printing had just started.
If your nozzle is too low, it is possible for the nozzle to scrape up a bit of the 1st layer, or to have some build up on the nozzle or heater block which can fall into a print at inopportune times. Give your hotend a good look, particularly at the part where the heatbreak screws into the heater block. If you see any filament oozing out the top of the block, that means your nozzle isn't properly seated against the heatbreak inside.