Various issues with first prints
Build my Mk3 yesterday, went through the preflight check today and it was all fine. Calibration was okay up until loading the filament. I sliced a nice sharp end on the filament, pushed it in, but it wouldn't feed in at first. Second try it got pulled in, but started spooling out the side of the extruder. I checked the alignment on the extruder motor, it was off, tried again. Same as the first time, just didn't pull it in.
Tried a new approach, I opened the extruder door, guided it into the hole by hand, and then went through calibration. seemed okay. I calibrated the Z-axis, and I think it is alright, but I'm aware that I didn't really solve the problem. Any idea why the extruder gears wouldn't be pushing the filament down the hot end hole, even when aligned correctly?
Also, I tried the Prusa logo and Batman. Both came out okay-ish I guess (I don't really know what to look for or expect in a print quite yet), but I noticed that occasionally a line of filament (on the interior) would be missing from the print while it was being made. Is this because there's not enough adhesion? Should I lower the Z-axis further?
Thanks so much for any help, I'm totally new to this and keen to learn. Any and all input appreciated!
Re: Extruder not getting filament into hot end hole
Okay, an update. I tried Benchy and Marvin. Not so good...
Benchy suffered from layer shifting, see the photo. I thought my X-axis belt was a little loose, but I checked the numbers and it's within the range Prusa recommends. Anyway, I decided to unload the filament at this point, take a break, and come back to it. When I returned the filament loaded fine for the first time. Maybe just lucky, but we'll see what happens next time.
Next up was Marvin, wanted something a little quicker. That said, I noticed some people with layer shift issues saying that reducing speed helped. So to pre-empt the problem I dropped the speed to 80%. Things were going absolutely fine, till what you see in the photo. The print just stopped. No idea why. From what I can see it was absolutely fine till that point. After I tried another one, it started the mesh bed calibration, but it failed due to debris on the nozzle - there was some filament hanging off. Would this have caused the previous fail, or was the excess filament there because the print failed? Chicken and egg situation here!
Anyway, photos are below. Comments appreciated.
Re: Extruder not getting filament into hot end hole
And another update. Tried Marvian again and it stopped at exactly the same place. Now I'm really confused. Opened the gcode file in Slic3r and it looks fine, not corrupted or incomplete. Help!
Re: Various issues with first prints
Check if the setscrew on pulleys is tightened against the flat part of the motor shaft.
If you try and take a cat apart to see how it works, the first thing you have on your hands is a nonworking cat.
Re: Various issues with first prints
Wow. Okay, so I contacted Prusa support after my second Marvin fail. While talking to them I printed a treefrog at 1.5mm layer height which came out fine. They suggested I had a loose axis - looking at my photos they said there were layer shifts everywhere, even on the ones I thought were okay. I had checked the belt data and it was within tolerance levels, but the X-axis had always seemed a bit loose to me. I went back in - by the way, if you're building a kit get this right first time, it's a pain to fix - and released the belt from behind the extruder. Tightened it up by one notch, made it tricky to get it back together but I managed it.
Have now printed Benchy, and it looks great. Marvin too. Working on the herringbone gears now before I start trying some of my own.
Re: Various issues with first prints
Congrats! You'll most likely want to do some more tweaking, but it's always gratifying to get that first good result.
And now, you've fallen into the clutches of the dark lord Benchy. Best clear some shelf space for lots and lots of useless little plastic boats.
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