[Need help naming issue] Print quality/ Overhangs bad near heatbed
Hi all,
On Friday I have assembled my fresh MK3 (also have an older MK2S) and I'm seeing the strangest issue I can't put my finger on - a friend of mine has exactly the same on his. It seems that print quality, or the quality of overhangs, seem to be utter crap for the first ~1cm from the bottom, anything above is beautiful, see pictures. Everything printed with supplied silver filament. The Makerbot headphone stand is with stock Slic3r settings (215/210,bed 60). I thought it might be related to bed temperature, so I've decreased it to 30, but no change, even with lower extruder temperatures (215/205 or 215/200 for the eggs) . The print fan is on all the time after 1st layer, with around 3800+/-50 RPM. Any suggestions/help would be very appreciated, I stalked the internet for 2 days and could not find anything similar.
Re: [Need help naming issue] Print quality/ Overhangs bad near heatbed
Hi
I'm new to 3d printing but i think your z height is too low, the bottom layers are getting too squished, there is build of pressure in the extruder as not enough filament is getting out, the higher you go up the layers the pressure in the extruder gets less so your layers are not as bad. try adjusting your z height a little. if I'm wrong I'm sure some else will let you know. also a picture of the bottom layer will also help people diagnose your problem.
Re: [Need help naming issue] Print quality/ Overhangs bad near heatbed
Fair point! I'll try that later. I don't have any prints with larger bottom surface to show (currently printing one) but I'll attach what I have. Strangely it didn't show up on a bench and the first layer looks good to my eye, but I'll double check that later and go as high as possible while still looking good.
Re: [Need help naming issue] Print quality/ Overhangs bad near heatbed
First layer squishing has nothing to do with this.
I dare say this is normal.
I have never seen a printer that will print these specific overhangs well (with PLA), because it's the incorrect design for FDM printers.
Look here: (look at the chamfer part)
https://rigid.ink/blogs/news/how-to-print-overhangs-bridges-and-exceeding-the-45-rule
Things like rounded upwards corners are impossible to print cleanly because they exceed the 45 degree angle rule.
Things that will make it better:
- print in 0.35 layer height: bigger layers will show this effect less because they will grip more onto the edge of the previous layer.
- print very slow: print at 50% or even 30% speed will make those extreme overhangs look a bit better. That's because there is insufficient cooling when printing at 100% speed. Rotate the display know withile its printing to slow/speed up the print moves, fan speed will stay the same.
- print in material that doesn't curl so much: PLA and ABS are notorious for curling, other stuff like PETG will not curl upwards so much. If you print the egg with PETG (240 degrees, 100% fan, 50% speed), things will look a lot better.
I too printed the eggs and the makerbot stand and have the same problems as you, but i could lessen the effect with a 3x times stronger filament fan (loud as f*ck) and printing at 33% speed for the bottom overhang part.
Also before anyone suggests "with with a lower temperature", yes this works to some degree, too, but leads to a lot of extrusion issues on the MK3. The closer you get to 200 degrees with PLA, the faster it will randomly clog. You'd need a geared extruder like the E3D Titan to force filament through the nozzle.