Am I printing too hot? too fast?
Hello,
I'm new in 3d printing, so excuse me if I ask about obvious things.
I'm printing models with thin walls and there are multiple problems on some areas.
This is printed with PETG, 0.35 layer height, 220°, 50mm/s, retraction at 1mm / speed 25mm/s.
It seems like there's a lot of stringing, blown appart by the fan, that get stuck between the layers.
Can someone tell me what I am doing wrong? Is it a setting problem? Is it my printer? Is it bad filament?
Also my printer is in an enclosure, I don't know if that's relevant to this problem.
Re: Am I printing too hot? too fast?
NOT AN EXPERT. Trying to help.
My PETG prints are also stringy, but not like what you show. Just a spare thread here and there when it jumps from thing to thing. Not really a problem.
When I go back to PETG, I intend to play with the retraction setting - which I think should be larger for PETG. I will try 2mm.
My PETG Settings are hotter than yours: 240/235 (first layer, others), with bed at 85/90. (I am using Hatchbox).
You should look at the cooling settings (I use Slic3r). It looks like yours not cooling properly.
My setting are:
Fan speed 30 to 50%
Bridgels 50%
Disable for 3 layers
Cooling:
Enable if lower than 20sec
Low down if lower tan 15sec
Min Print speed 5 mm/sec
Good luck. Also slowing down the print speed often helps with intermittent things like this.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Am I printing too hot? too fast?
@aaron.s5:
did you already calibrate your extrusion rate ?
furthermore:
i know that the petg properties may vary very much from brand to brand, but i used to print my petg @ 255°C (first layer @ 240°C) with 90°C bed temperature.
your 220° C seem to be very low for petg...
dem inscheniör is' nix zu schwör...
Re: Am I printing too hot? too fast?
Thanx to both of you. I will try again at different speeds and temps and post my results here.
Re: Am I printing too hot? too fast?
Well, I just got back to printing some PETG, and I set the retraction to 2.0mm (PRUSA default for PET was 0.8mm).
I can confirm that this completely removed the stringy issues I was having before.
Let us know how your testing goes.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Am I printing too hot? too fast?
Aaron
Be careful with retraction in excess of 1mm; it can cause blockage in the gap between heat break and PTFE. You can modify the PTFE to prevent this:
Use a pencil sharpener to add a chamfer to the lower end of the PTFE tube
Ensure there are no burrs on the end of the tube.
Unscrew the heat break from the heat sink by a quarter of a turn
Insert PTFE tube and lock in place
Tighten heat break into heat sink.
You will then be able to use retraction settings of up to 4mm without problems.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Am I printing too hot? too fast?
Aaron
Be careful with retraction in excess of 1mm; it can cause blockage in the gap between heat break and PTFE. You can modify the PTFE to prevent this:
Use a pencil sharpener to add a chamfer to the lower end of the PTFE tube
Ensure there are no burrs on the end of the tube.
Unscrew the heat break from the heat sink by a quarter of a turn
Insert PTFE tube and lock in place
Tighten heat break into heat sink.
You will then be able to use retraction settings of up to 4mm without problems.
Peter
Peter,
Thanks. I guess I got lucky. The print went wonderfully at 2mm. I will look into this. Thanks for all your help on this forum. I am reasonably new, but have read back in the forum a long way, and your help has been very insightful to me.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Am I printing too hot? too fast?
One thing you can check for next time is to print a temperature tower using your filament and check what temperature looks best / has the least amount of stringing. There are lots of them on thingiverse. Here's a link to the one I've been using with good results.