I was having problem printing the Make 2015 Calibration set.
The left one breaks off at 60 degree. So I tighten the belts and get the right one. But the bottom surface is still not perfect. How does a guy get 70 degree overhang working on a Printrbot Simple Metal?
Slow your speed down?
Printing tiny objects with overhang I found that the cooling rate was also a critical factor, so you may get the results from a combination of the two.
How does one control the cooling rate? I have the fan turned on at layer 3 100% but that’s the only thing.
Hej, what’s the matter with your bottom layers? They look horrible!
I didn’t print with a brim so the initial extrusion screw up the initial lettering which cause the horrible artifacts. With brim on, it looks decent. I am reprinting this with a slower speed setting.
Did your turn on the auto bed leveling option? (G29)
Yes it is on. A slower print has just finished. Same level of overhang errors.
Do you have a desk fan you can turn on when at layer 3 to see if lots more cooling helps?
I can look into that. I wish there is a way to tell CraftWare to lower the temp after a certain number of layers.
I don’t think you want to lower the hotend temperature as that might impact flow rate and give you other inconsistencies. Getting it cooled far faster once out was what did the trick for me. One problem with these test prints is are they realistic for the end design you’ll print? For example if a layer of the test print takes 2 seconds to print but your real target design takes 60 seconds to print, only part of which is the overhang, then you may find the results inconsistent as the cooling profile will be different.
It’s why I’ve had my eye on the work of Marius Popescu @L33TL4BS and wonder if a Melexis MLX90621 to give some layer temperature feedback would help us all with these sorts of issues.
You are right. Perhaps I am fretting over these for nothing. The prints come out ok and for most things that I make, there is no overhang.
@Mark_MARKSE_Emery That’s why I printed also this model as a second reference. It’s in German but I hope you will get it anyway. 
3DGeometrie: Printrbot Simple Maker: Testprints
Nice set Kurt!
Which direction is your fan blowing from? Does rotating the print change the outcome?
