top is not printing, calibration or STL issue?

[pluggedIN 1]

Hello Again!

I've been trying to print this: Low-Poly Pikachu

90% of it comes out great. The top, never finishes.

I can't quite explain what is happening. It's almost as if the back part of the head gets printed "higher" and the nozzle knocks into it. It's weird. Every thing else comes out great on super fine setting in cura. So is this some kind of nozzle adjustment issue, or is this just becuase of something in the STL? This happens weather the gcode comes from Cura, or from Simplify3D.

Thoughts on what to try?

[geert_2 556]

What happens when you sink most of the model into the build plate, so only the offending top parts are visible and printed?

[pluggedIN 1]

What happens when you sink most of the model into the build plate, so only the offending top parts are visible and printed?

Great minds think alike! I had that same thought before. The results are nearly the same:

[gr5 2,072]

So overhangs do this - they get raised edges on the edge that is overhanging air. Even on a mere 45 degree angle.

You need to do 2 things:

1) 100% fan. Max fan. Maybe add more fan. this helps quite a bit reducing the raised egdes to a minimum.

2) Make the part stick like hell to the glass. This is probably the only thing left for you to do. You should be able to pick up the printer with that little pikachu. More details in this video - I know it's a long video but it's packed with useful info:

[kmanstudios 1,120]

I have noticed that curling on edges with some filaments will create this issue.

In addition to gr5's suggestions, which the starting point, try to cut back on the print temperature and slow down the printing. This will make the heat differential less of an issue and let the fans sit on the part longer.

[pluggedIN 1]

I like that video! I cleaned off my glass plate better. Also, I took kmanstudios suggestions and printed slower and 5 degrees lower. Much Better!

So now I have the tangential question of those ears. How to make them less globby?

I also have an even more tangential question. I downloaded the gears from gr5's video. The gears did not rotate because of squish.

I only printed a few millimeters of the gears before stopping, and this pic is looking at the bottom. Instead of leveling the plate higher for less squish, can i change the flow out of the nozzle that would print the gears better?

[gr5 2,072]

The gear thing is already round so doesn't need quite as much squishing and it's also small enough that you should be okay with very little squish.

Alternatively there is an awesome feature in cura 2.7 - search for "horizontal".  It's something like "horizontal expansion first layer only".  Set that to about -.25mm and it will take care of your problem in the gear pictures.

As to the ears - that is due to not enough cooling.  Really the easiest solution is to print two pickachus in "all at once" mode - not "one at a time" mode.  Or print a 15mm square tower that is a few layers taller than pikachu. This allows one pikachu to cool while printing the other - it only needs a few extra seconds.  This makes a huge difference in ear tip quality.

Edited October 17, 2017 by Guest

[pluggedIN 1]

Alternatively there is an awesome feature in cura 2.7 - search for "horizontal".  It's something like "horizontal expansion first layer only".  Set that to about -.25mm and it will take care of your problem in the gear pictures.

I have NO idea what that horizontal feature does but it worked great! I used to be a huge Simplify3D fan, but Cura is slowly luring me back.

[gr5 2,072]

Set 1st layer horizontal expansion to positive 2mm and look at bottom layer versus 2nd layer. Then cahnge it to -1mm and look again. It's hard to explain in words but obvious when you compare the bottom 2 layers.