ABS 100% Infill Print Came Out Like A Hedgehog

[huangleike]

Hi, this is my first time posting a topic. Thank you in advance for all your help!

I'm printing a handle using ABS and it needs to be solid in order to be hard enough to hold a child's weight.

My printer is the V4 hotend. I use Simplify3D. The settings are as follow:

Temperature: 235 C for extruder, 110 C for heating bed
Printing Speed: 80 mm/s
X-Y Movement Speed: 160 mm/s
Layer Height: 0.20 mm
Infill: 100%
Nozzle Diameter: 0.35 mm
Extrusion Multiplier: 1.10 (This is by S3D's default since I don't know if there's any change for V4 hotend)
Extrusion Width: 0.43 mm
Retraction Distance: 1.40 mm
Retraction Vertical Left: 0.25 mm
Support Infill: 30%
Dense Support Layers: 2
Dense Infill Percentage: 70%

This is the first time I meet such situation. It looks like temperature is too high. However the raft is nice, and the first several layers look fine. So I wonder what the reason is. Is it caused by the 2 dense support layers? Because that's what I changed recently.

Thank you!

[Jules]

Couple of things:

1. If you haven't run any calibration squares to determine what the correct extrusion multiplier is for the filament, you need to do that. Setting the correct extrusion multiplier is covered here:

viewtopic.php?f=3&t=1964

Be sure to calibrate for both the width AND the height of the calibration square. There is a link at the bottom of that post that takes you to the discussion on how to calibrate for the height.

2. Your extrusion width of 0.43 mm is high relative to your layer height of 0.2 mm. Reduce that to 0.40 mm width. Looks like you are over extruding, and since there is no place for the excess filament to go at 100% infill, it's creating the hedgehog effect.

3. No fan. Zero cooling.

4. You will get better strength at about 80% infill. (Can't remember where i saw it, but there was a study done - actually a diminishing return on strength above 80%. More cracking or something, I'm sorry, it was a long time ago.)

Having said that, I would never try to 3D print something that would be used to hold a child. 3D printed objects can de-laminate if you don't have your settings correct. ABS CRACKS!!!

Just not worth taking a chance on your child's safety.

(However, let me also point out that I've never printed ABS, so my understanding is limited. For all I know it can hold up a truck. ) Once the guys who print it all the time jump in, they can give you some specific pointers on how to fix your print.

[huangleike]

Many thanks! I thought it might be something about extruding after I posted this too.

No it's not gonna actually hold a chile, it's just a prototype of a stroller

Couple of things:

1. If you haven't run any calibration squares to determine what the correct extrusion multiplier is for the filament, you need to do that. Setting the correct extrusion multiplier is covered here:

viewtopic.php?f=3&t=1964

Be sure to calibrate for both the width AND the height of the calibration square. There is a link at the bottom of that post that takes you to the discussion on how to calibrate for the height.

2. Your extrusion width of 0.43 mm is high relative to your layer height of 0.2 mm. Reduce that to 0.40 mm width. Looks like you are over extruding, and since there is no place for the excess filament to go at 100% infill, it's creating the hedgehog effect.

3. No fan. Zero cooling.

4. You will get better strength at about 80% infill. (Can't remember where i saw it, but there was a study done - actually a diminishing return on strength above 80%. More cracking or something, I'm sorry, it was a long time ago.)

Having said that, I would never try to 3D print something that would be used to hold a child. 3D printed objects can de-laminate if you don't have your settings correct. ABS CRACKS!!!

Just not worth taking a chance on your child's safety.

(However, let me also point out that I've never printed ABS, so my understanding is limited. For all I know it can hold up a truck. ) Once the guys who print it all the time jump in, they can give you some specific pointers on how to fix your print.

[Jules]

Cool! Good luck with it!

[MagicEngineer]

ABS it tricky. You can't use any cooling, but at the same time heat builds up in long prints causing what looks like shrinkage in the lower layers. Looking at the support columns I think you may need to reduce your bed temperature a bit about 25-30 layers into the print. As for the roughness of the upper portions of the print, you might be having ambient temperature problems. I have similar problems if I run my ac while printing ABS.

[insta]

Couple of things:

Having said that, I would never try to 3D print something that would be used to hold a child. 3D printed objects can de-laminate if you don't have your settings correct. ABS CRACKS!!!

Just not worth taking a chance on your child's safety.

(However, let me also point out that I've never printed ABS, so my understanding is limited. For all I know it can hold up a truck. ) Once the guys who print it all the time jump in, they can give you some specific pointers on how to fix your print.

I printed a skateboard. It held a fully-grown adult's weight.

[huangleike]

OK! I'll definitely try it out! Thank you!

ABS it tricky. You can't use any cooling, but at the same time heat builds up in long prints causing what looks like shrinkage in the lower layers. Looking at the support columns I think you may need to reduce your bed temperature a bit about 25-30 layers into the print. As for the roughness of the upper portions of the print, you might be having ambient temperature problems. I have similar problems if I run my ac while printing ABS.

[Jules]

I printed a skateboard. It held a fully-grown adult's weight.

See, told you my knowledge was limited!