more open infill, filling with epoxy?

[jbeale 0]

I am considering the possibility of filling the interior of an ABS print with epoxy to make it more solid. If I understand the "Layers" view mode in Cura 14.06.1 that infill shows as yellow, it seems that my infill is a square grid that forms separate vertical chambers. That means I would have to fill each column individually, and if the exterior geometry is not a purely vertical wall, then some of these infill columns will close off and become sealed at different z-heights.

Is there a way to get a more open infill (more like a coral structure, than a honeycomb), so fluid could flow throughout the volume with a single pour from near the top?

Also, can infill be turned off? If I go to Expert Settings and set "Support - Fill amount: 0%", the layer view still shows the yellow grid over the entire interior volume. If there is some way to remove all infill, I wonder if the sidewalls would then lean over or flop around during the print, and accuracy would suffer.

 

[jbeale 0]

Oops, I just realized that Fill Density % is on the "Basic" tab, not the advanced settings. A low value like 8% gives me a very sparse infill, and setting it to 0 % does remove all infill.

 

[antiklesys 3]

after reading this i am tempted of creating hollow prints and just drill a small hole on a side then fill the entire print with epoxy

 

[IRobertI 520]

Doesn't epoxy heat up as it cures? I have no idea if it would be enough to cause issues with PLA though.

 

[jbeale 0]

Does it typically work out OK to print with no infill at all? I was worried that walls would sag sideways during the print process with no lateral support.

Yes, the epoxy curing process is exothermic (heats up as it hardens). How high the temperature goes depends on the volume of material, and the type (fast or slow speed cure). For slow-cure epoxy which takes hours to harden, I have never even noticed the heat rise, at least for small volumes. I havn't done much 3D printing yet but I never tried PLA, so far I have always used ABS as it is less brittle.

Epoxy is probably more expensive per volume than PLA or ABS, so the first step would be just go to 100% infill, but I want to see if I can get higher strength with an epoxy fill.

I would like to try a strong material like this polyester filament http://www.amazon.com/Taulman-T-Glase-Polyester-Filament-1-75mm/dp/B00GOKYZ3I

but I am not sure it is available in the 3mm size. There is a 3mm "T-Glase" but the description is different and it does not say "polyester" http://www.amazon.com/Taulman-Clear-T-Glase-3-00mm/dp/B00KYA7KPO/ref=sr_1_7?s=industrial&ie=UTF8&qid=1403737573&sr=1-7

also, the comments in another forum suggest T-Glase is difficult to print with a 0.4mm nozzle, instead 0.7 to 1 mm is recommended. With a Ultimaker 2 I guess that isn't possible.

 

[IRobertI 520]

The walls are sturdier than you think, especially if you make them thicker than 0.4mm. But even at a single wall thickness (0.4mm) they are sturdy enough for lots of stuff that don't need to be structurally strong.

Also, sorry about missing the ABS part, my brain... it needs sleep... In fact, I should go to sleep right now, I need to get up early tomorrow.

 

[dirkels 0]

after reading this i am tempted of creating hollow prints and just drill a small hole on a side then fill the entire print with epoxy

 

@Antiklesys or design a small hole in the bottom of your print. Drilling in plastic can melt it.

Edit: after thinking it over designing a hole in the bottom probably does not work, cura would generate a shell around it leaving you still needing to drill a hole :-( Only way it would work is designing it from the ground up as an hollow object, but that is a lot of work.