best support material (PVA, HIPS, simply PLA, PETG)?

[jasu]

We've been struggling to get support material to work for many days now. So, I thought I'd query the collective experience of Simplify3D to find new things to try.

We print our models mostly in PLA because it doesn't shrink like ABS and we don't need the temperature resistance. PVA looks promising because it dissolves quickly in water. HIPS is cheaper but the solvent limonene is more expensive and an irritant. Our dual extruder is the Flashforge Creator Pro.

This is what worked so far:

• We printed the Hilbert cube in PLA with PVA support and HIPS support. Since the surfaces are horizontal and the support structure is compact the attachment between different materials worked reasonably well. PLA+PVA was easier. PLA+HIPS was a little harder to get to stick. Slower speeds reduced the error rate.
• We dissolved away PVA and HIPS from the Hilbert cube. Since there's so little surface for solvent to attack, it took much longer than expected from previous forum posts. Even the more quickly removable PVA was not fully dissolved after an overnight water bath. For HIPS in limonene it took several days and some poking with a toothpick.
• We can get PVA to stick to the glass bed when printed slowly and we can get PLA layered on top if the PVA underneath is compact and offers a large surface (PLA 200°C, PVA 190°C, bed 40°C). Not so luck for HIPS yet.

This is what failed already:

• The long times required for HIPS to be dissolved damaged PLA models.
• HIPS didn't stick to the glass bed as PLA does.
• HIPS printed on PLA raft didn't stick.
• PLA model printed on PVA support didn't stick.

What else can we try?

• BaronWilliams suggest to print PLA support under PETG or vice versa since apparently the 2 don't bond together like PLA under PLA and can be clipped off more easily.
• print PLA support under PETG and dissolve the former but it uses nasty chemical (drain cleaner)
• Airwolf recommend ABS with HIPS. Maybe we should change from our preferred PLA to shrinking ABS because it works better with HIPS. In any case, we had trouble getting HIPS to stick to the glass bed.
• Maybe we need to print HIPS extra slow onto the glass bed to get it to stick? So far we've been using standard speeds that work perfectly for PLA but failed for HIPS.

I really hope we can get that to work since peeling of PLA support under PLA models is a pain in the...

[Cutterpillar]

I was trying to use HIPS as a support for ABS prints. Ran into the same issue: HIPS does not stick to the glass. Another problem on top of that is that when we print main material we normally print a brim around it, so nozzle gets cleaned before starting the print of the part. With the second extruder which gets preheated before the job HIPS is slowly dripping and since it jumps onto printing support structures with empty nozzle there is no first layer being formed and hence the whole print fails as no supports are printed at all...
Another issue may be that the two materials require different bed temperature setting.
Haven't tried slowing the support extruder down yet.
I heard that the wipe pillar can be used to keep the nozzle clean. Is this related for both extruders or just the main one?

[jasu]

Hi Cutterpillar, I have not used Prime Pillar but I believes it's mostly use for printers that extrude multiple filaments through the same nozzle (see this tutorial).

We attachment problems for HIPS on our Flashforge glass bed for both nozzles. It's slightly better on the Ultimaker. For some reason we occasionally get the HIPS to stick but this is of course pointless as it is a single extruder. PVA sticks ok but both a difficult to print on with PLA once the support is down.