Taulman 910 - Supports too thick with 0.8mm nozzle

[Jory]

I've been printing large parts using Taulman 910 using a 0.35mm nozzle, which was stock on my PolyPrinter 229. While the parts looked good and support was easy to remove after some tweaking, the parts weren't quite strong enough compared to what I expected. I contacted Tom over at Taulman and he suggested using nozzles between 0.5-0.8mm to get the best strength, with the 0.8mm nozzles producing the stronger parts.

I started using a 0.8mm nozzle and wow, the parts were SOOOO much stronger. I noticed some issues with stringing and blobbing, which I addressed pretty easily, even though they were easily removed from the parts. The issue I'm having now is that the support structures are so thick that they are very hard to remove now. They are both thick (around 1.1mm), strong and are bonding to the part on the dense support layers.

Do any of you know of a good trick to use to print the support structures in a way that they will remove from the part easier but still provide the structure needed for large, detailed objects that require large amounts of support? I could maybe bump up the support structure underspeed but I want to make sure that I don't go too fast or the material can be under-extruded and come out all fuzzy and not provide good support. Currently printing at 24% for Outline/Infill of max 250mm/s speeds. Supports printing at 30%. Also, I have the extrusion multiplier at 1.00 since I still want to make sure I'm not under-extruding for the body of the parts.

Any good suggestions before I start printing again to avoid wasting too much of the 910, which is expensive to experiment with too much? Thanks everyone!

[JoeJ]

Thicker extrusions tend to bond better, which is why your parts are coming out stronger. It's also going to be why it becomes a bit more difficult to separate the support structures - everything is bonding together more. It looks like your printer only has one extruder, but a very easy way to work around this issue is to use an alternate material for the support structures that either doesn't bond as well to the parent material, or it can be dissolved away later. That's the best way to really increase performance from the supports.

But if you're stuck with a single extruder printer, you might want to try increasing the horizontal offset slightly. That has helped me in the past. If you are using the dense support layers, it's also useful to try some different dense support infill percentages, because sometimes a higher infill percentage will actually separate easier (85% separated easier for me than 70% on one of my printers)

[Jory]

I've been trying to play around some with the vertical separation and it's either bonded or separated too much and makes the underside of the supported areas look really nasty and lets the part sag. I'm thinking about manually adjusting the speeds when it's printing the dense support layers to see how what results I get. I wish there was a way to have the dense support layers print at a different speed than the regular supports if this does indeed make a difference.

[jimc]

If your using the dense support layers, that will make the support harder to remove. The easiest support to remove will be a single angle, default is 0. Try to keep the density at 30% or less.

[Jory]

What do you suggest for pillar resolution? Right now I'm using 4.00mm, but haven't really tried messing with it much. How is it different that support infill percentages?

[jimc]

Pillar resolution only makes the support grid finer to pick up finer details in models. Has nothing to do with the density of the printed support. 4mm is fine in many cases but 1-2 may be necessary on small detailed prints