Poor quality under support material

[shawnrw]

I'm having an issue with large prints where the support material is printed.

After the support material is removed, the quality is very poor. Please see the photos below. Another thing to note: the corner radius seems very inconsistent.

I assume I need to make some adjustments to the support setup prior to printing? Currently using MakerGear PLA/stock settings.

Thanks,
Shawn

[Bratag]

Firstly try avoid support in large areas if possible - slice the model in half and print and glue. If you are unable to do that then try turning on dense infil percentage (assuming S3D being used) and add some dense support layers. Basically that will allow you to us small support infil percentage and then right before it touches the part it will do dense infil and result in better looking supported parts, Unfortunately they will never be perfect but if I had to say you could print that part opening down with no support and be ok.

[Jules]

Firstly try avoid support in large areas if possible - slice the model in half and print and glue. If you are unable to do that then try turning on dense infil percentage (assuming S3D being used) and add some dense support layers. Basically that will allow you to us small support infil percentage and then right before it touches the part it will do dense infil and result in better looking supported parts, Unfortunately they will never be perfect but if I had to say you could print that part opening down with no support and be ok.

Yep, totally agree on all points.

If you want to print that horizontally on the bed, cutting the model in half and gluing is the best option, you would get a perfect surface on the print, with all of the nasty supported areas hidden on the inside. Jin came up with a way to do that in S3d, by positioning the model halfway or so below the bed (or wherever it makes sense to cut it), duplicating the model, and then flipping the copy over. The parts that are underneath the bed don't print. Then you could glue the two halves together.

One thing to realize when you print anything with these machines is that you always want to place the widest/largest flat area oriented face down on the bed. Rafts are never a good idea unless they are an absolute necessity, because support always does leave a funky surface behind on the print. Think about how gravity is going to affect the different faces of the print that have nothing underneath them. Support is a necessity sometimes, but if you can avoid using it by turning your object, or hiding the supported area inside the design, print it that way. (If there is a gradual incline/decline on a side face, support won't be necessary.) That's your second best option. You can probably print that with the opening face down on the bed without any support at all. It's going to take a lot longer to print, but that's the trade-off.

If you do have to use support for a sharply overhanging area (45°angle), use a couple of dense support layers at 70% infill...it helps.

(Oh, and beveled or rounded edges in your design create one hell of an angle for the machine to have to fight against, if you place the face they attach to pointing down. If you can, turn beveled edges vertical when you place the design on the bed. )

Just little tricks that you pick up as you go along.

[insta]

Just to contradict Jules directly, a dual-extrusion print with PVA & PLA, with 0 separation all around and 2 dense layers @ 100% leaves a flawless surface once dissolved and the hairs brushed away. In many cases it's hard to tell which was the supported side vs the top side.

[Jules]

Just to contradict Jules directly, a dual-extrusion print with PVA & PLA, with 0 separation all around and 2 dense layers @ 100% leaves a flawless surface once dissolved and the hairs brushed away. In many cases it's hard to tell which was the supported side vs the top side.

True.....Correct.....I am in error. I was not factoring in the miracle that is dual extrusion with dissolving filament.