Continuous Support Structure Under Holes

[blaknite7]

By default, when you apply support structure it will not put any structure if there is nothing to support over it. Normally this is good, but if you are printing a larger part with a series of holes or cutouts it will make the support structure very discontinuous. In these cases its more efficient and produces better quality if the support structure was continuous even though there may be an open area not requiring support above it.

It would be nice if the support structure algorithm noticed that there was an area that is completely surrounded by support structure and if this area was under some threshold the support structure would be continuous throughout. I've attached some pictures to illustrate what "typically" happens. This part is an upside down "U" with a series of holes. Automatic support is generated in Picture 1. Picture 2 shows a view from the bottom of the part where its shown that the support structure would not be continuous.

You can sometimes "trick" S3D by manually putting support structure and picking a larger "column" and having some overlap, but this can be problematic if the feature is adjacent to a thin wall. the overlap necessary to get support across the hole can result in support structure in unwanted areas on the other side of a thin wall.

Being able to set an area that this would work over (much like the "bridging area") would be a useful feature in S3D.

ISO View of Setup

Under-Support

[CompoundCarl]

It looks like you're using far too large of a support pillar size for that model. If you have tiny holes like that, and you want the supports to follow them, then lower the pillar resolution to 1mm or something smaller

[blaknite7]

It looks like you're using far too large of a support pillar size for that model. If you have tiny holes like that, and you want the supports to follow them, then lower the pillar resolution to 1mm or something smaller

This was just a quick example and wasn't a real part or print. Even by lowering the resolution of the support pillar you still have the same issue though. Depending on the spacing of the holes you can end up with support structure that has very short lengths (between the holes). its more efficient (speed wise, though it uses slightly more filament) to have 1 large support structure piece instead of an array of smaller pylons of support structure.

For example if you had holes that were spaced 2-3mm apart, its not practical to have 100 mini columns of support structure. One is likely to break during the print or you have to print very slow to make sure that doesnt happen, where as if the support structure neglected small areas that didnt need support the overall speed can be increased.

[CompoundCarl]

Well I doubt the software is ever going to ignore areas that actually need support, but I guess what's why they allow you to customize it. You can manually remove the areas you don't want if you decide you want to deviate from the norm

[blaknite7]

Well I doubt the software is ever going to ignore areas that actually need support, but I guess what's why they allow you to customize it. You can manually remove the areas you don't want if you decide you want to deviate from the norm

Quite literally the complete opposite of what you are thinking, I want it to ADD support where there should not be. More pictures:

The Part looks like this:

Part ISO

The print would look like this (1mm supports used, the smallest you can go), Notice there are a series of support columns because of the holes. this is less robust during a print and forces you to slow your print speed down due to the back and forth movement.

Print Preview - As Is

it would be better if the software did something like below, where the support structure was continuous across the holes. The idea is to get the support structure to act like a raft (it doesnt care what is above it). It would be best if the feature was controlled by area. so if there is an area below some user set threshold which is surrounded completely by support, the support structure would be added making one continuous block of support.

Optimal Support

Currently I only know 2 ways around this, You have to manually define larger support columns which when placed overlap in the area that doesnt need support, or to increase the "extra inflation distance" under the support structure. The former can cause problems with thin walls because it will put support structure on the opposite side if there is overlap (would upload a picture but I'm only allowed 3...). The latter often works but can be problematic if multiple parts are being printed adjacent to one another and the inflation distance need to "fill the hole" causes a larger part footprint.

P.S. -Yes I know there are different orientations you can print this in, its intended to be an example only....