Horizontal offset of supports

[billyd]

Currently if you are supporting a surface that is not planar to the x-y axis, if you set horizontal offset the surface will not be supported adequately, because the software offsets the support from the non planar surface treating it just like the vertical unsupported surfaces where you do want the offset. This results in supports that have a larger gap than requested. We should be able to set the software to ignore the horizontal offset for all supported non planar surfaces. The software wouldn't apply the horizontal offset to anything that is not vertical, per a user supplied range of angles (relative to the x-y plane).

[billyd]

Here are three pictures to help understand what I am talking about. The first picture shows zero horizontal offset and shows a nonplanar surface with a proper 1 layer gap. The second and third picture demonstrates what happens when a nonzero horizontal offset is applied (In this case 0.6mm) and the large gap that occurs between the supports and the nonplanar surface. And the last picture shows how a planar surface is unaffected by a non zero horizontal offset.

The software in it's current state makes auto generating supports on a model with nonplanar surfaces requiring support, impossible. Any model like this must have a zero horizontal offset and then the supports must be manually applied. If not many supports will be created too close to any vertical portions of the model and will permanently adhere to those walls. So you either have to manually remove potentially hundred of supports, or manually apply potentially hundreds of supports.

The software should be able to detect when a non planar surface is being supported and ignore the horizontal offset in those areas so the proper requested layer gap is created (typically one or two layers).

[DrD]

Interesting... can you please provide your .factory file with this exact 3D model? I'd like to play around a bit to see
if there's a setting combination that'll support the model properly without fusing the supports to the model, etc...

Thanks,

D.

[billyd]

Interesting... can you please provide your .factory file with this exact 3D model? I'd like to play around a bit to see
if there's a setting combination that'll support the model properly without fusing the supports to the model, etc...

Thanks,

D.

It's easily recreated, you can autogenerate supports for any surface that's not parallel with the XY plane (can be curved or straight) and apply a non zero horizontal offset (large enough to prevent supports from fusing to parts of the model) and you will see what happens. Depending on the severity of the curve or the angle of the flat surface and you will end up with useless supports unless you zero out the horizontal offset.

Edit this is not a v5 issue, this has been around for as long as S3D has.

[billyd]

Interesting... can you please provide your .factory file with this exact 3D model? I'd like to play around a bit to see
if there's a setting combination that'll support the model properly without fusing the supports to the model, etc...

Thanks,

D.

Another way of potentially approaching this from a logic standpoint is to only apply horizontal offset to those supports that will come into contact with unsupported portions of the model. So as an initial pass for support creation the software determines the portions of the model that don't require support (based on the supplied process settings) and any supports that will contact them get the horizontal offset applied, while all other supports remain unshifted. I have no idea if this is possible or practical, but it would be an awesome advance in auto support generation imo.

[gearsawe]

it was my understanding, look at the the single slice and does not produce a offset surface around the model. with 0 offset the support will be right up against the bead where the model. A 0.2 offset should be a 0.2 gap horizontally. One setting I did find messes with this a little is the dimensional compensation. so if you have compensation at -0.05 and support offset of 0.2 you then have 0.25 between the support and the printed outline.
this is offset a battle with what you are are showing.

My best way to control support is with two processes. I never like the whole layer skip but a way to control the gap.
One for supports and one for the model. then use the first layer height to control the gap. I can then have 0.15 gap with 0.2 layer height. the difference between the first layer heights controls the gap. something Cura can't do. also you can then control the width bead with this concept as well

[billyd]

it was my understanding, look at the the single slice and does not produce a offset surface around the model. with 0 offset the support will be right up against the bead where the model. A 0.2 offset should be a 0.2 gap horizontally. One setting I did find messes with this a little is the dimensional compensation. so if you have compensation at -0.05 and support offset of 0.2 you then have 0.25 between the support and the printed outline.
this is offset a battle with what you are are showing.

My best way to control support is with two processes. I never like the whole layer skip but a way to control the gap.
One for supports and one for the model. then use the first layer height to control the gap. I can then have 0.15 gap with 0.2 layer height. the difference between the first layer heights controls the gap. something Cura can't do. also you can then control the width bead with this concept as well

Yes there are ways around most any issue, but this is about improving the software. Being able to use auto generation of supports, and not have to worry about non planar surfaces if you use a horizontal offset other than zero. This is just simple math for the computer, looking at each support and deciding whether or not it will stick to parts of the model due to a lack of space, or in areas of support, determining whether or not the requested layer gap is being achieved (regardless of the horizontal offset requested). As the software is now, you have to manually remove any supports that will get stuck to the model, and use a zero horizontal offset in the case of supporting non planar to the XY plane surfaces, otherwise those surfaces will not be supported properly. This defeats the point of autogeneration, since you have to manually remove a potentially large number of supports depending on the model.

[billyd]

I'm bumping this to the top and quite frankly I can't understand why more people can't see just how important this change is and how big of an improvement it would have for complex parts requiring support.