Support brim towards the outside

[slikk66]

Often times I have a model I'd like to not print with a brim on it, but then there are teeny tiny support structures (<3mm round for example) that never stick unless I add brim to the entire print. Is a "brim for support only" option possible?

[ChrisTerBeke]

Related to https://github.com/Ultimaker/Cura/issues/3818.

[jackha]

Devs: see CURA-5487

[agibson2]

I was posting this same idea on the forum today and someone pointed me to this. This feature would be very helpful very often for me. I have prints where the object has a bit of detail on the bottom where cutting away the brim is very tricky or near impossible. I do need the brim for supports though quite often. This feature would solve that issue.

jackha, Is CURA-5487 something that regular github users can see? A search for 5487 doesn't turn up anything.

[fieldOfView]

CURA-5487 is a reference to an internal ticket, not publicly accessible.

[Ghostkeeper]

I'm closing this as a duplicate of #1950.

[seltix5]

Hello all, I have the support brim enable and it does nothing if I don't enable the brim in the build plate adhesion type... Is that normal? I have Cura 4.3.0 Thanks!

[Ghostkeeper]

Mind that the support brim goes towards the inside of the support. So you won't see it unless you look from the underside of the print or scroll down the layers to the first layer.

[seltix5]

hello, in my case I dont see any diference, I dont know if it may be because the support area is small but in that case the normal outside brim wold be a big help :D

[Ghostkeeper]

The brim there looks fine. I see a few extra contours inside the support.

It's indeed small, but that's what the normal brim is for as well. What you really seem to be looking for is a way to print the brim only for small shapes or something like that?

[seltix5]

hello,

i was locking for a "normal" outside brim. with the support brim disabled there is a very small diference but it wont result in a real diference when printing :

I was hopping for a outside brim like the one from the "build plate adhesion type" but only for support structures to increase adhesion for this small type of support structures :

[TheNitek]

I can confirm this. Support Brim only works correctly if Brim is enabled as "Build plate adhesion type". I would love to use the Support Brim independently.

[Ghostkeeper]

But you can! Here's a screenshot showing a skirt is used instead of adhesion, but still a brim for the support:

The support brim can be enabled even if the adhesion type is not set to brim. Doesn't that work for you?

[seltix5]

hello @Ghostkeeper , yes, for something like your example where you have a big space under the area you need to support the inside brim will work because there is space available for the brim to expand, but for models where it cant expand the inside brim will do nothing. For example, the model I printscreen before (https://www.thingiverse.com/thing:600732), the arm needs support, but that area is so small there is no space to a inside brim, without a plate adhesion brim the support will just fall. For this cases a support outside brim wold be perfect since the model itself does not need brim.

[TheNitek]

I like to use support brim in combination with tree support, but when using a Skirt there is next to no support brim. That's not how I'd expect this to behave

[Ghostkeeper]

Of course, if you have a piece of support that is surrounded by something else, it will not have a brim either then if it's going outside. There will always be special cases:

But there is something to be said about the support brim going towards the outside instead of towards the inside because of user expectations. We get this bug report once in a while, that people think the brim is missing but it's actually just on the inside.

There is also a similar technique to our current support brim: You can also set the initial layer support pattern to concentric and the initial layer support density to 100% to achieve a sort of brim, so arguably there are two features with the same function there.

On the other hand, part of the reason why we chose this solution is because it simplifies the behaviour a lot. If the brim for support needs to go to the outside, you need to have brim lines with interruptions where the brim is interrupted by the model. This is not conductive to adhesion or priming. It also simplifies the algorithm for collision checking between models (in the front-end) a lot.

[seltix5]

hello, this is not a bug report, it is more like a feature request since it is not possible to do it. As the original title and message of this issue :

Often times I have a model I'd like to not print with a brim on it, but then there are teeny tiny support structures (<3mm round for example) that never stick unless I add brim to the entire print. Is a "brim for support only" option possible?

Your 2 examples are not related to the problem since the problem in question is to print small supports. In booth your examples the support is big enough to support himself. To print small supports the problem is not if there is something surrounding the support or not, the problem is the fact the area occupied by the support is so small it will probably move because of bad adhesion to the plate. In this specific cases the inside brim cant help because the support area is too small.

I give you this example (https://www.thingiverse.com/thing:600732), if you try to print this without plate adhesion brim chances are the support will fall. The only option here is to enable the plate adhesion brim just to increase the support adhesion to the plate.

English is not my first language, i feel i may not be explaining the problem correctly.

I cant say I image the work to implement something like this, but since the plate adhesion brim already adds good brim to model and supports, wold not be possible to do this but only for supports?

[Ghostkeeper]

I could make the second example smaller and you'd have the same problem but less stable support. Whether the brim is necessary or not is irrelevant here. It was just to show a case where a brim on the OUTSIDE wouldn't fit either.

I cant say I image the work to implement something like this, but since the plate adhesion brim already adds good brim to model and supports, wold not be possible to do this but only for supports?

You'll notice that we're not creating any brim right now in any location where a brim could be touching something that doesn't have a brim. The reason for that is that the brim then needs to be interrupted.

This is the case for:

• Prime tower brim. Here we make the prime tower collision area bigger so that they can't collide.
• Support. Here we grow the brim towards the inside so that it can't collide.
• Brim on outside only. This prevents brims from forming in holes in the print. If there is a piece inside a hole, that piece should still get a brim but then the hole will also get a brim so that both sides have a brim again, which prevents a brim from touching something that doesn't have a brim.

To implement this, we'd have to implement cutting out pieces from the brim.

[seltix5]

and woldnt be possible to use same technic used with prime tower here? and only expand the brim until reaches the desired value or a colision area.

[Ghostkeeper]

The semantics we're using for the prime tower is to increase the disallowed area around the prime tower so that you can't place anything nearby that would cause the brim to collide. If you're also using a normal brim for the main print, that one goes around the prime tower brim.

This is not feasible for support since the support must be generated pretty close to the model, otherwise it wouldn't support the model any more.

[Ghostkeeper]

We've decided to defer the support brim going towards the outside. It would be good to have but the algorithmics involved don't make it worth our time for now.

[seltix5]

thanks for all the explanations, it is in the maybe todo list is already something good :)

[ivanmalvin]

Just wanted to add my two cents that I also feel an outer brim on supports would be extremely useful in many situations. I read this thread and understand it might not be easy to implement, but I hope it gets added.

It's pretty common that I have a model with a nice flat base, so it doesn't need a brim, but the supports often get small enough (or tall enough) that they have a good chance of failing from not having enough surface area adhering to the bed. Sometimes I resort to using an outer brim on everything, but the cleanup of the brim tends to ruin the appearance when you try to fit two separately printed parts together.

I do use the support (inner) brim option, which definitely helps, but it doesn't help when supports are small/narrow so there's little to no inner brim added from that.

[seltix5]

that's exactly my problem =)

[Neohkp]

You can set the distance from the brim to 1 or 2mm, this makes no sense, but it works ;-) You have a supportbrim but no objectbrim.

[seltix5]

cool, nice workaround! thanks for sharing

[krakilin0405]

I'm new to 3d printing and I was wondering where this feature is "Brim outisde of support", arg I hope they add this feature eventually. The above is a good around, I tested and it works, though I hate wasting material .

[jesta192]

The whole point of a brim is to be large enough to stick to the build platform. With the OP's example, an inner brim will never suffice (for any small supports like that). I'm glad the developers are considering this for the future but I'm not sure they realize why inner brims in these situations are useless!

@Neohkp's workaround is a great way to get by until this improves. Note that on one of my models a 2mm-distanced brim actually pushed the brim out from under the support in certain areas; I shrank it to 1mm and the whole support is on the brim.

[MightyMorpheus]

There is another workaround I found today. You can use Tab Anti Warping plugin in Cura and place some circles underneath the object. Supports will grow from that circles.

See here:

[tlhintoq]

Version 5.4.0-b1 Got here from a closed bug about brim on tree support so I'm thinking you feel this is the right bug for this.

I second the need for being able to have support brim on trees without having it on the model. This model is big and has no need for a brim that has to later be removed and cleaned up. But the tree supports at 1 wall thick don't stand much of a chance at holding on to the bed.

Normally I'd band-aid the problem with anti-warp tabs, but those stop 5.4.0b1 from slicing. Its beta with a 3rd party extension so I get that. But if Cura would just let us have a tree support brim without model brim we wouldn't have to patch and band-aid around the issue.

[pengoses]

Version 5.4.0-b1 Got here from a closed bug about brim on tree support so I'm thinking you feel this is the right bug for this.

I second the need for being able to have support brim on trees without having it on the model. This model is big and has no need for a brim that has to later be removed and cleaned up. But the tree supports at 1 wall thick don't stand much of a chance at holding on to the bed.

Normally I'd band-aid the problem with anti-warp tabs, but those stop 5.4.0b1 from slicing. Its beta with a 3rd party extension so I get that. But if Cura would just let us have a tree support brim without model brim we wouldn't have to patch and band-aid around the issue.

I believe the solution from Neohkp does what we all want now, though it's not very intuitive. Set a brim size and a brim distance. It only distances the brim from the model not from supports. There should be a way to make this functionality clearer though.

"You can set the distance from the brim to 1 or 2mm, this makes no sense, but it works ;-) You have a supportbrim but no objectbrim."

[tlhintoq]

Good band aide. I appreciate you pointing it out as I missed that while reading through the extensive thread. The other down side is it does mean you have to screw with settings that have been established on every printing profile you have created, then be sure to put everything back. I'm not saying that's rocket science, just that its yet another item to put on the checklist next to the monitor. The checklist of "do/check this everything time to band aid an issue" gets longer and longer.

[petecory]

Version 5.4.0-b1 Got here from a closed bug about brim on tree support so I'm thinking you feel this is the right bug for this. I second the need for being able to have support brim on trees without having it on the model. This model is big and has no need for a brim that has to later be removed and cleaned up. But the tree supports at 1 wall thick don't stand much of a chance at holding on to the bed. Normally I'd band-aid the problem with anti-warp tabs, but those stop 5.4.0b1 from slicing. Its beta with a 3rd party extension so I get that. But if Cura would just let us have a tree support brim without model brim we wouldn't have to patch and band-aid around the issue.

I believe the solution from Neohkp does what we all want now, though it's not very intuitive. Set a brim size and a brim distance. It only distances the brim from the model not from supports. There should be a way to make this functionality clearer though.

"You can set the distance from the brim to 1 or 2mm, this makes no sense, but it works ;-) You have a supportbrim but no objectbrim."

This workaround no longer works in 5.4 either. It is putting space between the support and brim. See the screenshot:

[tlhintoq]

@Ghostkeeper You saw the post above, right? That now even the band-aide work around doesn't work around?

This workaround no longer works in 5.4 either. It is putting space between the support and brim. See the screenshot:

Any chance this could get prioritized now that y'all are touting the new tree supports, but there's little way to make them work correctly?

[FabioM3]

Common Cura devs, prusa does this for ages...

[D1gitalCha0s]

How is this still not a feature...?

[tlhintoq]

How is this still not a feature...?

Not wrong. I was about to defend that there's been no version update since this was reported in 5.4.0 on 04July2023. Then thought... July, August, September and now October... That's a while... Oh then it was actually still a bug in the version before that, and before that... The most recent report for 5.4.0 is that that BAND AID for the bug stopped working.

I don't know. For years I kept trying other slicers... then I wind up returning to Cura for some reason or another. I hated a ton of the side effects from the Arachne engine since it alpha premiered so I should have seen this coming: Now they don't seem to be able to fix the simple stuff probably because its baked into that engine so deeply they just don't know how/where.

Cura was so proud of those new tree supports and I admit they do remove nicely - but now you can only use them if you turn on RAFT... freaking RAFT for every print... because its the only way to get some kind of a base for the tree otherwise a single wall trunk just doesn't have the adhesion cross-section to maintain a bond. So now every job I slice takes the model 5mm off the bed and full on raft: I feel like I'm doing resin supports.

I guess I'm going to give the latest PrusaSlicer another go. Its seeing more updates more often; and its hard to deny the volume of posts on the dozen FB channels I'm on that basically say the same thing:

Had a problem with stringing. Switched to PrusaSlicer and they're gone. Had a problem with idle oozing that stopped with PrusaSlicer. Speed went up and yet ghosting went down after I switched.

Maybe those are all annecdotal. Maybe those are all things that could be done in Cura too if one managed to figure out the 5 layers of settings inheritence to what the real values are at slice-time... But it costs me nothing to give it another go.

[onolox]

For me the travel engine of Prusa is atrocious, bumps all over the place.

[onolox]

There is another workaround I found today. You can use Tab Anti Warping plugin in Cura and place some circles underneath the object. Supports will grow from that circles.

See here:

For me the trees don't position themselves over the pads... they are allergic of pads... any idea why?

[tlhintoq]

@onolox Is that working with Cura 5.4.0? Because I had to uninstall that extension as of the update

[tlhintoq]

Just throwing this out there... Latest version of 5.5.0b1 does not have brim on tree supports.

[tlhintoq]

5.5.0 - Release version NOT beta

Support brims setting is still not being honored unless you have a general brim on the entire job. [x] Enable support brim and Build Plate Adhesion Should not be linked. Its a seperate checkbox. One should be able to turn on brims for tree supports which are commonly only a single .4mm wall and thus very little adhesion to the glass/bed, without having to have brim on EVERYTHING.

One option would be to have the Brim Distance from Build plate adhesion only apply to Build plate adhesion-ya know, the section this setting is found under. Because then we could set the overall brim to be far away from the model so its not a pain to remove - and still have a brim on the support. Sadly this distance setting is applying to both the overall model as well as the supports. So again, there doesn't seem to be a reasonable way to have a brim on supports without the side effect of having to cut supports off the model resulting in a visible defect and added labor hours.

[agibson2]

Yea. That is a problem I was hoping would be resolved by now (brim under support requires general brim enabled for the model). As a workaround though, I just set it to skirt and brim under support feature still works. Not ideal if you don't need a skirt but that is what I have been doing.

[tlhintoq]

I just set it to skirt and brim under support feature still works. Not ideal if you don't need a skirt but that is what I have been doing.

It never occurred to me to set skirt to trick the program into putting a brim on the supports. That's brilliant. Well... It would be if it worked with the current version. But as we can all see it doesn't with 5.5.0; not sure about earlier versions.

[agibson2]

I think you misunderstand brim for supports. Support brims go inward toward the center of the support areas instead of outward from the support. This works great in my experience as it gives the extra bed adhesion and helps the inside support lines to get attached together better with the outside of the support.

[onolox]

Cura by default uses trees that are too wide, I modified the parameters so it became more optimized (more like prusa), so brim inside only is not sufficient. Even with the thick trees that cura generates by default, inside only are not sufficient. For tall prints it needs to have outside brim too.

[agibson2]

If the support is tall and very skinny, etc, I guess that could be an issue. I haven't had that problem though. The base of the support tree with inside brim has been enough so far to not have issues for my prints. I hope they always have support brim going inward if they ever add that option to go outward for brim on supports. I have trouble removing the inside support lines off the bed at times so it is a big benefit for the brim to lock the inside support structures to the outside support wall.

The option to have outside support brim could be beneficial to me at times too though as sometimes there are tiny tree supports all around the edge of a curved surface on the bed. It is a pain to remove each individual one from the bed. Outward support brim would lock all of those little pieces together and make them much easier to remove.

I see the benefits to both ways of doing it and it would be nice to have both options (each one enable separately).

[tlhintoq]

I can see where inward bases on little supports for little things on little printers is fine. They're fine on trinkets and light switch plates and remote control holders etc.

But many of us do large things. Like @onolox said, once you optimize the supports to not be wasteful and so you can trim literal DAYS off a big job you need brims that act like brims. This job for example is a week long and stands 400mm tall, 400mm deep and about 200mm wide. Even optimized there was over half a kg just in single-wall supports. If I had left these supports defaulted it would have been another half spool ($20) and another 1-2 days just in support printing.