Partial BRIM possible - not around the entire object?
 
Notifications
Clear all

Partial BRIM possible - not around the entire object?  

  RSS
steve
(@steve-13)
Trusted Member
Partial BRIM possible - not around the entire object?

Greetings,

I have a circular part that is the maximum Y dimension and reaches the edge of the build plate. A skirt is not possible as it puts the print head out of range (which is fine). I would like to use a brim to help keep the part secured to the build plate, however just like with a skirt it will not fit. However a partial brim, not around the entire part but rather from say 2 o'clock to 5 o'clock, and 7 o'clock to 10 o'clock would fit and certainly do the job.

 

 

Two questions:

1) Is there any way to do this in the PRUSA slicer?

2) If not, is there any good substitute?

I've considered manually adding a 1-layer custom brim to the model however the first layer will print as one entire blob. It will require cutting off the fake brim but it may not be a bad option, I'm not sure. It looks like this in Blender:

 

Another option would be to add a shape in the PRUSA slicer itself (right-click, add shape), overlap it with the model in the positions mentioned and drop the height of the added object to the first layer height. The slicer will print these as two distinct objects which may make it easier to trim given the distinct perimeters, however at the overlap the print head will be running into the previously laid down filament, which the slicer warns about. Will that be a problem?

Lastly, are there any techniques during modeling (in my case Blender) for creating a partial brim? The challenge seems to be how to butt a "piece of brim" object up against the main print object such that it prints with enough contact to attach but is not part of the main object.

Thanks for any thoughts and comments.

 

 

Napsal : 05/04/2025 8:02 pm
Snuffleupagus
(@snuffleupagus)
Estimable Member
RE: Partial BRIM possible - not around the entire object?

@steve-13

 

It is possible to add an actual brim exactly as you show to only part of an Object in Slic3r.

Attach a Zipped copy of your saved PrusaSlicer project .3mf and I will demonstrate.

The project file must be zipped or the forum servers will not allow it to be posted.

 

Regards

Napsal : 05/04/2025 8:47 pm
John Lindo
(@john-lindo)
Trusted Member
RE: Partial BRIM possible - not around the entire object?

Split the part into 2 pieces, add male/ female tenons and glue together, you maybe able to print the 2 parts at the same time. 

I have added a photo of a box and lid that I split , see jig saw tenons and serrated tenons.

Napsal : 06/04/2025 3:29 am
John Lindo
(@john-lindo)
Trusted Member
RE: Partial BRIM possible - not around the entire object?

I have added a screen shot of a very large base of a box I 3D printed in 4 parts, using a typical woodworkers male/female tenons, 

The irregular shape I designed to put in my mill circular table, keeps the crud and moisture out. The lid also was printed in 4 parts.

I hope of interest and this gives you some ideas.

Napsal : 06/04/2025 4:05 am
steve
(@steve-13)
Trusted Member
Topic starter answered:
RE: Partial BRIM possible - not around the entire object?

Thank you for the quick response - I've attached the top and bottom pieces in ZIPped format. I appreciate you taking the time to demonstrate using Slic3r.

On that note - I use PRUSA slicer for the obvious ease and compatibility with my multiple PRUSA printers; would you recommend Slic3r generally? Or in situations like this where you need to fill a gap from the PRUSA slicer? When using Slic3r are there PRUSA profiles or any best known methods for configuration setup?

Are there any other common situations where someone uses Slic3r over PRUSA slicer?

Thanks!

Napsal : 06/04/2025 2:48 pm
steve
(@steve-13)
Trusted Member
Topic starter answered:
RE: Partial BRIM possible - not around the entire object?

Thank you @john-lindo for the response and screen shots, the tenons are very impressive especially since you need to get the tolerances just right to do that well.

I considered splitting this plate in two however it's part of a home beer-brewing key scale and is "load-bearing"; it needs to durable enough to support a fairly heavy metal beer keg going on and off of it over it's lifespan. Without some type of structure underneath I'm worried that any joint just won't hold up. Any type of structure (e.g. "joists") would increase the Z dimension which could be problematic as the keg sits in a small refrigerator and is height-limited (but it might be possible).

I appreciate the idea!

Napsal : 06/04/2025 2:57 pm
John Lindo
(@john-lindo)
Trusted Member
RE: Partial BRIM possible - not around the entire object?

That must be some heavy beer you are brewing.  LOL.

The 150 mm dia mill circular table weighs including the handwheel bolted to the top of the circular table to help lift out of the box is 22 kg.

The base of the box is 3 mm thick. Not failed yet after 3 years. 

All your forces when loading a beer keg into the fridge will be downward, hoping you load the keg on a flat rack surface, the rack in the fridge would be 

the first to break if the keg is to heavy. I hope not, what a waste of good beer. LOL

I allowed 0,25 mm clearance between male and female tenons for glue penetration,  , if you print the 2 parts using the same

printer, then any mis dimensional tolerances will be the same. 

Not sure if you deal in metric, 150 mm is about 6 ".

I lived and worked as a engineer in the USA for 26 years, what an awful set of numbers Imperial is, although I was born in the UK. 

MAGA but please adopt totally metric. It´s so easy, your dollar money count is metric so you are halfway there, LOL.

Napsal : 06/04/2025 3:56 pm
John Lindo
(@john-lindo)
Trusted Member
RE: Partial BRIM possible - not around the entire object?

SECOND PHOTO

Napsal : 06/04/2025 3:57 pm
John Lindo
(@john-lindo)
Trusted Member
RE: Partial BRIM possible - not around the entire object?

Steve

My error. 

I imported the Zip file and it loaded up in Imperial. 

I must of checked the wrong box somewhere when importing . It has never happened before or can I repeat it now.

Napsal : 06/04/2025 5:27 pm
Snuffleupagus
(@snuffleupagus)
Estimable Member
RE: Partial BRIM possible - not around the entire object?

@steve-13

Just in case you didn't notice, or maybe didn't receive it, I sent you a PM.

I know how screwy this forum can be, so I thought I'd mention it here.

Regards

Napsal : 08/04/2025 11:33 pm
John Lindo
(@john-lindo)
Trusted Member
RE: Partial BRIM possible - not around the entire object?

Thanks, how do I view Pm´s ? 

Napsal : 09/04/2025 3:56 am
Sembazuru
(@sembazuru)
Noble Member
RE: Partial BRIM possible - not around the entire object?

I haven't played with this technique yet (I plan to eventually), but check out this video on creating custom brims:

The technique being demonstrated takes advantage of some quirks of PrusaSlicer so I don't know if it still works on modern versions (it is being demonstrated on PrusaSlicer v2.7.1).

See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs

Napsal : 10/04/2025 11:39 pm
steve se líbí
steve
(@steve-13)
Trusted Member
Topic starter answered:
RE: Partial BRIM possible - not around the entire object?

Hey folks - I responded to @snuffleupagus over PM but wanted to respond here also to close out this thread.

The video posted above on creating custom brims is incredibly awesome! My slicer knowledge has always adequate enough to take my models and get them printed, with the most complex settings being filament and infill changes! In other words I would have never in a million years even thought that custom brims might be possible.

Custom brims not only help solve the challenge I had, but can be of value in everyday printing as they allow you to:

  1. Cut down on the material used,
  2. Reduce your print time, and
  3. Reduce the amount of brim cleanup you have to do.

 

In other words - if you ever use a brim you should watch this video!

Big thanks to everyone for chiming in and for the link to the video - if you haven't watched I highly recommend it, it's incredible informative.

Napsal : 15/04/2025 2:00 am
Snuffleupagus se líbí
Brian
(@brian-12)
Prominent Member
RE:

Just model the brim in cad and leave them separate bodies.  In Solidworks you uncheck merge.  I'm sure your cad has something similar. After importing into PS split it into parts.  Then make your brim all perimeters and they'll print as separate bodies.  Then the brim can be easily cut off with a sharp utility blade using the side of your part as a guide.

I've done this lots of times and it works great, it leaves no trace of the brim on the finished part.  I've done lots of custom brim+ mouse ears with a lug of material on them to give it some stiffness.  I got good with this after printing large PETG and ASA parts on the XL.  The large parts shrink and warp much more than on the smaller printers. 

Napsal : 15/04/2025 4:37 am
steve se líbí
Snuffleupagus
(@snuffleupagus)
Estimable Member
RE: Partial BRIM possible - not around the entire object?

@brian-12

I had for years created my brims in the manor you mention and found it to be adequate, however I found the methods shown in the video to be far superior to that, and to any mouse ear tools I've used to date in the popular Slicers, they were nice to have back then, but don't compare in today's world.

Now, not only can we have custom brims in any spot we like and in any shape, we have them with the full control of all the brim settings in Slic3r, and because of the way they are setup, they give us several levels of control over even the regular brim control offered by the software, several examples of this are offered in the video, however not all are mentioned. As well there is a companion video the guy did that shows how to make booleans to remove areas of brim that you might not want, so you can just use the regular brims and just remove the parts you don't like or need, and all of the brims and booleans you make are reusable, in any project. It's also faster to use because they are reusable Just import and place.

 

I'm very thankful to have learned this information, it's definitely worth checking out. 

Regards

Napsal : 15/04/2025 8:08 pm
Brian se líbí
steve
(@steve-13)
Trusted Member
Topic starter answered:
RE: Partial BRIM possible - not around the entire object?

Thanks @brian-12, that makes sense and yes I'm sure I can do that in Blender.

Having tried the exercise in the video I think the big key learning here in all of this, at least for me, is that I never knew or even considered that the - let's call it "brim print" is apparently treated differently by the slicer than what one would call the "normal print". The slicer appears to give the brim special treatment.

I always just thought a brim was normal printing with simply the flow rate and spacing parameters set differently, and of course automatically printed around the perimeter of the object. However the brim seems to be treated differently by the slicer, in that wherever it intersects an object that portion of the brim print is magically deleted. This is why you can have Object A on the build plate with a brim, place Object B with no brim on the build plate and then overlap Object B onto Object A's brim and not get an error regarding overlap because where it would overlap the brim is automatically deleted in that area.

I think once that's known the whole idea of custom brims becomes much simpler, whether they're created using the stock shapes created in Prusa slicer like in the video, or 3D modeling brim parts and adding them to the build plate like Brian mentioned.

Thanks!

 

 

Napsal : 15/04/2025 9:21 pm
Brian se líbí
Share: