Hey all,
I’m working on a lamp base that has flat surfaces at different heights. I am printing face down to minimize overall required overall supports and to have a nice topmost surface. A couple of the other flat surfaces are a few mm below the top surface, meaning, they end up being printed with short supports (since printing upside down).
The challenge I’m trying to resolve is that the actual surface under the support is pretty crappy. It is quite coarse and you can see very coarse layer lines. You can see what I mean in the attached images.
Does anyone have any suggestions for improving this? While I have been 3d modeling and printing for a few months, still a noob compared to the community here.
My main solution to this issue thus far is to design (and print separately) a cover plate over the rough surfaces, but I feel like I’m missing other approaches.
Thanks in advance.
There's some support interface print models that help you calibrate z distances and offsets.
Thank you, will have to find and try them out!
From a design perspective you could design a piece to slide in over the ugly section that prints flat glue into place, you could even make it a design choice with a different color and make it look intentional.
You could try using sharpie as a release agent. Turn on ironing for the top layer of support (it should still work without it, but it makes the surface smooth) and set the support interface distance to zero, then set it to pause after the support finishes and colour in the top of the support. Make sure you don't get sharpie on the actual part, because it will make the layers seperate.
Only downside is that it stains the part, but since you're printing in black it shouldn't be too noticable.
Slice it off, print separately and glue on top
Kind of what I did with the cover I designed and printed :)
Yep this will give the best result with minimal effort
If you're printing PLA, use Petg for supports or vice versa. PETG and PLA come apart really easily and leaves a good surface.
Great if you have a multi-nozzle printer but useless in my experience with a single nozzle.
Even with maxed-out purges, the layer that contains PLA and PETG is always very weak and snaps easily along the layer line.
Up your purge volume by factor 10, then work your way down. If you only have two 2 material changes it is not a lot of waste and the difference is day and night.
I purge to the max that Bambu Studio allows using a support interface layer (PLA<>PETG) and a quick bend always snaps it along the interface layer line.
If there's a way of fixing this, I'd love to know!
Oh shit, no wonder my large print I did a while ago just separated like it had no layer adhesion. Used PETG for the interface on PLA and I thought it was the print orientation or model, but because it was 450g and 12 hours, I didn't bother printing again.
I will say that PLA with PETG supports works VERY well on very small models or where strength won't matter a ton. I printed some straw decorations (the things that go over your reusable straw) and they turned out amazingly with clean surfaces
I would also say; since it hasn't been said already:
That top surface is the money maker, it's what you're presenting to the world. I'd sacrifice 9x the amount of plastic to make the interior all supported so that our top surface is consistently nice everywhere.
Alternatively; this could be a good time to add a big chamfer on one side and print the whole thing at a 45 degree angle. I can't ever justify showing supported surfaces like that; they never look good even with petg interface layer wizardry
Yeah, you and I feel very similarly regarding the quality of what is visible. That’s why I already designed a cover for the rectangular piece. The circular one is also going to be covered (by a lamp assembly). However, I’m using it as an opportunity to learn more so that I can get even better results later with less complexity (on the design side).
I just found out about support interface ironing, it makes a nice smooth interface layer but the layer lines will still show
Can you use two filaments?
I did something similar. I printed using classic supports, 0 tolerances and a different support filament. The print was PETG so my supports were PLA. I wouldn't recommend cutting corners and changing only the support interface material - change both. Your supports may fail if you do only interface and you're likely investing a lot of time to make this work
if you go this route try to using similar color materials because my black supports got a bit into my white PETG print
Sorry, should have included this is my post. Am printing on a BambuLab P1S, no AMS. So using two filaments with the current setup isn’t practical as I would need to do manual filament changes.
I would do what others have recommended, just set the interface material to be the other filament and from what I'm seeing here you should only have six filament swaps.
Thank you, have never explored doing that before. I will have to try some test prints for that.
Would that address the coarseness of the remaining surface under the support or is there something else going on there? It’s so much more coarse than what you normally see on a more finished surface.
It's a game changer, I use it quite often. You essentially create a solid support for the filament to rest on, so you should have much smoother results. you'll have to do a quick Google search to see how you do this without an AMS within your slicer but it should be doable.
Use 3 support interface layers, 0.01mm (not 0.1) interface spacing, and play around with .13 to .18 mm z distance. I don’t print much pla but start on the lower side.
Side note, reading the comments is a trip lol. It’s crazy how Bambu and the AMS has made people forget how to calibrate. iT jUsT wOrKs gUyS :)
Thank you! This will be good guidance for me to learn how to dial this sort of thing in!
No problem bro! Also something I forgot to mention, make sure to tune your bridging settings and set the fan speed to 100% for both the interface and bridge (first later of the print, over the support). For your bridging settings themselves, check this out: https://youtu.be/eaasEkFULKE
shallow supports with PLA are easy to deal with
PETG on the other hand is a nightmare and i hate it
Couple of additional details I missed in the post. I’m printing on a BambuLab P1S, no AMS. Filament is PLA.
Try this:
https://youtu.be/BOG9Li2PXMY?si=R0ODQEcnRfR_Jejb
Print it flipped over and try ironing instead
Couldn't you bridge the whole thing in a single layer and make the rest of the print over that bridged layer? Then punch through that single layer for the holes ofcourse.
I've heard there's a sharpie trick. If you put a stop into your print after the last support interface layer, you can color in the tops with a sharpie for less adhesion.
There's some experiments about increasing flow to create better bridges. You could add a sacrificial wall to the notch in the corner as a pillar for your bridge, then trim it with flush cutters at the end. Could do the same with the through holes in the middle, too. Have them be your pillars.
If strength isn't a concern, print at a 45 degree angle with only enough support to stabilize.
How is the quality of the top surfaces when printed at 45 degrees? I assume good otherwise you wouldn’t suggest?
No different than a vertical wall. If you're set down to .12 or especially .08, it won't be an issue.
Got it, thx. Explains why I sometimes see people printing at 45 :)
What supports are you using? I like snug for this kind of small area
All default support settings - tree.
try normal snug then
First go to Slant3d to get indoctrinated into designing your own supports. Then look up 'perfect bridges' here and on youtube.
Since this is just two spots at specific Z heights, you could def do a manual filament change to have a different material (like PETG) for the interface layers.
I would maybe print in 2 parts. Split the model on the step, and add a lap joint for alignment.
This looks like a good candidate for preprinted supports. Basically you design a support that can drop in. It should be slightly smaller and many people cover the top in painters tape. You add a pause in the g code for when it gets to the level you need support. That way there will be a nice smooth surface with no adhesion.
Thanks for the suggestion. Is this just another component I would design/model then?
It’s the inverse of the cavity that needs to be supported. So if you were doing a cube shaped hole you would model a cube the size of your hole and when your print got to the top of the cavity you would pause the print, pop your support cube in and resume print. It’s a way to get nearly perfect surfaces. It only works in certain cases of which yours would probably be one.
Yup, that’s what I was assuming. So in your example the cube support ends up being another component in the model I would design (or I suppose, could do in the slicer’s limited modeling capability). I foresee many a test print over the remainder of the holiday break! 😀
You could Boolean it fairly easily and then shrink by a small percentage. There’s a guy who’s posted on here before who has gotten some really good results but I can’t remember his name. If you can, either print the support with petg, use painters tape on the top or sharpie it so it doesn’t fuse to the model.
Use a 100% support interface, reduce the Z distance (I am currently using a single layer distance), and drop the support interface flow to 80% or lower. Leave enough room beside the supports to slide in a knife blade so you can pry them off. Once you get just a bit of the supports loose, the rest peels right off.