Avoid Supports, Sacrificial Layers and Bridging with this clever design technique
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- Опубліковано 8 вер 2024
- Joel Telling at 3D printing Nerd recently had an issue where his bridging included hole perimeters. Joel was designing some draw pulls/handles for the workbench that his dad made for him when he came across this lovely little design problem. There are a couple of ways you can solve this that i discuss in the video, but i think one is definitely the best.
Check out Joel Telling at 3D printing Nerd: / @3dprintingnerd
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I'm SO FREAKING HAPPY I saw this video, man. Such a great solution!
Haha I had no idea you did this and just talked about this in my vid too! Great solution for this problem and great vid. FDM is magical :)
I knew I already saw this method. =)
3D printing is a manufacturing process, and like all manufacturing processes it has it's design tricks. This is the first time I've seen this one, but I love it. But we need a better name for it. I would call it "Layered Bridging".
Well, it does have a rather attractive acronym in NPP-VHOOHT-ALT-TOH-TYWT-BATPTST. Hyphenation added to aid with pronunciation.
Interrupted bridge elimination.
Additive manufacturing
it is the cross-bridging method
Wow. This is amazing. I just tried it. This is so incredibly useful. I have this problem all the time. Thank you. Thank you. Thank you.
Oh man, this is exactly what i needed. But my part has a 50mm diam unsupported hole in the top (it's a rack to hold centrifuge tubes). I felt with the rectangle-square method that there would still be too much droopage. So I did a third cutout in the shape of an octagon and it's perfect!
so for the 3rd cutout, imagine repeating the second cutout (the square), but rotated 45 degrees. But don't cutout the whole square this time, just the octagon formed by the previous square the rotated one.
I started using sacrificial layers last year and I'm never going back to supports, you can do almost anything by bridging planes across the hanging areas. Your idea is great, approaching your hanging layer by crossing sacrificial layers is a pretty useful and eficient technique and not that uncommon of a problem (holes hanging on T walls), good video.
doing layer analyses and fixing bridging issues instead of using difficult to remove supports is so Pro.
for some reason cura wants to do the first bridge layer diagonally for me which fs up everything.
I also saw this in the models of the Prusa mk2/3 extruder I found on Thingiverse. Didn't really understand at the time why they did that, but this clears things up!
Clearly explained, nicely demonstrated, and humorously presented as always. Now I know how to put a round peg in a squarish hole. Of course, I'm still stubbornly trying to put square pegs in round holes, so if you have a solution to that, perhaps it can be the subject of a future video.
Lol
I've decided to create a blind hole not sure how Simplify3D will handle it. It worked, it preserved the hole. Going along the path of the machine screw from the bottom (with the part standing up), I have the following: extrusion between the bottom of the part and the bottom of the nut slot, a slot for the nut, an offset blind extrusion that results in a single-layer bridge above the nut slot plus a second hole for the rest of the screw length. If the diameter is correct, you just need to drill through one layer of plastic (0.2 mm in my model) using the bottom hole as the guide. I use three perimeters in my model, which results in only 10 minute longer estimated printing time.
Good job. Interesting approach to an interesting challenge.
Here's another idea...
- First, this is just a concept, i.e. I have not tested it.
- The idea is to use supports, but ones that will come off easily, and cleanly.
- Simplify3D can do such supports:)
- So, I created a simple test model, then sliced it... w/ supports.
- The "trick" is to use 'Extra Inflation Distance'.
- Normally, this is used to extend OUTSIDE the model perimeter to give something to grab onto for removal.
- But, in this case, inside a cavity, it extends the supports INWARD from the hole's perimeter.
- This gives anchors to bridge across.
- Of course, the motion during bridging is curved, so, the first layer or two might be a bit "misshapen", but it stands to reason that an "acceptable" hole could result.
- FYI, I have used support in cavities (sans the hole at issue here) w/ acceptable results.
- The advantage of this method is that it's relatively easy: just add some simple supports; and (in theory) it yields acceptable results:)
If this is a bit difficult to picture, I can post a screenshot from the slice, if anyone is interested.
You can use cone surface to connect any two profiles, use 45 degrees or angle 2:1 (about 63.435 degrees)
For this application you could also put a 45 degree angle on the overhang surface. The extra clearance won’t hurt anything and it’s a much simpler solution. This is what I thought when I seen Joel’s video as it is what I would normally do.
What overhang? This is a bridge not an overhang.
@@alejandroperez5368 You would turn the bridge into an overhang.
In all: a dedicated two layer chamfer. Nice work! "thumbs up"
Very good solution to the problem. For once UA-cam's recommended is useful.
great video thank you! hopefully the youtube algorithm shares this more so more people can design like this!
Brilliant! Thanks mate!
That was a very clever solution. Nice video too.
Solid thinking man.
I love your solution, great Job!
This approach works but has some downsides: It relies on the printing-direction the slicer decides upon as well as the objects orientation. That means that a hole designed in this way will need extra care during slicing.
But when having a first full bridging layer would cause problems then yes this works.
Oh this is great, big thanks!
Really good ideas
Thanks Adam, very well explained. Cheers
The one subtle downside to this approach is that the _model_ is now fixed to a specific layer-height, reducing your freedom in the slicer. I wish there was a nice way to make a model parametric on certain slicer settings.
If you design it for the worst case scenario (highest layer height), then it will still work at higher resolutions, but you would get a couple of extra unnecessary rectangular transition layers rather than just the two shown in the video.
Hey, that is awesome. Thank you! Hope I will remember this next time I need to do something like that ;)
Please install one of those programs that adds to the desktop recording what keyboard shortcuts you are using.
I will certainly remember that tip the next time I have a cut a hole in an overhang.
awesome. this is genius!
you are genius!!!
Very nice, love this way of thinking! How robust is this design against other FDM 3D printer settings like alternate layer heights?
This is brilliant.
Great solution, tks
Great work!
oh my very good
Yeah..but you have to figure it out how your slicer is going to bridge in that particular layer..I mean, you have do cad it, slice it, and cad it again..another solution cold be adding 45 degree angle walls up to the round one. But yes, a great solution!
Nice channel you have here ... And great solution too ! Love it :)
nice trick!
Great tip.
Greatly solution!
printing in that orientation would appear to be the weakest way to do it given the potential leverage of that handle. and circles can easier be printed vertically, and the point the hex nut recess makes would also be more like a vaulted ceiling and bridging would almost be avoided completely as far as i could tell. but still this is a good example for ideas, valuable video.
good thing to have in the backpocket but i prefer filling hole for one layer, faster, and doesnt take much time to punch it later. but if I was doing tons of prints this would be a time saver
I've done something similar to brake up a bridge, so that they don't have to span as far.
You could have raised the hole up a bit. And then put a chancre on the underside of the two outer edges of the circle. To meet the edge of the wall where the nut is going to sit against.
mind blown
print it on its side?
tensile strength will be lengthwise and in line with the actioning of the handle.
even the slight height difference in the bottom edge and the rounded top should print fine without supports...
How to rotate bridges to 45 degrees?
Really cool
Did you come up with this on your own? I noticed Prusa uses basically the same method on the MK 3 parts.
Wow, Thanks for sharing :-)
Slic3r PE adds supports just under the edges that need it and the rest is bridged...
Why not loft between the initial square cutout and a round hole a few layers up?
You have to loft way up, controling 45 degree (or litlle more )overhangs
Bridge with 8 thin filaments that cross in center. You can poke them out.
Cool solution, but would problems arise if you design the solution at 0.2mm and then slice at 0.15mm layer height? Also why not a hollow cylinder with a wall thickness that is the same as the nozzle hole or extrusion width (0.4mm) and just have a gap at the top (and bottom) 0.1 or 0.2mm for easier removal. It will be like custom designed supports that will be a lot easier to remove compared to automatically generated ones. Although with good settings in a slicer with manual editing of supports I can use supports and easily remove them. I have tried this successfully with nut holes for M3 nuts and screw, but I am not sure if it would work for smaller nut sizes. Can someone explain why popular slicers like CURA and slic3r still don't have manual editing of supports, since free slicers like craftware and ideamaker have this feature for 2+ years?
@@Vector3DP Really, this would be a neat feature in a slicer.
Alternatively, I often start a design with "layer height" variable, making it easier to update a part by making one tweak.
Nice
".... SO YES!"
Why not just use a brass insert?
Brilliant. Insta sub.
Like it. However, I personally like Joel's way better. Too many mouse clicks when, with Joel's way you click to convert the circle into a sketch entity and then click on the drill trigger to clean the hole. Clicking on the drill trigger is already something you have a high probability in doing anyways.
Glad someone else shouts at their tech problems, like the computer understands us!
U use MCM music lol :)
wish slicers did that themselves
Supports?
Yes, supports can be a pain. Anyway support pattern line are easy to remove
I'm trying to resolve this issue in slic3r, see github.com/slic3r/Slic3r/issues/4476 for info & pics. Still a it wip, but If you want to test, you can download here github.com/supermerill/Slic3r/releases
This could also be titled "How to get UA-cam subscribers in one video"
I mean cool, but it’s a hidden relief hole, why not make it all square?
In the case of the square-nut pockets in the Prusa parts, you might want more material against the sides of the nuts. You might also want to avoid all the questions from customers about why the parts have square holes for round screws. And maybe you just think round holes look better. But now that you've pointed this out, I'm going to really struggle the next time I'm faced with this problem, choosing between the simplicity of a square hole and the aesthetics of a round one.
MikeMike but with this one, it was against the thread, the other side of the nut, not the nut, which itself has a nice V groove to sit in..
Stephen Mott Aw, nuts. Your point is well taken. You're right in the case of the drawer pulls, but not necessarily in the case of the Prusa parts. Actually, I don't like the whole nut-pocket thing. The nuts in my Prusa parts kept falling out when I was trying to assemble my printers, and I wound up putting tape over some of the slots. Not cool. Printed threads? Tapped holes? Embedded nuts? Threaded inserts? Screwerk screws? I guess it depends on the part. All the options make my head swim.
C.R.T isn’t the skill there knowing what the specific slicer is going to do without support? And then if your into designing around how things slice, square is often better than a curve..
I would have just printed it on its side lol
why not just make the second hole square? later just temper it to a point at 45deg overhang. its not visible nor functional, justmaking life harder
Wow! Seems way too complicated.
Have you look at 'Lofts' ??
Just start with a rectangle hole like you did on you first layer and then use loft to a higher layer with a round hole. If the angle of the loft is at least 45, the print will have no problems.
BUT My ultimate question is: why do you need a round hole on that side of the nut slot anyway? Rectangle would do nicely, its just to give the screw someplace to go after feeding through the nut. And it sure doesn't need to be the same size as the screw. Just extend it to the wall thickness.
I dunno, maybe I'm missing something, but this sure seems overly complicated.
Nope!
It's just as ghastly a "solution".
The solution is not to design such poor parts.