Stop Snapping Your Snap Fits | Design for Mass Production 3D Printing

[@florianrudowable]

Calculation engineer here. Ways to make a clip more resistant to breaking: 1) Reduce the undercut of the clip (smaller “nose”) 2) Use material with a small E module (soft) 3) Reduce! the thickness of the cantilever (not intuitive! Then it bends more easily) 4) Increase the length of the cantilever (not intuitive and very strong influence, long clips bend much easier with less load on the material) 5) Use material with high strength (good connection quality between the layers, not the same as E modolus!) 5.1 -> Strong Layer Adhesion 5.2 -> Tilted Layers with strong direction towards tip of clip 5.3 -> Cone Shaped Clips with more material at foot than at tip

[@instantmuffin5]

I have designed and printed a part like this. I would like to add some additional points. 1) Reduce the thickness of the bending straw/base, but make it wider. Increasing the thickness is an intuitive mistake because while more surface area increases adhesion, it also makes the part more stiff and therefore less bendable and more brittle, and the separation force becomes higher on the outer wall because that part needs to stretch upwards more. 2) Instead of a rectangular or chamfered design for the head, use a narrow P shape instead. The rounding/fillet creates a good variation in bending force and angle upon insertion. Experiment with protrusion of the head and the fillet's maximum angle.

[@instantmuffin5]

Addition to 2). The P shape also reduces wear and allows for easier assembly and disassembly.

[@cosmic_cupcake]

yes. make it thin, make it wide, and make it long. And don't oversize the tongues for the amount of strength you need

[@conorstewart2214]

The shape of head depends on what it needs to do. A P shape is good for things that need to be taken apart again whereas a flat bottom face is good for things that aren’t supposed to come out again.

[@ГеоргийМефодьев]

Из своего опыта скажу что проще и надёжнее поменять материал на твердую или армированную резину, чем шаманить со слоями. Нейлоном печатать заморочно. Можно и сборную делать сделать часть резина часть пластик.

[@jessedowling1263]

Might want to revise that 'add a fillet to the bottom' to add a chamfer... fillets on first layers are never great.

[@takatamiyagawa5688]

1:33 Yeah, the way that's depicted, it technically creates a 90 degree slope angle at the bottom of the fillet. It'll print, but not quite as modelled. I thought elephant foot compensation was a task for the slicer, not the 3d model.

[@DrewLSsix]

​@takatamiyagawa5688 in a production setting, do everything you can in the model. Imo including supports in some cases.

[@UncleRedz]

Slant 3D has another video on snap fits, where they deminstrate that the bending part of a snap fit doesn't have to be in the same direction as the snap fit part it self. In this case, you can design the bending to be horizontal and still have the snap fit vertical. That was an eye opener, and its super useful when designing parts.

[@meanman6992]

Fillets, they prevent stress points

[@lajoyalobos2009]

Fillets, fillets everywhere

[@eggblight_ganon]

Avoid sharp corners in design

[@AckzaTV]

What's that?

[@lajoyalobos2009]

@@AckzaTV avoid 90 degree angles whenever possible as the corners are where cracks like to form. Rounded corners displace force more evenly than sharp corners

[@TheOfficialOriginalChad]

Eh, fillets have their place, but top surfaces is not one of them.

[@Splarkszter]

Finally you include "But what if you HAVE to print it like this" THANK YOU!

[@petermuller608]

Dude, the amount of knowledge you give out for free is huge! Thanks

[@slant3d]

Glad you think so!

[@curtis545454]

Further thoughts from a strength of materials perspective. This may be overkill for most people/designs. 1. Longer snap brackets mean less force is needed to deflect the bracket, and that means less stress on the material which leads to breaks. 2. Stress on the part, and location of failure, is concentrated on the base of the bracket. To spread out the stress, design the bracket with an ~15 degree taper (larger at base, smaller going towards snap feature). This will give you more snap force, more deflection, and less likely to fail. 3. Thickness vs. Width. The thickness of the bracket has much more of an impact on deflection force than the width. Try bending a ruler a few different ways (or something similarly flat) to see this in action. 4. Backstops. The bracket cannot break if you have a backstop that doesn't allow the bracket to bend far enough to break. Other features that protect the bracket can be helpful. 5. All snap brackets made to date are not optimized for 3D printing, so be creative! Your only cost is design time. A more in depth guide that can be a good reference. I wouldn't worry about calculations for most things, just the ideas behind it. fab.cba.mit.edu/classes/S62.12/people/vernelle.noel/Plastic_Snap_fit_design.pdf

[@tonyharion9816]

Great addition! Cheers!

[@newmonengineering]

If you want stronger, make them a seperate part, print them in the other direction laying down, then glue them on or screw them on. That is odd course if you absolutely need to.

[@georgestone8099]

I recently discovered the 45 degree trick for clips like that. Makes a MASSIVE difference to the tensile strength of them. I do it less steep than 45 degrees to keep quality high, and it still gives me great strength on small features like that.

[@Loosecannon16]

Last year I did a part like this, I used a multi-part approach: printed the ring flat (it was threaded inside), and those tabs, i printed separately with them flat on the bed, they had one caveat: they fit with a dovetail type connection. I joined them using epoxy glue and a rubber mallet. Overengineered? Sure! But its holding better than the original injected part.

[@erkishhorde]

Another small thing that can help is filleting the distal end of the clip to give it a small ramp to slide up while it's bending to fit inside the other part. This reduces the amount of time that the clip is at maximum flexion while pushing the parts together which can help a little. It also makes it a little easier to start the 2 parts going together and then you just give it a little bop and they pop together.

[@Karma-rb1vf]

Great info. Thank you for always sharing and increasing the knowledge of the community. The thing I would change is instead of a filet at the bottom where the part meets the bed I would use a 45 degree chamfer. This is because a radius starts at an overhang of 90 degrees. You can chamfer the bottom and then radius the top edge of the chamfer so it is a radius that starts at a 45 degree overhang.

[@bliantfive]

Thanks for showing that print. Now I feel better about mine. I hate when it's always a perfect one in a hundred print of a perfectly calibrated printer. This is how most prints will look like and that's fine.

[@jeltesteur8286]

Here's another solution i came up with the other day: attach the snaps all around with a ring at the top. the ring will deform, but not when it's connected to the ring at the base. it will become too stiff that way. so below the ring is a 45 degree chamfer leading down to a very thin ring just for support (0.4mm thick in my case). this is standing on top of the base ring. the very thin support is interupted at the snap hook 'pillars' by a slot while the top ring bridges those slots and is continuous. Wish i could add a picture here... works like a charm. allows for a flat on the bed position.

[@teardowndan5364]

If I had to join parts using some type of snap that has to handle relatively significant forces, I'd make pockets into both parts to accommodate separately printed hourglass-shaped "cookies" that snap into both sides. Then all parts can be printed in their optimal orientation instead of making compromises specifically to accommodate connectors and the pulling force across joinery is distributed dozens of layers deep into both sides. If the parts need to be taken apart, include some ejection holes to help with pushing the cookies out.

[@bj_]

I typically chamfer the bottom edges instead of filleting them so every layer in the chamfer has the same perimeter overhang instead of laying down most of that overhang on the second layer

[@PaulHopkins-nl2hx]

The real reason that the features break at the interface, is because of the toolpath pattern change. The same toolpath pattern (mainly the perimeters) on top of each other is the strongest bonding pattern. If you want a stronger pin, design the pin feature into the part, with a very small gap between. Then the pin feature is anchored in the part and the pin toolpath (perimeter) is the same in the part.

[@TioDave]

I've been working on a part similar to this. I've been printing it out of ABS and found that turning up the nozzle temp made a big difference. I also added fillets, which increased the rigidity. That in turn made reducing the catch size. I wrote off printing at an angle, because the part is so small and printing at an angle would add much difficulty. I'll have to think about it again and use some of your techniques to see if I can make it work.

[@AuxHex]

If changing orientation is not an option, but changing the material is, then TPU will provide the best layer adhesion. Rigidity can be improved by using rigid TPU with a rating above 95A.

[@Liberty4Ever]

Still loving these quick 3D printing design tips. I've been doing this a long time and learn something from every video I particularly liked the composite image at 4:55 that showed all of the design iterations chronologically from left to right.

[@ronshapper]

Also a longer clip has to reform les per length unit resulting in less stress. So you can make the pins run longer by cutting in the ring

[@h.y-chen]

I would just split the hook and ring , put 4 hole on ring and print 4 hook horizontally than glue together or use some one-time joint design

[@absolutelydahling7217]

A little over engineered in my opinion. Another option is to print on the side and add mock tree support into your model to handle the overhangs. There would likely be no inherent advantage aside from keeping a closer model to the original design, and potentially a bit less filament. Overall though solid advice and great content delivery. Excited to see more from your channel 🎉

[@conorstewart2214]

If I had to use snap clips like this I would split the part up, print the ring separately and print the clips separately so that the clips could be printed on their side and then slotted into the ring or glued, that also allows different materials to be used for the ring and clips. I know this isn’t a good option for mass manufacturing though due to the post processing and assembly.

[@kylekeith2285]

What modeling software is being used in this video?

[@Dr.Papanak]

I think it's Shapr3D.

[@falsenamen5002]

Your models are 11/10, It's only kinda sad the print quality isn't doing it justice

[@nubnubbud]

I make separate snaps. you print them separately, but they just snap in.

[@BramCohen]

Your suggestions about printing at funny angles always seemed odd to me when using a Prusa MK3 but since I got a Bambu X1 Carbon I've been using that technique a lot and it works great.

[@marcopolo1613]

Chamfer the bottom edge at a 45 degrees, not a round fillet, you will get a much cleaner edge.

[@tonyharion9816]

I truly appreciate these design for 3D printing videos! They are awesome!

[@SergeyRyabenko]

Every minute counts. Great video, I had this issue but was too lazy to figure it out.

[@olafmarzocchi6194]

Make it multipart: the clips are printed flat on the bed and the ring has slots so you can press fit the clips on it

[@rpenm]

Have you considered compiling these design tips into a reference document or wiki somewhere?

[@slant3d]

This channel

[@TheStuartstardust]

@slant3d what is your modelling tool?

[@Dr.Papanak]

Pretty sure it's Shapr3D.

[@jasongooden917]

one way to strengthen those clips is to design a hole all the way through it vertically. the slicer will see the hole as a wall and add wall thickness around the hole.

[@BlackICE1973]

another way is to use bigger nozzle. e. g. with 0.6mm nozzle you will get much better layer bonding.

[@Braincho]

Hi! Nice video like always. What can be done to make holes be more precise? I know about hole horizontal expansion, but what to do with non horizontal holes? Have a 3D shape as a cube, but with 8 sides instead - so how would you suggest to make holes with better and exact size? (Cura slicer and Ender3pro printer) Thanks!!!

[@deltafactory]

Is there a rule of thumb for optimal first layer surface area for your print farm, specifically the min/max for part adhesion and auto-ejection? Curious to know if you have any data on this, or even just gut reaction based on experience.

[@MAXimator70]

This channel is pure gold to me, thank you so much!

[@slant3d]

Glad you enjoy it!

[@slavikarg]

leave 1 or 2 small holes in every clip & insert a piece of steel needle

[@rosserobertolli]

These are all not the best option in my opinion, there is a lot of overhang combined with little bed adhesion. In my opinion the best way is to make those clips stronger and connect them to the main body with flat bridges that can twist for the desired flexibility

[@davorinrusevljan6440]

when you do printing and shipping directly to the end customer, how is post processing handled, like removing some parts of design that were included just to make it more printable, but should be removed in in the end product? Do you make custom quote on that?

[@cpk001]

Great videos. Which 3D design software did you use in this video?

[@Dr.Papanak]

It's Shapr3D.

[@jamesgates1074]

How about some kind of integrated spring connecting the snap?

[@daveoliver3909]

Clear and concise. Great content again.

[@slant3d]

Glad you enjoyed it

[@evanrhildreth]

Just avoid tabs. Print holes and tap them for screws, or use self-taping screws. Screws are secure and a sign of quality.

[@Pluto1010]

For me, these kind of videos are super helpful! Thank you 👍

[@AckzaTV]

Does bambu studio have chamfering? I wish slicers just had all these things i could just live in the slicer ... theres not that many things a slicer needs to replace most of what blender does for most people

[@IanBradbury]

Awesome. Simple yet effective solutions. Thanks.

[@radicsferi]

Newby here. 0:47 So we should use PETG instead of PLA. But layer adhesion strength tests on youtube prove that PLA works way better than PETG. Am I the only one who confused because of this? 🙄

[@kevinbowker2385]

Many thanks for sharing your knowledge!

[@Sembazuru]

Filleting the bottom edges? I though chamfer was better for that so you don't have to worry about extreme overhangs on the 2nd and 3rd layers.

[@hristoilchev]

I would just print the pins separate and flat and then glue them or slide in to hole in the ring.

[@kevzor64]

You never want a fillet on the bottom layer of a 3D printed part, that's like day one knowledge.

[@Hesous]

I see where you are coming from, and it's a good practice but a very small filet(like 2 to 3 layers high) actually gives a better result than a chamfer

[@nomojo1110]

This information is greatly appreciated :) Thank you.

[@DailyFrankPeter]

how about pinning it and heating the pin up

[@CADclassOfficial]

Love your stuff man!

[@CraigHollabaugh]

I always takeaway tips from your videos, thanks!

[@TS_Mind_Swept]

1:31 What do you mean fillet the lower edge? If that's on the print bed that's terrible.. (you've said it yourself..6.6)

[@tonyrivera6575]

Personally, I would print the clips separately laying flat and just insert them

[@fokushodl52103]

Movie about making/designing own supports? 🙏

[@LightOfReason7]

Good video and great ideas!

What's the software for designing?

[@Dr.Papanak]

Shapr3D

[@josephcatano4705]

I feel like I need a resin printer to make these prints a little easier.

[@slaughterman44]

is it supposed to look so rough?

[@montanaharkin]

Great tips!

[@AckzaTV]

Theres a cannabis grinder design with teeth that snap right off, how can that deaign be improved? I was really wondering, because in a tobaco grinder for example its like the teeth have to pass by each other etc, the teeth are just printed on layers. Ok chamfers? How do i add changers in bambustudio witjout just adding a triangle overlayed lol

[@andrewsad1]

I can't imagine plastic is the best material for a cannabis grinder, let alone 3D printed plastic. I'm not very good at 3D design, but if I absolutely _had_ to print out a 3D printed grinder, I personally would print it as vertically as I can without the teeth needing support. Don't want the tips of the teeth delaminating and getting mixed up with what you're about to smoke. But like. If you have access to a 3D printer, surely you have access to a vape shop that can sell you a nice metal tobacco grinder for cheap

[@maxmax4081]

some great ideas, thanks

[@smyperformance5223]

What application do you use?

[@slant3d]

Shapr

[@MakeKasprzak]

This was a good tip video. 👍

[@slant3d]

Glad it was helpful!

[@_droid]

PETG has better layer adhesion than PLA? First time I've ever heard that. Definitely never seen it.

[@two_number_nines]

TPU is nearly isotropic. If possible always print in TPU

[@alejandroperez5368]

@@two_number_nines Huh? LOL

[@georgestone8099]

@@two_number_nines Yep, TPU is massively underrated as a material. People think of it as only something used when you need something that's flexible but print with 6 walls and 25% infill and you'll have a very solid and extremely strong part.

[@ericolofsson]

From what ive seen. And of cnc kitchens tests ilts about the same but PETG will alow it to flex, while pla will crack and snap. PETGs adheasion are a bit more sensetive to printing temperature it likes it hot, printing with low cooling and a chamber. There also are a tendecy for people to under extrude PETG since it compresses and often behaves differently in the extruder.

[@user-yk1cw8im4h]

PETG is a lot stickier for sure, not sure why that’s even a question. Have you never once printed yourself and just “see” stuff on KZbin?

[@ZacHartley]

Great Video!

[@foebelboo]

when matte black filament

[@musikSkool]

Diagonal. Trust me, he's an Engineer.

[@yaritebaba]

Instead of FDM printing do it with SLS.

[@pedrohenriqueboscofi]

The "diego"nal side

[@UltimatePerfection]

I wish we had actual 3d printing and not just bunch of 2d prints stacked on top of each other.

[@GuardianLords]

If tolerances are really high*

[@Maisonier]

Amazing video! Liked and subscribed.

[@slant3d]

Thanks for the sub!

[@ulamss5]

Title implies alternative designs to snap fits, video content is about changing printing orientations and other minor design additions to reinforce snap fits.

[@ahmadhasan3258]

His printers are bad if they simply can't print bridges lol

[@antonkukoba3378]

PETG is worse from the layer adhesion standpoint. PETG just bends a bit better.

[@slant3d]

If you have petg layer adhesion problems you are printing it wrong.

[@lajoyalobos2009]

Hot PETG is very sticky stuff, almost too sticky. You may be overcooling it and/or have low nozzle temperature if you have layer adhesion issues. I print it at an absolute minimum of 240 C and oftentimes even hotter than that.

[@МУЅТ]

@@slant3dhe didn’t say he had adhesion problems with petg he said it’s worse than pla

[@wafflecart]

Never on any print have I needed a fillet on the layer in contact with the bed I think this is bad advice and only for old printers and software, plus it makes ugly overhangs. Modern ones solve this problem by #1 compensating for that expansion, and #2 using a load cell to get a perfect z height every time.

[@StasonKalbason]

Молодцом!

[@KnugLidi]

or don't use FDM

[@logitech4873]

What's up with your print quality? Looks terrible. And why would you round the bottom edges like that? Use chamfers!

[@wensz1]

So... from round we came to shitty octagon. With uneven tabs.

[@Karaon]

well it’s still doing the same thing avoiding issues with layers, but if you fancy it round, just go for it

[@cryptodutch1949]

That’s what design for production is about though, shaping your product so it strikes a balance between aesthetics, function and compatibility with the production method. (And a lot more)

[@jamesdibelka6718]

First!

[@ethanphillips447]

You know why don't we cut the trash comments and actually provide some insight or a more effective technique

[@SK-S2N]

Please talk slowly or give some gaps between your sentences.

[@HastaLM1987]

Но в таком случае кольцо становится очень слабым. Мой вариант который использую всегда на всяких защелках: 1. Печать кольца лежа как положено что бы оно было гибким и в то же время прочным. 2. Печать отдельно защелок с учетом вектора нагрузки. 3. Склеивание дихлорметаном кольца и защелки. Сотни таких деталей делал и сломать её можно только по тупости...

[@Uncle_Baby_Billy]

Great video!