Hello, I have an idea for a bike thing that I'd like to prototype that would need some kind of sturdy snap on / off fastener, a bit like a snap lock buckle mechanism perhaps. My questions are: a) what sort of plastics are suitable for that kind of use i.e. flexible and fatigue resistant and b) can they be 3d printed either for prototyping or production use? Advice appreciated. Cheers
I'd suggest designing whatever it is around a buckle/bracket/whatever that you can get off the shelf.
I do quite a lot of 3D printing at work and when the parts end up in daily use they end up quite disposable unless really over built (and it's the volume of plastic used that defines the time it takes to print so you can't just overbuild stuff if you want to scale up for production). Great if you wanted a one off before committing to a injection molding.
3D printed Nylon can work well.
Best going to shapeways or similar and getting it done rather than trying yourself as it's quite picky.
thanks, that was another thought and I've just had an idea of how to make it simpler... maybe. Is there a on-stop-shop for all my potential fastening needs that you know of?
Depends what you want to fasten?
For brackets etc try RS or Farrell? For buckles for luggage, clothing etc try places that sell outdoors material (Pennine outdoors etc) as they usually have a variety of bits. Or just trawl alibaba / aliexpress until you find a supplier.
thanks, I'll take a look through those and see if there's something that would do the job. I basically need to be able to attach one end of the clip to an M4 bolt and the other end to something flat via a bolt or surface attachment / adhesive.
If you can find exactly what you need off the shelf, that's obviously gonna be easiest.
You could definitely use something 3D printed for prototyping, things can be made flexible or rigid depending how're they're designed. I have been very impressed with how strong parts can be made (not even using specialist materials i.e. nylon etc).
Whether they'd last long term I couldn't say. I know I guy who made his own fatigue testing rig with an Arduino and a few steppers, it was very clever but also pretty simple!
thanks, I’ll take a look through those and see if there’s something that would do the job. I basically need to be able to attach one end of the clip to an M4 bolt and the other end to something flat via a bolt or surface attachment / adhesive.
As an example, I had a 3d printed handlebar mount for a magicshine type light. Despite the bolt (M3 i think?) being bery securely encased in the printed plastic, after about 6 months it eventually pulled out, the layers of plastic just began to pull apart with the weight of the lamp swinging around on top.
If it were me, I'd look carefully at the design and try and come up with something easily fabricated or a way of using something off the shelf.
Especially if you want to sell it. I can guarantee that 3D printing will make something, but it's more likely to be fragile, expansive, slow to manufacture and breakable than actually work. Especially if you use the words "clip" and "adhesive". A lot of plastics (including ABS and Nylon) have very low surface energies so despite the characteristically rough surface produced by 3D printing are a nightmare to find a glue that will adhere to them. And clip implies small areas of contact, and while 3D printed parts can be quite strong, you're limited to the tensile strength
of the least well bonded layers when printing.
For prototyping purposes, something 3-D printed will more than likely be fine.
I have printed stuff at work using PLA that has lasted pretty well, although we have also tried other filaments like PETG, PC and a few different nylon variants.
The thing is, PLA is dead easy to get pretty good results with. Virtually all the other materials have been a lot more finicky with regard to settings and getting good results has been more difficult.
Depends on the specifics of the design, something printed out of PLA could work fine for prototyping purposes. You could even modify the part design to suit 3-D printing just to prove the concept & then have a specific design for something like injection moulding if you went down that route.
I have printed several things for myself & friends out of PLA that are still going strong over a year later.
Good info, thanks a lot guys. You may be right that an off the shelf fastener would be simpler or a lower tech solution as proof of concept before trying to make something more finished.
It's given me some ideas to pursue so cheers !
Thing most people dont talk about is orientatiin of print. If you align the layers with the force applied you effectivly use the tensile strength of the polymer as opposed to the bond strength of the layers. You could always coat with epoxy resin (paint brush should be fine) making a sort of composite skin.
I've only used PLA though did try abs but it was too tempremental and PLA just worked.
Some useful info on 3d printing material properties here.
If you have a model worked up already you can upload it and get a price for your chosen material too...