Has anyone looked into small scale injection molding with 3d printed resins? Seems like the molds are good for <1000 quantity of parts which, at the scale esk8 is at, would make sense for things like custom connectors or similar. Upfront costs are looking like $4.5k for a small scale injection molding machine and a resin printer + resin. Formlabs post here: DIY Injection Molding: How to Mold Plastic Parts In-House
They also included a white paper in the post detailing the process.
Obviously parts would end up pretty expensive to hit cost parity but would be pretty cool for small scale production runs. I personally would really like to try this out for something (MR69 @BenjaminF), but I don’t currently have the capital to drop on something like this.
Connectors or something else small scale would be a really cool project to attempt if someone here has the experience in injection molding to apply to something like this.
Well I guess I’ll definitely be reaching out if 5 grand and a shop falls in my lap
But seriously, how viable do you think this process would be? I was thinking an overmold of the bullet connectors but I haven’t actually designed parts intended for injection molding before.
This would be awesome. I’m fumbling through a 3D printed panel mount MR60 and it would be great to have “real” ones available. Make a Kickstarter for it if it sounds viable?
It’s super easy. I almost took a video of the process earlier and now I’m bummed because they’re not scheduled to run for another week or so.
Bkv nylon would be my recommendation for material choice off the top of my head.
No promises but I may be able to find a decommissioned mold block with enough space for both core halves needed and the runners. We just cleared out a bunch of old molds to make space for 2 new injection machines.
No idea how they do it but the china guys do it apparently. Quality is pretty good too. However ive heard they save a lot of costs by using manual extraction etc.
It would be nice to see ESK8 parts made in the US instead of China. I think pulleys are injection molded. What are parts in ESK8 are commonly injection molded? Wheel cores? RIms? Anything else?
Pretty much all plastic parts are injection molded unless they are flat and can be water jet/cnc’ed. Wheel pulleys can be injection molded if made of a strong enough material (nylon, etc.). Motor pulleys on the other hand I have not seen in plastic except for the PEEK ones that @Skyart was testing out in a 3dservisas drive.
And PEEK is expensive
Also for my take, studied mold design and plastics engineering (a few years back tho), 3D printed cavities are great for prototyping in a production environment, but it’s a lot slower than standard injection molding, extra care has to be taken when designing and during production or you can easily destroy the cores (you basically inject in an insulator)… Resins that are good for mold cavities are expensive and they also need post processing, good when you need to make iterations but most of the time machining an aluminium cavity will be cheaper and get you better parts than printing cores ^^
At least that was the conclusion from someone I studied with and that worked on this as their internship project for more than a year in a big company.
If you want a small run of nylon parts, it can also be vacuum casted with special equipment, some companies do that
That’s something I have not thought of, machined and water jest cut plastic. There are some really tough and durable plastic like the nylon kind. Just leaned about PEEK from you guys today. I thing there are also plastics that are reinforced with carbon fiber strands. If you knew the right people you could make many of the parts made overseas here in the USA. It would be really nice to be able to support the domestic economy.
The biggest issue with injection molding and esk8 is the limited quantity we buy in. We could get parts made for ultra cheap but the up front ~$5k mold cost sets a far finish line for making back the money.
Say we could make MR69s for $0.02 per connector in bulk cost, you charge a few bucks per connector and make 99.9% profit more or less. That’s still ~1.5k connectors needed to be sold just to break even. It’s a big lump to swallow for a lot of people!
Meanwhile, I just got the prints today for 16 new molds from one company for a new product
), but I don’t currently have the capital to drop on something like this.
