FlyingLotus1983
commented
9 years ago - Trays: Felix and I are going to try and schedule some of Laura's time to do a production-ready version of the SMT trays and some lids, and some way for them to attach to the round carousel plate. I think she will be extremely useful to come up with a DFM version of the actual trays. We only need one part number at this point, that will be the same size and shape as the one we have now. Here's a list of the sub-tasks for the trays:
- [ ] Re-design the existing trays for DFM. We are designing it to be injection molded, although we probably won't buy the mold until after a successful Kickstarter campaign ends and we enter production. We can use SLA version of that part in the meantime, for demos. Sixteen of them in SLA wouldn't have been super expensive IIRC. However, if we are to offer 16 or so per machine to customers, with extras sold separately, then we will need to have them injection molded, the costs to do it any other way are too high. Laura is apparently pretty good in this area so we should use her as a resource.
- [ ] Will need to design a peel-off soft-durometer cover for the trays, similar to a film strip canister but rather the would be stretched a bit in the long dimension to fit over two barbed hooks, one on either end. Noel mentioned a technique to get these done that's much cheaper than injection molding, that can be used for soft durometer parts, and he might even be able to draw this part up for us. He had some great ideas, he understands what we're trying to do, and he's done similar stuff before.
- [ ] We will need to devise a way to better attach the individual trays to the round plate. It might be as simple as making the existing holes smaller so that they don't fit as loosely as they do now. Noel mentioned possibly putting o-rings on the three bosses that hang out from the trays, but I'm not certain that it's easy to put o-rings into a boss because of the way the piece gets ejected from the mold. Either way, we need to decide on something soon so that we can start the final design of the tray and the round plate.
- [ ] Frame Mount: We need determine what the final frame-mount will be. I had an idea last weekend that it should be hinged, so that it can be stowed out of the way when not in use. But at the same time, we don't want to make it too complicated.
- [ ] Round Plate: We need to decide what material to make the round plate out of, and once that and the tray-mounting strategy is decided, we can do final CAD models for it and have one fabbed. I would prefer anodized aluminum here but we would need to get a quote on this before we can say if it makes economic sense to do so. Techron-sprayed Acrylic might be cheaper and I do think that it would be strong enough.
- [ ] ESD safety: We need to design all of these peices to be ESD-safe. For the injection molded pieces, we should be able to spec conductive ABS pellets, etc. Metal is by-nature ESD safe but some coatings are not. Acrylic can be made ESD-safe by spraying with ESD conductive spray, but that's expensive and needs to be accounted for in the BOM. NOTE: I've opened up a separate issue for ESD safety as it applies to the entire machine.
WillD77