Here are some pics of a particular motorcycle tail light I want to replicate.
The back
The front
Iso view of front
To answer specifics:
Turmite, the thing is - these are already molded parts - so things like draft angles, thicknesses, etc have already been designed in. I have not modeled the part, because it's a relatively complex 3D shape, and it would take almost no time to laser scan it, whereas if I put it on the machine and uses the probe head, it would take hours if not days and whomever was gonna mold it would be re-doing it anyway
mc_n_g - I thought the variables were pretty constrained? I dunno, maybe I am wrong. In the case of the pics I posted, I want exactly what is shown. There are a few cases where instead of a mounting boss in one place, I want it in another place, or instead of a tab that slides through a board, I want a mounting boss. But nothing that would complicate the mold design (actually everything I'd change would make it easier).
Inspiration - the problem with that is firstly that vibratory finishing them would round all the edges, which will make the lens look like crap (i.e. won't do any diffusion really). Secondly, the light is maybe 5" wide, 4" high, and about 5" deep. So we'd be talking a BIG chunk of acrylic to start with, and many hours of machining. And I can't even imagine machining a few thousand of 'em
I was wondering if there was some acrylic casting process, although I don't think there is.
I know you can cast resin, but not with the clarity I need. I also had considered thermoforming. Maybe taking a flat sheet of 1/8" acrylic, and heating it up until it's pliable, then putting it on a positive image of the inside of that tail light, letting it "droop" over it, then clamping on a top section such that the cavity between is exactly what I want my finishe part to be. But I figure if it was as easy as that, then such parts as above would not be injection molded.
Thing is - the fact remains that various manufacturers make these. I used to sell some and I know the market is a thousand a year MAYBE on a hot seller, and the products run from 2 to 4 years in production. Other companies sell these parts for a price that lets me know there is only a few bucks in the plastic parts at most. So I'm wondering if I can approach a price of perhaps $10/part (part meaning clear front and plastic back) by having someone do the molding for me? Or if I would have to do the molding in-house to get that level of price?
Same with machining I guess... we have a lot of AL parts we make. If I had to outsource them, I could never make them at a cost that allows me to sell them on to distributors. But if I make them in-house, we do the fixtures and set-up, spend $3 in raw AL and can cost the part at $5 with machine time. If I was getting them made by someone else, they'd be $15-20/part or more, depending on how many I needed.
So, with the info above, can anyone guesstimate a ballpark cost to do a mold, an a per-part cost (on the acrylic lens + ABS back plate)??? Or is this something I'm gonna have to figure out how to do in-house (injection molding)?
Thanks!