But how much demand do you have for various parts to be reproduced? No matter how you look at it, to create metal parts for reproduction will require some sort of permanent mold. That will cost at least a few hundred. Then whatever materials that get used up in the production process. And finally the metal to create your parts, likely aluminum. So a door handle could end up costing you say $400 to get to production, not including the foundry. If you plan on making 100 door handles, then that makes sense. But you plan on only producing a few door handles, you're better off searching the web for parts from junk yards. It's one thing to carve a handle based on your own design, it's another thing to reproduce a mass produced door handle.
You would first have to create sort sort of permanent mold based on the original door handle. Then use that mold, to pour wax into. Then, take the wax door handle and put it into a ceramic mixture to create a casting mold. Then, melt the wax out of the ceramic casting mold. Now, you can pour molten metal into the ceramic mold. Once it cures, you break the ceramic away. This is a lost wax reproduction method. You could try to create a 2 part ceramic or metal mold that could have molten metal poured into it, and be used again and again. But you have to be careful on mold design and know that there will be more post production machining.
It's a lot of work to reproduce a metal part. You just have to determine is it worth it? If the parts cannot be found else where, then you're stuck with one-off production runs.
I'm currently working towards reproducing defroster vents for Opel GT's. I'm in a holding pattern due to funds being low at the moment and other things needing to be taken care of first. But, sometime next summer I want to be reproducing these vents. It will take some permanent molds out of metal or wood, to create silicon molds (also perm), so that I can pour a 2 part urethane. The finished parts should be pretty close to done, only needing minor post process work. I already know of 20+ people who want them, and 2 companies that are interested in large orders. I'll be able to make a small profit off of it, and when the time comes to purchase an Opel GT of my own (in the near future, again other things come first), I'll need these new vents. Original vents were made with 60's era plastics, so they are crap. No one has tried to reproduce them yet, in large number. So a large demand with zero supply. I already know that the market price cannot go above $100 per set of vents. My goal is $75 including shipping, and an initial production run of 100 sets. That goal does look possible, based on feedback and the initial financial planning I've done. I'm looking at spending ~$1,000 to get to production. ~$120 of material per ~7-8 sets of vents. ~$15 for shipping and packaging. ~1 hour of work per set of vents. All of this, is just a side project and not needed to pay any bills. I should make (profit) somewhere between $30-45 per set of vents, and if I sell 100 vents, that's not bad. All looks possible and has a decent amount of flexibility. Oh, and due to eventually needing new vents anyways, I want to do the production run if for no other reason than my own restoration project I'll eventually get into. Yes, I'm a certain kind of sick car nut, thinking about collecting and making parts for a restoration of a car I don't even own yet.
