Having a brass "gear" machined - where/how?

[Tom '74 911]

Hi -

I've taken on a 1972 Toyota FJ55 project this winter. One of the first things I found was a broken gear @ the rear window motor that raises and lowers the rear window. The original is plastic and apparently it's quite common for them to break. They are NLA from Toyota and are getting scarcer by the day it seems.

A few folks have had brass replacements machined. This is what I'd like to do. I have the original (in 3 pieces) and have started a CAD drawing of it.

I'm looking for a recommendation of someplace to go to have one machined - I have no experience w/this. Depending on the price, I'd be willing to have a bunch (50-100?) done that I could sell reasonably to help offset the set-up cost etc...

Any ideas?

Thanks,
Tom

[Tom '74 911]

Sorry for the crappy pics. I can take better ones if it'd help. One thing to note is that the "teeth" are not straight up and down vertically, but angled along the depth of the gear. Sorry if that's not clear, my "gear vocabulary" is limited.

Tom

[masraum]

There's another recent thread where someone is asking the same question, albeit about a different part.

[masraum]

How Much To Machine A Small Aluminium Piece?

[EarlyPorsche]

I would just have them cast in plastic again but better plastic. Plastics have come so far that the new one would likely outlive the rest of the metal around it. Google vacuum forming and plastic casting to get an idea. Any reputable shop in your area can be found on Thomasnet and from there can get you an estimate. Just know that your quotes will WILDLY vary. Also know that they get TONS of calls from dreamers so it would be in your interest to show up and have them quote you in person since they get so many "why can't you give me a quote over the phone" types calling. Best of luck.

[john70t]

That looks like a simple drawing to do.
FWIW, there are inexepensive webcam-->CAD programs that can start a basic shape to be tweaked.

The automotive world needs a machine shop that specializes in piecework.
Also look into 3-D plastic printing.

[Tom '74 911]

Thanks for all the quick responses so far. I'm assuming that I will have to send this out somewhere to be done - I live in pretty rural Idaho. I can/will create a CAD drawing, but I'm sure it would have to be tweaked. . .

Off to do some more researching. . .

Thanks,
Tom

[cel]

You might be able to purchase something close enough to modify. Try the link below, there are several companies that make small gears.

Gears Mfrs. | Power Transmission Resource

[TimT]

That window regulator uses worm gears.. the "worm" is the is the smaller of the two parts, it looks like a bolt.. the "worm wheel" is the part that is broken...

You might want to cruise some some of the mini-mill/mini lathe hobby boards... and see if someone would do a one off....There are some seriously talented people out there....


Making a worm gear

[911pcars]

Also called an Acme thread. Perhaps one source or an internet search term:

Acme Nuts | Acme Nut | Acme Screw Thread | Acme Threaded Screws and Nuts

Sherwood

[LWJ]

As for the "show up in person" idea. I used to sell fabricated parts. We dealt in truck load quantities. You do not need to show up but you will need to have a good drawing (CAD not needed) with an idea of what the critical dimensions and tolerances are. Different suppliers will have different volume needs. I like the idea of a hobby guy. Could be a great solution.

Larry

[nota]

lost wax ?

make a wax copy

make a plaster mold around the wax part
heat the mold
wax goes away
pour in metal
break mold
clean up part

[Jrboulder]

If they are a rare part that is NLA and pretty easy to make you would think that someone would do a reproduction...

[EarlyPorsche]

Originally Posted by nota

lost wax ?

make a wax copy

make a plaster mold around the wax part
heat the mold
wax goes away
pour in metal
break mold
clean up part

This is what you would want to do if not plastic. Machining them would be $$$

[911pcars]

Not sure the owner of the 1972 Toyota FJ55 is a machinist or fabricator, but reverse-engineering and/or manufacturing an accurate replacement isn't a typical DIY skill set.

I would suggest hunting down the FJ55 owners forum on the internet, if there is one. I think the audience here is contributing "start from scratch" type solutions which may yet turn out to be the ultimate solution.

How about a complete door? (albeit, 2009):
FJ55 parts...possible SW delivery.

Hope this helps,
Sherwood

[id10t]

emachineshop.com

The first one will cost you $300, another 99 will cost an additional $10. They have really simple design software, just draw it out (you may be able to import your CAD drawing) and get an automatic quote.

[nocarrier]

I have never used these guys but maybe they can help you out.

Rush Gears inc. -- gears delrin gears plastic gears bevel gears spiral gears worm worm gears spur gears helical gears phenolic gears stainless steel gears cast iron gears steel gears miter gears metric gears hardened gears heat treat reverse engineer