RC Car Gearbox Casing

I have an old 1/9 scale Kyosho Toyota 4 Runner - gas powered, which has a CCVT gearbox (really is a continuously variable transmission with Neutral, Forward speeds and Reverse).

The transmission is mechanically shifted using a servo.

However, due to the material used for the case (hard clear-ish plastic):
1) It starts leaking at the feet (where it's attached to the chassis) because the screw holes crack
2) The top post where the shift linkage is mounted breaks because the post is plastic and it breaks over time.

I'm thinking of coming up with a replica using aluminum. It would be stronger and would look way cool (anodized black maybe)

Challenges are:
1) A clear plastic/acrylic window on the side would be nice or a dipstick to measure the oil capacity
2) The internal structure of the shell is pretty complicated

The seal between the shells does not have to be fancy, we could just use RTV gasket maker

Attached are some pictures, I will post more details later.

You can see that in this picture, the top post is already broken.

Please let me know what you think about this idea. I had taken a class in CAD design (using Pro E) so I could do some of the design if I can get my hands on a CAD software.

If its one of, wouldn't it be easier to just mill it

Quote:

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Originally Posted by Guldberg

If its one of, wouldn't it be easier to just mill it

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Don't I still need a CAD design or can I just take the original part to a machinist who can then setup the machine manually?

You would still need a 3D CAD drawing. When you draw it, consider if the inside could be made simpler

Quote:

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Originally Posted by holson

Don't I still need a CAD design or can I just take the original part to a machinist who can then setup the machine manually?

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Nah, just take it to the shop as is. I do that kind of work all the time and even though the machine shop will have to take dimensions for themselves, chances are they'll do it more accurately than you would at home. Just be sure to bring all the internal pieces too~

Quote:

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Originally Posted by Guldberg

You would still need a 3D CAD drawing. When you draw it, consider if the inside could be made simpler

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A good shop will have software to make this. Just make sure the shop that does it has a good reputation and remember a one of might cost a lot.

I two have been doing some work in the RC market and it is a lot of fun.

Good Luck!