Info on making an Outboard lower unit...

[Kris Flynn]

Hey

If someone (say me) had access to all kinds of CNC and manual lathes/machine and mills and stuff like that(and also had the experience to know how to use them properly)...how hard do you think it would be to produce a one off lower unit? I'm thinking about one for electric use, that would be as scale looking and that would perform well (and be light)...

I really want to give it a go (not for mass production or anything, just a project i have been thinking about) and have been keen on looking into it for a bit...I understand the first (and main step) is to design the lower in CAD software, but people have design and CNC'd boat's out of Resin blocks then molded them to make perfect models, so could it be done with a lower for a one off?

Any input would be helpful

Kris

 

[Kris Flynn]

OK instead of making a completely new lower unit...what about thinning down a K&B one to half the cast metal thickness (to reduce wieght) and maybe add a bullet shape to it to make it look more scale and something like the hyperformance?

C'Mon your ideas are needed

Kris

 

[Jerry Dunlap]

Chris,

You could make a lower unit using brass tubing and plywood, and fiberglass cloth. Since you're talking about an electric motor, vibration wouldn't be a problem.

Thinning a K&B 3.5 lower unit would be an option, but a plywood lower unit would be lighter.

Jerry D.

 

[Kris Flynn]

Jerry

I Also thought about making one like you suggested but using balsa to get the shape right, then make a plug to make it in glass, or just glass the balsa wood one...but i thought it might be hard to get both sides to be perfectly symmetrical compared with using CAD/CAM stuff.

Have you yourself tried making a lower unit before? Or you have never had the need to?

Has anyone got an pictures of any of the hyperformance lowers so i can get a proper idea of a good shape to use (but not to copy it)??

Kris

 

[Jerry Dunlap]

Chris,

I've never had a need to make a lower unit. I think you're "over engineering" this project. "Eyeball" shaping of the lower unit should be more than adequate. Hey, you're not riding in the boat so if something happens it isn't going to cause loss of life of limb.

Jerry D.

 

[Kris Flynn]

Jerry, I suppose your right...i just thought the more perfect it was the better it would perform

If something happens it might cause the pain of having to make it again or rebuild it, wich isnt really as pleasant as running boats

Thanks for the advice

Kris