Gearbox DIY (4,5:1)

can u send me the CAD files?? @2D-Foiler

You can download the files and the list of materials here:

Gearbox 4,5:1 downloads

Best regards

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Thank you so much:grin:

??? how to open those files plz?

how to open it on Solidworks???


First download, then open.

? 4,5:1

At, the experienced builder Pacificmeister shows a 2: 1 ratio drive. On the the experienced VeFoil builder explains why he canceled the gearbox.

I think the 4.5: 1 ratio is too high. It is probably only needed to move the e-foil against the wind or when the rider has a big weight!

@WNT, keep reading, it’s not that easy. There are many posts here discussing the relationship of kv/proprpm/torque/props/amps/volts/efficiency… long list with complex dependencies. I had success with a 500kv 7:1 and 5:1 gearbox, my leatest 360kv 2:1 belt test is not working yet. I believe VeFoil has not foiled at all yet. We would all like to get rid of reduction gears but it’s hard and impacts other stuff. There are several other experienced builders here sharing their build details, some with direct drive success like Virus.

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Fuel outboarders with props about 120mm diameter have round about 5000 rpm on the prop, and the constructors have a lot of experience.
With the gearbox 4,5:1, we have max. 4933 rpm on the prop, because we have not 100%, it is less.
(Motor 500KV x 44,4 Volts / 4,5 = 4933). The current in the water is 25 Ampere, this is okay.
The rest will be done over the pitch of the prop, if necessary.

I think you miss only a good propeller, because I have not seen you any good. And of plastic, that’s totally excluded. I’m sure VeFoil will be successful without a gearbox. Probably now solves the sealing problem. However, the seal will be solved and then the impellers will probably be tested. The impeller can not of course be made of carbon (like the Virus) but of good aluminum or steel.

I have bad experience in plastic. I recently printed a highly efficient propeller on a 3D printer, but the blades bent at 400 RPM. If it was made of carbon, it would also bend, though a little less.

When you complete the prototype of the drive (without a propeller, but functional, reliable and faultless, with a 2: 1 ratio), I will help you optimize the propeller. Similarly, I want to help VeFoil. But as I have stated several times in my contributions, the propeller and the impeller must be of good aluminum.

Could you share the CAD files of these parts pls?

My next step is to complete all and use it on the water, when it’s all fine, I’ll publish the rest, too.
I hope beeing able soon to invest more time in the project as it’s possible at the moment.

Great! Hope to see it soon :smile:

One of the things I have noticed no one mentioning about the gearboxes is that the gears themselves can be cryogenically hardened (dropped into liquid nitrogen) to harden them. I wouldn’t do it to an assembled gearbox though. From my experience, if you pick the right steel to do it with, it will come out with more wear resistance than carbon steel. Just a thought I would throw out there, since someone is making their own gear box. Compared to the cost of a new gearbox, one could pick up liquid nitrogen for a very small cost.

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Same. I found a US distributor for Madler who has a minimum order qty for 6 of each gear, at a total of $352 USD. What a joke. Is anyone able to purchase these from Europe for us?

Inspired by you I did a mostly 3d printed gear box. Just did a test with the prop in water running off a 1hp router and it didn’t shred it’s self so I’m counting it as a success. Only the pinion gear is metal.


What material did you print with? Looks cool, did you calculate the strength of the gearteeth?

Nope did no calculations. Printed in PLA. I might re print the whole thing out of nylon to get s bit more durability.