Miles' Retro-Direct Gearbox

[Miles]

In fact, for large scale RC planes, they sell adapters that bolt to the front of an RC motor and step the speed down 2:1, 3:1, 4:1 (maybe 5:1???). Some use a slick compact planetary gear setup with helical cut gears.

I know I've seen some that used helical cut gears to run quietly. Something along these lines could make for a good first stage to enter your gearbox.

Thanks for your thoughts, Luke.

I'm trying to stick with 1 stage set-ups (2 stages to the wheel) though in this case it'll be 1 1/2 stage Inline gearboxes add too much to the length of the motor for my set-ups.

What I'm working towards is: 2 speed automatic transmission for the motor with probably a single speed or maybe 2 speeds for the pedals. Motor control by torque sensor on the crank. This is the kind of layout:

 

[TylerDurden]

Would doubled-up nylon gears be strong enough?

Not terribly elegant, I admit...

 

[HAL9000v2.0]

I use nylon gears in my dayly job often. I find out that out that it can last longer than steel ones (without lubrification). The only issue is when they are not aligned well then heat from friction kills them in hours. Combination of hard alloy small gear and nylon big gear, where small one is drive, last very long.

 

[Miles]

Would doubled-up nylon gears be strong enough?

Funny you should mention that - I was just wondering about the possibilities of running pairs of nylon helical gears back-to-back in order to balance out the axial thrust....... DIY herringbone

 

[recumpence]

Definitely - I had the Astro in mind for this, or an 8030 from David......

So, what's your plan for the double shafts, Matt?

Hmm, its a secret! :wink:

I will PM you about it.

Matt

 

[GGoodrum]

Would doubled-up nylon gears be strong enough?

Not terribly elegant, I admit...

Actually, they were already doubled-up, so this would be four of them. These are not nylon either, but glass-impregnated, hard plastic. Very tough. With a proper setup, I've never seen one wear out.

-- Gary

 

[Hugh-Jassman]

It's really a bummer to see the photos disappearing from these pages. I will try to find some that I had saved to my computer. But I don't have them all. If Miles has them hopefully he will"attach" them.

 

[spinningmagnets]

Thanls, Hugh