Miles' Retro-Direct Gearbox

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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Miles   100 GW

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Re: Miles' Retro-Direct Gearbox

Post by Miles » Feb 28 2009 2:37pm

liveforphysics wrote: 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 :mrgreen: 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:
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eTSR2.jpg
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TylerDurden   100 GW

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Re: Miles' Retro-Direct Gearbox

Post by TylerDurden » Feb 28 2009 3:06pm

Would doubled-up nylon gears be strong enough?
2xNylon.jpg
2xNylon.jpg (26.58 KiB) Viewed 1395 times
Not terribly elegant, I admit...
Have a Nice Day,

TD

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HAL9000v2.0   10 kW

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Re: Miles' Retro-Direct Gearbox

Post by HAL9000v2.0 » Feb 28 2009 3:14pm

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.

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Miles   100 GW

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Re: Miles' Retro-Direct Gearbox

Post by Miles » Feb 28 2009 3:37pm

TylerDurden wrote: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 :)

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recumpence   100 GW

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Re: Miles' Retro-Direct Gearbox

Post by recumpence » Feb 28 2009 4:10pm

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

So, what's your plan for the double shafts, Matt? :)
Hmm, its a secret! :wink:

I will PM you about it.

Matt
1% of the world's population can think "Outside the box". The rest are firmly stuck within the box. Where are you?

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Re: Miles' Retro-Direct Gearbox

Post by GGoodrum » Feb 28 2009 5:12pm

TylerDurden wrote:Would doubled-up nylon gears be strong enough?
2xNylon.jpg
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

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Hugh-Jassman   1 kW

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Re: Miles' Retro-Direct Gearbox

Post by Hugh-Jassman » Feb 14 2020 2:20pm

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.
retro direct roller drive.JPG
retro direct roller drive.JPG (129.07 KiB) Viewed 301 times
retro drive.JPG
retro drive.JPG (94.83 KiB) Viewed 301 times
Retro-direct gears 2 .jpg
Retro-direct gears 2 .jpg (117.02 KiB) Viewed 301 times
Last edited by Hugh-Jassman on Feb 14 2020 2:28pm, edited 1 time in total.

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spinningmagnets   100 GW

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Re: Miles' Retro-Direct Gearbox

Post by spinningmagnets » Feb 14 2020 2:24pm

Thanls, Hugh

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