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Re: How to mount a gear (cog) onto engine shaft

>> Can anybody tell me how I might go about mounting a gear onto the

> >> shaft of an IC motor? It's for an onboard electric starter thing I'm > >> working on. > >> > >> It's just occurred to me that there might be a cog available which > >> has a sort of collar on it with a set-screw in there.. this would > >> work I suppose but it'd be a threadlock nightmare.. and I kind of > >> had a plastic gear in mind. Still, does anyone have any ideas or > >> opinions? > > > > Why not think "Torrington"? A torrington bearing at the centre of a > > cog would grip the ground section of the crank allowing an electric > > motor to crank the engine. Once the engine is running, the torrington > > will disseangage. > > > > Bit over my head matey, but I have considered the one-way bearings as used > in pull-starters (those at the rear of the crankcase on small buggy engines) > which would be cool for this, however... > > my main reason for doing this is to run the electric motor as a kind of DC > generator once the IC engine is running :-) So it is not desireable to > disengage..

Ok, but I've got to ask, for what reason do you want a DC generator on a heli?

Reply to
Beav
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:-) it's not for a heli. It's for no specific purpose as yet..

Reply to
Carl Farrington

Maybe he wants to go for an endurance record????

Andy

Reply to
Andy Beetz

If you go with a brass gear, an "interference" fit would work. The shaft is slightly larger in diameter than the hole through the gear- heat the gear to expand it, and press it onto the shaft.

Reply to
TexMex

Not a good idea. The gearing to get the torque to get the engine started would cause the motor to rev to vastly unacceptable levels when the engine is revved up. Looking at the FEMA pictures it looks like about 8-10:1 gearing. That would have the motor revving to over 100K when the engine was at 10-12k!

Reply to
Paul McIntosh

Gotta remember to leave enough room for a cooling fan.

Reply to
Paul McIntosh

Hi Carl

I suggest you have a look at the Meccano range of bits and pieces, and also those used for model trains and cars. I remember using Meccano gears (pinion with set screw to hold it on the axel) when I was a kid.

David

Carl Farr> Can anybody tell me how I might go about mounting a gear onto the shaft of

Reply to
David

Ahhh, one of THEM projects :-)

Reply to
Beav

I'm thinking of using a pull-starter engine and removing the pull-starter, so it'll go on the other end of the shaft

Reply to
Carl Farrington

hmmm very true. Maybe I'd need some kind of dual gear thing where the first cog disengages as the engine hits a certain rpm. Might have to look into how those 2-speed buggy gears work..

Reply to
Carl Farrington

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