jerry howell -V4 Starter Motor

[RobConway]

Hi,
I am about to machine the mounting skids for a Howell V4 engine and I want to make some longer skids so I can eventually mount a starter motor directly engauged with the flywheel. I am really surprised that in the models of Jerry Howell he "seems" to have a DC motor which does not have a gearbox !. I assume if it was a geared DC motor you would need a one-way bearing and it could not be a generator. Anyhow I have found the knucklehead build which has got some great advice on starter motors however that is a geared solution.

Any advice on maybe a straight DC motor ? I do understand if it will work without gearbox I may need to run a DC motor with a high power PWM to try and control the RPM to around 500 ? Although with the flywheel maybe a helping hand (spin) will allow the motor to overcome subsequent compressions strokes.

Pic of the starter which also doubles as a dynamo in his design... I can scale the skid sizes based on this pic for now however interested on feedback for an actual motor

Thanks

Rob
Build thread: Robs Howell V4

 

[James Barker]

Perhaps the motor for an RC plane starter could be used in that application. I have two of them and they have a great deal of torque and are 12 volt driven.

BC1
Jim

 

[Eccentric]

Take a look at this starter arrangement. A small pinion with a large ring gear and a clutch.