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Post by Admin on Aug 7, 2024 20:17:55 GMT
The use of any and all hardware / software products to build the vg23air is OPTIONAL.
The purpose of the optional capability is to allow the operator to pursue a full or partial electronification of the engine.
Their are a number of esoteric reasons for using the Speeduino on an engine that is otherwise not electronic, you can monitor certain items, rpm, air fuel ratio, map sensors, oil temperature etc.
More importantly, by simply adding a crank-wheel and crank sensor, one could completely remove the 18 lb flywheel and associated charging and ignition and fire the spark plugs using the Speeduino and compatible ignition igniters, a huge weight savings, albeit, no 12 volt charging (but there are solutions to add that too, eg John Deere Dynamo)
By adding even more components, one can go full EFI.
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Post by Matt Naiva on Aug 10, 2024 16:10:16 GMT
"More importantly, by simply adding a crank-wheel and crank sensor, one could completely remove the 18 lb flywheel and associated charging and ignition and fire the spark plugs using the Speeduino and compatible ignition igniters, a huge weight savings, albeit, no 12 volt charging (but there are solutions to add that too, eg John Deere Dynamo" Don't we need to maintain some flywheel since the Prop is not providing the flywheel affect when a redrive is in place ? Matt |
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Post by Admin on Aug 10, 2024 21:18:15 GMT
I'll answer your question by asking you a question, how much flywheel do we need ?
The stock one is about 18 lbs
The racing one is 6 lbs, and provides a starting ring.
The racing one is intended for use on an engine that must idle and spin nothing, a ground vehicle.
The heavier flywheel, in my opinion is there to facilitate times when the engine encounters a sudden demand, tall wet grass on a mower application, to sustain higher revolutions as the governor kicks in.
The racing one, in my opinion is there to 1= provide a platform for the starter ring 2- Provide some force to allow the engine to idle 3- provide a minimum amount of force when dropping the throttle in a turn then flooring it again, to keep the speed up. 4- A lighter flywheel allows faster acceleration out of the turn to pass the competitor with the heavier flywheel/
Do we need a flywheel on the mag side of crank ?
I don't know
Do I intend to run without one and find out ?
Yep.
FROM E PROP DOCUMENTS
3- Could a propeller be "too light" ?
No.
It is sometimes said that a heavy propeller is required for the engine to "rotate" at
ground idle, that is, have a more constant rotating speed.
But if the speed variations are smaller, the variations in the forces between the propeller
and the pistons (on the whole mechanical chain, reducer or not) are more important.
And speed variations don’t cause damage, whereas forces variations, yes.
The major engines manufacturers give very low values of MOMENT of INERTIA.
This shows that there is no problem to put a very light propeller, with a very low Moment
of Inertia, on aeronautical engines.
Even a very light propeller generates a sufficient flywheel. With an ultra-light propeller,
the idle adjustment would be different, that's all
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Post by Admin on Aug 10, 2024 21:33:35 GMT
I translated this from french props and drivesSome of this goes in the other direction indicating the use of a flywheel, crank, reducer and prop as part of the spinning mass. It focuses more on the potential damage when using a gear box or belt drive that is not correctly set up Of note, it estimates up to 8% slippage when using a flat belt, 8% power loss and 1kw of heat produced at the belt. It also references the use of a clutch near idle to prevent the "chatter" or backlash problem. This may be why aero 100 uses a clutch. I see these as a huge safety issue, we say CLEAR PROP then start, and these clutch engines do not spin. A knowledgeable bystander could infer the engine is not running and enter the ARC DANGER area as the engine rpm is increased and the prop spins up. They also add weight. Increasing the idle rpm is another answer. Limiting ground idle is another, no parading. P.S. The John Deere dynamo would also add to the spinning mass, as would a belt drive mounted starter ring gear. in place of the mag side flywheel. Another P.S. The way I read this is, aside from catastrophic failure, the proof will be in the belt wear, as to whether there is enough spinning mass on the crank side of the redrive to prevent backlash on the prop side of the redrive. In the case of a smooth belt, it may heat and wear or fail. In the case of a toothed belt, it may wear teeth or even eat them prematurely with low service life. |
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