With the bearings inside the pulley, outboard support isn't a big deal as long as the shaft is robust enough. And the pulleys have to be far enough apart (pulley hub wide enough) for adequate support.
I don't think torsional issues are generally a big deal in this type of redrive with the prop sipnning on a fixed shaft, as opposed to redrives where there's some length of shaft to wind up between the driven pulley and the prop.
This is "In Development" at Chip Erwin's shop, Aeromarine LSA. Chip has years of experience in electric applications in his aircraft.
your link is NOT the correct engine! that's a 2-stroke in-line for aircraft not a 4-stroke v-twin. please correct your data
This is a legit concern with 'traditional' engines like VWs, Corvairs, Subarus, etc. I suspect that it isn't as big a deal with the industrial engines, because the PTO end of the engine is specifically designed for the side (bending) loads imposed by a pulley. It may not be for these, either, if their output shaft normally gets the drive pulley of the CVT in the UTV.
Can you clarify? When I looked at the Gaokin engines via Alibaba, I found a version for motorcycles that seemed to have an integral (manual) gearbox, and a version for UTVs that could be purchased with or without the CVT. The CVT for the UTV version appeared to be a separate component that we wouldn't want to pay for, but isn't that the version of the engine we'd want?
not the motorcycle version, the utv/atv/snowmobile version WITHOUT CVT and gearbox, it comes down to be the snowmobile version. we got a guy testing it in his snowmobile manufacturing industry as well, he's really happy with it, again I understand aircraft is a different animal and needs to be proven in aircraft, not like some others that are selling it to make money before even testing it!
as most of you know belt needs to be properly tensioned and is not (almost) idiot proof like a gear drive. I would love to see a rotax C drive or B drive be coupled to it, by all means help us out. yamaha engine is really taking off for the Bush planes and they got a company releasing a gear drive for it, so look into the yamaha inline 4 cyl snowmobile engine as well, looks to be better HP to weight ratio than the goakin?, guys check that one out as well. also based from a snowmobile engine but an in-line instead of v-twin. dont flame me Im no expert on the yamaha version yet, its been supercharged as well by steve henry on a highlander at 300hp! but I think shes a heavy beast now. MAYBE SKYTRAX CAN DEVELOP A GEAR DRIVE FOR THE V_TWIN??!! i will probe skytrax to see if there interested in building an adapter for his gearbox to adapt to the gaokin.
When I asked for redrive details so I could run a TV analysis, I was told I would have to buy one. That isn't 'sharing' in my book.
why are you basing your remark from my quote?, I NEVER SAID YOU HAD TO BUY A REDRIVE to run your analysis!? you must be referring to someone else? Okay Im done sharing anymore info on this subject.
I have had brief correspondence both with Kevin in England, and with the Ace Aviation PoC in India. Kevin gave me access to his Dropbox, which has a LOT of detail on his conversions. I haven't dug into it to see if the details of the redrive are there or not. You MIGHT be able to deduce all the relevant masses and spring constants from the detail drawings. I don't think either Kevin nor Ace actually know doodly about torsionals. And even Gates is pretty closed mouth about the stiffness of their sourced components. What I can say is that nothing I've seen about the Ace Redrives indicates that they have any sort of resilient decoupling element that would make them torsionally "soft". If one wanted to design one, say with a "Guibo" like a Rotax E box, I bet Ace would be happy to chew you one out of billet, for little money, decent quality, long lead time, and frustratingly slow, if any, communications.
YOU didn't say that - either Kevin in England or the Ace guy in India probably said it.
