Morning Folks
Nath, I did cosider putting the engine mid ship because I thought it might make the belt runs easier but weight on the front end becomes a problem. I even considered shifting the drivers position aft to counteract this but decided to go with the engine and driver position recipe used on almost all ZTR's. Front cowling will be completely new. Fortunately I have access to a guillotine and folder.
Norm, it's very literally two drives and two axles. Imagine bolting two frames together side by side having first cut th inner wheel off each. That's the principle. ..........and I did mess with the idea of doing just that but the machine would be very wide indeed!
Jack, I was very fortunate to get the the backing of Lockheed Martin. It means we have a foot in the door with the Mars manned flight project.
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I wondered many times, rather nervously why Greenfield had never done it. I say nervously because perhaps they did I try it and abandoned it for some reason that I would only discover after putting in all this effort. Who knows, that might still happen!
I didn't know that Dixon had used friction drive also.
AVB, you raise a couple of good points.
Access for maintenance is not as hard as it looks. I worked hard to make it easy to get the clutches in and out and accesss the tensioners etc.
I like simple elegant engineering and am annoyed that the back end looks like a rats nest but it's impossible for so much stuff to be in such a small space and not have it look that way.
The greenfield drive allows instant forward/reverse changes. Every kid who's ever driven one has put marks up and down the back yard trying to spin the wheels by charging forward and then stomping on the reverse.
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Drive clutch plate reliability is something I've thought a lot about. A normal Greenfield being manoeuvred in and out amongst trees and shrubs for example is subject to a lot of direction changes and clutch slippage and in my own case I've only just replaced the corks for the first time on my own daily drive after 34 years!
Increased cork wear is inevitable but given how long it lasts on a normal machine I think it'll be ok. That said, this is an experiment and working all this stuff out comes with the territory.
Cheers,
