The "Transcender"... comments welcome!

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Oct 19, 2012
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Wakefield, UK
I think the possibility of a screw drive being pedalled through snow would be quite unlikely. I think the grunt required would be a killer. Snow isn't uniform and the variability would adversely affect the pedaller. Water however could see the entire screw under water and would work quite well. Some experimenting to get the correct buoyancy leaving the screw in the water and the rider out of it will be needed. It'd effectively be a pedalo which aren't cheap to buy. It could also be in in-line tandem form with longer screws. I suspect the leisure market would love to see something like this.
 

Radical Brad

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Kakabeka Falls, Ontario, Canada
Interesting, never considered it as human powered, but if you could vacuum form some very large and light screw housing, it might work, or even inflatable rigid.

My original sketch assumed a very powerful electric drive in the 10,000 watts or more range (10-15 HP).

Brad
 
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Messages
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Paddles in water necessarily only work with the bit that's in the water. There's a lot of wasted effort. Screw drive is much more efficient though making them will be quite some task. It'd be easier to use two pontoons to float and a std propeller central at the rear - not remotely as cool though as the full screws would look.

Back of a fag packet calculations show a pair of 2m long screws at 25cm diameter would support 200kg (machine and person) without sinking though I haven't a clue as to how far down the screws would sit. Logic say's they won't be 100% under. To get fully immersed they'd need to be smaller with some extra buoyancy built in at a higher level. Leaving them poking out the water leaves them less efficient though shows of the cool screw drive.

I think that two screw drives would need to counter rotate to avoid crabbing. If both drives rotate the same way I'd expect to see some drift from forwards.
 
Joined
Oct 19, 2012
Messages
372
Location
Wakefield, UK
Interesting, never considered it as human powered, but if you could vacuum form some very large and light screw housing, it might work, or even inflatable rigid.

My original sketch assumed a very powerful electric drive in the 10,000 watts or more range (10-15 HP).

Brad
I think you'd need a powerful drive for any other medium than water. If limiting it to water - well we know a pedalo can be moved with relative ease by one person. Being a more efficient screw drive would only make that easier. A pedalo is about 100-130KG. Hopefully something like this could be lighter again making pedalling easier.
 
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