DIY human powered drive and prop design

No thrust achieved so no speed test?
Sounds like a simple solution - it failed.

I couldn't tell, did this work like a Hobie? Did they use a push mechanism, not a rotary input?
How did they get a return on the "pedals"?

I suppose there was a gear ratio increase from the pedals to the impeller. What did they do to get 1800 to 2000 rpm. Looks to me like they actually applied an electric motor to the drive shaft thru pulleys and v-belts.

Please explain anything about this article that worked. They apparently couldn't even seal the hull.
As I recall from "pedal power" the blades that worked were between 8 to 12 " in diameter. I bet they had problems with the size.

 

Did a little more digging today and found some interesting things. Some of it applies and the shaft drive bike system would work great if they'd sell just the drive, but they won't sell it by itself. I know that the other link was a failure but I found the approach interesting. That's why I posted it.

I know it's a bit redundant since there's a huge thread about developing a pedal drive already on the board, but I'm not an engineer, I'm a mechanic and machinist. I have to reason some things out differently than others most of the time since I suck at math. I'm starting the model of the boat already so I can get the measurements I need to build her, and when I'm done with that I'll give the model to my neighbor for her kids to play with since I'll have the full sized version afterwards. The actual boat will end up between 13 and 14' but to make it easier to measure the model will end up being 26 and 27" OAL. The beam of the actual boat will be 40" and it's asymmetrical so I can sit further back.

http://www.mie.neu.edu/sites/defaul..._Engineering/ME_2013_04_Hydrophilic_Husky.pdf

http://www.ijeert.org/pdf/v2-i2/7.pdf

http://www.treehugger.com/bikes/chainless-shaft-drive-bicycle-transmissions-by-sussex.html

http://www.dynamicbicycles.com/chainless/commonquestions.php#shaftalone

 

I wish you good luck, but this is a waste of time.

Start with something that actually works.

 

I think that's what they said to Edison as well.

 

Haven't figured out the prop drive yet, but I did get the model of the boat partially done and thought you guys might like to see what it'll look like. From the model the OAL will be 13.3', which is longer than I want but should do just about everything what I want it to do. The width is between 40 and 42" but that is roughly where I wanted it. The bottom was partially cut through and wet down so I could bend it, and you should be able to see it in the first pic. The wood is luan paneling and it works fine to do a model of what I want. Since I'm going to get measurements off it I decided to go from a 1 foot model to a larger version which is easier to get the details off. There's a very slight rocker to her and that's more than enough. The center brace will not be there when I'm done and the model will be finished and given to my neighbor for her kids to play with. They're young enough now not to use it but in a year or 2 they'll enjoy the heck out of it.

 

The more blades a propeller has, the less efficient it is. Only when there is a limitation on the diameter do more than two blades become a viable option.

 

I wouldn't expect a human powered jet drive to be efficient, but no thrust at all? That is surprising. That is until I see that they had no stators behind the impeller. I think the impeller only served to swirl the water inside the duct.

I think they didn't get to the pedal portion of testing. Once they discovered they had zero thrust using a motor I think there is not much point trying to pedal it.

 

Yes, and no Gonzo. Ever been to ENG-TIPS forum before? Besides, I'm looking at easily found or cheap purchase for parts. I done a lot of fabrication over the years and will scrounge things to make what I'm after. Pitch has something to do with the efficiency of the prop as well. This isn't a race boat but something that can be used on a body of water for pleasure and or fishing.