Hello there. I'm a new member, and a tinkerer in my spare time. However, I have no real prior experiance in aircrafts, and I had a neat thought recently: I want to set up a push prop powered by a 4-stroke engine on a mini-bike frame. The problem is I don't know how to figure for the thrust I'll need. I've found some formulas, but none that meet my needs. Because the bike won't be leaving the ground, I don't need to worry about lift or other aspects of flight, just thrust. Any advice? P.S. Sorry if there's a more suitable thread for this, I saw this and thought it the most appropriate.

I think I would be inclined to adapt something like this to your mini bike frame http://www.bikemotorkit.com/?gclid=C...Fag65QodPGAWJA. That spinning meat clever (prop) in close proximity to limbs and flesh would be worrisome to me[X(]

Plus, with the pusher prop behind the rider configuration, it likely would be hard to adequately cool the engine without an additional blower.

Yeah...but there's going to be a cage around the prop.Also, I'm talking about a mini-bike frame, not bicycle. I don't need help with design, I just need help calculating the amount of force.

Well then... good luck with that....attitude.

What about engine thrust is not a design characteristic?

But, "where angels fear to tread..."

go to http://www.rcuniverse.com/forum/m_42...tm.htm#4292791

Sorry, I misspoke when I said I didn't need help with the design. I meant I know the general setup I want, and I plan to make this fan-powered- and thus more unique. I also should elaborate a bit more: I plan to use a standard 4-stroke 1.5 horse engine, it has it's own cooling fan, as the power plant, and set it up with a pulley system & jack shaft to get more rpms out of the prop.

This whole idea is based on this: www.instructables.com/id/Propeller_Powered_Skateboard_1/

How do you determine the size and pitch of the fan ( I had thought that a 24x12 might work) and horse power of the engine?

If the fan were to be mounted off the back of the frame, how much space should there be between the mini-bike and fan so that the fan isn't starved of air?

up

Heck, This time of year you might as well build one of these babies! http://www.freepatentsonline.com/3861492.pdf

As Yogi said "you could look it up". Look at the link I sent before!

Thanks guys! Bass1: I think that sounds like a great idea, actually. It's very similar to what I wanted to do and I'll probably set it up with the ability to switch out the skis for wheels. Spaceworm: sorry, I checked the link before but didn't see the chart you were suggesting; that should come in very handy!