Hover weight to engine power ration ????
 

Does anyone know if there is a power to weight ratio for hovering? Let's say you have a .40 bushed engine, what is the maximum weight the plane can weigh and still be able to hover.

Thanks!
Soj

RE: Hover weight to engine power ration ????
 

Technically, for hovering you only need a 1:1 power:weight ratio. However, for good control authority and the ability to pull out vertically, you want at least a 1.5:1 ratio. I am not sure how much thrust you will get from that .40 bushing engine, but I'm guessing you would have a hard time finding a plane that is light enough, but also strong enough and large enough to accomodate that engine. However, if you moved up to a good .46 ball-bearing engine, there are a bunch of planes that will hover and 3D very well with it. Ex: the O.S. .46FX (or .46AX) and the Carl Goldberg Extreme 330. It is a profile plane, so it is good and light. A .40 wouldn't cut it, but a .46 is just about perfect.

Hope this helps,
Mike

RE: Hover weight to engine power ration ????
 

A good hovering ARF for a 40 bushing engine like the OS 40FP would be a Fun Air 40 ARF sold by Chief Aircraft. 3 lbs 13 ounces and hovers at about 3/4 throttle. I use an APC 11-4.5 prop.

The Fun Air 40 takes a little tweaking when you build it but man does it fly nice and it's very strong light aircraft.

Joe

P.S. There is a typo in your subject line: It says ration instead of ratio.

RE: Hover weight to engine power ration ????
 

LOL, Funny, I made As on almost all of my spelling tests when I was in school 30 years ago...:)

thanks for the info. I've got a OS .60 FP BNIB, but the silly thing weighs 23 oz. compared to 17oz for a .46 BB or 12 oz. for a .40 bushed engine. I'm not sure, but I think it is supposed to put out about 1.4 BHP at 15k RPM, vs. 1 BHP for the .40 bushed and I have no idea what the .46 BB will do.

I'm building a SPAD3DT, I don't know what it will weigh, but it will be nose heavy with the .60 up front, and then I would have to add weight to get the CG right.

Thanks again,
Soj

RE: Hover weight to engine power ration ????
 

I been trying to hover a 1:1 plane or a little over 1:1 and for someone like me whos never hovered its very tricky, yes for control authority you need 1.5 minimum plus to pull out, I can only drop out :)