I'm designing an aircraft around the YS .91 (4 stroke) and probably will use a 14/8 prop. Can those of you with experience tell me what the maximum overall model weight this combination will haul vertically? ... and hover?

Thanks!

around 7-9 pounds i believe

You'll probably need more prop than your original choice. The YS91 is right at home with a 14-10 or a 15-8 APC prop. The 15-8 will give you the most torque. Anyone try a 15-6?

I got just over 8 pounds of thrust on my 91 FZ using a 15-8. The 15-8 also had the best braking too.

Bob

Perfect. 8 pounds is my design target, so I look forward to that. Thanks for the prop recommendations, too. I've attached an image of what the engine is going in. I'm about 1/2 finished with the plugs, and will be making molds in a month or so. (More details on my web site if you're interested.)

hey how did u created that 3d model? im learning 3d studio max and im just wondering what program do u use....

Hi,

I'm a Mac user, but the program I use is available for PC too. It's "Cararra Studio". I design all my models in 3D first, to make sure all the internal components fit correctly, and to help me visualize how I'll build them. It's made by a company called "Eovia" at http://www.eovia.com

There's a lot more CAD stuff on my web site, including cutaway views, transparent models, and some animation. http://www.nextcraft.com

PS> I think MAX is the superior program, and am jealous.

hehe well i dont know if its the superior program but its very good

I have a YS91AC on my 60SuDoKhoi. I've been using an apc15x7 prop, but found a Zinger16x6 at MLH yesterday. I tried that prop today, and the engine seemed to be happy with that on 20/20 fuel. Today was a windy day, so I couldn't really make any comparisons, but it looks promising. Could I only find a wood 17x4 for my YS91ACs, ah, I'd be in heaven.
DKjens