jim.thornton

I've got an OS .40 (AX I think) and I broke a prop today. I have a couple of extras around... Can an APC 11x5 or 11x6 go on this motor or is that too big?

ChuckW

Is it a .40 or .46?

Both will work on the .46. Try both and pick the one you like best.

jimmyjames213

My Feedback: (2)

11x5

MetallicaJunkie

if its a 46 11x6 if its a 40 11x5......... but the 11x6 will work too

*edit let us know exactly what it is their is a big difference in between LA/FP and FX/AX engines

Jetdesign

My Feedback: (8)

Both will work on a .46. You will get more revs and better acceleration with the 11x5, maybe better top speed with the 11x6 and quieter operation.

You really have to try them and see what works the best for the particular plane. I found that the smaller (.40-.50) engines work best with lots of RPM, so I used a 5 pitch prop on both my .46 and .55.

jim.thornton

I wasn't sure about the AX, I was guessing on that. But it is definitely the .40 NOT the .46. I guess it would be an LA then.

I was just worried about under powering the plane as it is quite heavy for a trainer.

Campy

My Feedback: (1)

If the plane is underpowered, LEARN TO FLY "ON THE WING", NOT ON THE ENGINE. By that I mean you need to learn to fly the plane using the lift in the wing and the aerodynamics of the plane and also learn what the plane can and can not do. With a large enough engine ANYTHING will fly.

You would be surprised at the weight a small engine can fly. Yes, your takeoffs will be longer and flying into the wind will most likely be more of a challenge, but you will learn things about the plane AND flying that you would not learn otherwise.

In my opinion, if you can fly an underpowered plane successfully AND consistently, you should be able to fly just about anything.

Sandmann_AU

I'd have to agree with this. I have a Super Skybolt and a Harmon Rocket 3 that're both massively over-powered, but I often have more fun flying my Dual Ace, which has twin 40's and is right at the bottom of it's recommended engine size. Yes, it flies "scale" (ie: it flies like a real plane) but that makes it more enjoyable, not less.

Oh and with a 40 sized 2 stroke, I'd actually recommend a 10"x6" or maybe a 10"x7" rather than an 11" prop. You'll get more speed out of the 10". As with all prop choices, buy a few sizes and see what you like. The best prop is the one that flies your plane best.

Augie11

If it's a .40LA I'd stick with a 10x6. The 11x5 might work but you'll lose some speed.

jim.thornton

Thanks for the tips guys. I'm not too concerned with being overly underpowered and not being able to fly it. I'm concerned with being TOO underpowered where as soon as you pull back you stall.

This plane is fairly underpowered (it won't do loops or anything).

I was really concerened about the prop size because I broke my two 10x6 due to a bad servo installation and I only have an 11x5 or an 11x6. It's going to take a little while for me to get a new prop and I wanted to fly before that so I thought I would see if the 11x5 or 11x6 was too big for this enigne.

I'll give the 11x5 a try and see how that works. I would rather acceleration and pulling power over top speed anyway.

microsprint9

I found the APC 11x5 to be my favorite prop on my .40LA.

jib

I found the 11x5 to be MY favorite prop on my TT GP42, a very similar engine to the LA40. I tried the recommended 10x6, then 11x4, 11x5 and 11x6, before deciding. It's amazing how noticeable having the right prop can be. Play around with various props and you will find the right one for your plane/engine/flying technique combination.

Jack

Allfat

My Feedback: (1)

Yeah, you would be surprised. I was part of a collegiate design team last year during my senior year in a mechanical engineering program and we designed an rc airplane to lift payload. We had to use an OS 61FX engine per the rules and we had size limits on the plane. That 61 ended up lifting 28 pounds of plane and payload and flying the circuit successfully. This was a fourth place performance out of 45 other college teams. Wings are amazing things when they are designed correctly.

Luftwaffe Oberst

Bingo! I'm with MetallicaJunkie on this.

microsprint9

I agree, everyone at the field always laughs when i bring out my 120" 10lb B2 stealth foamy with a little TT PRO.46 powerhouse pulling it around the sky no problem, even takeoff is a simple hand launch ( no gear ).

The proof http://www.rcuvideos.com/video/10FootB22-wmv

And on the original question i can't seem to find an OS.40AX so you must have the .40LA so IMHO an APC 11x5 would be best.