I've recently finished building the Fun-51, and have with great joy had some exciting flights. I have an old OS MAX FP40 with a 10x6 propeller in mine and with that it behaves well, though somewhat too polished for serious action.

What are your engine / propeller experiences with this bird ? Anyone tried out a .40 engine with another propeller, in which it delivered some more muscle (i.e. not necessarilly speed, rather power) ?

/faktor

I ran mine with an LA 46 and it was pretty good but didn't have unlimitted vertical. AFter that I borrowed my buddy's OS 50 (whatever the new model 50 is) and it was pretty insane. Unlimitted vertical at half throttle. Move your CG back for more wild aerobatics.

Unlimited vertical with an Enya 45SS and an APC 12.25 X 3.75 prop. A OS 46AX, TT Pro 46, or Magnum 46XLS should be even better. The prop makes a big difference.

Seems like upgrading to a larger engine would be the wisest choice....

I'll try it out with a 11X6 or something similar to see if there's any change before switching engine. What prop dimensions did you guys use, and had the best experiences with ?

/Kris

I would try an 11x4 first. The 11x6 will be too much pitch. I used both the 12x4 apc and the 12.25x3.75 apc with a 46fx, and both were very well matched to the airplane. Oh, and what he said, move the cg back on this plane. Before the untimely demise of mine (stupid trees), I had like 3.5 ounces of lead in the tail and was thinking of adding some more.

Try an 11x4 or 10x5

I also agree on the tail weight. Mine has a ton.

I've been flying mine for almost a year with a Thunder Tiger Pro .46 with an 11 x 5 APC prop. It's my favorite plane, especially in high wind.

Ok, I'll give it a shot with the props you proposed as well as by moving the CG back a bit further. Thanks...

/Kris

I originally had a Supertigre 40 with an 11x4 prop. The plane would hover and did the most incredible inverted flat spins, the plane would literally not fall. The 11x4 APC prop also provided plenty of speed, IMO. The engine finally failed, it was 16 years old, so I got an OS 46AX and now run a 12.25x3.75 on it. I got a bit more power, but I lost the flat spins that were so nice. The OS is lighter than the ST 40 was so maybe I lost too much nose and tail weight to keep the momentum necessary for the flat spins.

BTW, I tried an APC 10x5 and didn't like it. The 11x4 provided much more torque with no noticable top end speed difference.

If you don't want to invest in a new, more powerful and HEAVIER engine, try a MACS pipe on that good ole reliable FP.40. I ran one on a Magic, with hi-power mid sized servos. That engine only weighs about 9.5 ounces, but the heavy, stock muffler, robs power and adds weight. with the MACS, short pipe, I could swing an APC 12.25 X3.75, 12X4 and 11.5X4. My plane came in under 3.5 pounds, with wing loading around 11-12 ounces per square foot. I kept moving my CG back until the flying CG test past, nearly same straight and level up side down as right side up. Makes 3-D allot easier. Also make sure you are laterally balanced. Great fun fly and starting 3D, just close coupled making hovers hard. Good luck

I've now equipped myself with a new set of props and are eagerly awaiting the flying weather in Sweden to improve...

A MACS pipe...sounds like a good investment instead of replacing a nicely working engine. Where can I find those ? Have you got the address of the manufacturers website or similar ?

/Kris