somegeek

My Feedback: (2)

I have a SSE with a OS .46AX engine and I'm learning some IMAC patterns to better hone my flying skills. Wondering what will produce the best balance between speed/thrust for these patterns with this plane/engine combo? Currently running a APC 12x6 but not sure this is the best prop as it only lets the engine run up to ~10,500 rpm. I've read that the sweet spot for power with this engine is 13,000-13,500? Someone suggested an APC 11x7.

Also - would removal of the internal baffle in the .46 AX muffler increase peformance?

Appreciate any input.

somegeek

Insanemoondoggie

You should be able to turn a 11x6 prop 13,000 plus.. If you like hovering try a 12x3.75 APC.

ChuckW

Try an APC 11x5 on your AX. I'm running one on my GP Cap-232. I like it a lot. RPM is usually high 13,000's, low 14,000's. As suggested, a 11x6 might be a good choice too.

somegeek

My Feedback: (2)

I've got both the 11x5 and 11x6 that I haven't tried on this plane. Will give this a whirl tomorrow.

No real desire to set this plane up for 3d but I did buy a 12.25 x 3.75 that I gotta give a whirl.

somegeek

ChuckW

I had the SSE with a Super Tiger .45 and APC 11x5. That plane was plenty fast and a blast to fly.

bkdavy

My Feedback: (1)

For pattern flying, you'll want the thrust and braking provided by a large diameter prop. I recommend you try the APC 12x4. It will give you the thrust you need to get good continuous uplines, and the larger diameter will help slow the plane on downlines. The 46 AX should turn that prop between 12,700 and 13,000.

Brad

somegeek

My Feedback: (2)

Just what I was looking for - thanks, bkdavy.

somegeek

rhagen

Wondering how you are getting the 12-inch prop to work on the SSE. Mine didn't have enough ground clearance. Are you using the stock landing gear?

somegeek

My Feedback: (2)

After market landing gear which is about 3/4" higher than the stock landing gear - bent the gear down just a bit on each side for a little more clearance...



I also land on a matted runway vs grass which helps I'm sure.

somegeek

somegeek

My Feedback: (2)

Took some readings tonight on my OS .46AX:

APC 11x5 - 13,200 (13,500 running lean max RPM)

APC 12.25x3.75 - 12,150(12,450 running lean max RPM)

Also have a hobbico exaust deflector attached - not sure if this causes a performance hit?

somegeek

ChuckW

You might try it without the exhaust deflector just to see. My .46-AX with a Slimline Pitts muffler actually gained 250-300 RPM when I added some silicone tubing extensions to keep the oil off the bottom of the plane so you never really know without experimentation. My new .55-AX just arrived yesterday. It's either going in my Twist or OMP Edge 540 profile. I can't wait to see how it runs.

sowega flyer

With those numbers that you took, a 12x4 would seem to be a great choice. I run a 12.25x3.75 on my Magic extra 300 with a GMS .47, and it does great, but the 12x4 would give you faster wind up when you apply the throttle. For the record, I have never tried a 12x4, so this is really just speculation.

bkdavy

My Feedback: (1)

I have the APC 12x4 on my GP Cap 232 (same class as the Sig Something Extra - very similar weight and drag). Using a TT Pro 46 (essentially a clone of the OS 46 AX) I get 12,700 RPM on the ground, unlimited vertical. I tried the 11x5 and was unhappy with the vertical performance, and it didn't get the plane moving quickly enough when throttle was applied.

These props are cheap - get a range and try them all - pick the one that best suits your style.

Brad

somegeek

My Feedback: (2)

I flew on a 12.25 x 3.75 yesterday and it did great with vertical climing. Flew a bunch of humpty bumps and the upline was great and the downline was slower than my other prop which was nice. Diggin this prop. Will also try the 12x4 APC.

Thanks,
somegeek

ChuckW

Got a couple of those in my field box, i think I will try one on my Profile Hots with a .46-AX.

somegeek

My Feedback: (2)

Removed my baffle and tooks some tach readings with and without the Hobbico exhaust deflector...

Engine: OX .46 AX
Fuel: Cool Power Synthetic(green)
Exhaust Deflector: Hobbico Exhaust Deflector .35-.90

Previous readings:
APC 11x5 - 13,200 (13,500 running lean max RPM)
APC 12.25x3.75 - 12,150(12,450 running lean max RPM)

Removed the baffle from the muffler. Definitely louder but in a cool way. [8D] Field I fly at does not have any neighborhoods around so this won't be an issue.

APC 12.25x3.75 - 12,600(12,900 running lean max RPM)

Removed the exhaust deflector

APC 12.25x3.75 - 12,350(12,650 running lean max RPM)

Engine seems to like having the exhaust deflector.

Nice boost of roughly 450rpm due to removal of the muffler baffle.

Will pick up an APC 12x4 this weekend and see what kinda numbers I get.

somegeek