Using an O.S. 46AX in a 5 to 6 lb. pattern ship, such as Javilin 40 or Goldberg Matrix 40 3D, I'm thinking APC 11-5 or 12-4....agree or disagree? I want maximum vertical performance, not speed...


Big_G

"Too much is never enough"

Hi Bigh G,
I am using APC 11x6 with the same OS .46 AX and a tower hobbies semi tuned pipe. Works fine for my Javelin II (also with the standard muffler)
Regards,
Jock

Big G

I can't answer your question because I'm wondering exactly the same thing myself,----only my engine is an OS FX 61? I would guess a 13/5, (if it's made), or 13/6. A 91FS could probably handle a 14/6--is that close?

Maybe we could both get some advice for our different sized engines. In my case, I'd like to keep the fuel limited to 15% nitro--(I know some are using heli fuel in their 4S, but I'd rather not).

Thanks in advance!!

Jock, how is the vertical performance...like in square loops or verticle 8's?...my Javelin arrives this week...

hi,
I have a .61 FX WITH an OS tuned pipe, i fly at 7000 feets , and i am using a 12x8 (0%nitro) in my Dash five.

I think that fx series work better with high rpm , so i think that you can use 11x 8 12x6 or somenthin else

what altitud are you flying?

I was flyin a 11*12W or a 12*11 in my dash five (OS 61RF-P)

big G,
I can fly the intermediate scedule just fine with this setup. Square loops, no problem Stall turn with full roll up, no problem. Vertical is not unlimited but absolutely enough and with the proper speed management it can do it all.
(I fly at sea level so this can be of some influence)

Regards,
Jock

I fly between 50-300 feet--how can you see it at 7,000 feet?--just kidding I fly in Western North Carolina, about 2000 feet. I have read that a larger diameter prop is more important for vertical. Like Big G--I want vertical--not necessarily speed.

A related question has to do with "K" Series props---their ad says the K-Series set of props by Master Airscrew is designed for 4S engines. I already have a 13X6 K-series prop on hand and I'd like to try it on my 2S OS 61 FX. Is there any design or safety reason why a K-Series prop can NOT BE USED on a 2 STROKE engine?

Thanks

A few of us at our club have put the APC 12.25x3.75 on OS .46FX and an Evo .46NT engine with excellent results. We are putting them on Somethin Extras and they will 3D with that prop. I was using an APC 11x4 until I switched to that prop and it was a big difference.

Ok, tyvm....Big_G

Go with an APC 12x4 I had that set up on a Lanier Razor with the .46 ax. It was setup as a pattern plane and that combo provided unlimited vertical, but still a lot more speed than I expected. the plane was I think about 5.5 lbs.

I've been flying a 46FX with APC 13x4 on 20% nitro with OS F plug, mounted on 4-1/2 lb Katana profile, and the performance has been very brisk, very strong verticals. A model that's a pound to a pound and a half heavier would not be quite as easy to haul around, but thrust is thrust. My Javelin was just over 6 pounds (by half an ounce) with YS63 power. Vertical was not fast, but it was plenty high enough. Propped that with a 13x6 APC.

that is interesting about your 13x4. what are your peak rpms?

I never checked the rpm's, and the 46FX has been replaced with an OS 70 four-stroke turning a 14x4. Guys at the hobby shop were skeptical about the 13x4, but I liked it, and will do it again.

I'll keep the 13x4 in mind. Some guys said the same thing about a 11x4 on my .46NT but it did very well. I may stick a 13x4 on it.