What is everyone getting with a 12x4 prop?

13200 i think. 15% cool power and macs muffler.

46fx, stock muffler without inner ring,10X7 prop 0% nitro =

12850-13000

Hey Stcolgre,

Got around to fly'n my profile today with a 12x4 APC bolted on.

OS 46 FX - stock muffler/with baffle
15% Nitro
K&B 4520 R/C Long glow plug
5 deg.C - 75% Hum.- 100' Elv.

12,400 RPM-Ground / 12,000 RPM Flying


Happy Fly'n....

The air was good and thick today...
Temp: 14 C
Humidity around 63%
Baffle removed
12800 RPM

The 46 was twist'n that 12x4 real good... To good in fact that I blew the horizontal stab right off the airframe! Besides a little covering to patch and the construction of a new stab. the damage was minimal considering it nosed straight in.
The plane was a TT Extra 300 Profile. I was never Keen on the stab design on those and it's not the first time it has been blown off. For those interested in profiles I would tend to find one with a solid balsa stab instead of one that has been stick framed.
TT states the flying weight at 4 lbs. BULL$#IT! Standart servos and a 46FX - 84 oz's.

Happy Fly'n....

Hey Pepe

Saw your post about blowing the tail off your TT profile. Wellll if it tastes like fish smells like fish it must be??? Myself and one other guy in my club had TT profiles. Mine was the blue G-200 and his the Extra (same plane). Well guess what half the horizontal stab left both of these in flight. I gave mine away to a guy who wanted to rebuild the stab, I didnt want to fool with it. That was after I had strpped all the stick coat off and monocoated the plane. It was positively the worst balsa and construction I have ever seen in a model.

Yep.... I agree with the construction, along with 90% of the other ARF's out there. I am leaning toward a Morris TopCat for a replacement. That or start building a Sig Something Extra I have? Sorry to hear of your loss(es). I had a good 100 flights under my belt with mine, so it is a no lost love deal and I think I will pass it on. Live 'n learn.

Happy Fly'n....

13900 with:

12x4 APC
UltraThrust Muffler
15% Nitro
OS #8
450' Elev, 85° F & 35% humidity
And that was on the 13th tank of fuel...

TGP

I will vouch for the quality of the TopCap. I have landed mine pretty hard a few times, including one pancake from 15 feet when the engine quit while entering a hover, and one direct impact with a light pole on landing. I wasn't going very fast on that one, but I caught a wing square about 2 feet from the ground, spun it around and landed on a sidewalk. Aside from a busted prop and some bruised pride there was no damage.

until now I thought I was the dummy. I had the TT 300 also. on the 1st flight the stab came off and .....STUFF! total loss. I didn't know it was common.

11.7K with a Zinger 12x4, Tower muffler, 15% Power Master on a cool day.

12x4 APC - 13200
11x5 APC - 13000
12.25x3.75 APC - 11700
9x10 APC - 13600
10x9 APC - 11600
10x8 APC - 12300
11x6 APC - 11500

All with 15% on a cool day at 6000' and Mac's muffler.

I have a newbie question for you guys. What benefit does removing the baffle/inner ring out of your 46FX give you?

It gives you several hundered more RPM from the reduced backpressure. The baffle is only there in an effort to make the engine quieter.

Fuel - 10% nitro.
Macs muffler
12x4
14200
But! With self made ceramics piston & sleeve, enlightetned piston rod & rebalancing shaft.

I am running the OS .50SX with APC 12x6 getting 11,000rpm with an Ultrathrust pipe and 15% nitro. I plan on moving to 11" props and testing this weekend to raise the rpm for racing....I am using a 3.5" spinner though which may not allow me to drop diameter and still fly the .60 size plane this motor is in. The Hanager 9 P51.
Enjoy,
Jim

I got 10500 rpm on the .50SX with standard silencer and 10% nitro with the 12X6 APC prop. That was with the engine richened for flight.

OS 46FX spinning a 12.25x3.75 APC @ 13,200 with a MCP on 15% nitro. Need to try a 12x4 APC since it can spool up a little faster and spins a little higher RPM also. Will post results when completed

I'm thinking, not too bad for a 46 size motor spinning a larger prop.

I get 12900 with a 12x4, but recently switched to a 11.5x4 for spool up reasons, bu this is on a Royal 46 so its almost the same engine.

*UPDATE*

I retuned my OS 46FX with a 12.25x3.75 and it spins 13,470 strong. This setup on a Spa3d is amazing.

Finaly tried an APC 12X4 on my OS 46FX as promised which spinned the prop at 13,680 RPM, Although it spools up faster than my APC 12.25x3.75 which spinned at 13,470. I prefer the 12.25x3.75 for 3D flying. The 12x4 didn't have the thrust compared to the 12.25x3.75. The 12x4 didn't hover as steady. Couldn't find the sweet spot on the throttle position that would hang the plane. The 12x4 prop flew the plane faster at a lower throttle position and didn't harrier as well also. The engine had to run higher RPM's to hover and harrier also. Don't get me wrong, the 12x4 is a great prop for any type of flying, but the 12.25x3.75 is a better 3D prop for this motor.

Just depends on what type of flying you are trying to do.

To answer your question though,

12x4=13,680 RPM
12.25x3.75=13,470 RPM

13500 RPM
APC 12x4
46fx
Morgan 15%
Tower Muffler
~1000 feet ASL

Has anone used the o.s. super silencer? how much power would this rob?

For reference, my Magnum XLS46 turns the APC 12x4 at 13,500 peak Typically set at 13,200 or 13,300 for flying with fantastic transition on my fuel and with this prop. Sounds like it is performing exactly in the ballpark of the better 46FX's.

Fuel: Wildcat 15% nitro/18% synthetic, with added 4% castor oil.
Glowplug: Fox Gold.
Muffler: stock Magnum with baffle removed.