Hi all
What is the recommended propeller size for Katana 46 with OS 50 engine?

Thank you!

I'm just about to complete a Katana myself with the OS50SX, and I'm planning to use the APC 12,25x3,75 Wide.
Great prop on 46-50 high rpm-engines.

Edit: ...that's if you like 3D and vertical climbs. If you like more sports and high-speed flying: APC 11x7, Robbe 12x5, or similar sizes.

Thank you Raidenflight for you replay
I think I will go with the APC 12,25x3,75 for now speed is less important I want to focus on 3D

Are you building the katana 46 v2?

APC 12.25 x 3.75 or master airscrew 12 x 4 with OS ax 46.

Had lots of deadstick issues due to vibration. Would be interested if you experience the same.

I haven't started its engine yet (part missing), I will start it this Friday and report if I will encounter strange behavior or vibrations...

Do you know if the Rear wheel of the katana is attached to Rudder? So it moves with it? Or its static?
Also what servo needed for the katana 46? Will standard servo satisfy it?

No Sharon, I'm building the heavier, full-bodied CMPro Katana.

I just finished one with a Saito 82 GK. A word of advice. The recommended CG at 5 1/4" from the leading edge is too nose heavy. The plane flies like a brick at the recommended CG. Make the plane more tail heavy by moving the battery and/or RX back in the wing. Move the engine in the mount to make it more tail heavy. I set mine with the RX and battery towards the back of the wing and then installed the engine to the recommended CG and it flew like crap. I added some tail weight to get it more tail heavy and it flew with the tail down in upright level flight and when rolled inverted the nose went to the ground. I had to keep down elevator to get it to fly level inverted. I have now moved the engine back in the mount but haven't had a chance to fly it. I know this should help because I have a 1 oz. spinner nut that I removed and it flew better. That is why I moved the engine back towards the tail.
I attached the tail wheel to the rudder to make it steerable. I glued a piece of plastic tubing to the bottom of the rudder and inserted the tail wheel wire in the tube. Easy to remove the tail wheel assembly if it needs replaced.
There are three guys that fly the same plane with standard Futaba servos without any trouble at all.
I'm flying mine with a 14x4 Zinger prop.

Hi madman
Are you talking about the Katana 46?

Saito 82 GK Weight (no muffler) 16.00 oz (454 grams)
Os 50SX Weight (no muffler): 13.80 oz (391 grams)

Saito 82 is 2.2oz (63 grams) heavier...

The tail wheel does attach to the rudder, however I chose to to avoid it and mounted the tail wheel to the fuselage bottom ie like a tail skid, but with a wheel. Ground steering with the rudder is ok ( I fly off grass).

Re: servos , Used standard servos in the wing, and hi-torques for rudder and elevator (hitec 635). Used a mini servo for throttle ( discovered later that the servo mount lugs broke wth vibration !)

It's the TMPro Katana 46 V2 profile. The 82 is so much more responsive than a 2 stroker. I have flown a Katana with an OS 55 on it and the throttle response is so much better with the 82. I can hover my Katana at less than 1/3 throttle where the OS takes almost half throttle. There is a big difference in weight between the OS and Saito mufflers. So the total weight difference isn't that much. The OS muffler is 95 grams(3.35 oz) where the Saito muffler is 1.6 oz. So the difference is 1.75 oz in muffler weight and the difference between to two engines is only 0.45 oz. which isn't that much. I'll take a 0.45 oz weight hit because the 82 can produce more torque and turn a bigger diameter prop which is better for 3D flying. I can use a 14x4 prop as compared to a 12x4 which will have more air across the control surfaces. I'm not sure what your point is comparing the two engines.
All weights are from the manufacturers specs.

I thought the 82 is heavier, I was wrong indeed the muffler compensate the engine weight.
Anyhow I implemented your advice and moved the plane logic & battery to the back of the wing, I will report next Sunday…

Thank you!

Just make sure that you make it more tail heavy than the instructions say. If you set the CG at 5 1/4" like the instructions say, It will fly like it's too nose heavy. You may want to make it slightly tail heavy with the battery and RX as far forward in the wing as you can and if needed move them back if you determine that it's still not tail heavy enough for you liking. I moved my motor back and flew it today and still needed to add a little tail weight. I haven't flown it since I added some tail weight. Mine isn't tail heavy for my liking.
Another thing I have had trouble with is severe foaming of the fuel in the tank with the engine running. I tried different amounts of foam and different density of foam to reduce the foaming. No luck. When I got above half throttle, the fuel would start foaming and the engine would surge from getting air in the gas line. Had trouble setting the HS needle. The engine would be rich go lean, rich, lean and so on. I finally removed the plastic zip ties and mounted the tank with rubber bands. This almost eliminated the foaming. he engine now has a more consistent WOT and the HS needle will adjust better. You may not have this trouble since you are using a 2 stroker. 4 strokers vibrate more. I still had to use about 2 inches of foam to reduce the foaming.
I'm starting to get the plane dialed in. So far I'm not impressed with the 3D flying of the plane but maybe I'll get it setup like I want it.

Re bubbles in the tank due to engine vibration, try mounting the tank of the wing ie make an extension from the wing leading edge and mount the tank on it. Makes a significant difference.