loves nitro

Im fairly new to flying RC planes, I've been soloing for about 4 months, Im flying a Sig Kadet with an older OS .46 LA engine. The prop I have on it is an 11/7, but the plane seems slow to take off, slow in flight, and it seems like it takes a 40 acres to turn her in flight. I know this plane is meant to be slow, but in the air the plane is like a bus, slow and not very manuverable. I've been told that the older OS .46 La engines aren't very good, and low on power, so Im not sure if the low power level, and very slow manuverability could be from the engine, or the prop. If you guys think I should try some different size props, could you recommend some sizes to try?
Thanks Much,
paul

JPMacG

My Feedback: (2)

To me, an 11/7 seems like too much prop for an LA46. I would try a 11/6 or even a 10/6. Props are inexpensive. It is good to experiment.

If your goal is to get off the ground in less distance then a lower pitch prop is the way to go.... like a 11/5. If you goal is to go fast in the sky then a higher pitch prop is the answer... like a 10/7.

Making turns is another story. If you have a transmitter with the capability, try mixing a little rudder with the ailerons. Some airplanes with flat bottom wings don't turn well with aileron only. Start out with just a very little amount of rudder deflection.

j.duncker

My Feedback: (2)

To much pitch for that engine plane set up.

An APC 12 ,25 x 3,25 will transform the take off and make it easier to land.

Alternatively any 11x 5 will be better than that 11x7. The grey Graupner props are a little more flexible than some and tolerate the odd prop strike better. APC props are brittle.

gene6029

I'm flying my Kadet with a now discontinued LA 40 & it does take a bit of runway to get airborn. Your LA46 should be a tad bit peppier than my 40, and i would try the 10-6 prop as suggested. As far as takeing 40 acres to turn, that has nothing to do with your engine. Even with my well worn LA40 it will loop, roll & turn as tight as i want it to, but you'll need to crank up your throws. If your radio allows, set up your elevator & ailerons for as much throw as you can get & put that on a high rate switch. Take off on low rates, get it up high & switch to your new high rates & i think you'll be surprised. My Kadet will fly inverted too with only the 40, but its no speed demon. We have people flying them around here with small gasseres & 91 four strokes, allmost all switched them to tail draggers. That plane can really come alive with a larger engine. ....Gene

loves nitro

Thanks alot for the good advice, right now the Sig has a Master air screw, but Im going to get a 10/6, an 11/5, and the APC 12.25 x 3.25 props and see just what happens. Also I really feel stupid, why did'nt I think of useing my rudder along with the ailerons to turn my plane??!! Sometimes Im a real knuckle head.
Again thanks for all the advice.
Paul

vertical grimmace

My Feedback: (1)

Those 3 props are perfect suggestions. I would try to stick with APC if possible as well. That 12.25"x 3.375" prop will work very well. Large diameter, low pitch props work well well on trainers.They really help to slow down when landing.

countilaw

The OS .46 LA is a very weak engine. You need to get the RPM up to get it into the power band. Swinging less prop usually helps gets the RPMs up. You might find a 9 X 7 will work very well. It will pull the plane faster and give you a better turning radius, and getting air bourne faster. All the previous suggestions are good and worth trying.

Frank

jester_s1

I'll advise against using a really low pitch prop for a trainer. That 12.25x3.75 is going to have a lot of pull, but it won't give you much forward speed. That makes it easier for wind gusts to push your nose up and make you stall, and will make turning harder in the wind also. An 11x5 will still give you enough pull to accelerate off the runway and do recoveries just fine, and it will also let you keep enough airspeed to have a bit to spare when you need it. That's still on the upper end of how much prop that engine can turn. You won't be getting max power with it, so you might even consider trying a 10x5 and comparing them.

Lightspeed1551

My Feedback: (4)

10x6

rgburrill

I use a 10x6 on a sport 40 and an 11x6 on a 46
BTW, nothing against APCs (I have them too) but for a trainer I use MAster Airscrew nylon props - much cheaper and will take a beating on those rough landings better than an APC.

MajorTomski

May I suggest that you increase the throw on your ailerons? A Kadet set up by the book does a full roll in about three seconds. If you add full rudder in the same direction as the aileron roll it will increase the roll rate down to 2 seconds. This is a leftover from the Kadets original three channel origins.

MTC YMMV, been teaching on Kadets for 18 years now.