Twin City Eagles Squadron

 

Visit Often!

I often get asked question about RC, with this part of our web site I would like to address some I get asked the most. So check back often and ask question. I will answer if I can or get you to someone that can.

 I will try to post the Question with the answer so things will be clearer. Thank You for stopping Pete Rosas

 

Q:
I am using the 9156's in a current plane and I keep stripping the same servo on the out board aelrion. Radio 14mz , tried programing it with it only . Then went to matchboxes . They seem to last longer but still the same result.  Could it be the geometry? And is there a way to check it? Maybe I could send a picture if you tell me the angle you want.

Jeff 

A:
It sounds like a geometry problem. I don't usually run any Synchronizers, but when I do I use this one.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCTS1&P=ML
      I spend a lot of time on geometry. One thing I found most people do is set the control horns on the aileron to the same height from the surface of the aileron. witch works fine for a constant cord wing but on a tapered wing it does not work. As you move out from the root the wing gets thinner, so the center of your hinge to the pivot point of your control horn gets smaller but looks correct. So set your control horn height from the center of your hinge point.  When you set your push rod length, servo arms, and control horns. Take your time, "Spend more time here then trying to program it out with your Radio or syncronizer" Center is no problem and I don't worry about full throw, I move the stick till I get about 70%-80% full throw and if I can get the servos to be "Quiet" when I hold the stick still up to that point ( in both directions) I call it good.  The reason being is in real flight situations when you go to higher throws the  servos are working hard to keep that deflection in the aileron. So both servos are pushing hard against forces that want to push it back, if this wasn't the case we would not need high
torque servos.  

  One other thing you may want to do is replace the extensions going to that wing. If you have a lead that is giving you an intermittent problem. when that servo briefly shuts down and the other is doing all the work in a high speed high deflection situation one of the servos will strip and  It could be either servo depending on a lot of variables.  I hope this helps.


Let me know what you find

Q:

Pete

I'm putting together an OMP Katana V2 70 I'm thinking one of the guys this summer told me you guys run OS 91's on them but can't remember if he was talking 2 stroke or 4 stroke?  I have a Saito 100 and YS 110 both NIB, trying to decide which to use.  Love the 110 on my EF Yak 68 but it is a 9 lb plane vs 6.5 or so for the new Kat.  Do you think the 110 is too much power??  I know the V2 comes in a little heavier than the original one but don't know how much more juice it'll need.  Ideas??

Thanks

Ken

A:

  We fly our Katana 70 on OS 91 4 strokes. and that is plenty of power. On a plane of that size it is just as important to keep it light as it is to have enough power, some times more important. To large of engine and you get into an entirely different flying airplane. with the larger prop it is harder to control pitch and ya, Because you are fighting much more torque and the gyroscopic effect of a larger heavier prop. Not to mention the added weight that you have to compensate with  even more weight at the tail. When an air frame of that size is over powered it is usually over weight, it may hover and torque roll at half power but it loses on all other flight characteristics. It becomes  harder to manage in a harrier,rolling harrier, knife edge loops, etc. With the right power the katana does all these with ease.

    I see this alot at different events I go to. Guys will use lager engines and have problems with flight characteristic and ask me to help them with set up when I say you have too much power they chuckle and say that's what the left stick is for. So the best explanation I have is take a large mountain bike wheel and hold it by the axle and spin it, grab both ends of the axle with each hand and try to turn it sideways or any direction and feel the resistance . The plane feels the same thing form the prop and it dosen't have two feet planted firmly on the ground. Now take smaller kids bike wheel and spin it the same way, It will take less force to move the wheel even at a little higher speed.

    Now for get every thing I said. you can also get to small of prop with to much RPM. via 2 stroke. A two stroke on the same plane will spin a smaller prop faster. but you lose the larger column of air over the tail feathers and inner ailerons that is needed to maintain stable control. So you have to find a happy medium.

   You really need to consider what you want the plane to do.You have seen my Katana fly and I use a OS 91 four stroke , 14-8 APC "Pattern" prop on Byron 15% nitro 18% oil content with an OS #8 glow plug with great results.

    Let me know how things turn out.

  Good luck.

 Q:

  Some stuff is coming along good other stuff not so good.  Can hover these 40 size forever with tail touches no problem but can't seem to get the torque roll down.  Harriers are coming but need work, need to spend about a thousand hours practicing slow rolls so I can get a better start on rolling circles.  Should spend more time on the sim but it just isn't fun for me-guess cuz there's no "pucker factor" :)

A:

Here are the best three tips I have to help with torque rolls

   First the rudder, Really you already know the rudder. When you are flying at yourself on landing in a cross wind you can run the rudder the correct way. and for taxing back, same thing. the nose of the plane is just a lot higher. When you are looking at the bottom of the plane and one wing is lower move the rudder stick toward the low wing this will give the correct rudder input to return to vertical.

    The second pointer to help you learn is to get the plane to rotate at a predictable rate. Lots of times when you are learning the plane will rotate 1/4 , 1/2 or 3/4  of a rotation and stop this is because to get the plane to rotate it needs to be a little back on its canopy.Because the CG needs to be directly under the prop and with the weight of the landing gear hanging out the bottom the plane it wants to fall forward and when it does it will stop rotating. Most planes require a little up input to get a

Torque roll going and small jabs of up to keep it rotating.

   And finally don't try to stay at the same altitude. You already have enough to learn. Set your throttle so you clime slitly and work on the other things. This will take throttle out of the equation and make the plane more stable and input more effective. When you ready then work on holding altitude.

  I hope this helps.

  Keep'em out of the dirt!(Snow)

 

 

Q: Pete

 I recently lost my best flying buddy to a woman. If I intentionally hit her with an airplane will the AMA cancel my membership?

 Signed

Sore Fingers

A:

Sore Fingers

 This Q&A section is not to be used as a " Dear Abby" section but since your question does involve an airplane and AMA I will attempt to answer.  Your AMA insurance is very good insurance and will cover you in almost any situation, however The "intentionally" part may raise some red flags, In my opinion you should contact a very good trial lawyer before you act on such aggressions. It is always best to weigh your options                     

 You consider your buddy your "best buddy" but he obviously does not consider you his. You have every right to feel gilted buy your "friend". His infatuation with this skirt may be short lived, Spend more time with your real buddies at the CB field. Give your buddy some time and space and hopefully he will come around. You know the old saying "If you love something let it go ,If it doesn't come back hunt it down and kill it"

Pete