rudder or engine thrust

[Tweaker]

	Quote: Originally Posted by SportFlyer
	What about those that don't have a lot of programmable mixes how do we get around that???

If you get the plane trimmed,thrust and cg set you should only need 4 mixes (that I can think of), I only use two at this point in my learning curve. I use rudder to elevator and rudder to ailerons for knife edge flight, the other two I think of are throttle to rudder and possibly throttle to elevator for downlines.

I'm a noob so I'm not real savy on trimming or mixing but I'm getting better and threads like this will help me get there.

Scott

[Al Lewis]

Haven't read the whole thread so if this has been stated I apologize. Run the plane in level flight at half throttle. Hit full throttle. If the plane turns to the left or right, up or down, then you have a thrust issue. If not, you have a trim issue.

[SportFlyer]

	Quote: Originally Posted by Tweaker
	If you get the plane trimmed,thrust and cg set you should only need 4 mixes (that I can think of), I only use two at this point in my learning curve. I use rudder to elevator and rudder to ailerons for knife edge flight, the other two I think of are throttle to rudder and possibly throttle to elevator for downlines. I'm a noob so I'm not real savy on trimming or mixing but I'm getting better and threads like this will help me get there. Scott

Problem is with the radio I'm running, I only have three P-mixes and I have to burn two just on the ailerons for rudder to aileron mix (2 separate channels for ailerons and I have to mix each on with rudder) and then I have a smoke mix so I'm out of mixes...I had the last mix for rudder to elevator but couldn't get it dialed in so I put smoke in and used it there instead....I need another radio...LOL!!!

[3D-Seth]

	Quote: Originally Posted by scott m lyons
	Hey Seth I usually do up line and bump my rudder trim till the plane flys uplines straight.Then do a throttle to rudder mix on a 7 point mix for three quarters to low throttle to center left.I usually end up with 3 degs right at full throttle and 3 degs left a low throttle.I found when I started doing inverted harriers with you're trim setups the plane would yaw alot.Now it tracks straigh no matter the atitude.Do you have to hold left rudder when doing harriers and high alfa stuff?

Thats a bad idea. Your airplane will roll funny that way. Why not set it with thrust and trim the rudder normally so you don't have a bunch of trim in the airplane? That will make just that much more work for you.

This is how I set my planes up for freestyle AND IMAC flying:

Find the CG at which I want the airplane to be.
Trim the rudder for level flight.
Check the thrust angle. Fly a vertical upline (pulling vertical with the wings LEVEL. I CAN NOT STRESS THIS ENOUGH). Most planes are good with the stock built in thrust, but everyonce in a while, you need to adjust this.

Without wind, no rudder is needed for a straight harrier. The little bit your rudder is trimmed does not affect 3D flight in any way. Theres so little deflection, and so little airflow over the tail, the airplane won't do anything with 1/2 degree of deflection on the rudder. Thats why we use 3D rates when we fly 3D high alpha stuff anyways.

Just my .02 though

Seth

[Sukhoikid]

I am wondering if RC planes react the same as full scale. When power is givin you usually have to give it right rudder to keep it in a climb or you will veer off left. I am taking aerodynamics in college next year, but was wondering if a rc plane has the same affect. One thing we got to consider though is the power to weight ratio we have with models that full scale doesnt have. I would believe this makes a difference.

[3D-Seth]

	Quote: Originally Posted by Sukhoikid
	I am wondering if RC planes react the same as full scale. When power is givin you usually have to give it right rudder to keep it in a climb or you will veer off left. I am taking aerodynamics in college next year, but was wondering if a rc plane has the same affect. One thing we got to consider though is the power to weight ratio we have with models that full scale doesnt have. I would believe this makes a difference.

I have really only noticed this if i you just bolt the throttle. If you smoothly/slowly transition, theres not much pull to the left.

Seth

[mrbigg]

Wasn't it Chip Hyde who uses a throttle to right rudder mix with a zero degree engine setting?

[Walt]

At 1/2+ throttle fly the plane straight at yourself at a safe distance with a no wind condition, preferably by yourself for obvious reasons. Concentrate on getting the wings dead on level coming towards you, its easy to see at this attitude. Easily pull the plane vertical at 1/2 throttle and watch the plane transition into the vertical climb. Adjust rudder trim for the plane to enter and establish the climb straight. when you get this down, go to full throttle and do it again. Usually if there's a trim issue that re appears it may indicate the need for more engine offset. It'll take time to dial this in but this was the way I was taught for the initial check and a starting point for rudder trim, it works. I have also found that if a plane is straight and your construction numbers are right there's usually no reason for a plane to require more than 2-1/2 degrees offset on the thrust line. I did mention usually BTW.....Prop's and CG changes will require you to start over again....

[Flybye Steve]

I hava a EF 100cc Yak and have found it requires considerable "right rudder" trim to sustain true vertical up lines. Interestingly, I have the "right" trim mixed out at low throttle for straight down lines. Also, I have a simular throttle/elevator trim; a small amount of "down elevator" at low throttle neutral in the middle range and a little more down elevator at full throttle. I have a DA100L on Grieves pipes with a Mej. 25/12 three blade prop. I'm not sure changing the engine thrust angle would work as well as the mixes. I also noticed there seems to be a much more pronounced tendency to pull to the left (requiring more right rudder) when transitioning into an up line at full throttle as opposed to feeding in throttle gradually during the transition. As the plane slows during a "Stall Turn" , it would immediatly start turning to the right until I mixed out the "right rudder trim" at low throttle. It seems complicated, but it works.

[nate428]

mixes have to be fine tuned between inputs on the sticks and actual flight path/speed of the plane... so as this transition happens the mix will under or over perform its function. i prefer to spend time to correct the thrust angle not the mixes, and have my plane fly correct all the time.

[The Dirt Doctor]

	Quote: Originally Posted by Flybye Steve
	I hava a EF 100cc Yak and have found it requires considerable "right rudder" trim to sustain true vertical up lines. Interestingly, I have the "right" trim mixed out at low throttle for straight down lines. Also, I have a simular throttle/elevator trim; a small amount of "down elevator" at low throttle neutral in the middle range and a little more down elevator at full throttle. I have a DA100L on Grieves pipes with a Mej. 25/12 three blade prop. I'm not sure changing the engine thrust angle would work as well as the mixes. I also noticed there seems to be a much more pronounced tendency to pull to the left (requiring more right rudder) when transitioning into an up line at full throttle as opposed to feeding in throttle gradually during the transition. As the plane slows during a "Stall Turn" , it would immediatly start turning to the right until I mixed out the "right rudder trim" at low throttle. It seems complicated, but it works.

I have a flight mode set just for the hammerhead stall turn - all of the rudder to ail and rudder to elev mixes are both turned off. On the downline I usually flip the FM switch back to normal flying with the rud to ail * ele mixing on.

Bobby aka TDD

[Flybye Steve]

TDD, Interesting approach. I,m wondering why all of this is required on this particular plane. I can't figure out if I'm now beginning to see these issues due to advancement in IMAC flying skills (the more you compete, the more you see smaller imperfections) or if it's an issue with this particular plane. This same plane won the Stortsman class at the Nationals so I have to wonder if Reiley had all of these mixes or just a lot of flying skill.

[The Dirt Doctor]

	Quote: Originally Posted by Flybye Steve
	TDD, Interesting approach. I,m wondering why all of this is required on this particular plane. I can't figure out if I'm now beginning to see these issues due to advancement in IMAC flying skills (the more you compete, the more you see smaller imperfections) or if it's an issue with this particular plane. This same plane won the Stortsman class at the Nationals so I have to wonder if Reiley had all of these mixes or just a lot of flying skill.

My guess is that he had both!! A plane that is almost perfectly trimmed out is much, much easier to fly than one that is not! Take that a pilot with lots of skill and it's a winning combination.

Bobby aka TDD

[jack strickland]

	Quote: Originally Posted by The Dirt Doctor
	My guess is that he had both!! A plane that is almost perfectly trimmed out is much, much easier to fly than one that is not! Take that a pilot with lots of skill and it's a winning combination. Bobby aka TDD

Hi Bobby
I have noticed a lot of posts refer to cg, but no one has stated where it must be. In my opinion there is only ONE placement of the cg, and that it is correct when at wide open throttle, flying level and rolling to inverted, the plane should not start to decend. As a general starting point for the cg, it should be near the thickest part of the airfoil, and move as required. It takes a lot of time to get this done, but when it is done, the plane will be a lot easier to fly, and the other adjustments will be easier also. Just my opinion. What do you all think?
Cheers

[JEFFRO503]

jack.....do you mean a slow roll or a fast roll? If it is going in a slow roll , and when it hit knife edge position , wouldn't the cowl start pointing downwards at that time? I myself am on the same page as you though. I "used" to like my airplane a little tail heavy for 3D type flight , but i have since moved my CG so it's centered pretty well. Pretty much hands off on inverted and right side up flight.....at least that works for me.