I did get into aerobatics but I haven't improved my flying yet

[graeme jones]

Just a word of warning that some of the more expert pilots may have forgotten. It is possible to reduce control movements using rates to the point where you will not have sufficient control to recover from your mistakes. At an altitude of 100 feet and airspeed of 100 feet per second you will only have one second until your aircraft hits the ground if, for example, you pull instead of push doing the slow roll. I guarantee you will not reach the rate switch in time. Either reduce rates with caution or practice at a higher altitude until proficient. I'm not going to explain how I know this.

Graeme

[Alan Pennington]

Hi Peter, Thanks. All I've got to do now is sit in a darken room and read and learn.

[Peter Jenkins]

Good point Graeme - just remember to fly 2 mistakes high. Most pilots new to precision aerobatics tend to fly far too low and close in. With a 50 size machine, aim to fly around 50-80 mtrs away from yourself. Don't come below 100 to 150 ft. Live to fly another day!

[ASH.]

Peter, Graeme, thank-you for your replies.. very informative!

I myself am an advocate for exponential and am always trying to turn-on other club member to it. Some just don't want to know.

I'm going to try using more, maybe 20-25% and see how that goes but moving the sticks to extreme ends to perform consistent manoeuvers will be far too alien for me, I know. I will have to learn, slowly learn to give up all that control.

Peter, I did not know Futaba servos come with positive expo, explains why negative has to be dialed in. I did read on one of the US trimming sites that 10% makes it linear.  What about rudder.. 100%, same expo?

"Live to fly another day!".. gonna make that my motto.. And not push the flight envelope and my luck everytime!

Graeme, I too fly with a 7C and I've tightened the tension screws up to max. It's okay, but I do want a set of HD Futaba springs. I know they're available from TowerHobbies in the States. Perhaps you or I can order them.. pm me if interested.

 

Ash

 

 

 

 

 

Edited By ASH. on 21/05/2015 01:51:13

Edited By ASH. on 21/05/2015 02:02:00

[Peter Jenkins]

Ash, I didn't say Futaba servos came with positive expo. I said that all servos, by their geometry have more effect on the control surface when the servo arm is at 90 deg to the (long side of the) servo case. The way to overcome this is different for different makes of servo. For Futaba you dial in negative expo while for JR you dial in positive expo. They both have the same effect of softening up the movement of the servo at the mid position.

Equally, if you want to increase the effect of the servo at its mid position then you set expo to positive in Futaba speak and negative in JR speak.

Hope that clarifies what I meant to say and clearly failed to achieve!

[ASH.]

Thanks Peter for clarifiying, it was probably my error in understanding.

Can you please tell me which page covers rates/exponential etc on your thread.

Regards

Ash

[graeme jones]

It's not even as simple as that, because the control surface has a rotary motion as well. If the servo arm and control surface arm were the same length, each degree of servo movement would give one degree of control surface movement. For F3A the control surface arm will be longer than the servo arm by a factor of 3 or 4 or more, to give reduced movement, as Peter explained at the start of his thread. That's what introduces the non-linearity. Picture the effect if the servo were made to move 90 degrees in each direction. Small servo movement at the 90 degree limit would give no control surface movement at all. I'm glad it wasn't this complicated when I started flying. It was more a case of guessing how much movement was needed (or using the kit manufacturers settings) and then being careful not to move the sticks too much.

Graeme

[graeme jones]

Ash - I forgot to answer re. Futaba HD springs. I've looked at these in the past and they seem to be the same as Futaba part number FUTM3640 which are only for 8U and 9Z Tx's. Don't think they'll fit our 7C's, but I could be wrong.

Graeme

[Peter Jenkins]

Hi Ash

I had a look through the thread and I think you've found an omission on rates and expo as I didn't address those specifically.

I use degrees of movement now and set up the lowest rate as follows: ailerons 10 deg, elevators 10 degs, rudder 25 degrees. I normally aim for this to be around 50% on the rates and use 35% expo.

High rate is double the above and I use expo that gives me the same movement at half stick as my low rates. I use this rate for spinning. I set expo at what ever gives me the same movement at half stick as I get on low rates. This means that if I forget to return to low rates after the spin, during the vertical down line, so long as I don't pull more that half stick I get the same response as on low rate. Go past half stick though an the control surface starts to move quite a lot!

Mid rates I normally set for around 75% with expo set as per above.

Hope that helps.

Peter

[Peter Jenkins]

If anyone reading this thread is motivated to try out competition flying in a supportive environment and are in East Anglia, there is still one place remaining for the New Pilot Open Day to be held on Sunday 31 May at the Raydon & District MAC.

You will get one to one mentoring/coaching on flying aerobatics and will be able to fly in a one round Clubman Schedule competition at the end of the day. All you need is an A Certificate. If you are interested then please PM me as soon as possible and I'll send you out a note describing the day in more detail as well as an entry form. Cost of entry is £5 with £3 for the BBQ. Where else will you get coaching from experienced aerobatic pilots (some of whom are in the current GB team) as well as seeing what the schedule should look like when properly flown.

nuff said!