Futaba Radio

[Ozzy]

Hi all in need of some advice.

I need to know if there is anything I can do to soften up the controls for the nosewheel/rudder. When I go to take off I end up zig zagging and I will eventually crash the plane if this continues. I have the D/R (Dual Rate) option for ailerons and elevators but nothing for rudder. I didn't want to adjust the EP (End Point) as I still want to be able to make tight runway turns. Has anyone else had this problem??

[David Ashby - Moderator]

Can you out on some (negative) exponential Ozzy? That would allow full travel with the stick response softened at the centre. 

[Ozzy]

This is the problem. On my Futaba TX I only have exponential option on channel 1 and 2. It doesn't cover channel 4 which it the rudder.

[Myron Beaumont]

Ozzy    Simple answer is   Use max. power blasts of propellor wash to make your rudder more effective when taxi-ing etc. at slow (ground) speeds  You can turn on a sixpence as we used to say before going decimal &/or digital or exponential for that matter .Cor blimey does anyone remember when all we had was a servo that only went one way & batteries were used that these days would be too big for the average family car .

Guess who ?

[Bob Cotsford]

if the nosewheel steers, can you not move the link to a hole closer to the centre of the servo arm, or to one further out at the nosewheel tiller end?  Is it that the controls are too sensitive, or just that you are overcontrolling on the take off run?  If the latter, try a few deep breaths to try and relax before opening the throttle - even just opening up slower can help.

[Myron Beaumont]

Bob     probably involves too many geometrical calculations for the new comer like Ozzy  Proves the point you can't really resolve all set ups digitally unless you're pretty close mechanically to start with (nevermind the extra unnessary loads on servos/linkages etc.)

Not getting at you Ozzy but I suppose we all (us old modellers) had to find out what to do without any help from things like the internet ,just self taught we were like your good self .That was & is the mainstay of this great hobby/obsession that a few of us old b-----s started in 1940 kit bag

[Ozzy]

LOL. Right!! What is happening is the controls are too senstive. I have no EXPO on the channel that controls rudder and nose wheel (both controlled on same servo). When Im taking off I give the TX little touches to try and keep the plane in a straight line but it steers too sharply. I then end up zig zagging as I touch to go one way but steers to far and then have to touch to go the other way. I then have no choice as I am going so fast I need to get it off the ground otherwise the plane might tip over. I have tried being as gentle as I can on the controls but its bloody annoying.

[Doug Ireland]

Why not do what the full-size boys do. Use a pull-pull set-up and attach springs at either the nose gear end or the servo. Softens up the steering and helps reduce the wear on the servo gears.

[Myron Beaumont]

Ozzy   I know exactly what you are saying .We've all been there ! Forget expo ! (as a solution)  All I can say really is keep her right into the wind on T/O (look at the flag or streamer) & most importantly DON'T over react with your corrections .ie Just a smiggin' of centralising or opposite direction applied NOT a handfull. Air is a slow response fluid NOT like a water born boat 's rudder .In other words Don't expect an immediate response to your (over) input from waggling the stick on the tranny In other words Softly Softly catchee monkey DONT PANIC!!!

Grumpy Myron  But hope to be of use

 PS Am battling through a green plastic bottle of cider so I can make a canopy/cockpit for my new model  sometime later so forgive me if I appear to be somewhat ineebreeated All in a good cause .No flying today Eh?

[Phil Claridge]

gale force 9 and peeing down here in sussex er no flying

[Tim Mackey]

Plenty of flying here on the big rock

HERE

sorry - off topic

[Doug Ireland]

I'm stuck on an oil rig, no flying out here either!!

[David Martin 2]

Hello Ozzy, been there mate with my Pilot QB20H's stearable nose wheel 25 years ago..!

I found I got through a few servo's with it due to no servo saver coupling incorporated (didn't know any different at the time), landings, even good ones, put excessive stress on the servo and Rx battery.

Since fitting fixed nose gear, the model can still be turned fairly tightly with full rudder on the ground with plenty blasts of prop wash, but making sure the front wheel is aligned straight, hardly any rudder correction is needed if you open the throttle slowly and are taking off directly into wind.

If you want to keep the stearable gear, I would move the pushrod from the front wheel to the innermost hole on one arm of the servo's horn and the rudder pushrod to the outermost hole on other arm of the servo horn. You'll have less wandering on take off but the combination of stearing wheel and full rudder will still give you tight taxi turns.

You really want to try and avoid the need for excessive rudder on take off as it counts as yaw once the wheels leave the deck and you could cartwheel it pretty smartly if not released quickly....

Edit...sorry chaps...just realised all my spouting has been covered previously. Should have read the whole thing and not just the question...

[Ozzy]

Thanks David.

Im new to this and didn't even think of the servo holes. I have adjusted the EP (End Point) on my TX but this doesn't soften the controls. I will move the push rod to the inner hole and set the EP to max so I still get a good turning circle. Hopefully this should soften up the nose gear. I think I should also move the rudder push rod to an inner hole as if the EP is set to max, this will reduce the amount of rudder on the controls as well. To be quite honest, I have not needed to use the rudder in flight anyway.

[Evan Pimm]

You will find that you will need very little steering movement  for a good turning circle, but then, how much taxiing  do you have to do?  Unless there is a  tortuous path to the runway there is very little point in having anything more than 10deg or so movement either way.  On takeof, with full up held in while accelerating the nose wheel will hardly be in contact with the ground and all steering is by rudder anyway,  and on landing you only need enough to turn off the active when it all slows down, assuming you haven't run off the end and engine is still running. Set the rudder up to do what you want, and the steering up on the outer hole on the tiller and the innermost at the servo, and that will be heaps.

Evan. 

[Ozzy]

Thanks 4 all your help. All I need to do now is wait for a good day for flying again

[Former Member]

[This posting has been removed]

[Evan Pimm]

True Eric, true, but I did say "Full up while accelerating", meaning  as speed is gathering. And yes, even with trikes, or rather especially with trikes, as reducing the nosewheel loads helps that acceleration, as anyone who has done any full size trike aviation will tell you. And the full size ones steer with rudder on take off, with, perhaps, a bit of diff brake assistance at the very start. So, I think my contention stands. Even my old fashioned Atlas and Curare prefer full up at the start of the takeoff run, and often lift the nose wheel off the ground right from the start, so all ground steering on takeoff is with rudder. The only exception I can think of is my UPF which prefers (or at least the pilot does) a bit of down elevator so that the tail comes up really quick, and the rudder is immediately effective in the prop blast, easing, as you say, as the speed increases near lift off. Try it, and you might even find that it works`As advertised', as they say .

Evan. 

[David Martin 2]

I must admit I really enjoy taxi'ing the model (especially my Pup) downwind 30-40 yards before swinging it round into wind then doing a half throttle lazy drawn out take off across the front of me.

I can see the tail lift and the first few little bounces before a long shallow climbout right from the side of the runway.

Don't think I'll do that tomorrow though with the maiden of my YT Spitfire..!

[Tim Mackey]

good luck - let us know how she goes ! Pictures too if poss

[Ozzy]

I would like to thank everybody for the posts. After all that messing around I finally worked out that the rear wheels were a little bent and that it must have been a bit windy the first time round. I just turned the rear wheels around so the model was lying more level.

Anyway as there was no wind today, and the sun was showing its face for the first time in weeks, I ventured to my spot and fired up the engine. At that point my heart was racing as I was worried that I would crash it. I taxied it out and done a low speed test to see if the model moved in a straight line which it did. I then opened up the throttle and took off with no zig zags.

So on my second attempt I have become more confident of taking off. I did lots of landings, approaches and cutting the throttle back in flight to mimic dead stick landings. On my last landing the model did swing to the left on the ground and a big twig sticking out of the ground saved it from going into a bush with no damage  Phew!!

[David Martin 2]

Nice one Ozzy...

[Doug Ireland]

Way to go Ozzy! Glad you got the steering problem fixed!

The heart-racing thing... that's why we all get hooked on this hobby in the first place! There is nothing more satisfying than seeing something you have spent time and money on in the air and doing what you tell it to do and get it back down again in one piece! Try explaining that to a golfer!

 Keep smiling!!!

[Doug Ireland]

Sorry to get off-thread for a moment but a response to Evans' post needs a reply.

I learned to fly at Tayside Avaition in Dundee back in the late '70's off a grass strip 2,000' long in a Cessna 150. We were taught to keep the stick back during the taxi to the runway to ease the weight on the nose gear but then the Elevator was held at neutral during the take-off roll and rudder used to keep straight. The usual exceptions to this would be cross-wind departures when the Elevator would be slightly negative and the Ailerons would be held toward the wind and then centered after takeoff. The aircraft was then "weathercocked" into wind once climb speed was achieved. Low wing aircraft are easier!

[Evan Pimm]

Doug, all my training was on Grummans, and it was stick full back easing foward as the rudder started to bite, low winger, of course. On grass two up you actually held the stick back until the nosewheel actually left the ground then kept it up to hasten the acceleration. Got my hand smacked landing for letting the nosewheel fall to the ground, next time the stick came back as the speed decayed keeping that wheel off the ground until even with full up there was unsufficient airspeed to keep it there. Instructor was much happier. Different strokes...

Evan