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. 

Oh dear, No sir.  That top Spit is just so famous that you should be ashamed.  K50504, prototype  Spitfire. And the other is a  mark 1 with the original Watts two blade fixed pitch that they all wore (19 Sqdn?)  prior to the BoB. Evan. 

I would have thought that a 12x8 prop would be far too big a load for a .55 anyway. Surely an 11x7 or 11x8 would be far more appropriate. Evan. 

I quite like him, but I'm not English... Evan. 

And waggling the sticks, Timbo, won't change the discharge rate of your tranny at all... Evan. 

Ah, another victim of the dreaded `downwind turn syndrome'. Lesson to be learnt; do not judge model airspeed with reference to the stationary objects around your flying field. Lesson learnt; when model stops flying, stick the nose down real quick. Well done to recover, most learner pilots whack in up elevator when the model does as described, with the inevitable results. Evan. 

And for those trying to wing warp, you will need to look at the full size warpers at OW. You can't use normal modelling stuff and dope as it all goes rigid, or twists up all over the place, then goes rigid. I think you will find there is no doping on the full size fabric, and it's only attached at the front and back, ie the fabric is allowed to 'float' around the ribs and suchlike. Evan. 

Well, I will try. The slat is a deep undercambered section about the same curve on the upper surface as the L/E of the wing. When fitted in place it is about half the depth of the wing. The L/E of the slat is a pretty blunt affair and is set  just below the height of the wing L/E. The distance out from the L/E is arrainged so the there is a gap about 3/4 of the chord of the slat and the T/E of the slat is adjusted to give about half that gap between the slat T/E and the wing surface. a pair of ply rib extensions fit at either end of the slat and match the upper surface curve. A pair of 'U' shaped pieces of 1/16 wire fit through the ribs and into ally tubes inset in the ends of the slat. The slat is solid balsa, made from a couple of bits of standard balsa L/E and T/E glued together and sanded to shape. And thats about all there is to it. Evan. 

Yer, I have a 'Large Model Trainer' that has both flaps and slats, about 7' wing and with a ST G2023. The slats are removeable (stick out the front type) so that students, when learning to use flaps, don't get into too much trouble at first. Later we remove the slats and then they learn all about the stall/spin thing. With the slats the model hasn't enough control power to get the wing to the stall angle, so it can't spin, without them it will. If there is a difference in airspeed at full power 'S&L' then I can't detect it, although I guess there must be. Evan. 

Lots of the early STOL's had fixed slats, the Storch being one of them...the Lysander another... It depends on the speed you want the thing to do at the other end of the spectrum, hence the auto slats on the 109 and the various L/e devices on modern transport things. For models, unless you want to be a pylon racer, at our speeds there is not much drag increase, and you can fix them in the 'Letterbox' fashion that the Me 163 did, and some of the modern light G.A aircraft do. These have less drag than the stuck out the front type, but a little more than the retractable sort. Evan. 

The CG will be where it always is-25% MAC. Just jack the model up to flying attitude, measure from the leading edge of the foward wing to the trailing edge of the rear wing and balance the model 1/4 of the distance just measured back from the front wing leading edge. The Beech wings are straight and about the same size so this method will give a safe balance for those first flights. After that well, just 'salt to taste', as they say. Evan. 

Find someone with some of those old RCM&E's where PR discussed the methods of nailing a set of slats on his STOL. All you need to know to get a set that works. Evan. 

Barrie,          Go to the `List' function in the menu, select what you want to change and just play with the thing with a servo  plugged into what ever channel you a playing with. You can then see the result of the playing, and you will quickly get the idea.  Mind you the 3810 is a pretty comprehensive piece of kit and can be a bit boggling to begin with. You can't break anything so have no fear. Read the specifics of the function in the manual and just have a go. Evan.  

Have another beer mate, trainers are done that way because upside down motors have some strange quirks, at times. You don't need to rotate carbs or anything else, but one day when you have a bit of time, take your trainer with the upright engine, turn it upside down in some stand or other, and attempt to operate the engine in this new fashion. you will get tired of the game after a while, then you will be able to help someone else with this idea. This is not to say it can't be done, it can, and very succesfully too, but it does require some experience at operating the things, which is why you have a trainer, with the upright thingie... Evan. 

Rob, there's probably nothing you can do at this point other than starting again, with a known accurate drawing of your chosen version and redrawing the plan with the correct outlines and sections. Any 1/15th scale four engined bomber will not be able to fly at 14 mph unless it is really light, and the four Saitos are already too heavy. You might be able to get it to do scale speeds at 1/6th scale, but the same admonishon applys. I really think you need to re-think the whole thing and perhaps lower you expectations, then build up over a series of designs until you have the knowledge and expertise to accomplish this task. Evan. 

Then again, unless you actually wish to strive to be at the top of the aerobatic/TOC world mode 2 will suffice...(Just how do mode 2 flyers do a rolling circle?) All other forms of aviation require the pilot to actually be in the machine..there is really no comparison between the two forms, in one you see, feel, touch the whole thing, in the other you stand on the ground with a little plastic box in your sweaty palms... Naturally, being a mode 1 flyer I tend to look down on `funny mode' pilots... Evan. 

Good to see, but what about all those listings that are not there? things like Atlas, Superstar, Equaliser, Pete Russels deltas? etc. Many of us have all these old magazines, and would like to be able to get a hold of the original drawings, rather than trying to enlarge from old mag repros. Evan.

Cor, this has got a bit long, hasn't it! We was only discusing what the diff was between PPM and PCM and now we are on batt capacities. Ah well, thats the way it goes. Sufficient to say that Fubaba rates its gear (including servos) at 6v and JR rates theirs at 4.8v. I guess the reason is that (down here at least) Futaba usually sells their gear sans batteries (ie intended for dry cell operation) and JR usually sells theirs with nicads. If you are going to use a nicad 6v pack then you will be using 5 cells anyway, (more capacity) so any increased current draw won't make much difference to available flying time. Lets get out and go flying. Evan.

Bob, I accept what you say, with the following observations; 1) Futaba gear is rated for 6v (dry cell) operation. ie. the failsafe recognises 6v as the normal operating voltage. 2) JR failsafe still works a 6v. Dunno about the rest. 3)All battery and switch failures I have witnessed have resulted in complete loss of volts, no failsafe, no warnings, just the complete destruction of the uncontrolled model. 3)I have an idea that very few people actually programme their failsafes anyway, and wouldn't know what the loss of throttle actually meant. The Rx's in all these systems must be factory programmed to recognise a low voltage in order to know when to operate the `low battery power/throttle idle' part of the failsafe regardless of the nominal operating (normal) voltage. I still reckon that PPM is the safest transmission for most club modellers. Evan.

Dickie, Surely you remember you old school electrical theory? The servo will need to provide a certain amount of power to move the surface, for our purposes here this will be volts X amps. If your supply volts is bigger, then current (amps) will be smaller for the same power output. All simple stuff. Evan.

Any change in the weight and/or RPM of the `spinning disc' will change the size of the reaction. Aslan, I agree 100% with what you say, but the question was whether the spiral airflow impinging on the fin was what caused the yaw on the model. For that we need to see if there is sufficient spiralling air to actually reach the fin, and at a large enough angle to cause the effect. My point was that there isn't, and you can see that there isn't with any airplane with a smoke system fitted. As most of these models have relatively large motor/prop combinations compared to airframe size they do represent the most likely type to be affected by the proposition. Evan.

Aslan, I have, and I have plenty of DVD and video evidence as well. It does not matter where the smoke is introduced, so long as it is in the slipstream of the prop, and reasonably close to it. By definition (slipstream) we are concerned only with the air directly behind the prop, and injecting the smoke through the exhaust system works very well. There is no visible spiral effect. Evan.

What we need is some form of visual representation of the airflow behind the prop, just to see what the slipstream really does. What, you mean we already do? Sure, just watch those show pilots with all those smoke systems, hovering, rolling etc, which way does the smoke go? Straight back, I'm afraid, certainly doesn't rotate around the fuselage. So I'm afraid that the old `spiralling slipstream' theory isn't borne out in practise, we will have to look somewhere else for our yaw reaction. `P' factor, as taught to full size pilots, has to do with the tilted disc of the prop on a taildragger and the relative airflow through the prop at takeoff. This can result in a difference in AOA between the `up' and `down' going blade of the prop resulting in a thrust difference from one side t'other, causing, again, a yawing effect until the tail comes up. Evan.

Depends on how many servos are to be used. I would not expect that the Yak would need much in the way of sevo power, provided that the linkages and hinges are free moving, (ie. will fall under their own weight.) Futaba systems are generally rated at 6v. so if you use a 6v. battery pack then the current draw will be lower anyway. I can foresee no problems. Evan.

Unless your rules/club mandate a `failsafe' then it really does not matter. A 25% Yak isn't a particularly large model, of more concern will be things like servo choices, battery capacity etc. With regard to radio failures/interference I read somewhere that over 90% of failures not immediately attributable to pilot error were caused by airborne switch and battery pack failure, in which case the `failsafe' couldn't have worked anyway. Evan.