The Wright Stuff

Hi Seraph, More or less right. To make it simple. think about a symmetrical wing lifting section. If the centreline of the section was exactly aligned (inclined) to the direction of travel, then the upward going aileron would (angle for angle) produce exactly the same drag as the downward one. Hence no adverse yaw. Of course, such a wing would produce no lift, so it has to be inclined to the airflow, which of course produces lift (and drag) on both sides. Under this condition, the down going aileron acts to add to the existing drag, whereas the upward going aileron acts to negate some of the drag: hence adverse yaw is inevitable for any wing that produces a net lifting force. This is simplified - in fact there are all sorts of viscosity and laminar flow factors too, but I believe that explanation is sufficient. Edited By The Wright Stuff on 10/04/2013 16:58:02 Edited By The Wright Stuff on 10/04/2013 16:58:21

Posted by PatMc on 09/04/2013 21:23:28: Posted by The Wright Stuff on 08/04/2013 14:14:49: One final point, another important factor is the fuselage shape and size. I learnt on a old Precedent T180 trainer. Big and heavy, maybe, but it was also a handful in the wind because the side of the fuselage was huge, so any given crosswind pressure could exert a lot of force! The amount of side area isn't a factor in a crosswind. Hi Pat, Interesting point - I guess almost a topic in it's own right - but I'm interested to understand further. I agree that in a steady state crosswind, the plane is moving sideways at the same rate as the wind, so you are correct - there is no resultant pressure. However, talking about stability turning in and out of the wind, or in blustery conditions, it would matter, surely, because a slim fuselage would act to 'damp out' sudden changes in sideways pressure in exactly the same way that the inertia from a heavier plane would do! If this is off-topic, I apologise! I'm not being argumentative - just interested to understand. Cheers

Interestingly, I am in the process of going in the opposite direction - just starting out in electric - but I'm still sticking with IC at the same time for my bigger models. For me it's mainly habit, and time available. I fly IC if I want to have a lot of flights, and spent 3 or 4 hours at the flying field - like at weekends or in long June evenings. I take the electric if I just want 20 minutes for a quick couple of flights after work. While electric needs a lot of time at home (before you leave or the night before) to charge batteries etc, with IC this 'faff' time is generally spent at the field - filling fuel tanks etc. Don't forget also, that cleaning the model down after the flights also takes time...

Ah, apologies - I misread the sheet wing bit. I stand corrected. Thanks Bob...

Hi Ian, Get a wet sponge and dampen (not soak) the wood on both sides, weigh it down with some heavy books or the like (protected with cling film), and allow to dry out overnight. To be honest, though, it probably isn't really necessary - it'll stay where you glue it when you add the ribs and the spars - the important thing is to ensure it's flat when you are gluing it...

Hi Seraph, Agreed that inertia is the thing that governs how much the absolute velocity will change from a given force, but I think BEB has a point that it's momentum that will govern the apparent 'stability' from the R/C pilot's perspective (i.e. to blow it off course by a fixed angle will require a larger force if the plane is travelling faster). In other words, we are considering velocity changes as a proportion of the model's existing forward velocity. However the end conclusion is the same: heavier model = faster model! One final point, another important factor is the fuselage shape and size. I learnt on a old Precedent T180 trainer. Big and heavy, maybe, but it was also a handful in the wind because the side of the fuselage was huge, so any given crosswind pressure could exert a lot of force!

I think each club will be different, and also the perceived approachability of instructors will depend upon the respective ages of trainees and instructors, as well as how socially active the club is. As a teenager, I found it difficult to approach other members to ask for training. It takes regular, frequent practice to achieve confidence, and timetabled training is probably the best approach to this, IF the resources are available within the club. Having said that, I think the most important thing is honesty: there are too many clubs that promise intensive training, but then find they do not have enough instructors to fulfil that promise.

With the absence of any ailerons to trim out any rolling moment, I'd be tempted to get it as close as possible. Having said that, if it's only a couple of grams, any slight mass assymetry is likely to be overshadowed by engine torque, and tiny assymetries in the wing shape anyway. I remember my very first built-up plane - one wing was exactly a penny's weight lighter than the other - so guess what I glued in there!   Edited By The Wright Stuff on 05/04/2013 12:52:21

Thanks for that chaps - I'll give that a try. Such a simple tip, and yet not in plain English in the ESC instructions. All my instinct wants to do is look at the carburettor movement! It'll be a while before I get out of the habit of taking the fuel bottle with me, though!!!

I have to admit I swear by the 'extra strong' Araldite for builds (in the blue tube), if you can spare the time (a couple of hours) it's a lot more convincing than the 5 minute version... I also use Loctite double bubble. It's expensive but we have cartons of it at work, and thanks to our Quality System it all goes in the bin as soon as it goes a day out of date! It doesn't stay in the bin for long! Stay away from the Poundland stuff, though!!!

Hi there, Sorry - this is a basic question but I can't seem to find the answer here! I've flown for years on IC and 35 MHz, but now got a Futaba 6J (my first programmable transmitter) and also want to learn electric. I bought myself a Parkzone T-28 as a relatively easy-to-fly model on which to get to grips with both electric and 2.4 GHz! It's the PNP version and I am using my Futaba 6J. I've already read that I have to reverse the throttle channel, and it's working OK, but I'm unsure if the throttle range on the Futaba is the same as the Specktrum system that the ESC is presumably factory set up for. For example, how do I know that WOT is actually giving the correct amount of power with the trim at 100%? I'm also concerned that there is a dead zone at the throttle closed position - i.e. I have to open the throttle lever by about 20% before the motor actually starts. Is this usually how they are set up, or should I set it up so that it starts within a few clicks? The ESC manual just talks about 1.2ms to 1.8ms versus 1.1ms to 1.9ms, but I'm not clear how this relates to actual stick positions... can I / should I simply use the channel 3 trim lever to increase the idle speed? I'm also confused by the fact that the throttle trim lever on the modern radios only affects the idle rather than the full range. This might be a good idea for IC engines, but I'm not sure how to set it up for electric, wherre the concept of an idle is (as far as I can see) redundant... Cheers, Ian Edited By Steve Hargreaves - Moderator on 27/03/2013 09:03:31

Hi there, I can't comment on the engine or radio, but happy to share my experience of the BH 'Air' planes. I had a Speed Air (which flew great until I destroyed it in a mid air) and then replaced it with a Super Air. I'm a big believer in 'you get what you pay for', and so while the BH kits may have a few minor drawbacks (undercarriage, flimsy covering etc), what do you want for £60? I think they represent fabulous value for money - I was in your position a couple of years ago. Happy with a high wing trainer and wanting to progress and gain confidence. For this I think the Speed Air or the Travel Air is ideal. I found the Super Air to be a significant step up - tapered wings mean higher wing loading and more pronounced tip stalls - basically it needs to fly a lot faster than the others. The Speed Air was a joy to fly - perhaps even easier than my high wing trainer in some ways. It's faster and has less self-righting stability, obviously, but it tracks dead straight, isn't overly sensitive to set-up, and basically flies exactly where you point it - like in a simulator! Take off is a doddle, and landings easy enough (even dead stick) provided you keep the speed up a bit and allow a decent space for roll-out. The big difference between the Speed Air and Travel Air is that the Speed Air has a tricycle undercarriage - easier to handle on the ground if the grass is a bit long! The steerable nose wheel works great. The downside of the Speed Air is (for some reason) it has a single aileron servo, which would mean you couldn't have flapperons etc later on. Hope that helps... Cheers, TWS

Saw one at the Farnborough Air Show. The seemingly near-vertical climb out and the way the pilot threw it around was absolutely incredible. I guess it has to be low on fuel (and passengers) when it did that!!!

This reminds me. I bought a caulking gun and silicon sealant from Poundland, to fit a fuel tank. First time I tried to use it, squeezing the trigger simply shoved the end off the gun. That'll learn me!!!

Is the adage 'light models fly better' always true? Even in strong wind? Apart from higher take-off and landing speeds, why do they fly better? I'm not disagreeing, just interested in what factors in particular with a heavier wing loading make it harder to fly. Am I naive in thinking that it simply has to fly faster in order to create the necessary lift? I am looking to learn to fly warbirds with a heavier wing loading so am toying with the idea of deliberately adding weight to my trainer to make it harder to fly!!! Is this a terrible idea?

Excellent news! I'm glad that I'm not the only one who's found this. Fuel (or at least some types of fuel) DOES go off! Pass it on!

No worries, and good luck. I know from bitter experience just how frustrating these problems can be.

Hi Bob, I have to say that I would definitely try new fuel, maybe with 10% nitro to reduce the needle sensitivity... I had a similar problem a few years ago that was solved instantly by using new fuel. I have heard people on forums strongly disagree with this, and claim that fuel does not go off. Perhaps that is true for some fuels, or in some situations. But storage light levels, temperatures, the degree to which the container is airtight etc etc all vary from person to person and could all have an effect. I keep my fuel container in a black bin bag in a cool place, with the lid tightly fastened. Got to be worth a try...

Hi John, The buzzing is the servo motor 'hunting' for it's centre position. Is it possible to remove the servo arm from the servo, or failing that, disconnect the servo from the aileron horn. If the servo stops buzzing when you have mechanically disconnected it, it might be that the control surface connections (you don't say the type of set up - one servo for both ailerons, or two servos?) are too stiff and are giving too much resistance to movement, hence causing the servo to work harder. Sometimes, the servo will continue to buzz even when not connected to anything. Sometimes they just do - particularly the cheaper 'standard' servos. To be honest, the odd little intermittant buzz here and there on one or two servos isn't going to cause too much harm - I've never had any problems with flying models that do that. The servo isn't going to be damaged. The risk is that the servo is stalled and drains the receiver battery more rapidly than usual, so you could test this by leaving it buzzing for an hour or two, and check the receiver battery voltage is still up. If it's OK with not draining the battery, to be honest it's probably not worth worrying about. Good Luck! Ian

Hi all, Am having exactly the same problem with my OS 46 LA, so I thought I'd resurrect this thread rather than start a new one. It just seems to be always running rich - sounding like it's four stroking (without the high pitched scream), and closing the needle valve just stops the engine. This started after I crashed it - it was fine before then! Cleaned it all up, and seems to start ok - nothing seems to be bent - just won't hit peak revs! Am checking for leaks, but I have a question. If air was leaking IN, then surely it would exhibit the symptoms of running lean. Is it possible air is leaking OUT during compression? Cheers, Ian

Good flying days are often in warm weather! I fly on my way home from work in the evenings, and have to leave planes / radios etc. in the car during the day. Not ideal, but I’ve no alternative. Done it for years (and on the odd occasion it has all got quite hot). I’ve never had any problems whatsoever if my 35 MHz radio gear or batteries get hot in a hot car (I can cope with an occasional wrinkle in the film covering). Just upgraded to 2.4 GHz, and I note that the new manual (Futaba) is totally plastered with warnings about not letting the Rx get too hot, and not to leave radio equipment in a hot car. Is 2.4 GHz stuff genuinely more sensitive to heat damage than older radio equipment? Or is this just overkill (or perhaps written for U.S. weather which can get hotter)? Anyone ever experienced damage due to leaving 2.4 GHz radio gear in a hot car? I really don’t want to remove the receiver from the plane every day…

Wow, thanks for all the advice guys - this forum seems way more active than most others I've looked at! To answer SDF's question, exactly the same as Martyn. I cut my teeth on 2 channel boats and gliders. I switched to Mode 2 when I moved to work down to Cambridgeshire (no slopes!) after uni, and found that that's what most people and most clubs in the area fly on - so it made it easier to get help. I'd only just got solo on Mode 1 (I originally learned oop north), so it seemed better to switch sooner rather than later. I have to say that on balance I find Mode 2 easier, because in those moments of panic when disorientated, I can just tell my brain to forget the left stick and I can sort it out with ailerons and elevator. But the downside is that I find it made me a bit lazy - because I COULD set the throttle at 1/3 and fly circuits on just one stick - I DID just that. Hence this thread! I guess years of playing flight sim computer games with a joystick also made Mode 2 slightly more intuitive for me. But anyway, this isn't supposed to create a thread about modes - pros and cons to both! I guess my situation is that I'm finding lots of basic web material and books out there about the 'getting started', and quite a bit of advanced 3D stuff, but not so much in between for the 'intermediate learner'. So if anyone can point me at any good books / webpages, I'd appreciate it. Thanks for the great welcome guys! Cheers, Ian

Hi all, I've got a Black Horse Speed Air as my second plane (and first low winger), and got to grips with it - I can take-off, land, throw it around and do circuits, figure of eights, loops, etc. I've recently converted to Mode 2 (having originally learned on Mode 1) and am finding it very difficult to get used to using the rudder. I can using to track on the ground during take-off, and I can do a basic stall turn, but I now find myself doing all my flying 'bank and yank' on the right stick alone. I find it impossible to use both sticks at the same time to to coordinate turns using both rudder and aileron. My brain just goes blank! Are there particular techniques I can use to improve this? I've read about practicing flat turns and rolls using opposite airleron and rudder, but the rudder seems to have very little effect on the Speed Air, apart from an ungainly skew sideways. Do I need more rudder throw?