Are 'recommended throws' really necessary?

[leccyflyer]

59 minutes ago, Jon - Laser Engines said:

This probably echo's what i wrote before in that other thread and i dont want to go off the rails so this will be my last comment on the subject unless there is a specific question.

 

As i said, my comments apply to normal sport, scale and aerobatic models and 3d stuff is different and i mentioned that as well. 

 

Still, its a fact that none is required in most cases and 10% will satisfy a very large proportion of cases where it is needed. If it wasnt true, i wouldnt be able to do it 😛 

But, that does not exclude cases like 3d or whatever. I only mention 10% as someone with 65% expo in their Spitfire might see it and go 'huh, why do i have so much if this chap's warbirds fly with none?' They then look at what it is they are doing, make changes, and get a better flying model as a result. This exact thing happened with a friend's H9 Spitfire. 65% expo...it was awful. 

 

Also another objection is it makes people lazy. As a beginner, instead of learning a new skill (like pulling the stick straight) they try to cheat and progress faster and this does nothing to make them a better pilot and in fact makes the whole thing more difficult long term as their core skills are lacking. Admittedly this is in part due to tedious flying in circles during training boring them to tears, so i get round that by going straight for basic aerobatic training once basic circuits are mostly ok and well before takeoff and landing training. A loop will easily show if you are pulling the stick wonky, and doing a loop is something even non flying people can recognise as some sort of achievement. So they dont get bored, and they move their sticks straight. Its a win win. 

 

Of all the previous expo advocates who's models i have adjusted to my way of doing things none of them have gone back to they way they were before. They all admitted they flew better and were easier to control, much to their surprise in many cases. Perhaps i am just a complete ninja when it comes to model setup? or i am the Eric Brown of model flying and do things others cant? but i dont think so. For the most part I dont think i do anything anyone else cant with the right instruction. I think most just followed a path and got as used to it as best they could. It just may not have been the right one. 

 

Anyway I am not saying it is not a tool with no use at all. 10% sorted out the ailerons on my stampe. Just that it is very much over used, incorrectly used and is normally the first port of call for adjustment when i really should not be. 

 

Its a snowball effect too. Reduced rates mean you can use a more aft c/g. This means less lead carried, a lighter model, perhaps a model that will not sit on its nose every 2 minutes as its nose heavy etc. (might be worth looking at leccyflier 😉 ) 

 

I only have a small box to write in and finite amount of time to write a post and so many of the things i recommend come about because of a spiders web of contributory factors. I cant pour all of it on the page as i would be here all day. Half the time i am not even aware of all the links myself and there's an 'oh yea, that is a thing because of this' moment when i realise one. 

 

So i resent the implication that i am a bit silly. i just have to over simplify everything to make it fit in a post and there is way more to it than 'booo expo bad'. 

 

 

 

 

Since I seem to be singled out in this post I'd note that I had previously stated that I don't usually use full rates except where it is necessary. I do prefer my models to be set up on the conservative side, with relatively small throws and the CG usually at the front of the recommended range, because I don't want a model that is like flying a tiger by the tail. The models which are sensitive to tipping up tend to be those with small wheels and the issue is worse in the winter with longer grass.  I'm not sure that has anything at all to do with using expo though and the two things seem to be getting conflated unnecessarily there, with some rather judgemental phraseology.

[Jon H]

15 minutes ago, leccyflyer said:

Since I seem to be singled out in this post I'd note that I had previously stated that I don't usually use full rates except where it is necessary. I do prefer my models to be set up on the conservative side, with relatively small throws and the CG usually at the front of the recommended range, because I don't want a model that is like flying a tiger by the tail. The models which are sensitive to tipping up tend to be those with small wheels and the issue is worse in the winter with longer grass.  I'm not sure that has anything at all to do with using expo though and the two things seem to be getting conflated unnecessarily there, with some rather judgemental phraseology.

 

I wasnt trying to single you out in a bad way, just that you mentioned a nose over problem and the interplay of rates, expo and c/g is one of the things i was commenting on. Its counter intuitive, but less rates will prevent nose overs as you can run the more rearward c/g with a less sensitive elevator. 

 

There is a misconception that a rearward c/g makes models a complete handful. It wont, as long as rates are reduced sufficiently and you dont move it outside a given range. This range is probably in the order of up to 20mm behind the rearmost recommendation in the kit but this will vary greatly depending on the model and incremental changes would be needed. You dont want to go ham and move it 3 inches in one go. 

 

If the specific reason your model noses over is its got little wheels then fair enough, but often models like Spitfires of say 60 size spend half their time sniffing the dirt and a more rearward c/g will help. 

 

The interplay between aircraft balance and control surface deflection can be used to really tame a model that is very tippy on the ground. Equally a model which is nose heavy and needs high rates to prevent tipping may be over sensitive in the air leading to the use of high amounts of expo. 

 

As i mentioned in my other post, these things are very intertwined  with eachother and you can adjust each to get the desired result. 

Edited February 16, 2023 by Jon - Laser Engines

[Richard Acland]

17 hours ago, John Stainforth said:

I usually put in the recommended throws (with the servo movements at "100 %"), and then program one or two lower rates settings (depending on transmitter) to say 40 and 70 % of those rates. I start with the lowest rates for a maiden, but ready if really necessary to instantly switch to higher rates. Then experiment with the higher rates and go from there. Usually, much of the first flight is taken up with flying the plane with one hand and making trimming adjustments with the other (or, better, with a helper). I agree with Jon (and many others): no expo. Expo softens the central position, but if one over-controls one is really in trouble.

I was going to say the same thing. I usually set the rates low for the first flight on elevator, ailerons and rudder, then if things are ok wind them up a bit. Nothing worse than something really twitchy on a maiden flight.

[john stones 1 - Moderator]

Lets not be getting highrate on an expo threads lads. 😉

[Jon H]

8 minutes ago, john stones 1 - Moderator said:

Lets not be getting highrate on an expo threads lads. 😉

 

Its all good, i think leccy misunderstood my meaning thats all. I wasnt having a pop at him

 

Oh and classic pun, 11/10

Edited February 16, 2023 by Jon - Laser Engines

[john stones 1 - Moderator]

Just a joke Jon, couldn't resist. 🙂

[MattyB]

3 hours ago, Jon - Laser Engines said:

This probably echo's what i wrote before in that other thread and i dont want to go off the rails so this will be my last comment on the subject unless there is a specific question.

 

As i said, my comments apply to normal sport, scale and aerobatic models and 3d stuff is different and i mentioned that as well. 

 

Still, its a fact that none is required in most cases and 10% will satisfy a very large proportion of cases where it is needed. If it wasnt true, i wouldnt be able to do it 😛 

But, that does not exclude cases like 3d or whatever. I only mention 10% as someone with 65% expo in their Spitfire might see it and go 'huh, why do i have so much if this chap's warbirds fly with none?' They then look at what it is they are doing, make changes, and get a better flying model as a result. This exact thing happened with a friend's H9 Spitfire. 65% expo...it was awful. 

 

Also another objection is it makes people lazy. As a beginner, instead of learning a new skill (like pulling the stick straight) they try to cheat and progress faster and this does nothing to make them a better pilot and in fact makes the whole thing more difficult long term as their core skills are lacking. Admittedly this is in part due to tedious flying in circles during training boring them to tears, so i get round that by going straight for basic aerobatic training once basic circuits are mostly ok and well before takeoff and landing training. A loop will easily show if you are pulling the stick wonky, and doing a loop is something even non flying people can recognise as some sort of achievement. So they dont get bored, and they move their sticks straight. Its a win win. 

 

Of all the previous expo advocates who's models i have adjusted to my way of doing things none of them have gone back to they way they were before. They all admitted they flew better and were easier to control, much to their surprise in many cases. Perhaps i am just a complete ninja when it comes to model setup? or i am the Eric Brown of model flying and do things others cant? but i dont think so. For the most part I dont think i do anything anyone else cant with the right instruction. I think most just followed a path and got as used to it as best they could. It just may not have been the right one. 

 

Anyway I am not saying it is not a tool with no use at all. 10% sorted out the ailerons on my stampe. Just that it is very much over used, incorrectly used and is normally the first port of call for adjustment when i really should not be. 

 

Its a snowball effect too. Reduced rates mean you can use a more aft c/g. This means less lead carried, a lighter model, perhaps a model that will not sit on its nose every 2 minutes as its nose heavy etc. (might be worth looking at leccyflier 😉 ) 

 

I only have a small box to write in and finite amount of time to write a post and so many of the things i recommend come about because of a spiders web of contributory factors. I cant pour all of it on the page as i would be here all day. Half the time i am not even aware of all the links myself and there's an 'oh yea, that is a thing because of this' moment when i realise one. 

 

So i resent the implication that i am a bit silly. i just have to over simplify everything to make it fit in a post and there is way more to it than 'booo expo bad'. 

 

...and yet you just posted 500+ words on the subject to "correct" those who are doing it wrong in your eyes! 😄

 

PS - If you really resent being called silly, maybe it's time to stop accusing those who choose to do things differently to yourself "lazy" and "cheats". Two of the best pilots I know use expo extensively for pretty much everything they fly (not just 3D models), and I certainly wouldn't call them that, especially given they could fly circles round me. There is more than one way to skin a cat.

 

Edited February 16, 2023 by MattyB

[Peter Jenkins]

One might also wish to draw a distinction between standard club aerobatics and that flown in competition using specialist aerobatic aircraft in F3A competition.  There the use of expo is standard as are, to most people, very low rates.  I'll stop there.  To avoid a punch up on the forum, if anyone wants to know why I take that view, please PM me and I'll be happy to expand.

[MattyB]

14 minutes ago, Peter Jenkins said:

One might also wish to draw a distinction between standard club aerobatics and that flown in competition using specialist aerobatic aircraft in F3A competition.  There the use of expo is standard as are, to most people, very low rates.  I'll stop there.  To avoid a punch up on the forum, if anyone wants to know why I take that view, please PM me and I'll be happy to expand.

 

Sounds a bit "lazy" to me; I can't believe you haven't been thrown out of your comp... 😄

 

Edited February 16, 2023 by MattyB

[Phil Green]

Try flying reeds then talk about expo and rates!   🙂

 

[Jon H]

57 minutes ago, MattyB said:

 

...and yet you just posted 500+ words on the subject to "correct" those who are doing it wrong in your eyes! 😄

 

PS - If you really resent being called silly, maybe it's time to stop accusing those who choose to do things differently to yourself "lazy" and "cheats". Two of the best pilots I know use expo extensively for pretty much everything they fly (not just 3D models), and I certainly wouldn't call them that, especially given they could fly circles round me. There is more than one way to skin a cat.

 

 

I didnt count the words! i gave as brief a reply as i could for those who didnt want to read a thousand posts on the other thread. 

 

But i dont apologise for thinking its the wrong way of doing things for the most part. I have plenty of reasons for why, most of which can easily dismiss the counter arguments from the other side. Is my low rate no expo policy a golden bullet for all situations? no, i use expo myself when needed. So why is the high expo option viewed so favourably? It cant always be the right thing to do now can it? And yet you seem to not give that ground. Peter's F3a example is a case where it may be advantageous. But, we have drifted into the realms of competition where the pilots are all of a high standard and every edge is critical. These guys (in the glow days) might have changed the heat rating of their glowplug to suit the day, or got a specially tuned fuel or something for that added .5%. This is not the club modeller, and my comments relate mostly to club flying, and mostly those of lower experience. 

 

My argument has always been the same. Start with none, add it later if you need to once everything else is set. 

 

As for the rest. Perhaps impatient would be a better word than lazy? But some are lazy, and some cheat. They dont want to learn to be the best, just be at the 'front'. Just look at those who ditch their trainer and immediately bin a spitfire as they were too impatient to learn what they needed to first. You cant say people never try to take a shortcut, even if it leads them the long way round. 

 

And your mates might be great pilots. I dont know them, dont know what they fly so cant comment on their skill level or how appropriate it might be for them to fly that way. Not that skill (as in pure talent rather than a taught skill) is relevant. And i have no doubt they are happy with the performance of their models, but depending on how they arrived at their current setup they might find added performance if they binned the expo and changed the rates. I just think that saying something is as good as it could ever be because its good enough is a little....lazy 😉 

 

 

Edited February 16, 2023 by Jon - Laser Engines

[J D 8]

           Could not find an expo or rate switch in the Tiger Moth I had a go at flying a few years ago, in fact few switch's in the cockpit at all.

[paul devereux]

On 16/02/2023 at 17:22, J D 8 said:

           Could not find an expo or rate switch in the Tiger Moth I had a go at flying a few years ago, in fact few switch's in the cockpit at all.

Thanks to everyone who has given me advice. I now think I understand how a computer Tx works (though the one thing I am still puzzling is what is plus and minus expo? I know what expo is, but I don't know how it can be plus or minus- as is, is 100%, you want to make the first movements gentler, do you go plus or minus?).

Another thought I had is as JD8 has said above- if you want to learn how to fly, you need to learn to fly. Dual rates, expo, gyros- aren't they taking away the learning experience? And if you program all this stuff in, have you really learnt to fly a RC plane? (I think I saw somewhere a Tx with a 'flick roll switch').

Just some thoughts from a newbie.

 

[Andy Stephenson]

The expo setting will change the stick sensitivity around neutral. Futaba, for example, uses the convention that a negative setting will reduce the sensitivity but other manufacturers use a positive setting to reduce the sensitivity. I guess it depends on how mathematically pure your thinking is on the subject.

 

[Peter Jenkins]

Hi Paul

 

Re expo, you can arrange the stick response to be gentle around the mid-point - this is the usual situation.  I cannot thknk why you would want to magnify the stick input around the mid-point.

 

Problem is that Futaba calls reducing stick sensitivity around neutral negative expo while Spektum and JR call it positive expo!  Not sure about other makes or Open Tx. 

 

Why do we use rates and expo in flying model aircraft?  Bottom line is that as we don't get any feedback to control forces in model aircraft unlike in full size so we need some way of dealing with this.  I personally use 3 rates for aerobatics (precision not 3D), landing and spinning.  Why?  For aeros the elevator has between 8 to 10 deg maximum movement, 12-13 deg for landing as I need to combat low level gusting or turbulence and 30-35 deg for stalling or spinning.  Ailerons are usually 10 deg and rudder 25 deg. 

 

If you start off flying with full control throws then you end up all over the sky as you try and get used to the delay of applying a control and the aircraft reacting.  It is quite possible to end up with pilot induced oscillation, particularly in roll where the learner just makes things worse.  Better to have less throw and learn to use that because you will find the aircraft reacts less violently to the applicstion of full stick.

 

I have flown with pilots who are all over the sky and find it quite frightening.  When I set up rates they suddenly become more confident that the aircraft won't bite and their flying visibly improves on that first flight with the rates tamed.

 

As you may have gathered I fly in competition aerobatics and when I show pilots my control throws they are amazed at how small they are.  However, I also use expo and this can vary from 15% to 35% and this is to mske sure that I can make very small sdjustments to the aircraft's flight path that the judges will not see.

 

I have had complete beginners fly my competition F3A aircraft and they have got on fine - any properly set up precision aerobatic is a pussy cat to fly ckmpared with some poorly set up sport models I have been asked to fly.

 

There is a lot of ill informed comment on learning how to fly without using rates or expo as using them is somehow cheating.  If that's how you want to fly your aircraft thst's fine but don't force it onto somrone else.  All I'll say is that many  of those who take that view do not demonstrate that they can fly accurately.  By that I mean really straight lines at a constant height and turning while maintaining  constant height.

 

As regards snap rolls, yes, you can set up a switch to trigger the snap roll but consider this; a snap roll is supposed to be a spin in the current direction of flight.  That is, the wing must be stalled and application of rudder and aileron generate an autorotation.  As soon as the snap condition is exited, the aircraft becomes unstalled and, if you got it right, wings level at the sameish height and the sameish heading.  I prefer to use logical switches, triggered by stick position (elevator and aileron) so that I can choose a left or right snap and either positive (up elevator) or negative (down elevator.

 

I hope that answers your question and would point out that I hsve never met an expert competition pilot who does not use rates, expo and logical switches.

[Paul De Tourtoulon]

+ or - is like is your glass half full or half empty,,,

[GrumpyGnome]

OpenTX/EdgeTX follows the 'norm' and has + to desensitize.

[MattyB]

I don’t even bother remembering tbh - when using expo I just add a chunk so I can see whether I’ve done so in the right direction, reverse the sign if I got ir wrong, then set the final amount. Crude but effective!

[Jon H]

7 hours ago, Peter Jenkins said:

There is a lot of ill informed comment on learning how to fly without using rates or expo as using them is somehow cheating.

 

Although i agree with much of the rest of your post, this is clearly aimed at me i will retort as my comments are far from ill informed.

 

I never said rates (on switches) were bad and in fact i use them heavily especially on warbirds where gear/flaps cause massive changes in response. I also never said expo was bad and should be banished. All i said was that it is over used, incorrectly used, and often completely redundant if the rates are set correctly in the first place.

 

As for cheating. Using a technical aid when learning to fly is counter productive but people do it to speed their perceived progress as flaws in their flying are not exposed. Taking such a shortcut will leave weaknesses in core flying skills which will ultimately be a detriment to the new pilot. Its why i am not a fan of these auto stabilised things either. Something as 'simple' as keeping your wings level is actually pretty hard a beginner but its more or less the centre of everything we do. All flying is based upon being able to judge the attitude of the model so 'cheating' with a level stabiliser means this vital skill will be weak and it will bite our new pilot once they transition to a new model without this aid.  Anyway the whole drive of this is that if your core flying skills are good, and the model has the right rates/balance etc expo is generally not required. if it is small amount like 10-15% is more than sufficient. 

 

8 hours ago, Peter Jenkins said:

 By that I mean really straight lines at a constant height and turning while maintaining  constant height.

 

This is what i mean when i talk about core skills. All pilots should be able to do this. Perhaps not to your competition aerobatic standard, but it should be well within the reach of all pilots to fly accurately. Sure a tiger moth will not be as accurate as a pattern model, but it should still be possible to fly it accurately within its own envelope of performance. 

 

One tech aid i do use a great deal is elevator flap mix to combat the change in trim on a warbird with gear and flaps down. No doubt many will now accuse me of cheating, but its no different to retrimming the model by hand. I can do this trimming by hand, and then undo it when i want to go around or takeoff again, but its a safer bet to have my trim pre set. Using this tech aid does not reduce my ability to trim manually or prevent me or anyone else from learning some other core skill so i will gladly recommend it to warbird pilots. 

 

 

 

 

8 hours ago, Peter Jenkins said:

I cannot thknk why you would want to magnify the stick input around the mid-point.

 

Neither could i, but then i met my 63 inch Hurricane and for some reason there is some sort of dead zone around centre stick on my ailerons so my normal rates and no expo gave a really soggy feeling centre stick. It was quite unpleasant as increasing rates to compensate left me with an extra 300 roll rate and horrible soggy middle still. So 10% inverse expo fixed it and it now feels normal with my original low rate applied.  Not had a model behave like that before but there we are. 

 

 

[Peter Jenkins]

Jon, my comment was not aimed at you.

[Jon H]

8 minutes ago, Peter Jenkins said:

Jon, my comment was not aimed at you.

 

Apologies, my mistake 👍

Edited February 26, 2023 by Jon - Laser Engines

[Rich Griff]

Love the red/white super tauri ?

[MattyB]

31 minutes ago, Rich Griff said:

Love the red/white super tauri ?

I think you may have the wrong thread…

[Rich Griff]

13 posts above, 3 pictures, the middle one, flying on reedies...

 

Even 80"s tx"s ( futaba challenger ) had "rates"...

 

The hi boy I had and the shadow were set up to quoted throws, rates set to 50 per cent, flew/fly really well. Shadow rates turned off for "violent" manouvers...

 

Rates on for realistic and more controllable/skilled flying. A non computerised radio set. Pilot inputs rather than electronic on board help.

[john stones 1 - Moderator]

Cheat is a harsh word, but if your box inputs to correct pitch/roll when you roll to knife edge and apply rudder ?

If you snap at the flick of a switch ?

If you disguise off center inputs to hide from a judge ?

If you have elevator come in when flaps deploy ?

 

You are using the TX to assist, it's pretty clear.