Rates and thumb waggling!

[The Wright Stuff]

Hi,

Another slightly subtle question up for discussion. An experienced flier watched over my shoulder as I flew yesterday, and commented that my thumbs were hardly moving on the sticks, even during turns, and that meant my control throws were far too high.

So, I understand all of the technical trade offs between throw and resolution, precision and linearity, etc. at the servo/model end. I also understand the effect of the transmitter settings (expo, EPA, rates, etc), but I guess I've never really thought too much about what happens at the human end: i.e. the precision available from my brain/thumb at different positions.

I fly with just my thumbs on the stick tips, and I subsequently had a play around with different rates. I find that close to the centre of the stick travel, I have a great degree of precision and can control the stick very smoothly. Further from the centre, I find it much harder to be smooth, because there is less mobility in my thumb at the extreme ends of the joint extension.

To be honest, I'm quite happy flying with high rates and only using a small proportion of the stick travel, I find the comfort factor outweighs the theoretical advantage of greater resolution by using bigger movements, but is there actually any drawback to flying like this? How do people generally judge how much of the available stick travel they routinely use during typical manoeuvres? The other option I have is to shorten the transmitter sticks, but again, is there a convention other than "just what feels comfortable"?

Cheers,

TWS

[john stones 1 - Moderator]

Only one way to set your sticks and rates etc up TWS

The way YOU like it,

John

[Stevo]

"So, I understand all of the technical trade offs between throw and resolution, precision and linearity, etc. at the servo/model end. I also understand the effect of the transmitter settings (expo, EPA, rates, etc), but I guess I've never really thought too much about what happens at the human end: i.e. the precision available from my brain/thumb at different positions."

Can you fly safely? under full control? Given what I have quoted here, I'm with John

[adrian lawrence 1]

I fly using rates as I am not so dexterous with my thumb movements as I would like. However I do know people who fly using no rates at all and have no problems. It's all personal preference how you fly, personally I would like TWS's dexterity, though sadly this isn't the case.

Cheers Adrian

[Chris Jones 7]

I fly the same way but recently I've been practicing for doing my B test. I can fly everything no problem apart from the two rolls. To get these slow enough I have to drop the rates right down to be able to fly them slow enough with enough precision to be able to maintain a constant rate. If I fly with the high rates the rate of roll changes as I add rudder and elevator. I don't think it will be a permanent thing for me but clearly it does have some benefits.

[FlyinBrian]

Posted by Chris Jones 7 on 08/08/2014 15:55:59:

I fly the same way but recently I've been practicing for doing my B test. I can fly everything no problem apart from the two rolls. To get these slow enough I have to drop the rates right down to be able to fly them slow enough with enough precision to be able to maintain a constant rate. If I fly with the high rates the rate of roll changes as I add rudder and elevator. I don't think it will be a permanent thing for me but clearly it does have some benefits.

You do not have to do "slow rolls" during the "B" just at a rate that requires that you need to input controls to keep the rolls level.

[john melia 1]

I can do a very slow roll , its the second one that causes me problems lol

[Biggles' Elder Brother - Moderator]

I accept totally that this is a matter of personal preference. But since you are asking this is how I do it - and yes it is a little different than you describe.

First I set the throws not via the TX - but mechanically on the servo arms - so full stick deflection is the maximum actual control throw I am ever likely to want in practical flying terms.

Then, I never use rates - instead I use a healthy portion of expo to "spread" the centre region of the control throw. The theory here is that 95% plus of all my flying will actually be in the central plus/minus 10% of the control throw. Only very few manoeuvres take you outside that zone for the style of flying i like to do, which is scale-like aerobatics. In that style of flying I find I only really use full (or even close to full) control movement in say stall turns and the landing flair. So, given I spend 95% of my control effort in the central 10% of the control surface movement I want that region spread out across say plus/minus 30% of mu stick movement to give me the best trade off between light and convenient stick movements, good "feel"/sensitivity and good resolution.

So, a slightly different approach - but one that works for me.

BEB

[ceejay]

BEB ditto

set mine the same way, also that way if, in a moment of need (panic), i can have full rates without finding and flicking another switch

chris

[Frank Skilbeck]

Posted by Biggles' Elder Brother - Moderator on 08/08/2014 21:49:51:

I accept totally that this is a matter of personal preference. But since you are asking this is how I do it - and yes it is a little different than you describe.

First I set the throws not via the TX - but mechanically on the servo arms - so full stick deflection is the maximum actual control throw I am ever likely to want in practical flying terms.

Then, I never use rates - instead I use a healthy portion of expo to "spread" the centre region of the control throw. The theory here is that 95% plus of all my flying will actually be in the central plus/minus 10% of the control throw. Only very few manoeuvres take you outside that zone for the style of flying i like to do, which is scale-like aerobatics. In that style of flying I find I only really use full (or even close to full) control movement in say stall turns and the landing flair. So, given I spend 95% of my control effort in the central 10% of the control surface movement I want that region spread out across say plus/minus 30% of mu stick movement to give me the best trade off between light and convenient stick movements, good "feel"/sensitivity and good resolution.

So, a slightly different approach - but one that works for me.

BEB

And that's probably true for the majority of us, but what TWS was saying is that he prefers to make the stick sensitive around the centre as he doesn't feel able to provide accurate control with the transmitter stick deflected far away from the centre. But the issue with this is that he has to set the throws to way higher than needed at full stick to provide the control input with just breathing on the sticks so isn't getting the full resolution of the servo as he never uses full deflection. I knw on one of my radios I can adjust the servo curve so the servo is at full deflection at only half stick movement, sort of opposite exponetional, and waybe that would work for TWS, sensitive around middel stick but with reducing sensitivity as the stick is defected further.

[The Wright Stuff]

Thanks chaps,

Useful comments, BEB. I guess in that context I effectively do the expo bit 'in my 'head', if that makes sense. It certainly helps with elevator on a few troublesome tail-draggers, where you need to plant the tail with an armload of 'up' on roll-out to stop them nosing over, but never need this much elevator in flight.

Much of my day job involves making infinitesimal adjustments to a micrometer scale with an allen key and a steady hand, so perhaps that has an influence.

The other explanation is simply that I'm lazy! It's just too much effort to move my thumb more than a couple of millimetres!

TWS

[Zarah khan]

I accept totally that this is a matter of personal preference. But since you are asking this is how I do it - and yes it is a little different than you describe.

[Steve Hargreaves - Moderator]

I'm with BEB on this one.....max throw & then tame it down with expo. Then if ever you NEED that full throw it's there waiting for you by banging the stick over rather than having to flick switches etc.. The only time I use "rates" is actually to switch in MORE expo on certain models during finals to allow finer control of the elevator for controlling the decent.....only certain models though...if they are a bit sensitive in pitch.

As the other guys have said all that matters is what works for you......one mans "touchy beast" might be another mans "responsive aeroplane".....

[ben goodfellow 1]

the instuction book of my new artf calls for , and i quote . " as much as you can possibly get "