Stixoz

G'Day all, i'm in the process of "tweaking" my boomerang 40 in the hope that my boomerang does come back

I want to input some very low control throws for my low rates, currently my low rate control throws are

Aileron 9mm
Elevator 10mm

High rates

Aileron 14mm
Elevator 16mm

I'm not to concerned about the high rates because i don't plan on using them, what i'm wondering is how low can i take my control throws on Aileron and Elevator before it's to low and i risk not enough control from a gust of wind/emergency.

Also when it comes to Rudder - Aileron mixing, i have my rudder setup to be out about 1.5-2mm with full aileron seeing as the rudder has to move almost 1mm before being flush with the tail i don't think this is excessive, i want to be on the safe side of caution so any advice there greatly appreciated.

Cheers

Stix

bingo field

I wouldn't try to go too low on the rates, the controls won't be effective, and you may have difficulty finding the rates switch to select high rates. Once you find high rates, you may find that difficult to control. I would go with the book setup for low rates. It should give you adequate control throws for normal flight. I don't use rudder / aileron mixing on any of my planes. For most of them, it is not necessary. You may want to experiment with it in the future on something, but not with this plane. Try not to make this too complicated, and you will have fun. It is almost as nerve wracking to try and help someone 8000 miles away as it is if you were here at my field.

Sandmann_AU

Hey Stix

I've only been doing this about a year but I'd have to agree with bingo field... keep it at what the book tells you for low & high rate throws, and don't use high rates till you're comfortable. You can still get in trouble (faster than you might think) with low rates and if you've set your throws short you won't be able to get OUT of trouble again. Don't forget getting into trouble usually takes a combination of gravity + engine power + control surfaces, but to get OUT of trouble you usually only have engine power + control surfaces so you'll all the throw the designer advised on.

The boomerang trainers are pretty stable and are very forgiving. I started on a boomerang 60 and ended up hacking it to put twin aileron servos in (to stop flutter at higher than expected speeds due to the large prop I ran) and ended up converting it to a twin engined setup using a pair of super tigre 40's I had floating around. It survived 2 circuits of the field, and only crashed because I'd put an ENORMOUS rudder on it (in case of single engine flameouts) and decided to see what would happen if I "twiddled" the rudder in flight. Instantly snapped off the entire vertical stab which became a 3rd vertical stab with an enormous elevator flapping around randomly. It made an impressive hole in the runway.

Whereabouts in QLD are you Stix? I'm in Brisbane, and fly at TMAC.

Matt

Sandmann_AU

Oh, and scrap the whole aileron/rudder mixing idea - it seems good in theory but all it'll do is fail to teach you how to use your rudder, and if it's set up badly you'll have no end of trouble turning without plummeting into the ground.

Jetdesign

My Feedback: (8)

Mixes are a bad idea at this point. The plane needs to be properly trimmed first, which includes a battery of tests to determine if things like CG, incidence, dihedral, differential, etc. are all set up correctly. Using mixes to fix things that are mechanically wrong with the plane is not the way to go.

Dual rates sounds cool. In reality, we all forget to flip the switch at some point, forget where the switch is, etc. (hopefully) until we've been flying for a while. Set the plane up on low rates and fly it. Get comfortable with it, learn it. Then you can say to yourself "hmm, I feel like it should roll a little faster" and at that point you might just want to increase the current rates, and not have dual rates.

Dual (and triple) are really for setting a plane up for 3D and for competition. I've got two competition planes and really only need dual rates on the rudder for big rudder moves. At some point you'll learn some throttle control, and find out that you can increase/decrease the sensitivity of the plane at different speeds, attitudes, and how the prop wash is blowing over the plane.

Gray Beard

My Feedback: (-1)

I must be setting up planes wrong?? I always have high and low rates except on my rudder??? My switches have never moved either so I always know where they are? Wow Joe, your switches move and hide from you??? Bad Radio!!! Just joking with you! I really do always have A high and low rate and I really never set A rate on my rudder though. A trick for Joe, add some expo into your throttle if you can. When I set up A plane for 3-D I set up triple rates and all on one switch. Sort of A dumb, dumber and stupid set up but it works. Only time I even mix in rudder to my ailerons is on giant scale planes that require A little rudder to make the plane turn in A scale manner for IMAA shows. I have the mix on A switch too. Lowering throws on A trainer could run into problems, most of them need the controls set as called for or the plane is sluggish and doesn't respond well. For trainers I set the controls as called for but add in about 60% expo for A student.

Jetdesign

My Feedback: (8)

If I had EXPO on my rudder I might not even have dual rates there, either! I agree that rates are important for 3D and some higher level aerobatic maneuvers. Not needed for for Sportsman's level pattern flying, and probably not for most other beginners.

I might have underestimated the OP though, now that I re-read the post. It was suggested to me when I started to not bother with mixes and rates until I could really fly the plane, and I've learned that that is some fantastic advice

I don't have expo on the throttle. Don't even have it on the rudder! The Airtronics RDS-8000 is a good radio, but a starter radio for competition flying as far as I'm concerned. It will be replaced within the next few years - maybe a graduation or christmas present in 2010

RCKen

My Feedback: (9)

This is very poor advice, especially when doing a maiden flight for a plane. There has been more than once that I have taken a plane up on a maiden flight and found that the high rates make the plane almost uncontrolable and the only way I was able to fly it back in for a landing is by switching down to low rates on the radio.

Dual rates are NOT just for 3D and for competition and recommending that they are is almost a bit snobbish. I don't fly 3D and I definitely don't compete, but all of my planes are set up with dual rates. There are many reasons why dual rates are good for us "every day fliers", but here's the main reason I do it. On many planes it's nice to have a lot of throw on a control surface, such as the ailerons, when in the air. But when it's time to land that much throw can make it a bit "twitchy" or sensitive when making an approach. However, by simply switching to low rates it's easy to bring the plane in for a landing.

Ken

j.duncker

My Feedback: (2)

Start by setting high rates to the recommended control throws. I would then set low rates to 60% on the tranny and add some expo as well 40% on a Futaba [ I you are using something else then ask around for a starting setting ] .

DO NOT GO TO SOMETHING LIKE 20% ON DUAL RATES YOU WILL PROPABLY CRASH ON LANDING AS THE CONTROLS WILL BECOME INEFFECTIVE AT SLOW SPEEDS.

Good tip coming up. When you use dual rates get someone to stand beside you to flip the dual rate switch if you get into trouble and need to revert to high rate in a hurry. Most low airtime pilots will have to look at the tranny to find the switch.

Gray Beard

My Feedback: (-1)

Story time and I will do it with A straight face. OK, maybe not but A true story. Last year I built a wonderful CG Extra for A friend as a gift. He sent me all his stuff and I built and set up the plane with a nice new 1.40 YS, an outstanding combo I mite add. I set it all up in my radio, a Futaba 9-C and my friend had the same radio. I use a lot of expo in all my planes, he is a racer and doesn't use it at all. I set both radios up exactly the same, his and mine. I did the maiden, surprise, two beeps of left aileron trim and it was perfect!! {that has been happening a lot lately, maybe I'm getting this stuff down now?} I flew the heck out of the plane and loved it. I took it up again with his radio, two beeps of left and it was right on the money. Problem was it was twitchy!! He then took it up and was all over the sky!!! Way too twitchy for him. All he did was hit the low rates and it was perfect for him. A stunt plane without expo for me is just wrong, for him it was A big problem but it was cured just by going to low rates. They do come in handy. On A trainer it's A must do thing. When flying my own planes I have way too much elevator for doing some stunts but I know what the sticks do so no big deal but when I want to smooth out and do some IMAC stunts and be very smooth I really have to go to low rates or I can over control just by dumb thumbing. Most the time I never use rates but they are there when I want or need them. I don't use them A lot but I know they are there!
Dang, that was a windy story!! Hope I made a point. I even tried to use all small A's.

Jetdesign

My Feedback: (8)

Ok, reading the original post: the OP is flying a basic .40 size trainer. There is no evidence that he has even flown a plane before. Where did these dual rate figures come from? Why is there a rudder-aileron mix - because you decided it needed it in the air, or because it looks cool or you saw others doing it?

Ken, you were the one that beat it into my head 6 mos ago that a basic 4ch radio was all you needed to fly a trainer, and that I shouldn't be playing with my 'fancy computer functions' or whatever while learning to fly a plane. That is like the best advice anyone has ever given me, and it came from you!

I agree I 'mis-spoke' when I said '3D and competition'. I should have said 'more advanced aerobatics'. Flying the pattern, doing figure 8's, rolls, loops, stall turns, cuban's, and even knife edges, can all be done on a (Nexstar) trainer on the suggested SINGLE rates suggested in the manual.

If we don't know that this pilot has even ever flown a plane, how can you suggest he be THINKING about dual rates, let alone using them???

Jetdesign

My Feedback: (8)

...

hmm, computer is being weird. has anyone else been having trouble with RCU's site taking FOREVER to load?

bingo field

Yeah, but I can blame it on my kids and wife..... Streaming Christmas music, and chatting while engaged in an MMORPG.

Gray Beard

My Feedback: (-1)

Not tonight but it happens. Most the time it is my puter or ISP. If I reset my DSL it sometimes clears up, most the time it clears up!!