I've put in about 45-50 flights so far on my LT-40. Ran an 11x5 for a long time while getting used to it and swapped out for a 12x6 which I am still flying. I tried a 12x5 earlier today and it required I rev up the engine more to get forward movement. Happy with the 12x6 I am thinking. What prop are you running on your LT-40?

Also - have many people increased their control surface throws for kicks and had good results? I know this is a trainer so it can only do so much, but I'd like a little more oomph in the throws for maneuvers and such while I learn more.

Been working on using rudder in my flights. Was pondering mixing with my Tx but I'd rather learn to do it manually. Takes some getting used to but damn it's nice once you get the basic rudder use down.

somegeek

The 12x6 is probably just right for your plane.

Your LT 40 can do a lot more than most people think. If you practice and get really familiar it is capable of simple snap rolls, rolling circles, stall turns(hammerhead turns), knife edge flight and just about anything you can think of. Obviously its design limits you to how well you can perform certain maneuvers but it will do a lot of fun stuff.

Im not sure what your throws are now but once you get really comfortable you can increase the aileron throw to give you whatever their maximum physical limit for throw may be. Go all the way in on the control horn and all the way out on the servo arm. Hang on becuase its going to get really lively when you do this.
On elevator I would say you could increase the throw to about 16 degrees on your high rate.
On the rudder, again just move the pushrod all the way in on the control horn and all the way out on the servo arm and take all it will give you. You can never have to much rudder throw on a knock around plane.

Of course all of this throw will make it a lot more sensitive unless you can add a little expo so you will have to learn to move the sticks in much smaller increments.

This is where dual rates start to come in handy. Setup your rate switches with normal throw for take off and landing and then flip the switch and go nuts!
Just be careful when you 1st flip the rate switches and get the feel for how the plane handles before you start wringing it out.

Thanks a bunch, Mike! Expo and dual rates sound like the trick. Have some stuff to tweak tonight. :-)

somegeek

Somegeek,
Have you sealed your control gaps??? If not, do it. That will make one of the biggest improvements in performance of the plane. You won't believe the difference.

Ken

Ken makes a good point. This is something that you can do with colored vinyl, monokote or lots of folks simply do it with scotch tape. Just cut a piece the length of the surface, fold the piece of tape, vinyl or whatever you use in half and carefully lay in in along the hingeline. Do this on both sides of the surface. You should do this on the ailerons, elevator and rudder.

I actually hadn't sealed the control gaps on my LT-40. Used Ultracote to seal them on my SSE. Will do the same on this one.

Thanks,
somegeek

It depends on what engine you are running. I have run a 10 X6 with a .40 and run 11X6 with .46. Works for me.

Hud

Control surface joints sealed.

Control surface servo range throws maxed.

Dual rates set
high for max throws
low for standard throws

Not sure what to set for expo? I know it needs to be negative so the initial stick to servo movement is slower than normal... Any suggestions where to start %-wise?

Appreciate the feedback.

huddlehd2 - I'm running a 12x6 APC on a .46 OS AX fwiw.

somegeek

What transmitter are you using? With Futaba you soften by using - expo, on a JR you use + expo to soften response.



Some transmitters actually have a display that shows the exponential curves, what you want is for the curve around neutral to look about the same on low and high rate, but on high rate as you increase towards full deflection the curve will get really steep as the control surfaces moves more to get to full deflection.
I would start with about -30 expo on the ailerons and elevator and -50 on the rudder for high rates.
Expo 101- What you are wanting is for the low rate and high rate to feel the same around center. That way when you flip from low rate to high rate you dont get too jerky.
I would be careful about *****g out the rate on the elevator too, I suggested about 16 degrees as a starting point for high rates. you can adjust it from there. If you maxed out the throw you could be up over 22 degrees and that isnt going to be fun for flying (yet)

If you have a good eye you can reasonably estimate it by finding 45 degrees and then eyeballing it from there. I would say be conservative as too much elevator can get you into a lot of trouble. Just guessing for an LT 40, I would say that you dont want the trailing edge of the elevator to deflect any more than about 1/2" up and down on high rates.

Like I said you need to be REALLY careful with high rates. The plane is going to be extremely sensitive and you have to get to low rates to take off and land. Take off and get up high, once you are at a safe altitude flip to one high rate at a time and fly around to get the feel for it. Especially elevator and aileron. The Rudder should not be that big of a deal.

If you sealed the hinge lines, you may try flying it on low rates first. Sealig the surfaces can make a plane a lot more responsive, that may be enough for you.[8D]

Another thing, look closely at your linkages. Make sure nothing is over extended or binding. On high rates there should not be a pushrod hitting anything or a connnection at the servo arm or control horn that is in a bind, misaligned or putting pressure on the linkages. The pushrods should not bend or flex at any point in the range of travel.
Everything should remain free and unbinded if all is setup correctly. Go very carefully when making these sorts of changes as overdoing it could damage the linkages, and make the plane difficult if not impossible to control.

Im concerned, I dont want you to overdo it and crash your plane or get yourself or someone else hurt.

J

IMveryHO a 12 x 6 is too much for the .46...it will work, but the spin up will be very slow.....

try the 12.25 x 3.75 will work very nicely

Appreciate it, Mike. [8D]

Using a Futaba 6EAXP.

Single switch for dual rates on my controller.

Stock recommended control surface travel per build manual:
Elevator - 9/16" up and 9/16" down
Rudder - 1" left and 1" right
Aileron -3/8" up and 3/8" down

Max throws when dual rate switch is thrown currently:
Elevator - 1" up and 1" down
Rudder - 1.25" left and 1.25" right
Aileron - 5/8" up and 5/8" down

All control horns and rods were adjusted and verified no bending or binding at max throws.

somegeek

cool... have a ball just be careful until you get used to it!

Will do. Any kinda 'tricks' I had been doing have been at 3+ mistakes high. Will do the same when kick'n in the dual rates. Gonna dial in the -30 expo on the ailerons and elevator and -50 on the rudder for high rates tonight.

somegeek

remember, those are not gospel, just starting points. You may end up dailing in more or less throw and/or expo depending on what you personally like. [8D]

Got a chance to try out full throws tonight - woohoo! Sure woke the plane up. [X(] Was a bit windy so I was getting tossed around up high but managed to do a few repetitions of where you put in full down elevator and left or right aileron. Plane kinda tumbed forward and ended up straight again in a short distance. Dunno what that is called but those are fun. Would turn on the D/R to mess around once up high and then turn it off when I was just flying casual circuits.

Fun stuff!

somegeek

good glad it worked out for you.. Now be careful and dont tear that thing up young man![8D]