Expo & D/R

[uniquexme]

guys, appreciated if some1 can advise what is Expo and D/R, and how much did you guys put on your trex450? thanks.

[Pinecone]

Expo is a function where you modify the output versus stick position curve. Normally if you move the stick 1/4 (from center) of the range, you get 1/4 of servo motion. 1/2 = 1/2, etc. With expo you can reduce the output versus stick motion in the middle of the travel, so the initial small stick motions don't give as much control, making it easier to fly. So 1/4 stick motion may only give 1/8 servo motion, but at 1/2 stick you get 3/8 and at full stick you still get full motion.

How much is a personal preference, but I tend to run 25 - 30% on a new heli and then tune until I like it. Realize that on JR + expo is what you want, on Futaba/Hitec you want - expo. The wrong way will make the center stick motion VERY sensitive.

D/R is dual rates. It allows you to set up two different sets of control throws. Not used as much on helis as planks. With dual rates you would set one switch position to be full throw and the other to be say 60% of full throw. Again making the response softer and easier to control.

I prefer expo because if I need full control, I don't have to throw any switches, I just move the stick further. I think dual rates are a throw back to older radio setups, but still useful for things like 3D airplanes where full control is a LOT of throw or FAI heli flying where you want very fine contorl for stationary hovering.

[uniquexme]

thanks for that info, really appreciated that. so u mean that on JR/DX7, +25% means that the Expo is more? large number = more sensitivity?

we dun use D/R on heli? pardon me as m newbie. thanks

[Pinecone]

Well, it is confusing. A higher number is more expo, the sign (+/-) tells you which way the expo is going (more or less sensitive at cengter stick region).

For JR + means less sensitive around center stick. For Futaba and Hitec - means less sensitive around center stick. Best case is like my JR 9303 you can SEE the full range curve so it makes sense.

D/R isn't used as much since you have to hit switches to go from low to high rate, and in helis you sometimes don't have the time to do so. You CAN use them, just that most people seem to not do so.

[uniquexme]

ok. noted with thanks pal.

[jaywhy]

Can you guys explain this to me about the DX7?

So - if I want expo on my rud (just 10), my Ail, and Elev (20%) - and I want them constantly on for my setup - I can go in the [D/R & Expo] and set the expo rate to 20% at both switch settings. Right now I've gotten used to ignoring those switches, so I don't want to have to worry about which position is the right rate I want.

This seems to work - I've cranked the expo up to 100 on elevator and it is working this way. HOwever, what is with the EXPO option in the [Swash Menu]? It flips between INH and ACT.

What is that? Nevermind, found this great thread explaining issues of EXPO in different areas: http://www.helifreak.com/showthread.php?t=45506&highlight=swash+menu+exp