RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 9415 views POST REPLY
Home✈️Aircraft🚁HelicopterBeginners Corner › Understanding dual rates and expo
01-07-2013 08:32 PM  7 years ago
Topic Vote0Post 1
Nelson34

rrApprentice

San jose ca

MyPosts All Forum Topic
Understanding dual rates and expo
Hi-so I understand the purpose of dual rates and expo. Expo can be used to help slow down a servos's reaction to stick input. Dual rates change the range of motion of a servo. Hopefully that's correct. What I don't understand is why to use them. I've read some people use them when flying 3D and switch to allow other people to fly a toned down helicopter. I've always flown my helicopters with one setting. And then do you flip all three servos or just one?
Also which is which on the tail servo-heading hold and I forget the other. One holds the tail in a straight or direction while the other follows the nose? This I'd used to dial in a gyro primarily? Thanks and hopefully this is in the right forum.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 08:36 PM  7 years ago
BarracudaHockey

rrMaster

Jacksonville FL

MyPosts All Forum Topic
Yes dual rates bring down your total range of motion. The end result is the controls feel less sensitive.

Expo...you have the wrong idea I think.

It will make the sticks less sensitive at center without sacraficing full throw as you move the stick further. It doesnt actually slow the servo down.

Lets say you dial in 25 percent expo on the cyclic.

As you move the stick away from center as you reach the half way point of stick throw the servo has moved only 25 percent, when you hit 75 percent of stick throw its moved say 60 percent, when you get to the end though its moved 100 percent. (those are just examples)

The more you dial in, the softer the center is to the point it becomes sluggish. 20 to 30 percent is good for smoothing things out around the hover, and for not getting interaction between aileron and elevator. Or when used on rudder, to not get interaction when moving the throttle.

Its strickly a personal feel thing, some folks like it, some dont, some use a lot, some a little.
Andy
AMA 77227
http://www.jaxrc.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 08:53 PM  7 years ago
Nelson34

rrApprentice

San jose ca

MyPosts All Forum Topic
Ok that makes sense thanks. So when using these, do you switch them all on or individually to preference?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 08:56 PM  7 years ago
BarracudaHockey

rrMaster

Jacksonville FL

MyPosts All Forum Topic
Its really a preference.

I usually just find what I like and leave it there. 25% expo on aileron, elevator, and rudder.

Make sure you set aileron and elevator the same.
Andy
AMA 77227
http://www.jaxrc.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 09:17 PM  7 years ago
Nelson34

rrApprentice

San jose ca

MyPosts All Forum Topic
Do you just have one setting for the most part and fly with that, or start with a setting, take off and then switch to 25%? Thanks again for answering my questions. I'm having a blast flying again after being gone for a year. I have a Blade 130 I fly in the front yard almost daily and a Nano for inside flying. I set up according to Blade's manuals, but just don't really understand why to have them and almost always fly in the first setting.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 09:28 PM  7 years ago
BarracudaHockey

rrMaster

Jacksonville FL

MyPosts All Forum Topic
I just set them up and leave them be.

The less switch flipping you're thinking about, the more you can concentrate on and enjoy your flying.
Andy
AMA 77227
http://www.jaxrc.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 09:36 PM  7 years ago
Rafael23cc

rrKey Veteran

Junction City, KS

MyPosts All Forum Topic
💎Sustaining Member
I use D/R on planks, but not on helis. It is programmed, but I don't use the switches. Expo I use on both planks and helis to "soften" the "feel" around center stick.

Rafael
Keep your feet on the ground, but your eyes on the sky.
Team Heliproz.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-07-2013 09:40 PM  7 years ago
HeliSmith

rrVeteran

Chico, CA

MyPosts All Forum Topic
Expo only effects the center of the stick. 25% expo is not a percentage rate for the travel of the stick. It is a percentage of a preset amount in the radio for expo. If you look on the monitor you will see it flattens the line out around center stick. So instead of being touchy around center now you have to move it a half a mm or so before it registers movement. It helps for shakey hands or if you are mixing in two inputs unintentionally.. Then you use expo. Expo is encouraged for heli pilots that need it.

Dual Rates can have the servo reaction rate slow for the first part of the stick travel and then fast for the second part. Say under 50% of travel for aileron it slows down the rate of servo travel but past 50% it is live servo action so super fast. Dual rates are discouraged for heli pilots it is no way to learn.
SHARE  PM  EMAIL  HOMEPAGE  Attn:RR  Quote
01-07-2013 10:32 PM  7 years ago
Nelson34

rrApprentice

San jose ca

MyPosts All Forum Topic
Ok-this is all great info. Thanks for the help. I don't see myself ever becoming a 3D pilot. I'm actually hoping to one day be able to just build, setup and fly a helicopter on my own. I can setup a Blade type helicopter and fly in all orientations, but not as difficult to build and setup as a larger heli. I've always needed help building and setting up my helicopter. I can fly my Radical 20, but I can't setup a radio for one, which is my goal for this year-to learn how to build, setup and fly a RC helicopter-and plane! My son is getting older and I'd like to one day be able to take him out and teach him.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-08-2013 02:20 PM  7 years ago
BarracudaHockey

rrMaster

Jacksonville FL

MyPosts All Forum Topic
Another example is, on my scale helis I run more expo so the heli looks smoother and more realistic in the air versus less for a 3D heli where I want crisp response.Andy
AMA 77227
http://www.jaxrc.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-09-2013 03:03 AM  7 years ago
dkshema

rrMaster

Cedar Rapids, IA

MyPosts All Forum Topic
Keep in mind that expo has "positive" and "negative" values.

This means that you can "desensitize" the stick-to-servo control around neutral OR you can make the stick-to-servo control around neutral even more sensitive than it already is.

With JR/Spektrum transmitters, "positive" values of expo flatten out the stick movement to servo response curve around neutral, making the controls less sensitive to small movements around neutral. "Negative" values increase sensitivity of the control around neutral.

For Futaba/Hitec radios, the opposite is true. Negative expo makes the stick feel around neutral less sensitive, positive expo makes the stick feel around neutral more sensitive.

-----

If I'm going to use different expo values on the same model, I'll slave the expo settings to the position of the flight mode switch. Flick on switch, everything else is taken care of for you and you really don't have to worry about where all the switches are when you're flying.

-----

Dual rates, at least for me, are useful in planks, especially when instructing a new pilot. Since dual rate settings control the total amount of servo movement for a given amount of stick movement, it's easy to set up a new flyer's plank to have lively and fast responses for the instructor, yet with the flip of a switch or two, tame the control response down to give the student a lesser chance of over controlling a model in the beginning. In the heli world, I cannot recall a time when I ever used a dual-rate setting. I generally set both rates equal, in the event a switch gets bumped, it does not affect the feel or flyability of the chopper.
-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-09-2013 01:37 PM  7 years ago
Nelson34

rrApprentice

San jose ca

MyPosts All Forum Topic
Thanks everyone for the input. Makes more sense to me now.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-09-2013 10:04 PM  7 years ago
T-Rex-Flyer

rrElite Veteran

Panama City, Fl

MyPosts All Forum Topic
Quick follow up question if I may, Expo can be both positive and negative to soften or increase sensitivity around center stick. What would be an application for increasing the sensitivity around center?
Thanks.

Sorry not intending to hijack the thread.
Terry.
If the wings are traveling faster than the fuselage, it's probably a helicopter.
SHARE  PM  EMAIL  Attn:RR  Quote
01-10-2013 12:04 AM  7 years ago
Nelson34

rrApprentice

San jose ca

MyPosts All Forum Topic
Ask away! Please!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-10-2013 12:47 AM  7 years ago
dkshema

rrMaster

Cedar Rapids, IA

MyPosts All Forum Topic
Off-hand, I can't think of a reason to increase the sensitivity of the control reaction around neutral, but the option is there.-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-10-2013 11:33 PM  7 years ago
flycatch

rrApprentice

Barstow, California

MyPosts All Forum Topic
If you fly thumbs than you will need dual rates and expo but if you fly fingers than this does not apply.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2013 03:32 PM  7 years ago
BarracudaHockey

rrMaster

Jacksonville FL

MyPosts All Forum Topic
Thats not a true blanket statement, again, it depends entirely on the person doing the flying and how they want their setup.Andy
AMA 77227
http://www.jaxrc.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2013 10:24 PM  7 years ago
HeliSmith

rrVeteran

Chico, CA

MyPosts All Forum Topic
Mostly everyone I know flies thumbs and doesn't use dual rates on helis. Most the guys I fly with don't use expo either. I do use expo. 25% softening expo on cyclic and 5% softening on rudder. This keeps me from mixing in unwanted commands when I am smacking it around.
SHARE  PM  EMAIL  HOMEPAGE  Attn:RR  Quote
01-13-2013 04:04 AM  7 years ago
Noobyflyer

rrVeteran

Clearwater, FL

MyPosts All Forum Topic
This is a great thread and Barracuda + dkshema nailed it.

It is so misunderstood and reading their posts was a great refresher. I appreciate it.

I use 25% expo on A, E, R and Dual Rate of 75% on the tail. It makes for a smooth heli for me. Sometimes the shakes haunt me, but with this setting the heli doesn't suffer.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
02-20-2013 04:00 AM  7 years ago
WEFlyer

rrNovice

Burlington Cnty, NJ

MyPosts All Forum Topic
Nelson34,

Where I have seen dual rates mentioned the most is for precision flying for both planks and helicopters. The main idea is to reduce pilot workload.

For planks I have seen in mentioned for rolls and performing loops /vertical maneuvers. Say you want to roll "X" degrees per "X" secs. Your normal max throw for aileron is 14 degrees. You only need 6 degrees to get the desire roll rate. You normally fly with 14 degrees so that at your low rate. Say 85% of the time. You set up the high rate switch so that the aileron throw is only 6 degrees max to perform the desire roll rate. Then when you do that roll, you flip the high rate switch for aileron and then you just throw the aileron stick either "full" left or right and concentrate on flying the straight line to go with it. Basically you have one less control to think about in performing the maneuver. Reduced pilot workload.

For doing piros on a helicopter it is the same idea. I have read this for I think the piro flip. A piro maneuver of some type in any case. You want to tail to rotate so many degrees per sec for the piro piece of the maneuver. So you set up the high rate for the rudder to max throw need to rotate at the desire rate. Say you only need 60% of your "normal" rudder throw so you set the high rate for 60 instead of 100 as you may only use this for 15% of your routine. When you do the maneuver, you flip the switch, throw the rudder either "full" left or right and then focus on the rest of the controls to perform the maneuver. Again the idea is one less control to worry about. You're reducing your workload to focus on the flying the maneuver precisely.

Now folks say they don't use rates for 3D but if you're flew competitions like the Heli Masters or F3N where you have "set" maneuvers that have a "precision" component to the 3D judging, this could certainly help you out.
SHARE  PM  EMAIL  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 9415 views POST REPLY
Home✈️Aircraft🚁HelicopterBeginners Corner › Understanding dual rates and expo
 Print TOPIC  Make Suggestion 

 8  Topic Subscribe

Friday, April 3 - 5:28 pm - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online