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Old 03-24-2009, 07:27 PM   #1
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Default Dual rate?

Hey guys,

What does dual rate steering mean exactly? What are the affects of turning it up and down, and how do you adjust it on a spektrum dx 2.0? Am I totally off here? lol

Thanks alot.
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Old 03-24-2009, 07:34 PM   #2
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its the amount your servo travels in each direction relating to your end point adjustment. if you have your paperwork for your radio it will explain it in detail. on the dx3 its the bottom button on the handle by your thumb. move it either direction and it will go up and down. up makes it turn more and down just the opposite. my explanation might not be totally accurate but its kinda hard to explain. best thing is to read the manual.
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Old 03-24-2009, 07:43 PM   #3
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i personally use dual rates (and expo) only in my helicopters and airplanes, more so for flight modes and not on cars. however, i use expo with my cars, around 35% on steering and zero on throttle.
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Old 03-24-2009, 07:47 PM   #4
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whats expo? does the dx 2.0 have it?
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Old 03-24-2009, 07:49 PM   #5
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In offroad I think expo should be left alone and let the finger do the work. Just my .02
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Old 03-24-2009, 08:00 PM   #6
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Originally Posted by rgrassey@me.com View Post
whats expo? does the dx 2.0 have it?

Expo is short for Exponential, and what it does is it slows down the transit time of your servo to turn left and right, in other words negative means it will take longer for your servo to complete a 180 degree turn, and positve expo speeds it up..Sorry Little man..DX 2. does not have it
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Old 03-24-2009, 08:04 PM   #7
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In offroad I think expo should be left alone and let the finger do the work. Just my .02
man, one comment at the track about you not running the state race, and you gota bust my b@lls...

i use it on steering only, and it calms down the "touchyness" around center (nutral). in other words it will allow the car to not be as touchy at higher speeds when needing small adjustments on steering.
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Old 03-24-2009, 08:06 PM   #8
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ok so should I adjust my dual rate if I feel my car isnt turning to its capibilities or should I increase the epas to each side? Also how would I adjust it on the dx 2.0?
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Old 03-24-2009, 08:55 PM   #9
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ok so should I adjust my dual rate if I feel my car isnt turning to its capibilities or should I increase the epas to each side? Also how would I adjust it on the dx 2.0?
Look in your manual of the dx2.0, it will tell you everyhting you need to know.
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Old 03-24-2009, 09:29 PM   #10
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man, one comment at the track about you not running the state race, and you gota bust my b@lls...

i use it on steering only, and it calms down the "touchyness" around center (nutral). in other words it will allow the car to not be as touchy at higher speeds when needing small adjustments on steering.
Nah bro, no ball busting here. I just personally dont like using expos in offroad racing. A few others in Dfw swear buy it and once I tried it I just dont see how they can drive with it, I know I couldnt. It just seems easier to me to slow down my hand/finger movements rather than the servos response being slowed down. That way if I need to up the pace I still can. I knew you were just f*ing with me about the state race, all is good meng.
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Old 03-24-2009, 11:44 PM   #11
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Expo is short for Exponential, and what it does is it slows down the transit time of your servo to turn left and right, in other words negative means it will take longer for your servo to complete a 180 degree turn, and positive expo speeds it up..Sorry Little man..DX 2. does not have it
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Originally Posted by roadracer43 View Post
its the amount your servo travels in each direction relating to your end point adjustment. if you have your paperwork for your radio it will explain it in detail. on the dx3 its the bottom button on the handle by your thumb. move it either direction and it will go up and down. up makes it turn more and down just the opposite. my explanation might not be totally accurate but its kinda hard to explain. best thing is to read the manual.
I am sorry but both of you are technically incorrect

Dual rates is where you have two servo epa points, controlled by a switch i.e. switch on gives your servo full throw and the switch off position gives you reduced servo throw.

Exponential varies the movement of the servo relative to the stick/wheel movement i.e. no exponential the servo should move linear to the stick/wheel movement and with exponential the servo will move exponentially to the stick/wheel movement. (That is of course if the servo arm and the control arm are setup up square to each other, if not then exponential can actually give linear throw to movement).

You can also have a servo curve with most high end radios which will give different amounts of servo movement at different points along the stick/wheel scale, here you can setup a throttle curves and even steering curves if you wish to do so.

What roadracer is referring to is EPA which is end point adjustment and my man jaz is talking about throttle speed which the KO radio has, from memory Futaba do not have this function. Expo has nothing to do with the servo speed.
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Last edited by Sam-E; 03-24-2009 at 11:55 PM.
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Old 03-24-2009, 11:49 PM   #12
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IMHO it is worthwhile having a little bit of expo around mid-stick with high speed servo's as it will tame the car down the straight aways (not much 10 or 15% is more than enough). I also use a little bit on the throttle as most 2 strokes do not give a linear output with regard to throttle opening.
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Old 03-25-2009, 02:47 AM   #13
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Here is how I have always learned this. EPA is the amount that the servo will throw it. Basically turning the number up will give you more throw on the Left and right sides depending on which side you choose. That is for steering. Same applies for the throttle servo or esc. More you turn it up the more power you'll have and brake is the same. Dual rate is more for the steering. If you have your EPA set too high it can eventually burn up the servo with that amount of force being pressed into. Dual rate solves this problem. You turn your dual rate down to make the servo not press as hard, but will still give that same amount of throw on each side, which in turn gives you more steering. I generally set my dual rate around 80-85 percent and depending on vehicle I usually have my epa at around 115-120 for both sides of steering. For throttle I like to be in the 80-90's range and then use EXP and turn it negative 80 percent for indoor electric, and for nitro I usually leave it at 0. Gonna try using it more outdoors this year since I have a MP9 and a Sirio Evo III. Don't want to be full tilt out there.
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Old 03-25-2009, 08:24 AM   #14
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Quote:
Originally Posted by Sam-E View Post
I am sorry but both of you are technically incorrect

Dual rates is where you have two servo epa points, controlled by a switch i.e. switch on gives your servo full throw and the switch off position gives you reduced servo throw.

Exponential varies the movement of the servo relative to the stick/wheel movement i.e. no exponential the servo should move linear to the stick/wheel movement and with exponential the servo will move exponentially to the stick/wheel movement. (That is of course if the servo arm and the control arm are setup up square to each other, if not then exponential can actually give linear throw to movement).

You can also have a servo curve with most high end radios which will give different amounts of servo movement at different points along the stick/wheel scale, here you can setup a throttle curves and even steering curves if you wish to do so.

What roadracer is referring to is EPA which is end point adjustment and my man jaz is talking about throttle speed which the KO radio has, from memory Futaba do not have this function. Expo has nothing to do with the servo speed.
Thanks Sam..Technically I wasn't trying to be correct, I was trying to help a new racer understand..That curve you are referring too is actually the speed in wich the servo reacts to inputs from your transmitter...which in actuality is the speed of your servo..Servo's will react quicker than we can, and that's what causes the twichiness that allot of people feel with their buggies, and truggies..By reduce the Expo, it slows down the reaction time, or speed of react.. allowing for a much smoother handling car..but thank you for the technical explanation....all that time hanging out with "the Drake" is paying off
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Old 03-25-2009, 08:36 AM   #15
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the drake Nice 1 Jaz


FWIW i turn my D/R Off on my 3pk for the sheer reason i don't want to be accidentally adjusting my D/R with my thumb while racing and potentially turn it down to where i don't have enough steering.....i let my EPA's do the thinking.
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