EPA, does it affect the esc?

Okay, so I am running a braking servo harnessed with the esc into the throttle outlet. If I use the end point adjustment feature, I know it will adjust the end point for the servo, but will it adjust the end point for the esc?

[Gustav]

In a word,yes.:027:
But if you're just reducing the braking side of the throttle channel then you'll still get full throttle.

If you have a radio with 3 channels and channel mixing,then you can use 3rd channel for the servo and have seperate epa for the mechanical and controller brakes (if you're still using controller brakes aswell)

Edit: there's a thought,if you use the same channel then the servo will move in the throttle direction too,i guess you meant can you set the throttle side of that channel to zero,the answer is no(not if you want to move-lol).If you have a 3rd channel with mixing then use 3rd channel for servo,mix with throttle channel and set throttle epa of 3rd channel to zero.then it will only move in the brake direction and the controller will still see full throttle.

another question, how do you reverse the direction/polarity of a servo?

[squeeforever]

on your radio.

[Gustav]

Do you have a 3rd channel with mixing for the servo? if not then you won't be able to reverse that channel or you're esc won't work and you'll have to have the arm on the other side of the servo instead.

I have a MX-3. How do I do channel mixing?

[Gustav]

I just had a look at the manual PDF,doesn't look like the MX-3 does channel mixing,sorry.JR xr3,xs3 and the spektrum dx-3 do.

[Gustav]

This isn't really a problem,you just need a nitro style sliding brake linkage,so the servo will move in the throttle direction but the brake linkage won't.Then just adjust the brake side of the throttle channel to adjust your brake EPA.simple.you can't reverse the channel though,you'll just have to mount the servo arm on the other side of the servo.

[BrianG]

I find that if you understand how a radio works, you can easily answer these types of questions so they make logical sense. These observations were noted and measured using an oscilloscope.

Each channel on the output of a radio receiver consists of a series of squarewave pulses. This is the same no matter what type of transmission medium it uses: AM, FM, PWM, DSS, etc. The pulses occur at a rate of one every 20ms (approximately), which equates to a frequency of 50Hz (again; approximately). The actual frequency is not really that important as long as they are consistent, repetitive, and frequent enough to be a valid signal. Typically, each pulse is "on" from 1ms at minumum servo throw to 2ms maximum servo throw. Servo "center" would be 1.5ms.

Incidentally, this is how failsafe devices work; they look at the consistency and repetitive qualities of the pulses to determine of they are valid and not just "noise". If not, it ignores the errant input signal and synthetically creates an appropriate pulse to send to the servo/ESC to cause it to go to failsafe position. But I digress.

When you increase your endpoints, you decrease the min to a little below 1ms, and increase the max to a little above 2ms allowing for a greater servo/ESC range. Decreasing your endpoints increases the min to a little above 1ms, and decrease the max to a little below 2ms allowing for reduced servo/ESC range. Adjusting the center varies the signal a little above/below 1.5ms. When I say "a little", I mean like 0.05ms (50us) or even less. Reversing the output switches the min and max signals, causing the maximum to be 1ms and the minimum 2ms instead, just as the term "reversing" applies.

So, for throttle, full forward would be 2ms, full brake/reverse would be 1ms, and neutral would be 1.5ms. Increasing the EP to, say 110%, would make the signal go below 1ms and above 2ms for more servo range. Decreasing it to, say 90%, would make the signal stay above 1ms and below 2ms for less servo range. Then the various positions in between would vary linearly between these measurements. Reversing the servo signal on the transmitter would put full forward at 1ms and full reverse at 2ms instead.

The steering channel works in a similar fashion; full left=1ms, full right=2ms, and center=1.5ms. As stated, these values can be adjusted a little based on servo centering, reversing, and EPA.

On some radios, you can set an exponential response curve so that there is little change when you move the control near the center position, but changes more as you move the controller towards the max/min positions. This would allow for more precise control near the center, which might be especially nice for steering at high speeds, or low throttle for rock climbing.

The servo or ESC takes these signals and, along with device programming, converts them to something it can use. So, the part that decides whether to brake or go into reverse is actually in the ESC. It just looks at the pulses coming from the radio receiver and the speed of the motor and decides what to do.

EDIT: Edited for accuracy and readability :).