Please help me understand: EPA vs. Dual Rate

[B0tt0mline]

Hi,

I am wondering about the difference between EPA and Dual Rate...

Currently I do it this way:

Use EPA for motor if I want to run slower.
Do not use Dual Rate for motor.

Use EPA for steering to decrease/increse steering if needed.
Use Dual Rate for steering to have the same steering on both sides.

Is this approach correct?
Is it also correct not to use Dual Rate for motor?

Thanks!

[Neil Skull]

You are a bit wrong i am afraid.

EPA is END POINT ADJUSTMENT. This means the amount of movement in each direction the servo will move, or could be the throttle and brake on electric.
Its very important to set the steering so as its not got too much movement that it hits into the hubs or wishbone. as you found you can decrease to have less steering but its only really for beginners and for onroad you look for that!

Dual Rate is a switch that you can set to have 2 sets of adjustments.
one could be with lots of expo or less EPA. its really more common for flyers to use Dual rates and not so much for cars.

I would keep it simple and set EPA to max on the throttle unless its a beginner then it could be good too use.

[BeachBuggyPhil]

I use 45% D/R on my Mardave but if my turning circle is to small I up it to about 55% D/R.
I use EPA to make sure that I turn the same size circle left as I do right.
If my car is to fast I have less epa on the throttle but keep the brake the same.
If i turn to far right I might need 90% right and 100% left EPA.

Hope it helps.

[sosidge]

With a Futaba radio (steering side), EPA is to set the travel of the servo at maximum lock, Dual Rate is then used to set how much lock you want on the track (anything up to 100%).

This seems like the logical way to do it, but from looking at some Sanwa manuals recently they seem to suggest doing it the opposite way! Which means you could have dual rate percentages in excess of 100% The old KO Esprit had yet another different way of doing it.

Throttle side of an electric car shouldn't need any adjustments to EPA as the ESC will be set up with EPA at 100%. Futaba radios have an ATL adjustment which is basically a dual-rate for the brake side.

I think the best advice is to follow the manual for your radio...

[Nightshade]

Originally Posted by sosidge

Throttle side of an electric car shouldn't need any adjustments to EPA as the ESC will be set up with EPA at 100%. Futaba radios have an ATL adjustment which is basically a dual-rate for the brake side..

So is using epa to reduce the throttle at a tight track the wrong thing to do?

[Nightshade]

....

[knighthawk]

I run the Futaba 3VCS
In the manual is says to set the EPA as :

1 Throttle (forward side) adjustment
Turn the throttle stick fully to the high side and use
the (+) or (-) buttons to adjust the throttle angle.

However, when using an FET amp, set to 100%.


I've always taken it as with ESC's ( ie FET amp ) the EPA is set to 100% to prevent overheating of the FET's due to not being allowed to apply full throttle

[sosidge]

Originally Posted by Nightshade

So is using epa to reduce the throttle at a tight track the wrong thing to do?

I would use less thumb or less motor rather than artificially limit the ESC with EPA.

Limiting EPA shouldn't cause damage to a brushless ESC although I believe it would cause brushed ESCs to overheat.

[Neil Skull]

Originally Posted by Nightshade

So is using epa to reduce the throttle at a tight track the wrong thing to do?

No not at all! its fine to do that!