ummm...what is EPA?

[Redfinger]

And why do I need it. I want to get a new controller and speed control, and I keep reading about the importance of EPA's and what not...please be kind to a noob and help

Ashton

[ROCKEDUP RICKY]

End Piont Adjustment

[Duuuuuuuude]

Originally Posted by ROCKEDUP RICKY

End Piont Adjustment

EPA's tell your servos when to stop moving side to side and your esc what full throttle/ full brake is. Without being able to set them, you may be getting too much or too little servo movement and/or the esc won't see full throttle.

[Redfinger]

so that would be useful for a dig servo, in having the tranny engaged, locked, or free, is that correct? And the only way a ESC effects a EPA wouls be in the determining if throttle positions?

Ashton

[ROCKEDUP RICKY]

Originally Posted by Duuuuuuuude

EPA's tell your servos when to stop moving side to side and your esc what full throttle/ full brake is.

He said it better. Thanks Chris.

[Duuuuuuuude]

Originally Posted by Redfinger

so that would be useful for a dig servo, in having the tranny engaged, locked, or free, is that correct? And the only way a ESC effects a EPA wouls be in the determining if throttle positions?

Ashton

Its usefull for any servo, it'll keep them from trying to over extend, which can make them burn out. You can also use them to get the same amount of steering throw from side to side.

They are almost essential for a dig unit. Without them you may not be able to get them to engauge properly.

The esc only knows what information its given. Just because you pull the trigger all the way back, it may not be the proper signal for the esc to go wide open. The same applies for reverse/brake.

Originally Posted by ROCKEDUP RICKY

He said it better. Thanks Chris.

Ain't no thang.

[Duuuuuuuude]

You might also find this usefull...


RC Crawler Glossary of Terms

[Narly1]

You can also use the EPA on your throttle channel to smooth out its response a bit.

The technical term in electronics for this is "scaling".

Think of it this way (using a Spektrum controller as an example):

Your ESC has a fixed range of operation, zero power to full power applied to the motor. The Spektrum controller can increment or decrement the full power (or braking) endpoint in "one percent" steps. So by setting the endpoint at 125% you are allowing the full power endpoint to be incremented by a total of 125 steps.

The math is 100% (real power units) / 125 steps = .8% of the total power per step vs 1% if you used 100% as your endpoint value. In electronics we say you have a "resolution" of 0.8% (per step).

Conversely, if you used 80% as your endpoint the resolution would be 100/80 = 1.25% per step.

Narly1

[celsiusprime]

Originally Posted by Narly1

You can also use the EPA on your throttle channel to smooth out its response a bit.

The technical term in electronics for this is "scaling".

Think of it this way (using a Spektrum controller as an example):

Your ESC has a fixed range of operation, zero power to full power applied to the motor. The Spektrum controller can increment or decrement the full power (or braking) endpoint in "one percent" steps. So by setting the endpoint at 125% you are allowing the full power endpoint to be incremented by a total of 125 steps.

The math is 100% (real power units) / 125 steps = .8% of the total power per step vs 1% if you used 100% as your endpoint value. In electronics we say you have a "resolution" of 0.8% (per step).

Conversely, if you used 80% as your endpoint the resolution would be 100/80 = 1.25% per step.

Narly1

That's not how the EPA works on my DX3.0. When I push the throttle EPA down to 50%, the car only goes half speed when I mash the trigger all the way. The Resolution that you're talking about sounds more like Stepping adjustments (not many radios have this). High step values make each step smaller, thus making a higher resolution. The EPA determines how much displacement (a.k.a. throw, throttle, steering, ect.) is allowed when the controlling unit (a.k.a. steering wheel, trigger, dial, ect.) is manipulated to it's extents.

For example:
At 100% throttle EPA, the car will go 100% of it's maximum speed when the trigger is pulled all the way.
At 75% throttle EPA, the car will go 75% of it's maximum speed when the trigger is pulled all the way.

[Narly1]

Originally Posted by celsiusprime

That's not how the EPA works on my DX3.0. When I push the throttle EPA down to 50%, the car only goes half speed when I mash the trigger all the way. The Resolution that you're talking about sounds more like Stepping adjustments (not many radios have this). High step values make each step smaller, thus making a higher resolution. The EPA determines how much displacement (a.k.a. throw, throttle, steering, ect.) is allowed when the controlling unit (a.k.a. steering wheel, trigger, dial, ect.) is manipulated to it's extents.

For example:
At 100% throttle EPA, the car will go 100% of it's maximum speed when the trigger is pulled all the way.
At 75% throttle EPA, the car will go 75% of it's maximum speed when the trigger is pulled all the way.

Haha just realized I left something out of my earlier post.

It depends what value you have your EPA set to when you initially calibrate your ESC.

Narly1

[crunky]

http://www.epa.gov/