what about just the capacitor its self. what size is it? Cause i can make it myself.

Knowing that receivers put out about 4.8 to 6.0V, I would get something with no less than 10V WVDC.

It really depends on what kind of noise you're having in the receiver. But generally, you can just start with a 10uF or a 47uF and just play with the magnitude (1uF, 100uF, 4.7uF, etc...) Not knowing what the cause is on the voltage rail makes it impossible to determine how much bypassing (which is what the Capacitor is doing) you need...

You're prob right but...
I'd also bet that there is alot of hash on that batt line & that would need to be removed before it gets into the esc's electronics & perhaps thats the main reason for the cap.

Would the cap would be 'big' enough to do much about ripple caused by the current switching action of the esc.The battery is effectively a huge cap with very low esr(?), the cap is effectively in parallel with higher capacity cap (the bat)

:) :)

The ultra best capacitors are tantalum capacitors, mainly use in computer motherboard to power up CPU and GPU. Tantalum capacitors should be arrange in PCB board, in parallel configurations. They last almost forever and got the most rapid charge / discharge power.

The next alternatives ( and cheaper ) are electrolyte low ESR capacitors.

If you want to lower the ohm, simply double the capacitors in parallel mode.

Don't use too many capacitors , 1. the car looks crowded, un-cool, geek. 2. There is impendance factor that somehow lower the battery voltage.... perhaps a few milivolts.

4700uF worked for me. 10v LOW ESR
Could probably have used smaller, but it solved my servo issues.
I would have thought the servo (& rx) should have had some sort of low capacitance bypassing built into the circuit.
Then again they dont build in reverse voltage protection into some rx & servos (a 20c diode) :mad:

There are two categories of caps. One is made to connect to the Rx. The other is made for the ESC. Most modern ESCs already have caps built-in.

Here is a cap made for ESCs. Take a look at the specs.

http://www.hobbywing.com/english/Art...?ArticleID=417

How would you hook these up to the ESC ( assuming you not just replacing exisiting caps )?

You add them to the power wires going to the esc,close as possible to the esc.
phil

Here are some that I run on my 1/8 buggys and truggys, a local guy put them together, Just like in the other posts you can buy them and just solder them together .

http://i50.tinypic.com/2hevg2p.jpg

http://i47.tinypic.com/rwtavp.jpg

I happen to have a KO Propo VFS-1 right next to me. These older brushed ESCs include a cap that just about as big as the ESC itself. The specs on the side of the CAP are as follows:

2700uf
25v