Futaba 2.4ghz system - Cap required?
 

Hello all,

I'm having a bit of a problem with my 2.4ghz futaba system, and my matrix speed controller.

Basically, off the start line, sometimes I get a bit of a stutter, where the power cuts out. This is typically on the first time I apply full throttle. It doesn't happen every time, and it is not linked to one particular set of cells.

Also, sometimes if I put my car down on the track for the first time, if I apply full throttle, down a straight, and then apply full brakes, the brakes don't work at all, and the car accellerates at full speed, until it hits something. (Only minor breakages so far! :woot:).

What I think is happening, is that the radio system is losing power, when the maximum current draw is being applied to the motor? Does that make sense?

The Nosram matrix I have, does not have a power cap on it.

Would it be advisable to fit a spektrum capacitor? would this help?

Thanks,

Chris.

Hi Chris,

I was thinking about what you said on Friday about this. I don't remember seeing a capacitor on Neil Craggs B4 attached to his receiver, but I am sure he had one attached to the power wires on his Speedo. This maybe what is causing your problems, but it might be worth checking the manual. I know my novak said that you MUST always use one, and when I didn't on my old Novak Cyclone, I had terrible dumping problems for some reason (this was with 2000 cells mind), but once fitted the problems went away.

http://www.oople.com/rc/photos/works.../OOP_7789.html

It is jus to the right of the speedo in the above pic.

HTH
Mark

Hi Mark,

The latest versions of the matrix speed controllers (as in your photo), include a capacitor. My version didn't, but the fact that they added one to the later models, tells me it would be a good idea.

However, I'm thinking the spektrum power capacitor that plugs into the receiver would be the best bet?

Try both. I read that the spektrum one stops glitching, but not really the problem your having. I would say fit both, then you won't have a problem, or its with the setup on the speedo. Do you have it on NIMH or is it on auto battery detect.

Try that as well.

Mark

the version I have doesn't have a lipo mode, so I guess its on the right setting.

I'm having trouble finding a spectrum capacitor at the moment!

I think you could make one up with an old receiver plug and some thin wire. Just get the matching cap from maplin!! I might have a receiver plug you can use of an old servo, so you could use that wire as well!

Just need to find out the spektrum cap rating.

I will try and find out for ya!

Mark

Hi Chris & Mark.
The details on my Spektrum cap is: 10V. 4700uf. 105 Deg c.
Hope this helps.
Mark

Cheers for that Mark.