Help Please
 

I am running the 3pk spektrum setup with a quantum2 speedo and a ko2143 servo with 4700 caps attached to the batt input of the transciever and battery input for the esc.

Everything works fine with stock and 19T motors but I gave a glitch problem with mods. I am experiencing a problem where the car will spontatiously turn when under power or go to a state where throttle and steering points do not return to neutral and lock in position.

Has anyone else had this problem? Can anyone out there running a quantum2 with a ko2143 in mod let me know what they vhad to do to get it to work?

Thanks,
Mark

Well, you've just started a trend, my friend............... :nod: :lol:

Re: Help Please
 

The Quantum2 BEC circuit is the issue. The higher draw mod motor is causing the voltage to drop enough that it effects the BEC. The low voltage causes the Spektrum to "reboot" and thus your control problem. Are you sure this is the latest version of software in your transceiver?

That's what Horizon is telling me. I have to units that both due the same thing, 1 of them has been verified to have the new firmware.

Mark

Do you think it would work if I installed 2 4700uF caps to the batt input?

I was going to try the dbl cap thing but since it runs for about 1min before failing I thought it might have something to do with the BEC being overloaded and not be able to sustain a high enough output to charge the cap @ lower draw times.

mtveten, I'd try the double cap test.

Be sure to wire the caps in parallel (positive to positive, negative to negative) to get a total of 9400uf of capacitance.

One cap doesn't work? I had only a small cap and it worked with my Quantum. . .

Cap Size-

I recently used a 3300mfd Cap (6.3 volts) at its working just as good as the original 4700 (16v) cap I initailly installed on my other car. Since the voltage is so low, its not utilizing the full capacitance of the cap rated at much higher voltage, so the 3300 may acctually be better. Got it from Radio Shack, about 8 of them for a few bucks.

verified

How did they "verified" that 1 of your Spektrum has & the other does not have the new frimware before you send them ?

Henry E.:batman:

well I sent 1 of them in and they updated it, the other one I don't know for sure if it has the new firmware or not. I suspent that the unverfied unit does have the new firmware since it has the faster bind time that is only supposed to occur with the newer version.

Mark

I know its probably been asked before but does this system work with older model Futaba radios?

I have a Futaba 3PJ which is about 5 years old. I don't like the feel of the more modern radios but I believe the TX module is still the same.

I tried it on the older brick style Futaba FP-T3PB and it worked, but I haven't used it racing. I justed tested to see if it works. The spektrum is back in my 3PK. The modules looks the same but have different part numbers and I've switched modules from the brick to the 3PK with no problems. So the spektrum should work on the 3PJ if its a module based radio.

How do you install a capacitor on the receiver?

I did it by soldering a cap to something like this:

http://www.glasselevator.net/bob/ima...tm3820-209.jpg

and plugging it into my receiver in one of the open slots (besides the throttle and steering).

I soldered the negative (usually marked with a stripe) terminal of the cap to the black wire.

I got the plug at my local hobby shop.

B

dang it I finally got my spektrum set up yea baby, even got an extra reciever for the 12 scale!

This might be a silly Q from a nitro guy:
But why don't you all wire those power hungry servos up like the 7.2V servos? just have 2 diodes inline on the positive lead on the servo to give a 1.2V drop from the 7.2V battery (or 3 or 4 diodes if your worried about too much voltage). That way the only thing your ESC BEC circuit is powering is the receiver. Maybe still install a cap but this could be much smaller. You should have no power problems then. Would give the servos a much better power supply - if its dropping in voltage to knock out the receiver your servo performance could be also suffering (maybe only very small amount).