Carol Moran radio/motor issues?

[buzzltyr]

Hi All,
I've been running my Carol Moran in my pool for a couple of months now. And I'm having a problem I can't quite figure out.

As I run the boat out, to maybe a distance of 10 feet, the motor cuts out, and then restarts. Then cuts out, restarts, etc.

I am using the Dumas 480 motor (with three caps on it), a Tazer 15 ESC, and a Hitec receiver. I am on 75mHz AM. I'm running it on a four cell 2500mAh pack.

When I do a range check, it seems OK. The only "negative" I have, is that I've just led the antenna around the interior of the hull, rather than have a vertical antenna.

I chose the Tazer because someone here had used it with the Dumas motor, and said it worked well.

Any thoughts on what I am missing, and what else I should be looking at? My other boat (the Pat Tritle Marina I built), seems to run fine on the same radio system (different motor and ESC).

Thanks for any help/advice!

Mark

[Umi_Ryuzuki]

Sounds like you have everything in there properly... Did you properly set the ESC?

It could be confused as to what neutral, full forward, and reverse are.

[LtDoc]

Mark,
The first thing that comes to mind is that the ESC may not be 'happy' with the current draw of the drive system. Don't put a lot of faith in that, it's just the first thing I'd check, sort of. Actually, it would be the second thing, the first thing is to take a look at the 'rest' of the wiring, see if something might not be exactly right (I'm good at getting things sort of backwards at times). Good luck!
- 'Doc

[patmat2350]

AM is just plain glitchy. And the glitch rejection logic (or lack of) built into the receiver and/or ESC may lead to the shutdowns.
If the ESC is going into thermal shutdown from feeding too much current to a hungry motor, you'll be able to feel the sizzle on its heat sink.
FM (or 2.4 Gig) rocks.

PM

[buzzltyr]

Thanks, all. I've checked/double checked all of the wiring. Seems to be fine.

I have not thrown a meter on it, as I assume that running it on the "hard" is not going to show me too much, due to the lack of resistance from water. Am I correct in that assumption?

I haven't checked the temp of the ESC after running it a bit, but I will.

I agree that 2.4ghz rocks, but not currently in the picture.

I'll throw a meter on it to satisfy my own curiousity, and check the temp after a run.

Thanks again, Umi, Pat and LtDoc!

Mark

[Rex R]

mayhap its running into what it thinks is a low voltage condition and simply shutting down to save the batts?

[Ghost 2501]

a 480 motor with a 15A esc, hmmm, well I run a speed500E on a 15A on 6v, however your "cuts out then restarts" reminds me of what my southampton was doing, that has 1x 4ch rx on 40mhz, 2x 15A esc's and a 4.8v battery pack, running a pair of speed 200 type motors that were in the original boat. out of water she was great, in the water she was a P I T A, turned out the problem seemed to be that day a loose connection from the battery pack to the rx, as I unplugged the charged battery and replugged it. seemed to cure it.

Try charging the 4.8v pack overnight, a good 17hour charge, it should read around 6v when hot of the charger, then settle around i'd guess at 5.6v after a couple of hours or so. try that, then monitor the battery for a couple of hours after taking her off charge, see how far it dips down. one 12v pack i had went from 14v straight off the charger down to 2v withing 2 hours.

before you replace anything try all your connections first!

[Captbill]

I had the very same problem in the pool with my Springer. (Cheap Futaba AM--I mean the cheap 39.95 one from TH) I had to take the antenna out of the boat and make sure it was vertical. Only then did it work right and no problems.

(Now the Springer's sporting that Spektrum 2.4Ghz and no more vertical antenna!)

[green-boat]

I had the same problem with a PT boat of mine, anything past 15 feet and the motor would cut out. It would only happen when the boat was in the water. I ran ground wires to everything metal with no luck. If I grabbed the servo wire to the ESC the problem would go away. I ended up running the wire thru several iron core torroid chokes and twisting every paired wire there was. It helped but I was never 100% sure I corrected it.

I was using a $40 Futaba, Novak ESC and 2 700 series motors.

[buzzltyr]

Ghost, sometimes my fingers don't type at the speed my brain is moving. :D My original post is incorrect. The motor is the Dumas 4.8V motor. I would size it at maybe a 300 motor, if that.

I put the motor on my meter, and at WOT it is pulling 0.6 amps. So I don't think the current is excessive for an ESC rated to 15 amps.

I ran it around my pool for five or six minutes, and the ESC is stone cold. Curiously, I only had the intermittent start/cut-out happen once, instead of every time.

I rechecked all the wiring, and it is all pretty tight. Of course, given the size of the model, the wiring for the receiver/ESC/Motor/battery is all pretty close together. I have seperated the ESC from the receiver as much as I can.

I'm beginning to think that it is indeed the antenna combined with the AM band. Next time, I'll try taping the antenna up and see if the problem persists.

Thanks everyone for the thoughts and advice. It is sincerely appreciated.

Mark

[Ghost 2501]

can you get the RX up high, out of the hull and into the super structure,?

[buzzltyr]

Ghost, it is possible to move the receiver up a bit into the superstructure. I'd probably have to add servo extensions to the ESC and the rudder servo.

Mark

[LONGBIKE]

buzzltyr,

Hey its your radio system "interference" I have chased this around so many times with those cheap radio systems and nothing will fix it.

Upgrade to one of those JR systems I forget the name, they run for around $110.00
and you will see no more problems. Truse me I have been there so many times.

Jeff

[mfr02]

As longbike says, its an interference thing. I would consider moving the aerial to the opposite end of the boat away from the motor, twist paired power wires, and think hard about whether the capacitors are actually working.
A change of motor might be the cure - some motors just run rough, producing local interference, and are irredeemable.

[buzzltyr]

Again, thanks to all for the diagnostic help and the suggestions to fix it. My radio is indeed an older, inexpensive Hitec 2 channel 75mHz AM radio. I may fool with the antenna a bit, or think about upgrading the radio to solve all of my problems.

Mark

[Ghost 2501]

go fm if you dont want spektrum. however, spektrum does sounf the best idea at the moment