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[nick_75au]

I'm helping out with a club members boat, with 2 large Pittman motors in it. turn on the transmitter and receiver operate the servo and all is good. As soon as any motor input is operated the boat goes crazy and motors and rudder don't stop jittering until the receiver is shut down. I've twisted the motor and power leads to the ESC (an Elecrtonize 15 amp mode) I have swapped receivers,  I'm going to try a 2.4 Ghz Set in a couple of weeks.

I believe the problem is the motors themselves, being so noisy that they continue to interfere even after the motor input is set back to neutral. Do people generally suppress Pittmans.
I think a good clean out internally would be a good Idea as well. Any thoughts?

Thanks

Nick

[dodgy geezer]

Remember that you get radio frequency interference which you can address with capacitor suppression, and interference being transmitted down the power lines, which you can address with ferrite rings. 'Earthing' the frame of the motor to the prop-shaft is also a good idea...

[malcolmfrary]

Do people generally suppress Pittmans

Suppressing any motor has never been a bad idea.  Some motors are already suppressed, but even with these, there is no cast iron guarantee that the parts are working, so fitting your own is a GOOD IDEA.  This always assumes that the brushes/comm are not throwing showers of sparks. A scored or pitted commutator and/or dud brushes will negate any attempt at suppression, as the sheer quantity of brute force will fight its way past any level of finesse.

[nick_75au]

Thanks for the replies

The motors are similar in appearance tho Toesup's motors in his MHT with longer cases including the brush holders, though the wires are attached with eye terminals under the screw cap.


I will definitely get everything grounded and suppressed. I think the motors are generating enough interference that they continue to generate spurious signals even at neutral after a throttle input as the motor winds down?

Nick

[FullLeatherJacket]

http://modelsolutions.ca/articles/SCRDecember2007/SCRDecember2007.pdf
http://modelsolutions.ca/articles/RadioControlModelerSummer2006/RCBoatModelerSummer2006.pdf
Chapter and Verse here from an authority on the subject.
FLJ

[Subculture]

I'm surprised you get that much interference from Pittman motors- these are good quality motors with multi pole commutators and generate minimal sparking.

Just a long shot, but have these ESC's got BEC's and if so, have you removed one of these BEC's by isolating the 5 volt wire from one of the plugs. Two BEC's feeding into the one bus can cause this kind of trouble.

Andy

[nick_75au]

Hi Andy,

I am surprised as well, as you say they are supposed to be the ducks nuts

No BEC,  1 speed controller, a Electroize 15 amp.

FLJ thanks for the article, refreshes the memory.


Wont be able to see the model till Sunday week

Nick

[FullLeatherJacket]

You're welcome, Nick.
Don't forget to keep the Rx aerial well clear of all the power wiring in the model, and preferably make as much of it vertical as you can (e.g. fit a whip aerial). I've never been a fan of coiling it around the inside of the hull - just another possible thing to go wrong.
You shouldn't have any such problems with a microwave radio.
FLJ

[nick_75au]

On the day when I twisted up the wires I tried the receiver and aerial out of the boat as far from the power wiring as possible, made no difference at all? Couldn't do much more pond side.

Nick

[FullLeatherJacket]

I think those motors are going to have "ballast" written on them before you spend much more time, effort and hair on the problem! IIWY I'd wait until the 2.4 Gigglehurts arrives then make that the final trick.
Remember W C Fields' immortal line:
"If at first you don't succeed, give up - no need to be a damned fool".

FLJ

[nick_75au]

After getting Michaels gear and having a play around I have isolated the problem.


The transmitter is creating the interference. I have a similar transmitter and swapped all components of the installation to isolate the faulty component. Of all things it just had to be the most expensive one

The motors are Sagem not Pittman , they are definitely high quality industrial motors. A single AA alkaline cell can turn them over.

Thanks for all your input

Nick