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Trouble at the pool

R/C Submarine modelers

Trouble at the pool

Postby Feet Wet » Sun Jun 24, 2012 6:17 pm

I took Nautilus,571, down to the local kiddy pool, makes for a great test tank, to try her out for the first time with an OTW dive module. I had roughly trimmed her at home and confirmed the functions were working as they should. When I fired up her reactor at the pool I noticed that there was ALOT of jitter, especially in the pump control. In the water it was not too bad, but the pump control was not working right, it would not hold neutral position
Now, this kiddy pool is a pool, full clorination and filtration, and the pumps were running on hyperdrive.
I am wondering if there isn't a noisy pump. When I got home and reset the reactor, all was quiet, as it should be.
Has anyone else run into a similar situation? Or am I nuts?(rhetorical ? )
Jonathan
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Re: Trouble at the pool

Postby PaulC » Sun Jun 24, 2012 6:22 pm

Jonathan,

Sorry to hear about your troubles. The chlorination in the pool could have been an issue but normally you get at least a little reception before it fails. Were the electronics working well poolside or did you test it? I have had jitter issues before and they were ultimately traced back to a failing receiver.

Is this a DeBoer 571 hull?
Warm regards,

Paul Crozier
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Re: Trouble at the pool

Postby Feet Wet » Sun Jun 24, 2012 8:31 pm

Hi Paul,
Yes it is one of Dennis's hulls.
The jittering started poolside, and control was actually better in the pool than out. I've run numerous times here with my Jimmy carter without an issue, but usually NOT when the circulating pumps are running so fast. Also, the electronics seemed fine when I got back home.
I wonder if someone makes a RF meter that detects and measures in the surface spectrum.
Jonathan
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Re: Trouble at the pool

Postby Giovanni » Sun Jun 24, 2012 9:51 pm

It sounds like there is an RF interference from the motor.
You can buy an inexpensive digital total dissolved solids test meter for around $15.00 and check to see if the pool water TDS is above 400parts per million. If it is over the limit, the high TDS will not allow the chlorine to oxidize and sanitize the pool water and the high TDS will somewhat block the radio signals. TDS is a collection of dirt, body oils, body salts, water minerals, underarm deodorants, cosmetics, urine and other strange things that may be unmentionable.
A quick and simple method of sensing a high TDS, when swimming, is the pool water will taste salty and usually will sting your eyes.
Dry salt lake beds are the remains of TDS.
I have personally tested public swimming pools that were over 2,500 ppm and had the health department close the facilities. You tend to get ear infections and sickness from criptosperidium.
Most public aquatic water parks are plagued by this. :shock:
Kind regards,
Giovanni

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Re: Trouble at the pool

Postby subkraft » Sun Jun 24, 2012 11:44 pm

I had similar problem testing 1:72 type & in the bath. The minute you picked it up to put in the water everything would jitter crazily. I'd wondered if it was a function of the cast iron bath......
“The difference between genius and stupidity is that genius has its limits.” ~ Albert Einstein.
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Re: Trouble at the pool

Postby Sub culture » Tue Jun 26, 2012 3:30 pm

Try it again, or try a different venue. Could be some local radio interference, unlikely but possible.

I should think the pump is well surpressed as supplied, you could try winding the motor leads round a couple of ferrites if the problems persist.

As the boat was having issues before it was placed in the drink, I would be looking at things other than the pool being a problem.

I would also look carefully at the ESC and the built-in BEC to see if that is behaving itself.
'Why are you staring at an empty pond?'

Want to dive your boat in crystal clear water? Then you had better Dive-in- http://www.diveintomodelsubmarines.co.uk
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Re: Trouble at the pool

Postby JWLaRue » Tue Jun 26, 2012 6:31 pm

It doesn't sound like the problem you experienced is in any way due to the quality of the pool water if you had the problem before you put it in the water..though if the interference appeared to be lessened when in the water, that could be due to having too high a level of dissolved solids and/or ions in the water.

You didn't say - was this an indoor or outdoor pool? We've seen problems with some indoor pools that have a lot of exposed steel girders on the underside of the roof. The general opinion is that it could be due to signal reflections causing interference.

-Jeff
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Re: Trouble at the pool

Postby Feet Wet » Wed Jun 27, 2012 3:59 pm

Jeff,
It was an outdoor pool, with the pump/filtration house also above ground, infact about 25 feet from where I set up. It is about 15 ft from the edge of the pool. And yes, in the water there was less of a problem than out.
I have run other models there frequently, without a problem. that was last year most recently, and the pumps were not running nearly as hard as when I experienced this episode.
What I am wondering is can ac motors create the rf inteference that I seemed to experience.
As Isaid, when I got home, into the basement and tried the model, all was quiet, as it should be.
Thanks all for you suggestions
Jonathan
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Re: Trouble at the pool

Postby JWLaRue » Wed Jun 27, 2012 5:50 pm

Jonathan,

Good clarifications. Yes, A/C motors are quite noisy from an RF perspective....so that could easily be the culprit.

-Jeff
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Re: Trouble at the pool

Postby Scott T » Thu Jun 28, 2012 1:19 pm

Try turning the pool pump off if you can and see what happens.
Turn your submarine on and walk away from the pump house
to see if it stops jittering.

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Re: Trouble at the pool

Postby Feet Wet » Thu Jun 28, 2012 4:48 pm

Scott,
Yes great idea, howeve it is a municipal pool and I am already a persona non grata. The mothers think this nuc will harm their kids. The kids are smarter than the moms. The PD gets a laugh when they are called down for submarine in the pool.
Gotta love this country!
Jonathan
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