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Sneeck
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01.17.2006, 11:52 AM

You sure there are no busted cristal's/ wire's/ connector's or anything else? Did you try other battery pack's?
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BrianG
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01.17.2006, 12:31 PM

Making the ESC-to-motor wires as short as possible makes sense. The combination of the square wave AC (PWM) and high current will have a tendency to "transmit" noise from the wires themselves.

If you have, or have access to, an oscilloscope, you can make a small coil of wire (about 10-15 turns around a pencil of any small guage should do) and hook up the o-scope's leads to it. Set the horizontal sweep to 1ms/div or 10ms/div (higher the better) and the vertical sweep to .5v/div (or maybe one notch less). Then move the coil near suspected noisy areas and watch the display for any increase in signals. It will appear as a bunch of jagged peaks closely spaced. You'll probably catch some noise from the air in general, so get a baseline with everything off first. You probably won't catch the exact frequency of the offending noise without playing with the horizontal sweep - and even then it may be hard to trigger to get a reading, but you should definitely see the voltage increase as you get near the offending area(s). You can also move the coil away slowly to see how far the noise radiates to guage how far you should place your other components.

Common shielding methods include wrapping a braided conductive cable around the offending wires and connecting to a ground point, and using an RF choke. The RF choke, as the name implies, works mostly for higher frequencies (at least 10kHz).

Edit:
Sometimes simply twisting or braiding the wires helps to cancel some noise. Of course this would only be possible with the receiver wire since the others are too big to do so effectively.

Last edited by BrianG; 01.17.2006 at 12:50 PM.
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coolhandcountry
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01.17.2006, 01:40 PM

That sounds good brian. You lost me though. Not sure what a oscilloscope is. Not sure how to work if i did. I have tried other battery packs. 16cell gp 3700 20 cell gp 3700 and 26 cell gp3300. I think I even tried some ib 3800 16 cell packs. I tried a 7xl feigao as well. Had to change motor mount to get it on there to. I am open to suggestions. Please tell me something to try.


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  (#19)
Sneeck
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01.17.2006, 01:46 PM

Did you try to run the system not installed in a truck?(so everything doesn't touch any metal). Also you checked the receiver and transmitter's crystals?
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squeeforever
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01.17.2006, 01:46 PM

try and put your flm chassis on it and see if its something to do with the gorillamaxx chassis.
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BrianG
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01.17.2006, 03:15 PM

Quote:
Originally posted by coolhandcountry
That sounds good brian. You lost me though. Not sure what a oscilloscope is. Not sure how to work if i did. I have tried other battery packs. 16cell gp 3700 20 cell gp 3700 and 26 cell gp3300. I think I even tried some ib 3800 16 cell packs. I tried a 7xl feigao as well. Had to change motor mount to get it on there to. I am open to suggestions. Please tell me something to try.
An oscilloscope is a box with some type of monitor on it which enables you to actually see the waveforms of AC signals (and DC too, but that can be done with any multimeter). There are a (sometimes overwhelming) number of controls allowing you to select a setting which will allow you to view a whole range of voltages and frequencies from very low (10Hz) to very high (GHz, although the higher the frequency it can view, the more expensive it is). It is a VERY useful tool for anyone doing anything with electronics - actually, it's indespensible.

Here is a page which explains better than I can: http://en.wikipedia.org/wiki/Oscilloscope

You might be able to do the coil thing I explained in my previous post with a multimeter, but it will have to be able to measure a range of AC frequencies - most of them only measure AC close to 60Hz accurately.

Any electronic repair shops and maybe technical schools/colleges will have one. If your issue is not resolved, maybe they will let you bring in your R/C to perform the test I mentioned for a small fee, if any. No matter what, it will be cheaper than blindly buying possible solutions until something works (unless you have that much disposable income). If I had a BL setup, I'd perform the test for you and report my findings to give you a starting point. Actually, since you are having this issue, I might do the test once I get my BL stuff just for the heck of it. :)

Last edited by BrianG; 01.17.2006 at 03:19 PM.
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  (#22)
coolhandcountry
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01.17.2006, 03:26 PM

I ran the system on my flm squee. It works on that chassis with a transmission. I ran the same esc and motor 7xl on the flm. Ran a couple packs threw it. Was having fun ;). It was different crystals threw the different transmitters and rx put on the truck. I am going to put the stuff back on the truck and mount things different ways to see what is what. I may put the tranny back on the truck with 7xl and 36120 to see If that works with out the center diff. I find the problem sooner or later. If I can get the system to work on the truck with tranny I know it is the mounting that the problem is.


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  (#23)
coolhandcountry
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01.17.2006, 08:28 PM

I tried to run the esc touch the motor on bench. It worked perfect. I mounted it back on truck with some stuff a little different. I don't know results yet. Seems to be better but not 100%. Could I have my motor to low on chassis. How could I shield my motor with something? I was wondering if maybe the motor builds up electricla field and transfered to the chassis cause it is so close to it. Any opinions on this.


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BrianG
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01.17.2006, 09:20 PM

It is possible the motor is electrically noisy, but the metal motor can does offer some sort of shielding. I would suspect the wires to the motor before anything else. As far as the chassis goes - I suppose it is possible to induce a voltage in it, but it is quite big and not exactly an ideal "antenna".

Instead of shielding the motor, I'd shield the more sensitive parts; like the wire(s) from the Rx to the ESC and/or the Rx itself. Shielding the motor might reduce its ability to dissipate heat.

Also, metal gears rubbing on each other produces noise; I've heard that is why you will rarely find a servo with all metal gears - one will be plastic or metal coated plastic. Does your tranny have all metal gears and are any wires right next to it?

Something else to look at: Try not to run wires parallel to sources of noise - especially the Rx-to-ESC wires. Try running them perpendicular to each other if possible.
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  (#25)
Gustav
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01.17.2006, 09:27 PM

Quote:
Originally posted by coolhandcountry
I tried to run the esc touch the motor on bench. It worked perfect. I mounted it back on truck with some stuff a little different. I don't know results yet. Seems to be better but not 100%. Could I have my motor to low on chassis. How could I shield my motor with something? I was wondering if maybe the motor builds up electricla field and transfered to the chassis cause it is so close to it. Any opinions on this.
That's funny,that's excactly what i was thinking but didn't know if it was possible.The motor is extremely close to the chassis and it is one BIG magnet.
Also would make sense that when you tried a different motor,it was improved and not quite so close to the chassis? I'd try shielding with foil to start with between the motor and chassis.Frankly i couldn't tell you if there is a scientific basis but anything is worth a try at this point.

Strange that it works with the schulze though,makes me think it's noise from the BKs causing the problem,have you tried the esc further from the chassis?(on the shock tower for example)
   
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  (#26)
MetalMan
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01.17.2006, 09:29 PM

It might help to shield the wires coming from the motor by wrapping aluminum foil around them. If your motor is low, and the wires are close to the chassis, the chassis could pick up some interference (it's possible) and carry it to the receiver.

There are so many possibilites, and any of them could work.


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  (#27)
MetalMan
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01.17.2006, 09:36 PM

Quote:
Originally posted by Gustav
Strange that it works with the schulze though,makes me think it's noise from the BKs causing the problem,have you tried the esc further from the chassis?(on the shock tower for example)
That is very possible. When I ran a Warrior 9918 in my Rustler, I would get terrible radio range. But, when I switched to a MGM Compro 12012, it seemed as if I had unlimited range.


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  (#28)
crazyjr
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01.17.2006, 10:49 PM

come to think of it Dafni would talk about limited range with his radios at times and he uses bk controlers


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  (#29)
Dafni
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01.18.2006, 02:45 AM

Quote:
Originally posted by crazyjr
come to think of it Dafni would talk about limited range with his radios at times and he uses bk controlers
True, but that was when I still used crappy AM radios!


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  (#30)
crazyjr
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01.18.2006, 08:27 AM

ok wasn't sure on the radios


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