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Old 05-18-2010, 06:57 AM   #31
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Originally Posted by warnos View Post
Did a bit of testing today.. I changed everything in the car including the servo motor two caps on ESC and spetrum cap on the RX.. which is a new 3500 but also have a 3001 pro.. had a 1/12 scale RX battery just for testing.. with the battery I had no glitching at all... but when I went back to just having the RX cap.. I would get glitching at the end of the straight from full throttle to brakes.. (no brakes and no steering).. so there has to be some kind of power problem from the tekin to the spektrum.. where the power for a small amount of time causing the RX to loose all power and leaves the ESC at full throttle..

With a 12th scale battery on the RX and no red wire from the tekin plug.. the problem was totally solved.. but I cant believe this is the only solution where you have to resort to using a 2nd battery to power the RX and servo...
If a battery pack works, but a cap doesn't, that would suggest that the power is dipping, but for too long for the cap to compensate.

What size cap did you fit?

I wonder if a larger cap would solve it?
Also interesting that it is almost exclusively a Tekin/Spektrum issue

Hmm, I might also try a 7.2V servo taking it's power from the battery pack instead of receiver.

Do these data loggers people use, record any info about throttle position and what the receiver/ESC is doing with the signal?

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Old 05-18-2010, 07:17 AM   #32
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but I cant believe this is the only solution where you have to resort to using a 2nd battery to power the RX and servo...
It's not, if it's a power dip from the load put on the Tekin BEC [steering] made worse by the main battery being drawn down under load, a higher rated UBEC should let you stay at 1 main battery to charge, and keep more juice to the radio.

Another test to add to my list this weekend.

At this point, with the added current we're pulling out of batteries with spec class motors, I'm not sure the RS's BEC has enough priority to keep the radio going. Maybe UBEC with more current rating will be enough to keep everything lit off?

At this point, I'm too invested in Spektrum to remotely consider changing all my vehicles over to something else.
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Old 05-18-2010, 07:42 AM   #33
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Just used the standard cap for the Spektrum.. its rated at 10v 4700uf.. so I would have thought its enough.. obviously not though.

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Originally Posted by Skiddins View Post
If a battery pack works, but a cap doesn't, that would suggest that the power is dipping, but for too long for the cap to compensate.

What size cap did you fit?

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Old 05-19-2010, 06:41 AM   #34
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Originally Posted by Cyclone Bender View Post
I just installed a Tekin RS in my Cyclone 3 weeks ago and so far so good. I am running a Spektrum DX3R Tx with a SR3100 Rx, a JR z9100s servo, 5000 40c LiPo's with Deans connectors, Hacker 17.5, and a AMB. I have the antenna tube strapped flat to the upper chassis then turns 45 deg up over the motor towards the rear shock tower. So far I have not had any noticable hits but I do have regular "cogging" or "hesitations" from the motor for the first few warm up laps then it goes away. It is like the motor isn't sure which way to turn. I have read all the loss of control postings and dread the day it might happen to me.
My local track only has about 10 guys that are not running DSM and we get about 2 DSM hits a day on everything from our top TC drivers to kids with their Spec Slash trucks, so I can't say that the cars with Tekin's are any more prone to hits or running away than anybody else. I have noticed more Spektrums that need to be rebound and Tekins that need to be reset or re-sync'd than anything else....
Just my local 2 cents....
Have you tried puting the aerial striaght up and see if it still glitches ?
If not then its something else and unlikely the reciever.

Cogging at low speeds can be motor or sensor related and in some cases i have seen and experienced cogging from being over timed at full speed/throttle.
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Old 05-19-2010, 06:50 AM   #35
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I tested yesterday by fitting a lipo regulater to my battery lead on the esc.
The regulater is supplying the reciever with power and it worked great with no signs of jerking. As soon as i put everything back and left out the reciever cap it would jerk or turn left as i accelerated hard from a standstill.
Used a Nosram 5amp lipo regulater which is the same as the LRP.
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Old 05-19-2010, 08:40 AM   #36
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Awsome idea.. I am going to do the same thing.. way better then using a 2nd battery. At least if you get a run away you will be able to steer.. I have a Yeah racing one I used on a Nitro car..so that should work...

Cheers

Quote:
Originally Posted by razzor View Post
I tested yesterday by fitting a lipo regulater to my battery lead on the esc.
The regulater is supplying the reciever with power and it worked great with no signs of jerking. As soon as i put everything back and left out the reciever cap it would jerk or turn left as i accelerated hard from a standstill.
Used a Nosram 5amp lipo regulater which is the same as the LRP.
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Old 05-19-2010, 10:06 AM   #37
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Do you guys know the specs of the cap that spektrum sells? Instead of paying like 6$ i could go buy one cheaper and make my own. :P
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Old 05-19-2010, 01:25 PM   #38
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Quote:
Originally Posted by razzor View Post
I tested yesterday by fitting a lipo regulater to my battery lead on the esc.
The regulater is supplying the reciever with power and it worked great with no signs of jerking. As soon as i put everything back and left out the reciever cap it would jerk or turn left as i accelerated hard from a standstill.
Used a Nosram 5amp lipo regulater which is the same as the LRP.
UBEC, lipo regulator, same same.

But, good to know, which suggests the RS's BEC is giving up for some reason under load.
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Old 05-19-2010, 03:17 PM   #39
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Its a 10v 4700uf..

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Originally Posted by TL_XXX-S_racer View Post
Do you guys know the specs of the cap that spektrum sells? Instead of paying like 6$ i could go buy one cheaper and make my own. :P
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Old 05-19-2010, 04:24 PM   #40
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Okay, thanks. hopefully this fixes the problem. I dont want to be on edge thinking it could happen any time.
I did find out though to clear things up, that it usually happens on hard acceleration with steering. There is so much draw from the battery, and voltage flowing from the servo and esc, that the receiver "browns out" and goes below the minimum operating voltage. This is why the car would continue at full speed or keep steering since it looses signal with the Tx and could take a second or two to reconnect.
hopefully thats clear and i explained it somewhat correctly.
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Old 05-19-2010, 04:52 PM   #41
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We have seen the problem where the the signal has problems even when not under full load etc.
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Old 05-20-2010, 12:27 AM   #42
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Default Regulator

Just put one of these regulators on and gave it a hard test today. put a extension cable in the RX with the red wire removed so I didn't have to take it out of the tekin plug and stuff it up for hotwire... car lasted fine for over an hour went through a couple of batteries.. lots of hard braking at the end of the straight.. of course since I had this in I could steer but didn't loose brakes either..

Have two switches now though to turn the car on.. Don't run the cap anymore and this regulator is probably smaller anyway. Gives good peace of mind that if the car is going to run away.. ( which I hasn't again ) but just if it does I can at least steer out of a problem..

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Old 05-20-2010, 03:13 AM   #43
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So it would seem the problem is with the RS's BEC dropping out.

I'll be picking up a regulator shortly.

Thanks to the guys who have been testing all the theories and potential solutions.
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Old 05-20-2010, 06:44 AM   #44
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Who makes a good regulator, apart from Novak, I had problems with theirs?
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Old 05-20-2010, 06:57 AM   #45
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http://www.amainhobbies.com/index.ph...age-Regulators

Several options out there. CC makes some popular ones.

Me personally, I'm going to skip on anything that has a built in cut-off, no need as long as the cutoff is set on the RS.
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