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HiTec 7955TG causing glitch

HiTec 7955TG causing glitch

Old 08-31-2010, 09:10 PM
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Default HiTec 7955TG causing glitch

So frustrating. Just installed new MMP and servo. Wanted a JR but they had none so I "settled" for a 7955TG.

Looks great on paper, but this thing is a really frustrating me.
Pulled some OLD crappy beaten servos out of the bin and out of other cars/trucks just to test. I have a lot!
JR works fine
Futaba works fine
Airtronics works fine
Spektrum works fine

HiTec causes a strange "pulse glitch" slow and steady. It's a full system glitch, motor and servo and even the receiver light. Everything "pulses" in sync.

ANY HELP? Never had an issue where a servo could bring down an entire electrical system.

MMP
Losi Motor
Spektrum Rec
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Old 08-31-2010, 11:01 PM
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You need a BEC.

The high torque servo's will draw too much power from the receiver (especially Spektrum receivers) and the receiver looses power for a second.

Add a CC BEC and it will be good to go.
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Old 08-31-2010, 11:20 PM
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Too bad you had to settle for such a horrible servo. hahaha

Hope you dont hate it to much cuz its never going to break on you.

Get the castle BEC and run 7.2V to it.
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Old 09-01-2010, 12:03 AM
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Originally Posted by R-E-A-P-E-R- View Post
Too bad you had to settle for such a horrible servo. hahaha

Hope you dont hate it to much cuz its never going to break on you.

Get the castle BEC and run 7.2V to it.
Yup, the castle BEC might work
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Old 09-01-2010, 07:10 AM
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OK, I was REALLY frustrated last night.

It just seems ridiculous to me that the "high end" stuff doesn't work out of the box. CC has this reputation as super robust and blah blah blah, and I have to track down a bunch of extra crap to strap on to the buggy. Just seems kinda weak.

On the search for a BEC now.

Thanks for the input and help guys, very much appreciated.
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Old 09-01-2010, 07:18 AM
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That ESC was designed for a 1/10 scale application

None of which require a servo that have 333oz of torque

That servo pulls alot of power from the system. So you cant really blame Castle or another manufacture of your going beyond the designed spec of the esc. Even though the esc works great for 1/8 buggies that was not its intended use. So the trade off is you need to run an external BEC. Which is very small by the way
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Old 09-01-2010, 07:38 AM
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I'm using the MMP & 7955tg @6v.

With the sr3520 RX I don't need a cap or BEC.

With my other three 2.4g RX's I need ether a cap or the BEC or both.

Is anybody else using the sr3520 & not having any problems ??????
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Old 09-01-2010, 10:10 AM
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I run that same setup @ 7v bec I know the servo can handle up to 9v but check your receiver specks. I have no problems
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Old 09-01-2010, 05:01 PM
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7955 is one of the best servos on the market period sell to me Ill buy for cheap the problem in your application.
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Old 09-01-2010, 06:07 PM
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You need to get rid of that piece of junk.

Trade you a far superior Futaba 3305 for it

ThunderbirdJunkie is just generous today, so act fast!
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Old 09-01-2010, 07:07 PM
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I had the same exact setup...why I dont know... but any way all I did to fix it was put a glitch buster on the rx.
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Old 09-01-2010, 10:11 PM
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The bec on the MMP is sub-par for sure. The absolute worst is the Spektrum S6040 which is intended for 1/10. It draws so much current, it can cause the esc to shut down and reset even without a servo arm. Seems fine on my regular Mamba max though.

My solution? The futaba S9551, low profile servo. Small, lightweight, and gets the job done, even in 1/8 buggy.
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Old 09-02-2010, 07:18 AM
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Originally Posted by SpEEdyBL View Post
The bec on the MMP is sub-par for sure.
Agreed, in my testing last night everything else that I tried worked perfectly. Not going to bother listing it all out, but every combo we hooked up without the MMP worked just fine (some of which are OLDER than most of people on this forum!)

Can't find a CCBEC anywhere local either. Found the CCBEC Pro, but that thing is ridiculous and is NOT going on my buggy. Anybody have a CCBEC they want to part with? I'd meet you at OCRC or WestCoast.
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Old 09-02-2010, 09:31 PM
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FIXED: Picked up a CCBEC and a Castle Link today.

Programmed the BEC to 6 volts and hooked everything up. It worked, but the servo seemed a bit sluggish. Cranked the BEC up to 7 volts and now it seems great.

Any dangers in running at 7volts?

Also, does the CC MMP cause a weird sound when braking? The stock losi didn't make a strange sound but the MMP I'm getting a strange kind of dull squeal when hitting the brakes at speed.

I dialed in a nice throttle curve too. WAY smoother down low compared to a stock Losi. Now I'm on the mission. Going to pick up a new Tekin, probably the 2050 and run the sensor wire.

Car seems to work well. Gonna try to stop by the track and run a few packs before racing starts tomorrow and will be racing at West Coast RC on Sunday. Anybody familiar with this setup I'd be stoked if you'd come by and take a look.

My layout could use some help, but I'm so sick of working on the car it's gonna stay the way it is for awhile. Need to lengthen the on/off switch wires (Castle Creations, what the heck were you thinking? It's like 2" long)

Lap times will tell the truth is what I say. Car is lighter, better balanced, and has way smoother throttle response now. I'm thinking I can squeeze a few tenths off my times.
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Old 09-02-2010, 09:41 PM
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People still use an on/off switch?
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