# motor studder



## Jeff99 (Dec 27, 2005)

I just bought a Novak GTB yesterday, put it in my car, went to the track and ran a few packs through it with a 13.5, it worked flawlessly. Then decieded to put in a brushed motor, after changing the profile from brushless to brushed I ran my car for about 2 min and it started to studder, I figured it was just the motor, But then I went back to brushless and it was doing the same thing. Has anyone had this happen before? I changed the cap but that didnt fix it. Any help would be appreciated.

Thanks,
Jeff


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## swtour (Oct 8, 2001)

Jeff,

Did you get a GTB with the built in LIPO CutOff?

It sounds as though you may be getting the Low Voltage studder based on how long it takes to kick in...which is what I'm told the LIPO cutoff units do to advise you the voltage is getting low.

Check your settings in the directions and make sure this setting is not active (Unless you are USING a lipo)


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## Jeff99 (Dec 27, 2005)

swtour said:


> Jeff,
> 
> Did you get a GTB with the built in LIPO CutOff?
> 
> ...


I did get the one with lipo cutoff, I just checked it and it is off. i forgot to mention that it would only studder at full throttle, I could go half throttle with no problems.


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## swtour (Oct 8, 2001)

> I did get the one with lipo cutoff, I just checked it and it is off. i forgot to mention that it would only studder at full throttle, I could go half throttle with no problems.


That makes it sound like the LIPO cutoff even more. That's when the ESC would see a MAX Voltage drop and try to shut itself down.

(I fought with this on my LRP Esc w/ LIPO cutoff..and I was CERTAIN I had the LIPO turned off...and it was doing almost exactly what you describe your GTB doing.

I think I reset it about 15 times - before I realized I set it wrong and kept turning the feature ON instead of OFF)

NONE of my GTB's have the LIPO Cutoff, so I'm not sure what to look for on that setup...


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## stoneman (Jul 16, 2003)

That is what my LRP did when I had it in lipo mode. It ran fine untill I pulled the triger all the way then it would just shutdown. then I would wait a secound or two and it would run again untill I pulled the triger back again. But I think the GTB has an external lipo cut off attached to the cap.


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## slaz (Jan 13, 2006)

sounds like a problem i was having does a new gtb 4-cell have a lipo cut off?


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## swtour (Oct 8, 2001)

slaz

The 4 cell version isn't equipped with the Lipo cutoff since 4 cell is already lower voltage than a lipo would be.


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## 2Groovy4U (Nov 6, 2004)

Ok to throw another wrench in this. I have a GTB 4-cell running 10.5 paved oval doing this also. It does it about 1-2 min in a run and then off and on for next 2 min. 
I also have a LRP TC Spec did same thing. put a ground wire on it and never again. (knock on wood)
So is it static?


Raymond


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## swtour (Oct 8, 2001)

...I had forgotten about Raymonds GROUND wire deal - that was quite a while back when it first surfaced... Another idea!!


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## Re-rack-em (Jul 14, 2005)

I had the same kind of problem with a brand new 4cell GTB, for some reason
my batteries where causeing the problem, 4200ib's got new packs and the problem went away. Is there a thread that tells how to check for lipo cutoff
I have a 2007 Comp Sphere and just bought a lipo I would like to make sure
mine is on.


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## ta_man (Apr 10, 2005)

2Groovy4U said:


> Ok to throw another wrench in this. I have a GTB 4-cell running 10.5 paved oval doing this also. It does it about 1-2 min in a run and then off and on for next 2 min.
> I also have a LRP TC Spec did same thing. put a ground wire on it and never again. (knock on wood)
> So is it static?
> 
> ...


Where does the ground wire go from and to?


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## 2Groovy4U (Nov 6, 2004)

ta_man said:


> Where does the ground wire go from and to?


I have mine on -battery wire on speedo and running to aluminum shock tower on HD Pro3 which this is grounded to carbon fiber.

Raymond


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## Jeff99 (Dec 27, 2005)

I do recall picking up my car and getting shocked from the tire. which battery wire would I run the ground from?


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## JDW (Oct 29, 2006)

I have had some surging problems usualy due to a cut in the batt cover causing a ground on the chassie.

But last week had a problem with it but only after 3 min of racing car was a rocket then it would start slowing up and then speeding up.It had a 6 cell GTB not sure if it has the lipo cut off on it or not bought it used I changed it to the GTB I have been using to see if it will go away this week.

Running Spektrum 3001 pro with a spektrum cap 4 cell futaba S9650 servo 13.5 motor.

This car was put togeather out of stuff (esc,RX,motor) I had not run befor so it might be hard to chase down.

Motor was running around the 170 deg but never shut off because of thermaling.

Jake


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## 2Groovy4U (Nov 6, 2004)

Jeff99 said:


> I do recall picking up my car and getting shocked from the tire. which battery wire would I run the ground from?


Run the ground wire off neg on speedo. 

Raymond


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## JDW (Oct 29, 2006)

Just wanted to post up changed the gtb to a nother one I had and had no problems with it so I guess it was the GTB surging.

Jake


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## norminwv (Nov 6, 2002)

If running a spectrum receiver make sure you rebind the system when changing a speedo or servo. Ive had this problem and that corrected it.


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