RC Electric Off-Road Trucks, Buggies, Truggies and more Discuss electric RC off-road, buggies & trucks here. Also discuss brushless motors, speed controllers aka ESC's, brushed motors, etc

Trucks stutters bad

Reply
Old 10-18-2012, 03:49 PM
  #1
mtlrcguy
Thread Starter
 
Join Date: Apr 2011
Location: Kirkland , QC, CANADA
Posts: 20
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Trucks stutters bad



I am new to RC for the most part. I just got a used short course truck but it stutters no matter what I do when I press on the throttle. Both in forward and reverse.
What can it be?

mtlrcguy is offline  
Reply With Quote
Old 10-18-2012, 03:52 PM
  #2
SyCo_VeNoM
 
SyCo_VeNoM's Avatar
 
Join Date: Jul 2007
Location: chicago, IL
Posts: 12,761
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

brushless, brushed?


as for stuttering could be many things
poor batteries, bad motor, bad ESC, radio dying, gearing, or bad servo(yes they can cause it)
SyCo_VeNoM is offline  
Reply With Quote
Old 10-18-2012, 04:19 PM
  #3
mtlrcguy
Thread Starter
 
Join Date: Apr 2011
Location: Kirkland , QC, CANADA
Posts: 20
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

Ah sry, brushless.
mtlrcguy is offline  
Reply With Quote
Old 10-19-2012, 02:46 AM
  #4
john01374
 
Join Date: Nov 2006
Location: ABC WORLD, IL
Posts: 2,550
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

If it's brushless then I would start with the battery... A dead battery or one that can't supply the necessary voltage will make the motor studder badly. Make sure the battery is fully charged and try again. If you know someone with a LiPo pack try that.

Poor signal would be my next guess. I had a RTR brushless truck that would move about 10ft then studder. Turned out the receiver was toast right out of the box....

My last two guesses are the most expensive to fix but could be the problem. An over heated brushless motor will act the way you are describing as well and there is only one way to fix that and it's replacing it. Same goes for the ESC. Normally when they overheat they just die. Sometimes they live one with poor performance.

Start with the battery and receiver and go on from there.
john01374 is offline  
Reply With Quote
Old 10-19-2012, 03:52 AM
  #5
controlliner
 
controlliner's Avatar
 
Join Date: Mar 2009
Location: Ontario, Canada
Posts: 1,187
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

It may be a condition called "Cogging". It may happen if you are not pushing the amps to the motor. It may be the battery gone south, Worst case it may be a toasted field coil on the motor or the ESC.
controlliner is offline  
Reply With Quote
Old 10-19-2012, 04:37 AM
  #6
phmaximus
 
phmaximus's Avatar
 
Join Date: Jun 2008
Location: Adelaide, AUSTRALIA
Posts: 6,554
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

might just need a coffee, im like that in the morning.
phmaximus is offline  
Reply With Quote
Old 10-19-2012, 07:26 AM
  #7
SyCo_VeNoM
 
SyCo_VeNoM's Avatar
 
Join Date: Jul 2007
Location: chicago, IL
Posts: 12,761
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

BTW forgot to add the list of what I said could be wrong is what I would work from in that order
Problem with diagnosing BL trucks is that without a 2nd set of electronics its very hard to be 100% certain seeing you have to swap parts out one at a time

Sad thing is if it was brushed it would be way easier to diagnose
SyCo_VeNoM is offline  
Reply With Quote
Old 10-21-2012, 05:29 PM
  #8
Sigma.40
 
Join Date: Apr 2010
Location: Traverse City, MI
Posts: 1,048
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

Is it all speeds or just when you start to move? Does it smooth out when you give it more throttle?
Sigma.40 is offline  
Reply With Quote
Old 10-22-2012, 04:40 PM
  #9
mtlrcguy
Thread Starter
 
Join Date: Apr 2011
Location: Kirkland , QC, CANADA
Posts: 20
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

Thanks everyone, I am going to try and get my hands on another ESC to try.
The battery is fully charged.

Sigma, its only when I start to give it a bit of throttle at the beginnig. Once I get the revs up it goes away.
mtlrcguy is offline  
Reply With Quote
Old 10-22-2012, 05:00 PM
  #10
SyCo_VeNoM
 
SyCo_VeNoM's Avatar
 
Join Date: Jul 2007
Location: chicago, IL
Posts: 12,761
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad


Quote:
ORIGINAL: mtlrcguy

Thanks everyone, I am going to try and get my hands on another ESC to try.
The battery is fully charged.

Sigma, its only when I start to give it a bit of throttle at the beginnig. Once I get the revs up it goes away.
that would be cogging generally from over gearing, or funky motor KV's
like I had a 1200kv motor that would do that like crazy. Turned out to be a defect in the companies 1200kv motors...
SyCo_VeNoM is offline  
Reply With Quote
Old 10-22-2012, 05:24 PM
  #11
Sigma.40
 
Join Date: Apr 2010
Location: Traverse City, MI
Posts: 1,048
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad


Quote:
ORIGINAL: mtlrcguy


Sigma, its only when I start to give it a bit of throttle at the beginnig. Once I get the revs up it goes away.
As someone else wrote, its called cogging. And I believe its perfectly normal. My Stampede 4x4 does it and so did the Slash 4x4 that I used to own. I think it has something to do with not getting quite enoughvoltage (?) at first when you gently or slowly pull the throttle back. It happens to me the most when the LVC kicks on (which is when the esc cuts the power going to the motor). Its never gotten any worse for me so I, personally, wouldn't worry about it.

EDIT- Are you using NiMH? If you have access to a lipo or at least an NiMH with more cells try that. Cogging is lessened with a more powerful battery. Its almost nonexistant on 2S unless you REALLY pull the trigger back slowly. You could also try gearing down.
Sigma.40 is offline  
Reply With Quote
Old 10-23-2012, 11:03 PM
  #12
BKoz559
 
BKoz559's Avatar
 
Join Date: Jan 2008
Location: Madera, CA
Posts: 1,248
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

To add to this: a LiPo is capable of supplying much higher current and thus cogging effects are often reduced.

The cogging itself is a fact of life with sensorless brushless motors. Until the rotor inside the can spools up and creates a current with one of the 3 coils around the can, the ESC can't detect it's oriention so the rotor will bounce back and fort a bit between two magnetic fields. Once it's spinning, the ESC can "see" the rotor's position and the timing of the coils will follow the poles of the rotor.
BKoz559 is offline  
Reply With Quote
Old 10-24-2012, 10:23 AM
  #13
mtlrcguy
Thread Starter
 
Join Date: Apr 2011
Location: Kirkland , QC, CANADA
Posts: 20
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Trucks stutters bad

Thanks guys, I will play with it and maybe just learn to live with it as it may be normal for what I have....
mtlrcguy is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 03:46 AM.