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Old 12-11-2006, 08:54 AM   #1
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Default Brushless Carpet Stadium Truck Problems - HELP

My son and I race Novak Super Sport + brushless systems in stadium trucks on an indoor carpet track with jumps.

In 6 race weekends, we've burned up both systems, and now one of the remanufacturing units we just got back from Novak is starting to act up.

Are we doing something wrong?

We're geared at 12.28:1 (87/17 x 2.4) which is where we are supposed to be.

The last system that blew up raced fine in the first qualifier. For the second qualifier, it just didn't start. If I'd spin the spur gear a bit, that seemed to help. I looked at it afterwords, and after hitting the throttle and the motor not spinning, the ESC would have blinking blue and green LEDs. I removed the pinion completely (to make sure the trucks drivetrain wasn't binding up causing the motor to fail) and the motor still didn't work.

This weekend, my son's freshly refurbished ESC and motor did the same thing. At the start of the race he had no motor. Someone bumped into his truck and got it rolling, then it took off.

The only thing I can think of is maybe our slipper clutches are too tight so when we're landing off the jumps, the back wheels hit and stop spinning for an instant, the motor stops for an instant and is being damaged somehow.

Anyone have any ideas????

Thanks.
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Old 12-11-2006, 11:36 AM   #2
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It could be the slippers being too tight or gear mesh too tight or over geared a little. Did you ever check the motor temps? They should not exceed 175 F. I've had the SS4300 and now a refurbished SS5800 and never a problem so I can't help but think it's something in your set-ups.
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Old 12-11-2006, 11:42 AM   #3
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Thanks for the reply.

It happens at the start of a race, after the truck has been sitting for an hour.

And like I said, I even took the pinion off (so there was zero drivetrain drag) and it still did it. This was the night after a race (so the motor was cold), just trying to figure out the problem.

After a 5 minute race, the motors may be warm, but not anything I would call hot, I'm sure below 120 deg, probably less.

So, my theory is we're abusing the motors somehow by landing jumps with slipper clutches set too tight and sort of "dead spotting" the brushless motors. Can that be possible.

I called Novak last week and he made it sound like the Super Sport+ ESCs may not be perfectly reliable. He said I could get a GTB for $30 more if I send in a SS+ that has failed repeatedly.

Thanks again.
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Old 12-11-2006, 11:48 AM   #4
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With the Super Sport systems motor temp is generally not an issue. The Speed control typically struggle a little to keep up. You still shouldn't be seeing anything other than thermal shutdowns if the speed control is overloading. I assume that you are running on Ozite carpet or something similar so static electricity damage shouldn't be an issue.

I would recomend the GTB upgrade option. For $30 more that's a no brainer. You can then put in a stronger motor down the road if you like.
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Old 12-11-2006, 11:56 AM   #5
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Thanks. Yea Ozite or something similar.

A bunch of other people are running brushless with no apparent problems. I'll just need to check around and see what others are doing or not doing compared to me.

It was a real bummer to get my son's new (remanufactured) SS+ and 13.5 back from Novak Friday, run it Saturday, and have it not start one of the qualifiers until he got "bump drafted". It worked fine the other 2 qualifiers and main. Hopefully it was just a fluke (but I doubt it).

Thanks again.
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Old 12-11-2006, 01:17 PM   #6
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Oh, if they work but have a hard time getting started then it almost has to be someting to do with the position sensor (the bundle of thin wires from motor to speed control). The sensored design of the Novak stuff is specifically designed to fix that problem so if you are having start up problems then that's almost certainly what it is.
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Old 12-11-2006, 02:10 PM   #7
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Scott, the other thing you may want to try to help keep things cooler is install the Sintered rotor and upgraded endbell.
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Old 12-11-2006, 02:30 PM   #8
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Thanks Gary, but I don't think it's an overheating problem. The motors are never hot to the touch.

We race on Saturday, and on Sunday night - 24 hours after we last raced - I hooked up a battery, removed the pinion gear (so no drivetrain drag), squeezed the trigger, and nothing.

It seems like 2 out of three times, if I just rotate the spur gear a bit, and hit the trigger again, then the motor will take off just fine.

So, it appears like the motor has a "dead spot", but I don't know if that is even physically possible with a brushless motor. Maybe it is a sensor problem.

Anyway, I'm getting tired of sending brushless systems back to Novak for replacements.

Keep those ideas coming.

Thanks.
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Old 12-11-2006, 11:11 PM   #9
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Definately a sensor problem. Did you send in the motor with the ESC? If not I would do that.
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