RCCrawler Forums

Krakker · 02-17-2011, 07:02 PM

Not really sure what to make of it, but after only a little bit of tuning and a bunch of hotwire settings, I got the twin FXR's butter smooth. Went out today to dial in the tire setups and weight of the front wheels since I'm running a couple new combos.
Got a 1/2hr in and it just went to crap. Smelled like Dog squeeze too. I got it home and checked it out, cap was attached but the front FXR would stink everytime hooked up. The rear FXR still runs the test motor like a champ, front one just makes the motor give a squeal.
Anyone ever fry one with out the cap pop'n or could the cap still have given up with out shooting across the room?

AreCee · 02-17-2011, 07:42 PM

The cap may pop when shorted or with reverse polarity (plugging in the battery wrong).

The innards can die for a number of reasons, heat being a common cause. Also a jammed motor can cause a lot of resistance frying the FETs.

Krakker · 02-18-2011, 07:56 AM

Looks like I'm going to have to pay the replacement cost and send it in. Even though I just openned a month ago to setup their placement and wire'm up I've had it for a year.

Think I'll hit radio shack and get a better cap just to be safe.

I'm sure it's not the motor can, both Blitz 35T's are new.

AreCee · 02-18-2011, 08:07 AM

No, not the motor can but a jammed motor (bound up) can increase the resistance to blow an FET. However, I would have expected the FXR to thermal and shut down when overheating.

A friend accidentally reversed the polarity and the RS fried but the cap didn't pop. Caps are not protection devices but are to smooth out any voltage spikes like a filter and then to provide voltage during periods of high drain. They also help the ESC run cooler.

Krakker · 02-18-2011, 01:34 PM

Perhaps the cap it self was faulty. I did talk to Sherri, at Tekinand she's going to replace it for me. Their customer service is really good.

Thanks Sherri !!!

AreCee · 02-18-2011, 02:38 PM

My bet is on a faulty FET or FET board. Caps rarely go bad on their own. You can even run the FXR or any Tekin ESC without the cap but you risk overheating the ESC. I've had the cap break off and it still worked.

The only time an FXR ever failed was because of the board's FETs.

I've had an RS go dead but that was due to a faulty USB connection while updating the firmware.

Not only is Tekin's CS great but so are their techs.

So much better than orange or blue.

Krakker · 02-18-2011, 03:02 PM

Quote:

Originally Posted by AreCee

Not only is Tekin's CS great but so are their techs.

So much better than orange or blue.

True that!

Yeah, the fets frying makes sense. I'm sure it was just a fluke, everything looked OK but sure smelled BAD.
Gonna stop the shack tonight and pick up some bigger caps for the 2 of'm.
I've seen threads about running the 16V-1000uf but they're really big. I might just go with the 16V-470uf and call it good.

02-17-2011, 07:02 PM	#1
Krakker I wanna be Dave Join Date: Nov 2008 Location: Where freedom is earned. Posts: 2,011	Smoked FXR WITH OUT pop'n the cap. Not really sure what to make of it, but after only a little bit of tuning and a bunch of hotwire settings, I got the twin FXR's butter smooth. Went out today to dial in the tire setups and weight of the front wheels since I'm running a couple new combos. Got a 1/2hr in and it just went to crap. Smelled like Dog squeeze too. I got it home and checked it out, cap was attached but the front FXR would stink everytime hooked up. The rear FXR still runs the test motor like a champ, front one just makes the motor give a squeal. Anyone ever fry one with out the cap pop'n or could the cap still have given up with out shooting across the room?

02-17-2011, 07:42 PM	#2
AreCee RCC Addict Join Date: May 2008 Location: Chicago/Bloomington Posts: 1,505	The cap may pop when shorted or with reverse polarity (plugging in the battery wrong). The innards can die for a number of reasons, heat being a common cause. Also a jammed motor can cause a lot of resistance frying the FETs.

02-18-2011, 07:56 AM	#3
Krakker I wanna be Dave Join Date: Nov 2008 Location: Where freedom is earned. Posts: 2,011	Looks like I'm going to have to pay the replacement cost and send it in. Even though I just openned a month ago to setup their placement and wire'm up I've had it for a year. Think I'll hit radio shack and get a better cap just to be safe. I'm sure it's not the motor can, both Blitz 35T's are new.

02-18-2011, 08:07 AM	#4
AreCee RCC Addict Join Date: May 2008 Location: Chicago/Bloomington Posts: 1,505	No, not the motor can but a jammed motor (bound up) can increase the resistance to blow an FET. However, I would have expected the FXR to thermal and shut down when overheating. A friend accidentally reversed the polarity and the RS fried but the cap didn't pop. Caps are not protection devices but are to smooth out any voltage spikes like a filter and then to provide voltage during periods of high drain. They also help the ESC run cooler.

02-18-2011, 01:34 PM	#5
Krakker I wanna be Dave Join Date: Nov 2008 Location: Where freedom is earned. Posts: 2,011	Perhaps the cap it self was faulty. I did talk to Sherri, at Tekinand she's going to replace it for me. Their customer service is really good. Thanks Sherri !!!

02-18-2011, 02:38 PM	#6
AreCee RCC Addict Join Date: May 2008 Location: Chicago/Bloomington Posts: 1,505	My bet is on a faulty FET or FET board. Caps rarely go bad on their own. You can even run the FXR or any Tekin ESC without the cap but you risk overheating the ESC. I've had the cap break off and it still worked. The only time an FXR ever failed was because of the board's FETs. I've had an RS go dead but that was due to a faulty USB connection while updating the firmware. Not only is Tekin's CS great but so are their techs. So much better than orange or blue.

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Thread: Smoked FXR WITH OUT pop'n the cap.