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Old 02-17-2013, 08:29 PM   #1
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Default Revtech 17.5 melting down

So ive had 2 revtech 17.5 melt down in the last 2 race days. I dont really know what is going wrong, I was running them on blinky mode with max can timing, geared at 96/45 in a xray t4, tekin rs pro with a thunder power lipo. With a fan on the motor it was coming off the track at 160-170 Degrees. Both motors shorted out and melted the stator down after 3 heats of racing. Just wondering if there defective or if others are having a problem with this as well. Looks like ill be switching to Reedy.
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Old 02-17-2013, 08:37 PM   #2
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From your profile and sig, you seem like an experienced racer so I would rule out transmission bind as a probable cause. Ratio at 4.05 is relatively safe imo too...

How was the performance with that setup?
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Old 02-17-2013, 08:40 PM   #3
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Ya the car has no binding issues internally, it hauled ass with that setup.
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Old 02-17-2013, 08:41 PM   #4
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My revtechs never felt right above 160, check your temp gun make sure its not under-reading.

That said, they've never failed me.
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Old 02-17-2013, 08:43 PM   #5
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Unfortunately, that's not the first time I've seen something like this happen. While it's probably a somewhat random occurrence, I've seen a few of these motors short out and melt down after a few minutes on the track. Personally, I've melted down 2 Revtech 17.5s at 140 degrees, and witnessed a fellow racer's Revtech motor fail at 100 degrees after 3 laps. These motors run strong, but the risk of premature motor failure led me to switch motor manufacturers after two of them went up in smoke at "normal" operating temperatures.
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Old 02-17-2013, 08:53 PM   #6
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Stock rotors being used? I think timing being maxed may be your issue. The end bell already has a lot of timing at the zero setting, and you can dial in a lot of timing on a revtec. Here is my theory on fans. Do we need them, YES. Do we misgear because of them, I say yes also. I have seen fans drop motor temps by 30 degrees. Lets say without a fan, your motor would have came off at 190-200, what would you do? Gear down, or take timing out right? I think fans mislead us because even though the motor is cooler when we temp, it is still working very hard to do what you are asking it to do, and it's not like we can get internal temps. But I think you are running to much motor timing.
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Old 02-17-2013, 08:54 PM   #7
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That is a lot of static timing, don't you think? Any fans or heat sinks?

It shouldn't have burned down, but when it did, was it cool with a trail of smoke down the back straight or just stopped working?
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Old 02-17-2013, 09:16 PM   #8
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I don't think any motor should melt at 170 unless there's something wrong with it. May be a good idea to switch brands...

I have pushed so many motors of different makes well above that and they're still fine...
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Old 02-17-2013, 09:18 PM   #9
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That is a lot of static timing, don't you think?
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Old 02-17-2013, 09:25 PM   #10
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I've run my rev tech 17.5 at max timing and geared at 3.70 in my xray t4 and no problems. Still runs great. Temps are about 160f.
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Old 02-17-2013, 09:37 PM   #11
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Ya both of them left a trail of smoke down the straight When i ran my D3.5 17.5 i could run it over 200 and with no problems, same with the D3 17.5 i have in my pan car, its come off at 250 more then once and still pulls strong. Guess ill just built a reedy next, since the one in my vta runs really strong and cool.
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Old 02-17-2013, 09:49 PM   #12
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If it went up in flames it was a lot hotter than 170. I have burned my Revtech 17.5 to 200 or so in a touring car, it didn't like it but it still works fine. For good performance, burning aside, I think you had too much timing. Mine likes about one hash mark less timing than the max for touring car.
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Old 02-18-2013, 07:22 AM   #13
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I'm probably not as experienced as you but I had a similar issue last week. My two issues were my fan and temp gun. My fan was fine but side piece racing makes a 5v fan that solved my issue. It dropped my temp 30 degrees. I blew 2 revtechs in a week.

I'm running

Xray T4
Lrp sxx v2 blinky
Revtech 17.5 w/ht rotor / full timing
Savox 1258
Killer volts 100c lipo
Gearing - 96/51 at Horsham pa
Gearing - 96/48 at critters in nj

Ill bet it's your fan!!!
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Old 02-18-2013, 08:11 AM   #14
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OT: This is exactly the reason why blinky is losing popularity here... Blinky was meant to narrow the playing field and keep costs down but racers actually spent more in search of the fastest motors/setup and blowing a few along the way...

Go Turbo! Hehehe...
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Old 02-18-2013, 08:39 AM   #15
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Quote:
Originally Posted by cyanyde View Post
I don't think any motor should melt at 170 unless there's something wrong with it. May be a good idea to switch brands...

I have pushed so many motors of different makes well above that and they're still fine...
I wouldn't push a Schuurspeed or a Novak to 170, but a Revtech should have lived at that temperature. Chalk up the failure to a manufacturing defect perhaps, but these "defects" seem to be rearing their ugly heads with some regularity. I swapped brands, and consider my Revtech experience a "lesson learned".
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