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MMM gettin really hot lately -
10.05.2009, 11:28 AM
Thought I'd throw a question out to internetland for you all. Been using a MMM for almost a year in an RC8. Worked great on 4S with a 1512/2D, for the last month I've been using a T8 2250kv truggy can motor. I've had the fan die before, and it's always been fine without it until I could get some new ones. I've been without a fan for about 3 weeks now (trying a different brand) but I need the right connectors to use them. Yesterday I thermalled for the first time that I can recall after about 7-8 minutes of really hard practicing on a medium-large track. Motor 110 deg, batts 88 deg, ESC 190ish but it was probably way hotter as I didn't get a temp very quickly. I was running 15/46 timing low, start power low, punch control off. I thought I might be overgeared so I tried 14/46 for the first qualifier. After 2 practice laps and a hard 5 minutes it came off at 200 deg. I saw that a fellow racer using a RC8/MMM/2650 combo was geared 16/46 and I temped his MMM at 120 right after his run, so I though maybe I'm undergeared, so I tried 16/46 for the next qualifier. Well, it came off at 212deg (BTW, when are these supposed to thermal?). Well, we got rained out so I didn't have a chance to try anything else, but I'm stumped. I had rigged up a fan to run directly off the receiver for the next race but we got rained out. A buddy mentioned that maybe some of the FETs were damaged and the rest are compensating for it, I have no clue at this point. Everything feels normal when driving it, has plenty of punch. Any opinions?
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