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Old 03-20-2009, 11:06 PM   #1
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Default Question about running 6s with epa turned down to 60%

Just built a truggy with mmm 2200 combo.All the good zippys are sold out besides this 1
http://www.hobbycity.com/hobbycity/s...idProduct=7639
So I was thinking about getting a couple and turning my epa down a bunch to control total rpm.
Is that hard on the speedo?
heard guys say do not do it in the past.
Thanks
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Old 03-20-2009, 11:27 PM   #2
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imo dont do it just buy 2, 2 cells or get get another 4 cell from a diff company. 6 cell is too much smc makes a nice batt look at thier stuff
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Old 03-20-2009, 11:36 PM   #3
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I wouldn't run that battery, it's only 15C with 5000mah, so your discharge is only 75amps, CC I think recommends 85A-100A.

I've heard the same thing that ESC's don't like EPA adj, especially with that much power.

I'd go with two good 2s lipos 20C 4000mah and wire them for 4s or even go 3s if you want the zippy's from Hobbycity at least you'll have some power for a reasonble price...

http://www.hobbycity.com/hobbycity/s...idProduct=6417
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Old 03-21-2009, 12:17 AM   #4
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jason, hows it going, didnt make it to washtenaw anymore i seen, we had some good competitive racing, running 6s with the epa turned down would be the same as running 4s all the way up, that battery is heavy though, i run the true rc 4s2p 8000 pack in mine and cant notice the weight, its 145 bucks, handles the current great, lmk what you decide
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Old 03-21-2009, 12:23 AM   #5
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acually i seen that battery is only 75 bucks! wow, i would definatly go for it, most of the time i turn my epa down on my truggy, maybe only to 85% or so, but still it has no effect on the speedo
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Old 03-21-2009, 04:58 AM   #6
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Quote:
Originally Posted by jasburrito View Post
Just built a truggy with mmm 2200 combo.All the good zippys are sold out besides this 1
http://www.hobbycity.com/hobbycity/s...idProduct=7639
So I was thinking about getting a couple and turning my epa down a bunch to control total rpm.
Is that hard on the speedo?
heard guys say do not do it in the past.
Thanks
I use zippy 6s 5000 but 25c. But I use a smaller pinion n less powerful motor. When I run 4s 5000 zippy I use 2000kv medusa, wen 6s I use medusa 1600kv
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Old 03-21-2009, 05:32 AM   #7
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esc runs best/coolest at full throttle. running at 60 wuld cause all sorts of unnessary heat build up.
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Old 03-21-2009, 06:12 PM   #8
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Quote:
Originally Posted by auto2 View Post
esc runs best/coolest at full throttle. running at 60 wuld cause all sorts of unnessary heat build up.
that was old brushed esc's. brushless esc's are not like that
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Old 03-21-2009, 07:27 PM   #9
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I've heard both sides of the epa adjustment "arguement" but in my experience, my MMM/2200kV combo heats up more when the epa is set low than when I'm running at full speed. I've never thermaled but it gets hotter. Whether this is because of a lower speed/less air to cool the ESC and motor or because it's less efficient I don't know. I've really only noticed the heat when I've adjusted it really low, like 35% for my son to run around. All I know is it gets warmer this way. Despite that, if you can fit a 6S 5000 in your truggy then I'd say go for it. It took some modifications to get a 5S 5000 in my 8ight but it's a buggy, not a truggy. You might have more room. Oh yeah, and definitely get a better C rating. Avoid a batt with less than a 100 Amp rating. I'd at least get the 20C, preferably the 25C.
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Old 03-21-2009, 09:08 PM   #10
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Ya greg, missed racing with you guys more.After guys at our local track saw mine run,Now there about 10 of em.who would of thunk it! So I had some guys to run with local. Now were doing some rippin at some back yard tracks already

Thoughts on comments
All the most ideal hobbycity(low price) bats are sold out.
6 times 15 is 90amps? peeps are using 4s 20c/80amps.
My 20c 30c 4s 5000 never gets over 140.How hot can they get? I some times use 400mah a minute.
6s will fit a truggy no prob.
Buddy is gonna let me try his 6s 5000 tommarrow.
Let ya no what I find out.
Keep in mind I am just exploring budget minded options with long runs time in mind,ect,ect

Seems to many peeps found out about hobbycity.
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Old 03-21-2009, 09:55 PM   #11
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Quote:
Originally Posted by jasburrito View Post
6 times 15 is 90amps? peeps are using 4s 20c/80amps.
I think you may be calculating amps incorrectly. Amps = C rating x mAH not s x mAH.

Yeah, the hobby city batts are sold out but frankly, I don't think I'll buy another. I've had two packs, a Rhino 4900 5S and a Flightmax 5000 5S. The Rhino had a cell die after about 5 runs. I replaced the cell and it's worked great for the last 20 runs. The flightmax has a cell that's dropped 0.2 volts, hovering at 4.01 volts. It won't charge higher. It works fine other than that. But those kind of defects are unacceptable IMO. Quality control must be a little low in China. Go figure. I'm not dogging on Zippy, I may just buy another in the future, but you get what you pay for. I'd buy a 2s of the same type and C rating so you have replacement cells when one dies in your 6s

I found a used 6S 5000 Lightning Power on eBay for $49 "buy it now". Hopped on that sucker real quick. I've put 10+ runs on it now with no problem. When it comes time for another Lipo, I may gamble on a used premium lipo rather than a new zippy.
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Old 03-22-2009, 08:14 AM   #12
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Quote:
Originally Posted by big greg View Post
that was old brushed esc's. brushless esc's are not like that

quote from castle creations web site

"Speed controls are very sophisticated electronic devices that pack far more computing power than the poor old Apollo system (not the ice skater). You really need to pay attention to size them correctly. You always want to keep everything scaled such that no particular part is too large, or perhaps in some cases, too small for the others. Contrary to prevailing wisdom, keep everything inside its envelope and you will have a better chance of having a successful flight. Always size the controller and the batteries such that they are happy pulsing along at the maximum throttle.

Don't take chances and try to run at half throttle, because you are only fooling yourself. Half throttle is really full throttle; it is just pulsed thousands of times a second so that the motor rpm is effectively raised or lowered. "
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