stunthanger.com
Electric Stunt => Gettin all AMP'ed up! => Topic started by: Dave Adamisin on August 25, 2011, 08:14:11 PM
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We've been running an Arrowind 3526-05 KV=685 on 6s rear mounted in a Brodak ARF Strega for a couple years. It has been a very reliable and powerfull system. Recently Dennis asked me to fly the new 13x5.5 WEP APC prop. The testing went well but I noticed before the testing began that the motor bearings were getting a little sloppy so after I finished the tests I felt the motor deserved a little tlc. I pulled it down and found that the rear bearing seemed like the source of the "slop". The 3526 has a single 11x5x5 (od, id, width) ball bearing in each end of the motor. While I was at the Boca site picking out a new 11x5x5 I got a call from Dennis and we started talking about adding a second bearing to the rear of the motor. After some spec sheet prospecting I decided that the second bearing didn't need to be the same size as the current one so I picked out a 8x5x2.5. If it doesn't work out I still have stock to play with. The next try would be a pair of 12x5x3's. Anyway, I did it today and ran back to back static draw runs with 4 different props to make myself comfortable that I got the new one concentric with the old ones. The draw was identical at all points so it's time to fly. Here are a couple pics. Note the "shroud of Northville" to keep the chips out of the electrical bits. I turned an arbor to hold the housing.
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Cool.
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I see Elvis in that shroud!
Seriously, more bearing support can't hurt.
Dean P.
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I see Elvis in that shroud!
Seriously, more bearing support can't hurt.
Dean P.
Hmmmm... I see Bruce Campbell...
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You've been watching too many episodes of Burn notice LL~
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And I can't get "Bubba Hotepp" off my funnybone either.. Ever watched it? Elvis in a old folks home battlin a mummy. AWESOME.
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You've been watching too many episodes of Burn notice LL~
hey whats wrong with burn notice,, Fionna is ,, I mean uh, the show is pretty entertaining,,
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FWIW I took the motor out today and put a couple flights on it. It is actually quieter and it ran 20 degrees cooler..... B4 adding the bearing the motor would make a subtle "clatter" in square corners. There was no evidence of interference between the magnets and stator while I had it apart so I attribute the noise to bearing complaints. That was completely gone today. Have to get some more flights on it to see how it holds up. I also lubed the bearings with some Mobil 1 5w30. This lubrication thing has been bugging me since I first looked at a motor and started thinking about what might go wrong with it. I have never felt comfortable with "permantly lubricated" anything. "Permantly" is a lot like variable infinity as it doesn't describe any of the varibles such as load, temperature and total cycles. I plan on lubing the bearings on a regular cycle like maybe every 10 flights put a "drop" on both ends of the motor and watching for seepage and "flingage". The motor construction is so simple that inspection is a none event. Just bolting something in and waiting for something to happen seems less than realistic. Spending a lot of money on it and feeling "safe" sounds too much like Blanche Dubois. You have to to take the time to get in control of the varibles.