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Old Sep 21, 2010, 12:12 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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turned out very nice herb. i look forward to seeing her fly in so cal some time.
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Old Nov 19, 2010, 01:07 PM
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Herb's Avatar
Irvine, Calif USA
Joined Feb 1999
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Thanks for the comments

Well the anticipated maiden did not take place yet since the taxi test at the field resulted, at the end of a 5-min test run on the ground, in a shorted 1515-1.5 motor (on 9S 4000's , 94A measured, 2900W measured), a blown brand new 100A controller due to the shorted motor, and a fire in the plane that reduced most of the rear servo wiring to charcoal ...

Luckily that was all the damage as we got the batts quickly out of the plane in seconds (one of them sits right next to the esc)...

Now I got a second brand new 120A TGY HV HK controller (the poor thing got initially blamed for the fire, but now I think it had nothing to do with it), the 1515 motor still fibrillates, I redid the servo wiring, and finally need to do major surgery to get the fan & motor out (which clearly has a short in one of the three Y's). The 1515-1.y will then go back to Steve Neu ...

Looking at the long can HET 700 motors as an alternative to get the MiG-21 into the air, eventually.

.
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Old Nov 19, 2010, 01:18 PM
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You need a good test pilot!!!!
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Old Nov 19, 2010, 02:11 PM
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Need to fix the motor problem first before we break the sound barrier.
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Old Nov 19, 2010, 08:03 PM
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Now all you need to do it get a proper radio!!!!

JR12X!!!!
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Old Nov 28, 2010, 07:05 PM
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Awesome Mig 21, I have the het version (unfinished) . Is this from the plans they sell on ebay? Looks a lot like it ..
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Old Nov 29, 2010, 01:35 PM
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Irvine, Calif USA
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Yes it is ... see post no. 1

http://cgi.ebay.com/RC-plans-Giant-D...item20b550b371
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Old Dec 10, 2010, 01:26 PM
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Irvine, Calif USA
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Shorted (?) Neu 1515-1.5 going back to Neumotors, no visible sign of any malfunction from the outside ...

MiG-21 taxi test was at 94A, 9S 4000's, 2940W initially (hot off the charger).

.
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Old Dec 10, 2010, 05:02 PM
Put a bigger motor on it!
gtfreeflyer's Avatar
Costa Mesa, CA
Joined Feb 2007
1,439 Posts
94A for taxiing. Gotta love trying to drive around on Fairview's "runway" You'll probably pull less amps in flight. Let me know when you plan first flight so I can come videotape it
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Old Dec 11, 2010, 01:04 AM
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Irvine, Calif USA
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Jonathan ... it had been planned as a dry run

To test how hot the esc & motor would get, I was concerned about the esc not getting enough cooling, check the steering & general ground handling - all things easier to do at a local field than at home The MiG was airborne after I hit the first bump.

It was agood thing that the short & fire happened on the ground and not in the air.

The maiden is planned possibly at Prado or some other location with a nice long runway - when I get a New motor ...

.
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Last edited by Herb; Dec 11, 2010 at 01:09 AM.
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Old Dec 29, 2010, 02:08 PM
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Irvine, Calif USA
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Shorted Neu 1515 motor sent in on Dec 10 ... three weeks gone by, two e-mails, no reply ...

I ordered a HET 700-68 motor, similar to Neu 1515 (actually "same as Neu", whatever that means in China ), got it in three days EMS shipped from HongKong (free shipping).

New 120A HV controller (old one caught fire when the Neu shorted), re-programmed for "no brake", "slow start" , "low lipo cutoff", low advance (7 deg) & low PWM freq (4 pole inrunner as Neu).

Mounted it in the fan, checked the rotor balance one more time, installed it in the MiG-21 ... I think it's ready to go.

I used aluminum pieces to balance that rotor, man that thing is so out of balance. Now it seems smooth as silk, we'll see

.
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Old Dec 29, 2010, 02:34 PM
Put a bigger motor on it!
gtfreeflyer's Avatar
Costa Mesa, CA
Joined Feb 2007
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Quote:
Originally Posted by Herb View Post
Mounted it in the fan, checked the rotor balance one more time, installed it in the MiG-21 ... I think it's ready to go.
.
Sounds great Herb. Now, can you please do something about this rain? You may need to build some floats for this plane.
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Old Dec 29, 2010, 03:00 PM
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Irvine, Calif USA
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Jonathan, the forecast for Dec 31 2010 & Jan 1 2011 looks pretty good

http://www.accuweather.com/us/ca/los...t-weekends.asp
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Old Jan 06, 2011, 04:29 PM
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Irvine, Calif USA
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... After three weeks finally got a call from NeuMotors service. Stator shorted out due to a manufacturing defect, they will replace complete stator under warranty. I should see my 1515-1.5y motor back at the end of the month
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Old Feb 05, 2011, 08:10 PM
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Awesome jet herb!!!!!!! Where is the video?
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