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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Robertc on October 22, 2010, 11:26:48 AM

Title: New Cobra-E
Post by: Robertc on October 22, 2010, 11:26:48 AM
Just finished my take apart Cobra-E.  This is basically my piped Cobra 9 redesigned for electric and styling changes.
Whole plane fits in a hard case golf case, so good for airlines.
First flights tomorrow, weather permitting.

645 sq in
59 oz.
Hacker A30-10xl
Hacker 55 ESC
Hubin FM-9
APC 12-6p
Title: Re: New Cobra-E
Post by: Glenn (Gravitywell) Reach on October 22, 2010, 11:32:42 AM
I mean totally WOW!  Three things that make it perfect.....
1.  It's a Cobra
2.  Its yellow
3.  It falls apart BEFORE flying!

Do you have any shots of your take-apart system?  By the way....absolutely beautiful, love your choice of colours. H^^
Title: Re: New Cobra-E
Post by: Crist Rigotti on October 22, 2010, 12:15:57 PM
Whoa!  Nice!
Title: Re: New Cobra-E
Post by: Matt Colan on October 22, 2010, 12:34:48 PM
WOW!!! Fantasitc!!  I love the cheek cowls!!
Title: Re: New Cobra-E
Post by: Robertc on October 22, 2010, 01:26:36 PM
" Falls apart before flying" - most unusual compliment I've had :)

The take apart system is what Tom Morris/ Control Line Central sell.

The stab was the problem.  Ended up with a 3/16, thick walled carbon tube
and small bolts to hold it in place.  We'll see how good of  an engineer I am.
If I'm no good, then I 'll have a plane that falls apart while flying.

Bottom pic..
Title: Re: New Cobra-E
Post by: Dennis Adamisin on October 22, 2010, 02:43:38 PM
That is GREAT!  Sounds like you hit all the right targets too.  We'll be waiting for the flight test report too!
Title: Re: New Cobra-E
Post by: Rob Smith on October 22, 2010, 06:22:44 PM
Great looking model Dennis! I'm anxiously awaiting a flight report.

Rob
Title: Re: New Cobra-E
Post by: William DeMauro on October 22, 2010, 06:28:13 PM
VERY NICE!!!!!!!
Title: Re: New Cobra-E
Post by: Dennis Adamisin on October 22, 2010, 07:15:22 PM
Great looking model Dennis! I'm anxiously awaiting a flight report.

Rob

Yup it is, but no thanks to ME!  ;D
Title: Re: New Cobra-E
Post by: ptg on October 23, 2010, 10:13:37 PM
VERY NICE, SPLENDID.......Very nice on the eyes! 

PTG
Title: Re: New Cobra-E
Post by: Rob Smith on October 24, 2010, 12:45:03 PM
Whoops! and I wondered why I need bifocals.

Great looking model Robert!

Rob
Title: Re: New Cobra-E
Post by: Larry Wong on October 24, 2010, 01:02:38 PM
Robert:  That's a great looking airplane ( ELC ) is on the way. let us know how it flys  ?   It's hard to explane what makes a ELC fly diffrent, I think the 12x6 EP ( P ) is part of it and Will's FM 9 timer with ease of on field adjustment is it.  Congrats.  #^ #^ #^
Title: Re: New Cobra-E
Post by: Jason Greer on October 25, 2010, 07:30:46 AM
Beautiful Cobra Robert!! Well done!!
Title: Re: New Cobra-E
Post by: Tim Stagg on October 25, 2010, 08:28:09 AM
Robert,

Great looking plane!!!!!!!! Question, where does the cooling air exit??

Tim
Title: Re: New Cobra-E
Post by: Robertc on October 25, 2010, 12:12:05 PM
Wow, somebody had to notice that.  The cowl in the picture was doctored in Photoshop a bit.  There is a gap of about 1" between the back of the cowl and the gear
for the air to exit.  This is a temporary cowl until I figure out a new one.  Good eye.

I did make a couple of 1 min 20 sec flights Saturday.  Had a heavy battery just to make sure it had
enough weight in the nose, so I'm nose heavy with that battery, which is good as it was designed
for a lighter battery.  Didn't have it with me.  Also, the handle needs more spacing, so trimming
there as well. Plane flew well considering.  Next weekend, more flights.

Robert Compton
Title: Re: New Cobra-E
Post by: Dean Pappas on October 25, 2010, 05:12:13 PM
Photoshopped! You're killing me, Robert! ;D
Actually this is an opportunity, as a test put a little bit of a wicker-bill on the front edge of that hole, and the hot air will be sucked out very neatly.
The question is how much cooler, if at all, are the guts in the system?

take care,
Dean
Title: Re: New Cobra-E
Post by: Robertc on November 15, 2010, 10:56:32 AM
Finally got a full flight in.  First short flights with the Hacker esc had the rpm way off.  The Hubin programmer showed
the rpm at 8600, but reality was 6100.  Found out that I needed the programming cable for the esc to set it up
for C/L use.  Now that all is working correctly, I'm happy with the set up.  The Hacker motor is great.  After a 5 min 25 sec
flight, motor was hardly even warm, esc was hardly warm and the battery was the same.  Took 2150 out of the battery
at 9000 rpm, which gave 5.4 sec lap speed.  About the only thing I don't like is no prop brake with the esc.  It's not active
with the set up I was told to use.  I've bought a Phoenix Ice 50 I'll try soon as well.
Compared to my AXI/ Phoenix 45 set ups, the Hacker set up runs much cooler.
Title: Re: New Cobra-E
Post by: proparc on November 16, 2010, 10:57:03 PM
Drop dead gorgeous! Normally don't hang out here. Boy, I am sure glad I did.
Title: Re: New Cobra-E
Post by: Dean Pappas on November 17, 2010, 07:36:51 AM
Hi Robert,
They sure glide like an anvil with a windmilling prop, eh?

later,
Dean P.
Title: Re: New Cobra-E
Post by: Robertc on November 17, 2010, 08:17:40 AM
My old combat plane glides better than the Cobra-E does with a winding prop.  Makes it hard to whip as well.  Still managed
a couple of good landings.
Title: Re: New Cobra-E
Post by: Dennis Toth on December 02, 2010, 05:40:49 PM
Robert,
Great looking ship. Can you give some details about the battery mount and other equipment location. I'm getting started on coversion of the Scribe and it looks very tight on space, might have to do a top loader.

Best,               DennisT
Title: Re: New Cobra-E
Post by: PerttiMe on December 03, 2010, 12:35:45 AM
Doesn't a brake on the ESC stop the prop?
Title: Re: New Cobra-E
Post by: Robertc on December 03, 2010, 10:33:49 AM
In the configuration I'm using on the ESC, it does not allow for the prop brake to be active.  Helicopters
do not want a prop brake.  Hard to auto rotate wit the blades stopped.  I'll probably switch to a Phoenix Ice 50,
get my prop brake back.  Just too lazy to solder on the plugs right now.