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Oct 06, 2010, 08:55 AM
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smoothvirus's Avatar
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Build Log

My Carl Goldberg Electra Project

Back around 1992-1993 or so, right around the time I moved out of Mom's house, I bought an Electra Deluxe kit from the LHS in my hometown.

Did not get around to building it until sometime later, somewhere in the 1990's I built the vertical and horozontal stab. Around 2000 I built the right wing at a friends house. By 2003 I was splitting a house with some other guys and the Electra was stored on top of my wardrobe. I didn't have room to build it and it wound up sitting there for 7 years.

I bought a house of my own about a month ago and even though I'm still a bit cramped for building space, I want to finish her up and fly. Part of my plan was to go out and get myself a RTF foam sailplane to learn on, so I purchased a Radian a couple of weeks ago and have been flying that.

Last night I pulled the box out and checked to see if I still had all the parts after all this time. Thankfully it looks like everything is still there. I went out last night and got some building supplies, and began work on the left wing. This is going to be my first build ever.

After 18 years the Electra design is a bit dated now. I plan on omitting the Turbo 550 motor, spinner, and prop that came with my Electra. I'll go with a brushless motor, ESC, and a folding prop instead.

Pictures coming soon. In the meantime I'm reading these threads:

I only hope I can make mine look as nice as theirs!
Last edited by smoothvirus; Oct 15, 2010 at 07:52 AM.
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Oct 06, 2010, 12:57 PM
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smoothvirus's Avatar
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Doing some lunchtime research on brushless motors for my Electra. It appears that most people doing this sort of conversion recommend this engine:

So here's my newbie questions:

This is an outrunner motor, so that means when it's powered up, it spins, correct?

Would it have to be mounted in a different way from the Turbo 550, or can I complete the fuselage as per the original plans and just pop the A22-20L into the mount instead of the Turbo 550?

-- edit

There's also some pilots running this engine in the Electra:

which my LHS sells, so this could be a safe choice

And some pilots are running this one:

gah, the choices are dizzying. Looks like all of them would require modding the firewall and mounting to that.
Last edited by smoothvirus; Oct 06, 2010 at 03:05 PM.
Oct 07, 2010, 11:27 AM
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Originally Posted by smoothvirus
After 18 years the Electra design is a bit dated now. I plan on omitting the Turbo 550 motor, spinner, and prop that came with my Electra. I'll go with a brushless motor, ESC, and a folding prop instead.

Pictures coming soon. In the meantime I'm reading these threads:

I only hope I can make mine look as nice as theirs!

Actually, the only thing that's really dated about it is the power package that you're not going with. The plane design itself is still around in various forms from several manufacturers. I flew an Electra back in the day. It was a pretty decent floater! Back then, a 15 minute flight meant bragging rights.

Good luck with it! I can only imagine that with todays power packages that it will be that much more fun.

Oct 08, 2010, 12:08 AM
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P Farley's Avatar
I have had three of these over the years, soft spot for me, it was the first plane that I ever built and flew. The first was built exactly according to the plans. It was heavy, and barely pulled itself into the air, but once there, flew susprisingly well. It met a goal post and was not repaired. The second fell victim to one of those people that think its OK to walk over to the area where planes are on the ground....with their dog...that is not on a leash. Anyway. The one that I still have today, I built a few years ago for fun to see just how one would fly with more modern tech. I used an Eflite Park 450 890kv outrunner spinning an 11x6 folding prop, Eflite 20 amp speed control, Thunder power 1320mah 3 cell battery. 2 Hitec HS85BB servos and a small JR receiver. I put the battery to the front of the battery tray in a sort of box that I built to hold it. Mounted the servos as per the plans. The outruner motor goes in front of the firewall and is spaced out to line up properly with the stock nose cone, at the recommended downward angle. That white plastic half pipe motor mount sent with the kit was not used. I beefed up the fire wall too. Dont worry about adding weight there, I still had to add about an ounce to the nose when it was all complete so that the plane would balance. As for the wing, I built it as per the plans, but with a flat center section, no dihedral, only the ends of the wings tip up, but only about half as much as the plans state and washout at the tips done by bending and reheating my covering, again, as per the plans. When I did the tips, I did not use that guage-stand thing that they supply, just simply propped the tips up the same amount on both sides. The plane has plenty of power for good climbout and does not get hot even after long full throttle runs. In glide mode! Holy cow, its funny. I have several expensive, modern thermal gliders that I enjoy, but with this old design, now a bit more powerful, and way lighter, I can run the motor for about 30 or 40 seconds, shut it down, and fly until I get bored! I am amazed at how well it flies and how easy it is to stay up riding hot air. It can fly so slow that I can catch it right out of the air by grabbing the fuse as it goes overhead! (I dont recommend flying at yourself) I have had several occasions where others at our local flight spot have waited for me to land because they did not believe that it was an Electra, only slightly modded. It does not like anything more than a slight breeze though! Mine is just too light for windy conditions. I'll post some pics soon.
Oct 08, 2010, 12:31 AM
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P Farley's Avatar

Here are the pics

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Description: Top of Fuse.  Battery Tray with Battery.

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Description: Battery tray.

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Description: Fuse bottom.

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Description: Battery tray in Fuse...lots of room!
Oct 08, 2010, 01:18 AM
Who said Kiwi's can't fly!
Grunta5's Avatar
The 22-20L is spot on .. its a grunty beastie . Used one on my Wanderer and itll go vertical, not that you want to really (?) but it means you can climb out on half throttle and have power to spare if you get into trouble plus the battery will last longer ( duration)
I use a 2200 3s and it all balances without nose weight.
props a 9x5
good luck with it

Oct 08, 2010, 11:19 AM
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smoothvirus's Avatar
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Originally Posted by P Farley
The second fell victim to one of those people that think its OK to walk over to the area where planes are on the ground....with their dog...that is not on a leash.
The exact same thing almost happened to my Radian when I maidened it two weeks ago. Fortunately the dog was well trained and the owner called it off before it ate my plane.

Thanks for the powerplant/ESC/battery recommendation, and those pictures are a BIG help.

How did you space out the motor to work with the stock cowling?
Oct 08, 2010, 12:14 PM
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smoothvirus's Avatar
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Do you guys think this combo would work?

Folding Prop Spinner 35mm Folding Prop Spinner 35mm
Aeronaut CAM 10 x 6
hexTronik PRO 36A BESC (backordered)
hmm.. all the appropriate ESC's at Hobby King seem to be backordered..

for this motor I need a spinner for a 3mm shaft, correct?

--edit: maybe this ESC instead.
Last edited by smoothvirus; Oct 08, 2010 at 01:05 PM.
Oct 08, 2010, 12:37 PM
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P Farley's Avatar
Yeah, the dog thing is interesting...I am a dog person, own a 110lb Black Lab, love'em. A good size group of us fly at the local highschool, there is about 50 acres of nice mowed green grass and it is about 1000 ft. wide, the whole area looks more like a public park than the back of a school, on the weekends there are all sorts of people out using the space. Some of these dog owners almost seem to have an we arent suppose to be there, and that its OK for them to let the (big) dogs run free, with no leash, which I really dont have a problem with, until they purposely walk right through the small area that we have planes on the ground. Sometimes your in the air with one, following it, and also trying to watch your plane on the ground so that it doesnt get trampled and kicked around.

I have seen dog owners sense a bit of frustration from us R/C guys, they say "thought you guys arent suppose to fly here?" I tell them that the local school district allows electric and non-powered flight, and remind them that there is however a Leash Law! Then add that "our planes dont crap all over the field where kids play" Seems to end it pretty quick.

OK. As for the motor mount, I did much the same thing as some of the pictures in the replys above, I beefed up the firewall, then made a spacer of sorts from a block of hardwood, and sanded it down to the odd shape it needs to be to mount the motor angled to the side and down, so that the output shaft on the outrunner was centered. I used hardwood because balsa does not alow for a very good base to mount (screw) the motor to. I also used an aluminum "turbo" type spinner that allows air to get right to the motor throught the center of the spinner itself, and drilled two cooling holes in the cowl (hind sight may have looked better on the bottom) Hope that helps.

I eliminated the center dihedral from the wing mainly because I have a few sailplanes that have a flat center section too, and they fly sooo well, that I thought I would try it here, and it flies very well. Hope this helps.
Oct 08, 2010, 02:08 PM
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pilotpete2's Avatar
P Farley,
Great pictures of your Electra build. My first RC model, way back in '88, way the Electra, actually, I've built two. It's a timeless model, but certainly needs the updated touches you've added. That lipo looks positively lost on the battery "door". We've come a long way from the days of flying one of these with a 6 cell sub C Nicd pack.
I liked your comments on the issue of dogs around the flying site. As an animal lover who happens to be "owned" by a Belgian Shepherd mix, I appreciate your view on owner responsibility.
Best of luck with your new Electra
Oct 08, 2010, 02:57 PM
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smoothvirus's Avatar
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The Electra comes with a 1 3/4" spinner, which is about 44mm. So a 35mm spinner is too small.
I am assuming what I need is this this spinner. It says it comes with an adapter...

so confusing for a first-timer!
Oct 09, 2010, 05:53 PM
Who said Kiwi's can't fly!
Grunta5's Avatar
yep 3mm shaft on the 22-20L

Oct 09, 2010, 07:41 PM
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doc993's Avatar


Rehabed my electra this year,and it has flown all summer. The plane is powered buy a master air screw folding prop, gear box and brushed 550.
I just had a brand new motor fail after about an hour of flying, so this winter it will be converted to a turnigy 35 36 1300, with the same prop.This plane will fly for hours in good thermel conditions no problem,it does not like gusty conditions, but light steady wind is good.Good luck with your electra, mine was built in 1988 was never flown untill this summer,Im so glad I kept it.Its a real confidense builder.
Oct 09, 2010, 09:08 PM
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Built a new body from old plans. Wing and tail feathers from original Electra in the 1980's.

Eflight 450 outrunner Turnigy 30 amp esc and 3 cell 2200 lipos. APC 10 x 6 folding prop.

Had to extend the fuse about 4 inches in the nose, move lipos into nose along with ESC. Balances nicely and with a decent nice day get flights longer than an hour.

Adjust motor down thrust until little or no throttle to elevator mix is needed.

Currently flying via JR PCM 10X with FlyDream 2.4 module and a 6 channel FlyDream receiver.

Fun plane

Oct 13, 2010, 01:22 PM
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Building continues, I'm nearly done with the wing. Trying to work when I can, while taking care of things for the new house as well.

I'm building on a ceiling tile that's on the coffee table in my "man cave". This photo is from when I was working on the left half of the wing on Friday night:

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