Twin .020 Jr Skylark build thread
09-08-2010, 09:59 PM
#352
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RE: Twin .020 Jr Skylark build thread
Demon is the master of pop bottle cowls and canopies.
As soon as the parts come in I'll get together with him and finish this up!
As soon as the parts come in I'll get together with him and finish this up!
Like I've said, that's like French kissing your sister, IT JUST AIN'T RIGHT!!!!![:@]
09-09-2010, 04:44 PM
#354
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RE: Twin .020 Jr Skylark build thread
Brian would NEVER hack anything, and he's totally into maintaining the vintage appeal of ths cutie. Wait and see, wait and see... 
Master? Nah, just another guy with a band saw, 2x4s and a heat gun. [8D]
D
Master? Nah, just another guy with a band saw, 2x4s and a heat gun. [8D]
D
09-15-2010, 10:08 PM
#355
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RE: Twin .020 Jr Skylark build thread
Parts are here. Each motor weighs .9 oz and each speed controller is .3 oz. A 3s 1500 battery will weigh about 1/2 oz more than the lead in the nose.
Darin and I started working on the conversion. We tested the motor setup with a couple props and routed the wires through the wing. Black GWS 6x3 3b props cut down to approx. 5" to give about 8 amps each should work well. We figured better than 1:1 thrust. I am very excited about the conversion. As soon as life allows the plane will be finished and flying.
Darin and I started working on the conversion. We tested the motor setup with a couple props and routed the wires through the wing. Black GWS 6x3 3b props cut down to approx. 5" to give about 8 amps each should work well. We figured better than 1:1 thrust. I am very excited about the conversion. As soon as life allows the plane will be finished and flying.
10-01-2010, 06:23 PM
#356
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RE: Twin .020 Jr Skylark build thread
GWS came out with 5X3-3b counter rotating props. Tested and got 6.4 amps 75 watts each, pretty near perfect. Getting closer...
10-02-2010, 09:18 AM
#358
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RE: Twin .020 Jr Skylark build thread
Test flight will probably be two weeks from now if weather allows.
I'm converting to pull pull on the rudder and elevator with 1/16" ply control horns along with lighter gauge pushrods on the ailerons. After removing the push rods the plane sits on the nose gear without nose weight. Every gram aft of the cg counts. With a 2200 3s pack installed the plane balances by moving the receiver aft of the wing saddle. If I tuck the receiver in the noseblock (already hollowed out above the gear) I can use a lighter battery for balance.
All up weight with the heavy 2200 pack is 22.75 oz. ready to fly
Should be good for two six minute flights before refueling.
I'm converting to pull pull on the rudder and elevator with 1/16" ply control horns along with lighter gauge pushrods on the ailerons. After removing the push rods the plane sits on the nose gear without nose weight. Every gram aft of the cg counts. With a 2200 3s pack installed the plane balances by moving the receiver aft of the wing saddle. If I tuck the receiver in the noseblock (already hollowed out above the gear) I can use a lighter battery for balance.
All up weight with the heavy 2200 pack is 22.75 oz. ready to fly
Should be good for two six minute flights before refueling.
10-02-2010, 01:01 PM
#360
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RE: Twin .020 Jr Skylark build thread
Ok,
Finished the wiring and ran up the motors with a watt meter and TNC tach. On a freshly charged battery I was getting 150 watts and after everything was running for a few minutes the voltage came down and so did the watts. Settled in at about 134 watts with 16,000 rpm on one and 16,200 on the other, about 46 mph if Thrust HP is correct. I didn't measure the run time, it was getting boring holding the wing and a little noisy with those two three blade props zinging. Should sound cool in the air! The motors and speed controllers stayed cool to the touch and the battery was barely warm.
The nose weight wasn't too bad to get out, only took a few minutes. I used a 3" deck screw and a pair of lineman pliers to pull at the corners. I was suprised to see a second layer of lead under the first but it also came out pretty quick. Hollowing out the upper part of the nose block on the other hand wa a little harder. Going thru the layers of ply was difficult. I had to hold the Dremel flex shaft attachment right at the end of the wand in order to get into the nose. I left about 3/16" top and sides but used the top of the gear as a gauge.
Need to vacuum out all the dust and stuff the receiver up in there. The battery will be pushed right against the servo leads and hold it in place. The rudder and elevator servo mount is located perfectly to hold the battery in place.
Finished the wiring and ran up the motors with a watt meter and TNC tach. On a freshly charged battery I was getting 150 watts and after everything was running for a few minutes the voltage came down and so did the watts. Settled in at about 134 watts with 16,000 rpm on one and 16,200 on the other, about 46 mph if Thrust HP is correct. I didn't measure the run time, it was getting boring holding the wing and a little noisy with those two three blade props zinging. Should sound cool in the air! The motors and speed controllers stayed cool to the touch and the battery was barely warm.
The nose weight wasn't too bad to get out, only took a few minutes. I used a 3" deck screw and a pair of lineman pliers to pull at the corners. I was suprised to see a second layer of lead under the first but it also came out pretty quick. Hollowing out the upper part of the nose block on the other hand wa a little harder. Going thru the layers of ply was difficult. I had to hold the Dremel flex shaft attachment right at the end of the wand in order to get into the nose. I left about 3/16" top and sides but used the top of the gear as a gauge.
Need to vacuum out all the dust and stuff the receiver up in there. The battery will be pushed right against the servo leads and hold it in place. The rudder and elevator servo mount is located perfectly to hold the battery in place.
10-02-2010, 06:43 PM
#361
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RE: Twin .020 Jr Skylark build thread
Glad the lead came out OK - I think it was one piece folded in half - plumber's lead, good stuff, you can cut it with a pair of scissors, and it's cheap.
Sounds like this will be a good plane for you. I'm glad is has new life. I enjoyed buildeing it, now you can enjoy flying!
Sounds like this will be a good plane for you. I'm glad is has new life. I enjoyed buildeing it, now you can enjoy flying!
10-11-2010, 02:05 PM
#362
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RE: Twin .020 Jr Skylark build thread
Brian maidened the Jr. Skylark twin under electric power today. I'm sure he'll be along soon to fill you in on the details, but here is a link to the vid:
http://www.youtube.com/watch?v=blyqrPAc9Xk
And a shot of Nick (right) and Brian (left):
Congratulations, Brian! And, very nice to have met you, Nick!
D
PS: Could someone provide some pointers on imbedding the video on the forum? TIA
http://www.youtube.com/watch?v=blyqrPAc9Xk
And a shot of Nick (right) and Brian (left):
Congratulations, Brian! And, very nice to have met you, Nick!
D
PS: Could someone provide some pointers on imbedding the video on the forum? TIA
10-11-2010, 04:32 PM
#363
RE: Twin .020 Jr Skylark build thread
Great picture, congrates.
I'm still a little perplexed however because by the time you add up the cost of the two brushless motors, two mounts, two speed controllers, all the connectors and LiPo batteries, along with props and hardware, it comes to about what a decent pair of TD .020 would cost and be far less hassle to retrofit the TDs.
I'm still a little perplexed however because by the time you add up the cost of the two brushless motors, two mounts, two speed controllers, all the connectors and LiPo batteries, along with props and hardware, it comes to about what a decent pair of TD .020 would cost and be far less hassle to retrofit the TDs.
10-11-2010, 10:53 PM
#366
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RE: Twin .020 Jr Skylark build thread
I am delighted with the plane! It was a little windy but considering it was my first flight it went great. The best part is the landings. Throttle back and start pulling. She settles right in.Once the cg is dialed in and new HS-65 servos are installed I'll be flying this plane every chance I get. I may try some APC 5.5x4.5 counter rotating props to get a little more speed but the three blade props really look and sound cool.
http://www.headsuprc.com/servlet/the...lectric/Detail Brushless motor $11.95x2
http://www.headsuprc.com/servlet/the...ushless/Detail ESC $16.95x2
http://www.headsuprc.com/servlet/the...ck-with/Detail Stick mount $1.75x2
http://www.headsuprc.com/servlet/the...r-3.0mm/Detail Prop Adapter $2.50x2
GWS 5x3 3b prop LHS $1.50
GWS 5x3 3b pusher prop LHS $1.50
6 amp Ibec LHS $8.95
Deans connector $2.00
y servo harness $5.00
Headsuprc.com shipping $2.00
Already had 3s 1p 2200 lipo pack Hobby King $20.00
$104.00 total conversion. I couldn't find two TD .020's for that.
http://www.headsuprc.com/servlet/the...lectric/Detail Brushless motor $11.95x2
http://www.headsuprc.com/servlet/the...ushless/Detail ESC $16.95x2
http://www.headsuprc.com/servlet/the...ck-with/Detail Stick mount $1.75x2
http://www.headsuprc.com/servlet/the...r-3.0mm/Detail Prop Adapter $2.50x2
GWS 5x3 3b prop LHS $1.50
GWS 5x3 3b pusher prop LHS $1.50
6 amp Ibec LHS $8.95
Deans connector $2.00
y servo harness $5.00
Headsuprc.com shipping $2.00
Already had 3s 1p 2200 lipo pack Hobby King $20.00
$104.00 total conversion. I couldn't find two TD .020's for that.
10-15-2010, 08:56 AM
#373
RE: Twin .020 Jr Skylark build thread
Yea, this time the maiden had a LITTLE more authority.........
FB, thx anyway for being test pilot last year.
Nic
FB, thx anyway for being test pilot last year.
Nic
FB
05-24-2013, 07:17 AM
#374
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RE: Twin .020 Jr Skylark build thread
Thanks WEDJ for this build thread! I found it tremendously useful as I built my 3-engine Jr. Skylark "Tri-Lark". I picked up an old kit at a swap meet this spring. Although the wood was in bad shape and many parts were missing, I had to buy it since I owned one over 40 years ago.
I picked up a couple of used Pee Wees with the intent of building it as a twin. However, after reading of your issues, it seemed the .020s would not be enough so I went with a Golden Bee in the nose as well.
Getting all three to run at the same time is a challenge! But, it is what makes it such a special plane. Rudder, elevator, and three unthrottled slimy screamers fantastic! It's a very good flier, with plenty of rudder authority (thanks to all that dihedral) for when and whatever engine stops first. Usually the center .049 runs the longest, and it flys well with just it. However, it is still controllable even on just one .020 (it won't maintain altitude, but can be landed in the grass with it running).
I plan to bring it to S.M.A.L.L. in Little Rock next weekend.
I picked up a couple of used Pee Wees with the intent of building it as a twin. However, after reading of your issues, it seemed the .020s would not be enough so I went with a Golden Bee in the nose as well.
Getting all three to run at the same time is a challenge! But, it is what makes it such a special plane. Rudder, elevator, and three unthrottled slimy screamers fantastic! It's a very good flier, with plenty of rudder authority (thanks to all that dihedral) for when and whatever engine stops first. Usually the center .049 runs the longest, and it flys well with just it. However, it is still controllable even on just one .020 (it won't maintain altitude, but can be landed in the grass with it running).
I plan to bring it to S.M.A.L.L. in Little Rock next weekend.