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Lazy Ace Biplane build from coroplast

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Lazy Ace Biplane build from coroplast

Old 03-19-2019, 04:40 AM
  #51  
Joystick TX
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It's close to 18 lbs right now.

The sink rate is deceptive in the video, the winds are pretty strong. It sinks at an angle of about two or three degrees with no headwinds. It's hard to get it to come down, it will fly with only two or three clicks of throttle.

Once the engine gets broken in, the prop will be changed from the 19x8 to a 20x8.
Old 03-19-2019, 09:22 AM
  #52  
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Wow 18 lbs, mine weighs in just over 10 lbs maybe with the float on another 3 lbs YS 1.20 lots of power. I notice no difference with the lifting tail I even have a cradle that fits on the top wing and take up gliders. I have increased the rudder by 50% and the elevator the same. I had a few bad releases where the glider ended up hung up and near cross ways on the cradle and I was sill able to land the thing with full control. It is one of my favorites for sure. I really like the Telemaster as well also a lifting tail.

Dennis
Old 03-19-2019, 12:48 PM
  #53  
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The lifting tail was not an issue at lower speeds. The lifting tail worked well with the narrow range of speeds possible with a glow engine. With a heavier plane and a 30cc to 40cc gas engine, the lifting tail created way too much down thrust which made the plane hard to control over a wide speed range due to the pitch changes. Going to a conventional tail and just using engine down thrust allows a wide speed range with no pitch changes or ballooning.

I also increased the rudder size to help control the plane better at low speeds.
Old 03-19-2019, 04:35 PM
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Couple of other Lazy Aces in the club that have gassers they are no faster than mine a 10 or 12 pitch prop at 7 to 8000 rpm is actually slower than an 8 pitch prop at 10,000. They all have the original lifting tail no adverse effects. If speed was a problem then my vertical dive to landing should show a marked tucking under as I come straight down from altitude after releasing a glider so I can take the next one up. My speed in a dive far exceeds anything I have seen a Lazy Ace do on the flat and level.

I even had one set up as a Triplane with 3 OS .61s it would drag the thing straight up from a short roll but wasn't much faster and far less fun then the lighter single engine.

Last edited by Propworn; 03-19-2019 at 04:38 PM.
Old 03-19-2019, 07:06 PM
  #55  
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All I can say is that mine started to dive at WOT. It was not stable in pitch over the entire speed envelope.

With a symmetrical airfoil on the stab and engine down thrust, it is now stable at all speeds and does not balloon when the throttle is chopped.

I'm not saying that my plane is faster than your plane, or any of the others, just that the lifting tail does not work correctly on mine over my speed range.
Old 03-20-2019, 06:11 AM
  #56  
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Could it possibly have something to do with removing the stagger or any of the other changes you made. Not criticizing just trying to understand why yours displays a tendency to tuck at speed when none of the 3 or four I have flown have no such tendency. Power shouldn't be an issue one had a Supertiger .65, YS 1.20, 32cc gas motor and the tri motor.

The heaviest I have flown mine is with the ashes of a departed friend to be spread over the flying field somewhere around 17 lbs. I did not know the cremated remains could weigh as much as 6 or 7 lbs and this was with that weight 6 inches above the top wing. No adverse flying characteristics.

Dennis

Last edited by Propworn; 03-20-2019 at 06:17 AM.
Old 03-20-2019, 06:40 AM
  #57  
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It could be a number of things. I had to remove the wing stagger or add about three pounds to the nose in order to get the plane to balance correctly. I also have -3 degrees incidence in the top wing to make sure it stalls after the lower wing. There are a lot of tradeoffs in aeronautics.

The plane is about 1 oz tail heavy right now since I added the 40cc twin. The engine is a little heavier than the 35cc and the standoffs are a little shorter, but the two changes did not cancel out exactly. It is not enough difference to cause any flying issues.
Old 04-07-2019, 06:35 AM
  #58  
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Had to do an emergency repair at the field. One of my tail-wheel springs broke and I didn't have a spare.

This actually gives me better control in the grass.


Yes, there is a heavy duty servo with metal gears, so it should hold up pretty well. Even if it does fail, there is a good chance it will be on the ground.
Old 06-15-2019, 06:56 AM
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I became a little nervous having only one LiFe battery for the receiver, so I put in two 1,100 mA LiFe batteries to provide redundancy.

I never had any problems, but several planes have been lost due to LiFe battery failures at our field.

Have 211 flights, 10 min. each, so far and this is still my favorite plane.

Last edited by Joystick TX; 06-15-2019 at 06:59 AM.
Old 08-20-2019, 01:26 PM
  #60  
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My DLE 40 Twin engine has not had good compression from the start. It did pick up a little but not nearly as much as the DLE 35 that I took off the plane at flt #150. I had a total of 248 flights on the plane today. I decided that with 16 hours of run time on this engine, it isn't getting any better.

I had a Bowman ring for a DLE 20 from a couple of years ago that I never put on an engine, so I just got a second ring and put them on today. The compression is way better already and I haven't even run the engine.

One thing I noticed during the ring swap was that the right cylinder had a lot of carbon on it and none on the left.

Can't wait to see how it runs when the weather cools off a little.
Old 08-20-2019, 05:11 PM
  #61  
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I couldn't wait for the weather to cool off. It did get down to 103, so I gave the rings a 5 min break in time and put one 10 min flight on the plane.

It has way more power than it did this morning before the ring change. It was about 87 degrees when I flew at sunup and I couldn't get good vertical performance. This afternoon I had unlimited vertical at 103 degrees. The hesitation on takeoff at the midrange transition was also gone.

When I replaced the rings, I set the needles back to the factory setting and didn't adjust them yet, so the engine is probably running a tad rich.

Love the new rings.
Old 09-02-2019, 04:40 AM
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It took a while, but the plane is finally featured in Focal Point of the September issue of Model Aviation News. It may encourage others to build big planes out of coroplast.

It now has 253 flights on it, that's over 42 hours of flight time, and it's still my favorite plane to fly.

I realized there were no pictures of the plane with the 40cc Twin engine.

Last edited by Joystick TX; 09-02-2019 at 05:01 AM.
Old 01-07-2020, 01:47 PM
  #63  
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Default Flew today with one wing.

Today on 10 min. flight number 307, I flew the LA with the top wing removed.


It flew great. It was hard to tell the difference between flying with or without the wing. I did notice that it did land a little faster, maybe 2 or 3 mph. There was no difference in the slow speed flight, the plane still does not stall, it just mushes and slowly loses altitude.


Last edited by Joystick TX; 01-07-2020 at 01:52 PM.
Old 01-14-2020, 08:15 PM
  #64  
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I finally got around to making the cutouts for the new engine on the old cowl.

Old 01-22-2020, 10:33 AM
  #65  
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Since the plane flew well as a low-wing monoplane, I decided to add some ailerons to the top wing so I can fly it as a parasol wing type plane. It shouldn't require any trim or balance changes in that configuration either.



Last edited by Joystick TX; 01-22-2020 at 10:40 AM.
Old 01-24-2020, 05:18 PM
  #66  
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Finished the ailerons and flew a couple of flights this morning. Roll is a little faster, didn't notice any other differences.

Now that there are ailerons on the top wing it's time to try the plane in the Parasol wing configuration. Weather permitting that will be done tomorrow morning.

Old 01-25-2020, 01:45 PM
  #67  
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I flew it twice as a parasol winged plane. Flights 317 and 318. It flies great, it did take a lot of up-trim since the wing incidence is set at -3 degrees. Landing speed was a little faster than the low-wing style, due to the wing incidence, it is a little harder to get it to flare correctly.

I'm going to put a "3 N 1" decal on it. Biplane, Low-Wing Monoplane and Parasol-wing Monoplane.

Last edited by Joystick TX; 01-25-2020 at 01:52 PM.

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