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Thank you!

And more lift: the propeller wash should counteract the wing vortices, lowering induced drag Looking at that first toss, it seems like the propwash in conventional arrangement was forcing the wing to work even harder to make any useful lift, keeping it from gaining any altitude

My choice to have the propellers rotate inboard was not accidental. I’m sure you’re familiar with P-Factor. It’s what causes the descending blade of the propeller to generate more thrust than the ascending blade - particularly at high angles of attack and high power settings. So I had to decide how to best use this to my advantage. As I was solving for slow flight (I fly in a confined park) - I felt it best to have the counter rotating props turn inboard so that as I was operating close to a stall - that thrust vector would be closer to the centerline of the aircraft in the event of any difference in throttle response. This configuration is common in multi engine training aircraft. While it is true there are planes where the propellers counter rotate outboard have better performance, they sacrifice low speed handling and will have a higher minimum controllable airspeed. I had already fought a defective ESC, and had motors that didn’t spool up at the same speed - so I chose inboard rotation to further minimize any additional potential asymmetry.

The inability of the conventional (tail) designs to fly was because the elevator could not generate the pitching moment at the speed of my throw. Had I launched into a stiff wind, or by means to gain a higher airspeed - it would have flown. The wing is an inverted KFM - its lift is a direct function of angle of attack. The plank design is actually hindered by the fact that the elevon shares the duties of an aileron and an elevator. Furthermore - when elevons are functioning as an elevator, their effective arm (in a plank) is much shorter than in a conventional design where the elevator is much further aft. The saving grace in my build was that the entire wing (save 20mm at the root) was in the direct induced flow of the propeller - and thus had the effect of power steering (by the induced flow being vectored by the elevon when the motor was powered). Before I flew it - I would hold the airplane at the CG, and could feel the pitch and roll forces while the propellers were turning. As far as the wingtip vortices - they were swimming in a confused sea. The propellers extended 80mm beyond the wingtips. It was an interesting exercise, and I learned a few things, but I have no desire for a carbon fiber haircut - so that plane is parted out.

Yeah - that was a one and done. Those props extended 80mm beyond the wingtips. Thanks for your comment!

Yeah - I’ve got some ideas stewing around. They won’t go wasted.

One day I’ll get back to playing with tailsitters. There are somethings I really like about them. It’s on the list - it’s just a question of time. Thanks for your comment.

I started with gliders and whatnot - I do enjoy them. My very first build was an old Wanderer glider. That plane was a monster to transport - but flew at a walking speed. That said - I live in Arizona - so I may not be the best judge of what a good thermal plane is - out here it gets so hot you could toss a rock into the air and it may catch a thermal and fly away. It’s been a long hot summer. Thanks for your comment. You’ve planted a seed.

I loved the sound of them airborne, and I do love watching the V22’s. I’ve seen a few close up at different airports and off field locations. I think they’re an amazing plane and I hope they find civilian applications. I’m a helicopter pilot as well as a FW guy- so I’d love to fly them.

My wife will assure you - I can be very unburdened by knowledge - especially in the garage with a beer or two. That’s how you end up building planes like this one. Thanks for your comment!

I must have missed your earlier question. The Laser is a G. Weike LC1290 - with a 100W RECI tube. I run it with a Rudia controller, and Lightburn on a cheap pc for a driver. The water chiller is a CW-5200. Otherwise I’ve got a generic fume extraction fan, and a small compressor for air assist. It’s been a workhorse for many years. Let me know if there is anything else I can tell you.

@@usefulaircraft thanks!

Exactly what I was thinking. Maybe it would be interesting to explore VTOL with this design. Put the engine mounts on some kind of rotating mechanisms.

I love the osprey - but the complexity of tilting the entire engine, and yet having a transverse gearbox to bring power across to the other motor in the event of a power failure blows my mind. I’d love to fly one - but I wouldn’t volunteer to be a test pilot on them. For my use - I like the idea of tailsitter FPV stuff where the camera pivots for hovering operations, and then tilts to follow the relative wind as the plane transitions is pretty cool. One day. One project at a time.

@usefulaircraft I recall Painless360 posted some videos on setting up iNav for transition from vertical to horizontal, but not exactly what you're describing describing. Could be a starting point though.

I may give it a try. Thanks for your comment!

Yeah - it was one and done. Underhanded may have been a better idea - but I have no intention to revisit this project - it was a little hazardous. I appreciate your comment - I should have thought about the underhanded throw.

I'm using a CO2 laser. It's a 100W tube, so I'm running it at low power and high speed to only cut the top layer and melt some of the foam. That works well for the hinges. The cuts are just that- higher power and lower speed. It just takes patience and time playing with your laser to learn the speeds and feeds that work best for you. Try a local maker space and see if they have a laser you can learn on. That's how I started. Thanks for your comment.

The propeller is a 3052-3. I'm out of the shop, so I'm not certain the manufacturer, but those are the specs I recall.

Sorry for the delay - work disturbs my hobby sometimes. I don’t hold true to the percentages. I started holding strict to the numbers - but for various reasons I fell away from them. Furthermore - I later flipped the wing and didn’t change anything and it still flew. At the end of the day - I think the bulk of my lift is coming strictly from AOA. It’s the kid with their hand out the window of the car feeling the changes in pressure when they rotate their hand. I guess I’m a heretic in the church of plane building. Build it and see if it’ll fly. Works for me.

Thanks dude!

Thanks!

Amen!

I use CorelDraw for the actual drawings - for the rest of the design stuff? I started off by copying other airplanes at first. I wanted to learn to iterate fast - so I focused on the tools that would let me build quicker, fail faster, and ultimately end up with a plane that I liked. There is a lot of gatekeeping and bullshit that folks will cite as gospel - especially online - but at the end of the day, it’s up to you to send her flying, and it’s up to you to bring it home. Build a thousand lousy planes, and you’ll start learning what works for you and each one gets better. Eventually you’ll end up back at the flying field, standing before your peers with a plane that outperforms theirs in the metrics that matter to you. And best of all - you built it. Nothing is better than joy of flying something you built. Anyone can whip out a credit card and buy some blown foam. It’s the real dudes that bring something new to the field. Go build it, and send us pictures of what you create.

Prop wasn’t too heavy - it was remarkably light for its size (but also kinda brittle - although I wouldn’t have expected any prop to survive that). CG was good, and the plane had the load carrying capacity - the was just undersized for the torque of the motor. When I maintained enough airspeed, the ailerons were able to counteract the torque, and it flew and I was able to bring it around. I got too slow in the end, and the torque rolled her into the ground. All in all - I just wanted to make an odd sized motor fly… and we’re not done with it yet. It’s got at least one more turn around the patch.

Size matters.

@@usefulaircraft surely does, but can't tell what the exact wingspan is, 50cm or 20" if that is the same as in your latest build video?

Wait until you see the twin.

You read about torque, p factor, and gyroscopic effects - but the physics become very real when you hold it in your hand. Good on you for giving it a try!

No worries - your criticism isn't harsh. It was built to fly a motor that landed in my lap. Torque, p factor, and gyroscopic effects are one thing on paper - but a whole different matter in the hand. I knew before I built it - that it would be an exercise in exploring the minimum controllable airspeed, and as you can hear in the video - I'm taking that in, and planning every input, as it's not as simple as a throttle jab - the motor would roll the plane. That's why I put her down rather than attempting a go around. I considered it a success as I was able to maneuver it around the field. There were no aspirations that this would be anything other than a flying challenge. Motors of this size are outside my wheelhouse. I like building small planes that I can travel with. Motors like this do require a bigger plane - but the really large stuff isn't something I feel compelled to build, own or fly. There's other dudes that love the large stuff - and that's awesome - but I'm not that guy. I do however feel that for me it's best to build and explore concepts first hand as you get a better understanding of the fundamentals in a way that will shape your designs going forward - and in a manner you may not absorb by simply reading from a book. I love the kids building their first planes, and while I want them to fly, I also like to let folks learn lessons via exploration - and that means you're going to have some failures along the way. Either way - it was a good day at the park. Thanks for your comment.

It did sound amazing. I loved the prop noise. ...and I may have already built a twin. ...but I gotta go to work.

@@Andy-df5fj Sometimes you just gotta see what happens. I knew it was doomed from the drawing board, but it was the fastest way to play with the motor and prop and feel the torque first hand from a large pancake. The airframe could handle it, it was controllable at higher airspeeds, it essentially Vmc'd as a single when it got slow. Keep the speed up, and she flew controllably. Call it science for the children. Either way, the next plane is nearly done. Another one built for fun. If you wanna fly that airframe well, I love it with a 2205-2300kv and a 6045 prop for RC. Put a FC in it, and you won't hear it running waypoint missions overhead. Thanks for your comment.

@@Mike-mm6jp they're fun to play with. Remarkably efficient, and interesting to learn how to best use them. I thought about it for a pusher, but I'm going to play with them in a twin first. That prop disc is no joke. I've got a pusher or two they would work in, but I want to think about it as I don't like dragging props on landing. They may end up in a quad or hex, but first I wanna play more with them in wings. Thanks for your comment.

@@billcedarheath387 it did sound amazing...

yeah - this was just something for fun. I had a few odd parts land in my lap - and I wanted to play around with them. While I'm not into building huge airplanes (I'm space constrained) - I thought why not strap one on my high wing and learn first hand something about torque, p factor and gyroscopic forces. It was fun - and I just wanted to see if I could get her around the patch - and I managed - but a go around was not an option - as I was already below a minimum controllable airspeed for roll control. Scratch building is fun - and I get so much more satisfaction flying my own - plus you learn a ton. Good on ya for building, and I'd love to see some of your designs. Thanks for your comment!

@@usefulaircraft ruclips.net/video/YPSK5cO9IsM/видео.htmlsi=NdZhXKHB5F73O9HQ

He showed it off in a video. It’s an 80watt CO2 laser if my memory serves me correct.

@@billcedarheath387 Thank. you! Can you like or tell me which video? Do you know the brand?

@@ShahriarFarkhan he’s had it for 10 years or so. I’m sure the exact one wouldn’t be available after that period of time. Bed size is the important part. You need to be able to fit sheets of foam board into it to cut aircraft pattern. A smaller inexpensive Co2 laser wouldn’t work. I don’t know which video it was and I’m not spending all that time going back to rewatch them to get you an answer. It’s worth your time watching all of the videos as they are all quite good and have a lot of information in them on the hobby. He has spoken about the laser in a few video talking about having a cooling unit as well as running the laser at 70% duty cycle to extend the life of the laser tube. All of this is from multiple videos. You should watch them all and it’s not a bad thing to support the channel as you do with a like on each one you watch. I’m sure Brett would appreciate that.

@@billcedarheath387 I very much appreciate the detailed response. I've been researching lasers and trying to find a unit that can fit the large foam board and balsa wood for parts. Thank you :)

@@ShahriarFarkhan You’re probably looking at a cost that will be $3k USD or more. OMTech is a popular brand.