Thanks, E-Zone-ers

[Lon Enloe]

After reading and heeding some of the very thoughtful threads in the Modeling Science forum, I convinced myself that I could design and build my second plane from scratch, if I kept my eye on what others had done successfully. Since I enjoy building as much as flying, I decided to give it a try--and it worked! Put the finishing touches on last night, and gave it a whirl this afternoon, before the next snowstorm hits here in Colorado tomorrow or the next day. Got in about half an hour total time in the air. Nothing fancy--3 ch, a GWS brushed motor and 8 NiMH cells, but it's stable enough for a newbie while responsive enough to be fun. It loops from level flight and I can even fly it inverted for a bit.

The design parameters were taken from the plane my son and I have learned/are learning to fly on, a Great Planes BLT. I decided to be aware of, but not paranoid, about weight, and to reduce drag where possible. The latter seemed to have worked--it's noticably faster that its predecessor, but it's also happy at half throttle.

Anyway, to anyone else who's thinking about trying the design thing--go ahead, jump into the water. It's a blast!

[BMatthews]

Well isn't that a fine job! I especially like your use of curved outlines. Especially since this is your first design. It's obviously not your first build or covering job though. Looks nice from here.

[Salto]

What a beautiful model!! Is that a carbon fibre tail boom? More pics please.

Graham.

[Lon Enloe]

Thanks very much for the positive comments--I'd be pleased to pass on some more pictures.

Building the rounded parts was actually kind of fun--the curved edges of the tail components are laminated 1/32 balsa strips, soaked in water until flexible, then pinned (with lots of pins!) to the desired shape. Let 'em dry, then run CA over them, and you're good to go.

I suppose I should have said that this is my second model that could gain altitude--I also built a Spectra by Great Planes (which gave me several square feet of covering experience). Unfortunately, the provided power plant for that plane won't let it climb in the high altitude here in Colorado Springs--but I did learn, from all the running into the ground I did, that Great Planes uses a really strong wing structure in their designs, so I copied it here, with a few mods. I don't like using just a dowel on the leading edge of a park flyer(airfoils are relatively precise shapes, after all) so I made a "hollow" leading edge out of 1/32" strips. I also braced the trailing edge strips to stiffen them. It seemed worth the minor weight penalty to hold the airfoil shape on both ends.

Yes, the back end of the fuselage is carbon tube--amazing stuff! The last few inches consists of a small carbon tube telescoped into the larger, with the small tube also going into a balsa block, so I can have lots of flat mounting area for the horizontal stabilizer, and still smoothly transition to the fully round cross section of the main tube.

I'm also attaching a bottom view--one of the E-Zone member's suggestions was to color a model dark on the bottom and light on the top to help keep orientation, and I'll attest that it works, based on this bird's maiden flight. It really took off, and was farther away than I expected very quickly. Being able to keep orientation easily was probably the difference between success and failure for the first minute or so it was in the air. E-Zone members are full of good ideas--it's been very helpful to be able to tap into their expertise getting started in the hobby.

[BMatthews]

It looks even better in the detials. Nice work. You obviously enjoy building to fine standards. That framework shot shows great attention to detail. I foresee some lightweight scale models in your future...

If that leading edge molded? Or is it a V buildup? Once again a nice detail.

[Lon Enloe]

The tip of the leading edge is 1/8" square spruce, turned approximately 45 degrees, and sanded to shape. 1/32" balsa goes back from that 3/8" on both the top and bottom. I couldn't get a single 3/8" width to make the curvature of the airfoil without cracking, especially on the eliptical tips, so instead I butted three 1/8" x 1/32" strips together and sanded the irregularities at the joints out.

Hmmm...I hadn't considered scale modeling...any thoughts on a subject? Given how see-through the lightweight coverings are, seems like an early aviation subject would be appropriate. I love the Golden Age birds, but the stability on some of those looks questionable. Maybe a Lockheed Vega--that was a high-wing, Clark-Y airfoil, wasn't it?

[BMatthews]

Oooo... You've got the bug now... :D

Go check out the Electric Scale area for inspiration. In particular look up some of the Earl Stahl adaptations. And then go to www.theplanpage.com and click on the Earl Stahl plans clicky thingy. Be sure you have a napkin or two handy to soak up the drool.

The Fairchild 24 is a pretty one if you don't mind the idea of some half shell construction then the Curtiss Seagull is a natural. Lots of dihedral even in the full sized one. Then there's the Rearwin Speedster and the .....

Print 'em out and then find an enlarging photocopier to blow them up to size as required. Also it's just about time for you to learn to use tissue and dope. Some of that followed by an airbrush job with some well thinned down Floquil plastic model paint will provide the finest and lightest finish you can think of. You can find all you will need at www.peckpolymers.com . And if you need any more inspiration or therapy to deal with your new love of fine balsa stringers then check out some fine craftsmanship at www.smallflyingarts.com . Not much radio but lots of nice designs that can be modified.

Having said all that the electric scale forum right here has one of the finest groups of balsa crafters and innovative thinkers I think I've ever seen on the web.

[niner_zero]

Lon - Very nice park flyer. Good color scheme too.

[davidfee]

That is your second model? Oh man... it's just gorgeous! As the others have said, the details are really superb. You should be very proud of that model... I certainly would be!

You've made my day, :)
-David

[HELModels]

I like the tail mounting scheme. I should have used that on my boom, but complicated it by molding a carbon fiber mounting plate.

If you ever want to lighten it up, try a CDROM motor with Lipo. Power System forum here has lots of good info. Gobrushless.com has motor kits, simple and light.

Any more flight reports?

[Lon Enloe]

Well, since you asked, let me tell you where the evolution of this bird has gone: After flying it in the configuration pictured (3 ch) I decided to replace the wing with one that included alierons, keeping the same airfoil (modified Clark-Y) and generally, the same wing planform.

One trick I then learned the hard way--my tail mounting scheme was susceptable to rotating when torqued by a roll moment, until I put a pin in it. (See my post "Crazy--but true--story" for the whole convoluted tale!) With that issue solved, I flew it until I felt comfortable with ailerons. Then, I wanted something more aerobatic, so...

Keeping the same tail and same wing planform as the original, I started a new airframe. Modifications were: a built-up fuse, a low wing, a symmetric airfoil (Eppler 168), no dihedral, and two aileron servos to implement flaperons. Based on the confidence I had gained with its predecessor, I figured that I could handle something with less inherent stability.

The result is shown in the attached photo. Since that picture was taken, I've stretched the ailerons to get a 50% increase in aileron area, and have just this last week put in a Balsa Products BP-12 outrunner motor in it to replace its GWS 350. I tried building a GoBrushless motor, but couldn't get it to play well with my ESC. The BP was a reasonable alternative. Next step--replace the batteries with something that can deliver more current than the AAA packs I'm running now--that'll let me get the full performance out of the outrunner motor.

The current incarnation flies cleanly, slows down nicely to land, and doesn't seem to have any tricks even with a lot of flap dialed in--at least, I haven't stalled a wing tip on landing yet. It has more capability than I have skill (I roll more clearnly to the right than too the left, for example) so it's just what I need at this moment.

Nothing beats designing and building your own stuff, in my estimation. Besides the learning-by-doing aspect of making mods to the airframe, if it doesn't work, you know who to point the finger at, and when it does work, it's a GREAT feeling! I've been pleased to say that by taking an incremental approach, each step of the way has been flightworthy and customized to where I'm at at any given time. I'd highly recommend the scratch-building experience to anyone!

[Sparky Paul]

You appear to be on the right track for whatever you'll be doing..
Good work, and lots more to come, I'm sure! :)