Puffer and Guppy

[TEAJR66]

These started as an exercise in SketchUp. I built Puffer and the foam proofed out well. The plans were a success. Today I put electronics in Puffer and it flew great. This is a standard tail volume and tail moment that I use for my smaller scratch built acrobatic planes. The wing is a standard three break wing that is based off the FT Simple Soarer wing geometry. The difference between Puffer and Guppy is a 90 degree fuselage rotation. I have not tried Guppy yet.



Sorry there is no flight video. Just not possible rite now.

8x6 prop, 24gram Hextronic 1300kv motor, 10 amp HK ESC, 3S 1000mah battery, and four 9gram servo's.

Peel the paper off the inside of the fuselage, it helps achieve the curves. All the tape you see in the picture is not required. That was just used as part of my proofing process. Plus I like to skin the belly because I belly land in rough terrain.

Just mark the wing slots, don't cut them till the fuse is assembled. Use the constructed wing to proof the marked wing slots before cutting them out.

Fabricate a firewall (I used a water bottle lid).

Cut an access hatch in the nose from about 1" behind the firewall to the first wing break.

The wing is 30" long and has 5" of under camber at each end (under camber is optional and roll rate will increase without it). If you don't want to print the wing plans. the measures are simple enough. 5" from edge of foam (trailing edge) to second break (score cut). 1 1/2" from second break to first break Score cut). 1 1/2" from first break to Leading Edge (double bevel). 6" to end of bottom plate. Size ailerons as desired (at least 8" - 10" from wing tip toward center and end of bottom late to trailing edge). The spar is two pieces thick of foam 18" x 1", centered between the 1st and 2nd break, side to side. This will leave one inch open at each end to sandwich the aileron servo's between the top and bottom plate.

Here are the plans. Once they are open in PDF, use the snapshot tool to frame in as tight as possible the fuse and stabilizers you want to build. Print that snapshot as POSTER at 100% and it should fit on six sheets of paper. Do the wing the same way and it also fits on six sheets of paper.

 

[PeterGregory]

Cool designs, pretty fancy with curvaceous dimensions. Combattable? I should thing so.

 

[TEAJR66]

Definitely combattable!

The curves were the point of the exercise. I found a symmetrical airfoil and traced it using Bezier curves. Then played with some of the proportions to make one thicker and one thinner. Then intersected the two foils and made a curvy fuselage. It translated to foam well enough so I put electronics in it and viola!

Let me know if you try one.

 

[earthsciteach]

Awesome looking planes, Tommy! I really like the lines of the fuselage. Bet they have a tremendous roll rate.

 

[TEAJR66]

Flight Video

I was able to get a flight video.

I have a slightly better one with a much better landing, but people are cursing in the background. So, I went with this one.

 

[SP0NZ]

Awesome work Tommy. I like it.

 

[TEAJR66]

Earthsci, Sponz,

Thanks. It was something I whipped out after playing with curves in SketchUp. It's no Bloody Baron or nnP-39, but I like the way it fly's. And I won't cry when I auger it into the ground.

 

[earthsciteach]

I'm excited to build the Guppy with Eddie via interwebs this afternoon! I laid awake thinking about it last night. I'm suck a geek!

 

[earthsciteach]

Tiled plans are printed and I'm taping them together at the moment. ((Thanks for the Snapshot Tool hint, Tommy)) Waiting for Fasted2629 to be released from work so we can build this thing together via video chat. I'll try to post up progress as it happens.

 

[TEAJR66]

I just spent another battery through mine today. I am liking it more and more. It has similar flight characteristics to my first favorite scratch build, SporTEA. A low wing, arrow shaft fuselage plane that I played with for a year.

https://www.youtube.com/watch?v=fw6XzMuO-lw

It fly's well through a wide speed envelope, has great authority on all control surfaces, and it is a pretty easy build.

 

[earthsciteach]

We were building so intensely last night that I didn't stop to take pics. Here's where my Guppy is at this morning. Eddie pretty much made the same progress with his Puffer. I like this build!

 

[Fasted2629]

ok so the debate is to under caber or not to under camber the wing that is the question

 

[TEAJR66]

Make the first one with the 5" under camber for each tip. Then you can either cut under camber off as you go, or you can replace the wing with a tapered symmetrical.

 

[earthsciteach]

I maidened my Puffer a few minutes ago. It flies very nicely, but I have to tame the elevator WAAAAAY down! I don't think I took it above 1/2 throttle except for launching. I added expo to the elevator and ailerons and lowered the endpoints. As I expected, the roll rate is "blurry" and snap rolls are very crisp. Unfortunately, I didn't get it on video because my camera battery was dead. I'll get a vid of its second flight and post here. Fun little airplane, just like I thought it would be!

Here's the second flight. I increased expo of the elevator and ailerons and reduced the endpoints on the elevator (I think a bit too much-can't get it to snap roll after making the changes). This is a fun plane! Reminds me a bit of flying a Bloody Wonder. Maybe its because I don't have much time on this plane, but I felt like I was more up on the sticks than with the BW. I like that, though. If I have time tomorrow, I think I'll try with the cg shifted a bit more aft. She wouldn't spin at all tonight. Stall characteristics are very gentle. Moving the cg back might make her a bit more fun in that department.
Here's video: