dgjessing

I have no expectation of winning or anything, but what the heck . If not for the contest, this would be the third effort in my park flyer quest; well, it still is, but now it's in a contest as well!

The first two were pushers in a couple different configurations, neither of which I'm particularly happy with... so back to basics. It's going to be a rather small thing (24" wing span) with a conventional, motor-in-front arrangement. The wing is going to be short, but wide (7.25" chord) with a symmetrical airfoil, no dihedral. I'm after a reasonably aerobatic plane that I can fly in nearby parks.

The electric stuff is all going to be salvaged from earlier planes. I've got several Hobby King "donkey" 1550 kv motors and matching esc's, so it's getting one of those. I've done other planes with these motors that had 42" spans and flew acceptably well (but kinda slow), so I'm hoping this one will have plenty of power.

So anyway, today I sketched out the basic design and started on the wing. Blue foam blank with metal guides hot-glued on temporarily:



The setup for doing the hot-wire cutting:



The hot wire cuts right through any excess hot glue that squeezes out from under the guides, and the guides pop right off with a sharp yank:



After trimming edges with a straight edge and a razor blade, and sanding the worst of the rough out with a big sanding block, I cut grooves for wood spars in the foam, and cut the spruce spars too on the table saw:



And finally I glued in the spars:



That's enough for today .

By the way, you may have noticed the blatant "product placement" of Titebond in the picture. In other efforts I used Gorilla Glue - it doesn't work well for this particular application due to it's expanding property. The wood spar gets pushed out of the groove as the glue sets up, and you end up having to plane off a significant portion of it, reducing the finished strength. With Titebond (or any other similar glue) the spars remain fully seated in the slots.

CHELLIE

Very nice wing It does not matter if a person wins This contest or not, Its just Fun to Build and Fly a Rc Airplane and Better yet if you made it yourself I hope I win so I can keep my Lipo LOL, Just Kidding Take care, Chellie

quorneng

That looks very workman like.
I shall watch with interest.

dgjessing

Thanks!

Started on the fuselage this afternoon. First a pine and plywood "skeleton" including the motor mount and a bulkhead which will support the landing gear, and a pair of $tree foam sides which will be glued onto the "skeleton" tomorrow.



I also put a coat of BIN primer on the wing. All that stuff weighs 3.7 oz at this point.

Crashalott

Nice wing, lookin good Dave
Crash

pmullen503

Good job on the wing. I'll have to try the BIN primer. Does it add significant dent resistance?

dgjessing

I think so. Makes the finish (packing tape, in my case) stick better too (after being sanded and washed off).

dgjessing

A little work on the fuselage, a little on the wing:



All that stuff now weighs 4.3 oz. Before covering the wing weighed 2.4 oz, afterwards 2.85 oz. So, (scribble, scribble, scribble...) the packing tape covering weighs about .186 oz per square foot; not much .

quorneng

It may just be me but that nose looks a bit long given the motor will be on the front and the battery behind.
If this is so it means the two heaviest items will be both well ahead of the CofG or does the battery go above/below the wing.

CHELLIE

That is Looking Great, Keep up the Nice Work, Chellie

mclarkson

Looks very nice. Mine is definitely gonna be the most raggedy-a$$ plane in the contest.

dgjessing

Not much today... Did the main landing gear, which (I hope) is high enough to allow taking off from relatively tall grass in an unkempt park, and I salvaged a bunch of stuff from an older "donor" plane:



I think I'll be OK balance-wise... I can put the esc pretty much anywhere to adjust things. I plan to do the tail feathers then put all the components in their desired locations and see how I'm doing. That will determine where the esc goes.

dgjessing

Over the past couple days I have added a 1/16" plywood panel to the underside of the tail end of the fuselage to serve as the bottom rudder pivot, and thrust bearing for the tail skid:



... and stuffed all the electric bits in place:



I'm going to wait until the last minute to close up the top of the fuselage, since I'm not planning an access hatch above the wing.

So here's the whole thing right now:



AUW is going to be around 14.5 oz.; certainly not light weight for a 24" wing span plane . Oh well - theoretically, that should make it handle wind well, eh?

Crashalott

Lookin good Dave Keep her going.
Crash

dgjessing

OK, all I gotta do before the maiden flight attempt tomorrow is the battery hatch:



13.7 oz AUW, CG is at about 30% back from the leading edge, which I think is going to be about right. I expect that it's going to need to move pretty fast, given the weight and the smallish wing; it probably won't work well as the docile "park flyer" I was after. But I do expect it to fly... (probably a bad idea to say that out loud ).

We'll see. There will be video . The weather report is looking good.

CHELLIE

That looks sweet Dont forget that I get to do the Maiden flight on it OK, Just kidding, you might want to start with the CG at 25% from the leading edge and move it back from there if needed, I always start out with a tag nose heavy CG for a Maiden Flight, its just cheap insurance Take care and have fun, Chellie

tobydogs

dave,outstanding plane! i like the compartment layout,very cleanly done. she going to fly nice and should be pretty agile aerobatics. reminds me of my uproar. stu

Crashalott

Lookin good Dave
Lookin forward to the maiden.
Crash

quorneng

Can't wait for the video.
ps
I always maiden my planes in 'private' and if all goes well I video the second flight!

dgjessing

Me too . In this case, although I videoed the second flight, I've put the third flight on YouTube. The second flight went well, but the dead stick landing was not particularly elegant .

Anyway:

[media]http://www.youtube.com/watch?v=iFy3-gEcJ3Y&feature=youtu.be[/media]

I'm quite pleased with it! It's super maneuverable (maybe too much so, see below) but also able to fly pretty slow, so it's going to be good as a "park flyer" after all.

And it's incredibly sturdy . During the 5th flight I thought I'd see what high rate on the ailerons felt like; unfortunately I was only about 1/2 a mistake high, and it spun *soooo* fast, and, well, it plowed in straight down under full power



The motor was completely underground, and rather difficult to pull out. It's toast; fortunately I have two more of them. But the busted-out firewall is the only damage! New one is already glued in place, and I expect to fly it again tomorrow. I'm going to tone down the ailerons with transmitter programming before going up again .

CHELLIE

Super nice build and flight You sure got that done Quick That is one plane to be very proud of, and its a Tough little Bird too, Take care and Have fun, Chellie

quorneng

Well done!
It looks a very competent flyer and a good landing too!

dgjessing

Thanks!

Flew it several more times yesterday & it did great. The repairs actually helped - I made the new firewall out of 1/2" nine-ply plywood and the additional weight in the nose makes it better.

After checking it out at the "real" flying field I flew it a couple times at a local baseball field - it is definitely a "park flyer"

CHELLIE

Sweet

CHELLIE

Give your plane a Name and add it to your thread title for judging purposes, Thank You, Chellie