Jart - Build Thread - RC Groups
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Aug 04, 2004, 04:03 PM
Vitruvian JART
Reed's Avatar
Build Log

JART - Build Thread

So I've decided the only thing that will get me off my butt to finally build this thing is to do a build thread. I've disclaimed before re: my building skills but it can't hurt to do it here. If you want the best possible advice for building planes there are others to whom you should go. A partial list of those whose knowledge I'll be stealing in this thread reads like this:

Phil Barnes
Carl Maas, Jr.
Paul Masura
Joe Cormier
Russ Thompson
Robert Cavazos
Ralph Roberts
Craig Toutolmin
Tim Bigley
Tim Neja
Ken Russell
Leagun James
Brian McLean
etc, etc, etc...the list is endless.

Here are the drawings I used to begin this project. They were created in Illustrator but you could easily do a good enough job with a pencil and paper.
Last edited by Reed; Jul 22, 2008 at 01:32 AM.
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Aug 04, 2004, 04:13 PM
Vitruvian JART
Reed's Avatar

The foam begins...

Starting with a couple of sheets of 3/4" blue foam, I blocked out enough to cut out the fuselage. Two sheets were joined with a light coat of 3M77. Then I printed out the full-size drawings and laid them over a sheet of 1/32" ply so I could cut out some templates...
Aug 04, 2004, 04:17 PM
Insert custom witicism
Jeff Charlot's Avatar
Looks great Reed, I'll be watching this closely. I'm just about ready to bite the bullet and scratch my first project.
Aug 04, 2004, 04:22 PM
Registered User
TFLG's Avatar
Looks pretty sexy. My only concern would be that the fuse towards the tail is too skinny and will be very prone to breaking. not to mention awfully small to put a linkage in to.

Aug 04, 2004, 04:23 PM
Vitruvian JART
Reed's Avatar


Here's my little set-up for cutting foam...darn simple, really. Just a dimmer switch connected to a socket going to a battery charger.
Aug 04, 2004, 04:27 PM
Vitruvian JART
Reed's Avatar
Originally Posted by TFLG
Looks pretty sexy. My only concern would be that the fuse towards the tail is too skinny and will be very prone to breaking. not to mention awfully small to put a linkage in to.

Yep, you got that right. The linkage is ok, I checked that out (well, hopefully) and my thought on strength is just to add some carbon back there and rely on that forward fin to help out. BTW, the drawing is not quite right back there as you'll see. (edit 2006: the plans above are now the current drawings).

This reminds me to encourage everyone to chime in as they watch here. I'm bound to need some help as I go along.
Last edited by Reed; Apr 12, 2006 at 03:00 PM.
Aug 04, 2004, 04:30 PM
Vitruvian JART
Reed's Avatar

Bowed and Bent

And here are the bows I've been using so far. Could have used a smaller one to hack out the fuse but it turned out ok.
Aug 04, 2004, 04:40 PM
Vitruvian JART
Reed's Avatar

Ooooo, Sexy...

I cut the top airfoil shape first (it's an 8020 airfoil sized up to the length of the fuse and fattened in the back - see TFLG's comment above) so I'd have a nice smooth side to lay the profile templates on. You can see the bottom template still stuck to the foam that's been cut away.

In these pics I've already done quite a bit of sanding to get the fuse shaped properly. I think I used 220 wrapped around a chunk of flexy foam that I got out of an electronics package.
Aug 04, 2004, 04:50 PM
Vitruvian JART
Reed's Avatar

Picture of the Corrs

Beautiful, eh?
Aug 04, 2004, 04:57 PM
Just tape it, it'll fly
Pete-O's Avatar
Cool. Now I get to see how I'm 'sposed to do it. I didn't bother with templates for my fuse, just marked it at key points and cut off sections, then sanded per eyeball.
Aug 04, 2004, 04:58 PM
Vitruvian JART
Reed's Avatar

Picture of the CORES

Sorry, got a little sidetracked, though I imagine dutchydawg1 will quite enjoy that little diversion.

Here are the cores I cut using a hybrid method of the swing-wire made famous by TFLG (https://www.rcgroups.com/forums/showthread.php?t=191128) and standard upper and lower templates used with bow-cut cores. I didn't have a popsicle stick (https://www.rcgroups.com/forums/showthread.php?t=258798) so I used a chunk of wood from the scrap heap as a handle. The wire is just some SS leader wire - don't pull too hard, though!
Last edited by Reed; Aug 05, 2004 at 01:40 PM.
Aug 04, 2004, 05:07 PM
slopetrash wannabe
I love it, another free education/inspiration. That thing looks like a deadly weapon. Way cool-ROCK ON!!
Aug 04, 2004, 05:13 PM
Free as a bird now.
Like TFLG said... sexy!

Looks very nice Reed, it ought to be a total rocket ship on the slope too. Thanks for doing the build thread. I love to see someone else's plane come together online. This is particularly nice cause it's an original plane, and it isn't another foamie.

Are you going with lost foam, or are you gonna make a mold from the plug?

BTW, I am about half way finished with a new original design glass sloper of my own. I'll be posting pics soon.
Aug 04, 2004, 05:16 PM
Slope Stud

Free carbon

Hi Reed,

I think that is a very sexy plane, if you send me your address I will send you out some Prepreg carbon tow and some prepreg carbon weave to stiffen up that tail section.
I am definitely watching this thread close.

I will try and get a picture out later but I HAVE too go fly now.

Aug 04, 2004, 05:17 PM
Vitruvian JART
Reed's Avatar

The Kit

Here are all the parts as they come in the kit - oh wait, there is no kit.

Now the really interesting stuff starts. I'll be glassing the fuse first, hope to get to that tomorrow.

BTW, I should say something about the parameters I used to design this bird. This is an off-off-and way off-scale classic jet profile. I chose the side-view shape just because I like it, even though it creates some problems in construction and that pointy nose will be hard to keep intact after a few one-point landings. Looks-wise, I just wanted something I could really relate to in the air.

More important than looks, for me, is how this thing will fly. The wing is a sort of PSS/60" combo job - 8" root, 4" tip, 1 1/2" LE taper, 56" span. I'm using a 6062 airfoil because it flies well inverted and it's fast. Not the greatest airfoil for heavy wingloading and hard turns, but that's my compromise - I plan to bring the wingloading in at 18-20 oz. with ballast provisions to bring it up to around 24 oz. Dry AUW should be around 50 oz.

I'll be bagging the wings and tail feathers because I wanted true flying surfaces all around and because I wanted to try bagging. This plane won't be for formation flying, it's for me to tear up the sky all by me lonesome. I wanted something that's very neutral, very aerobatic, and goes right where you point it. We'll see.
Last edited by Reed; Jul 12, 2006 at 07:19 PM.

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