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Old Apr 07, 2008, 02:47 PM
Registered User
Portland, Oregon, USA
Joined Mar 2007
80 Posts
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A New Racer (Scratch Built Without Plans)

Hi all, well it's been a while since I have posted anything so I thought I'd show you guys what I have been working on. This plane started when I got a razor plane tool for shaping balsa parts. I got it after seeing someone who had made a set of wings by carving them out of a board of balsa. So I thought that looked like fun and a quick way to make wings so I gave it a try. I made the wings without a plan for what they would be going to so after I had made them they just sat around collecting dust for a while. During this time I had been working on a Herr Gee Bee F/F converting to RC. My worktable was situated under a railing for the stairs in my apartment and something had been placed on the railing. Of course it was bumped and fell right on the fuselage of the Gee Bee crushing it utterly. However the landing gear survived so I kept them. Some more time passed until one day while looking over my collection of airplane stuff I held the Gee Bee landing gear up to the wing I had made and the idea for this plane was born. I then made a few sketches and then got started building the fuselage. After getting the basic shape of the fuselage made I then made paper cutouts of the tale pieces and held them up to the fuselage and shaped them until I had what I wanted. I then used the paper templates to make the tale parts. I just got done installing the servos and push roods for the rudder and elevator. I still have to install the hardware for the wing mount, install the aileron servo and wires, make a cowling, make a tale wheal, and finish the under side of the fuselage, a few other little things then cover it. I was going to use an E-Flite Park 450 outrunner just because I already have one but I'm now thinking this is going to be too much over kill. What do you guys think? Any suggestions?

Here are the planes specs so farÖ
Wing Span 35.5Ē
Wing width 4Ē
Length (with out cowl) 19.5Ē
Weight
(Including, 2cell 1320 mAh Li Po, Thunderbird 18 ESC, all servos and receiver) 9.65 oz

Thanks,
Nate
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Old Apr 07, 2008, 02:57 PM
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Xpress..'s Avatar
United States, CA, Alpine
Joined Oct 2007
20,936 Posts
Looks clean.
That is a pretty light racer. Should fly really good.
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Old Apr 07, 2008, 03:00 PM
KLH
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Hayward CA / Valley Springs CA USA
Joined Jan 2001
1,778 Posts
Very nice!! My favorite way to scratch build, ie: NO Plans!!

Kern
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Old Apr 07, 2008, 03:32 PM
Sink stinks
Montag DP's Avatar
United States, GA, Atlanta
Joined Apr 2005
4,523 Posts
Very nice! I have a lot of respect for people who can make something that looks that nice without plans or pre-cut parts. If it flies too, well, then that's even better.
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Old Apr 07, 2008, 04:58 PM
Fly long and land softly
Jim_Marconnet's Avatar
Madison, Alabama USA
Joined Oct 2005
5,390 Posts
Where can we get the Plans?

Looks Great!

Where can we get the Plans!

Just kidding on the second part.
Jim
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Old Apr 07, 2008, 11:55 PM
Registered User
Portland, Oregon, USA
Joined Mar 2007
80 Posts
Thanks for the comments guys. So can anyone recommend an engine that would be good for this model? The airfoil is flat bottomed and not that tall so Iím thinking itís going to need to be flown fairly fast. It would also be nice to be able to use a prop in the 5 to 7 inch range for a more scale look.
Well Iíll keep working on it and post more pics later.
Thanks,
Nate
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Old Apr 08, 2008, 06:53 PM
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USA, FL, Orlando
Joined May 2003
7,977 Posts
You did a really great job, I'm impressed.
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Old Apr 09, 2008, 03:06 AM
Registered User
Portland, Oregon, USA
Joined Mar 2007
80 Posts
Thanks taekwondo, yea I really enjoy building things this way, solving one problem then assessing the next step and so on. I spent a bit of time this evening working on the plane. I made the wing mounts with two nylon bolts and T-nuts in the rear of the wing and a carbon fiber post in the front of the wing. Pretty standard stuff. I also sheeted the inside of the fuselage to make plenty of room to mount the battery and receiver. I plan on making a hatch behind the wing to give more access to the interior so I guess Iíll start on that next.
To anyone who has wanted to try this way of building I say go for it. Take it slow and double check your measurements, make paper templates and build something that will fit your own taste.
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Old Apr 10, 2008, 01:48 AM
Registered User
Portland, Oregon, USA
Joined Mar 2007
80 Posts
Well here is my progress for this evening. I sheeted the bottom and made the access hatch. I decided to do something a little fancier than just using screws. So I made the latch knob look like some kind of ďscaleĒ detail. I used a basswood post at the opposite end to hold that side in position. Where the latch hooks on to the fuselage former I glued on a bass wood ramp to create a tight fit and give a durable surface for the latch to slide across.
Well thatís it for tonight.
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Old Apr 12, 2008, 01:39 PM
Registered User
Portland, Oregon, USA
Joined Mar 2007
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Last night I got to work making the tale wheal for my plane. I forgot to take a picture of the wheal construction before I added the fairing so I made a drawing of it. For the stem of the tale wheal I doubled the wire back on its self after going through the wheal. I used some fly tying thread to rap the two wires together. I then spread CA over the thread. Then I cut out a section of pop can and used a hole punch to punch out a disk of metal to use in-between the wheal stem and the fuselage. I made the disk ďbowelĒ shaped buy placing it on an oak board and then hammering a steel ball barring into it. I then made a hole in the disk and threaded it onto the assembly, convex side up. After that it was just a matter of making a template for the fearing and cutting out the pieces, laminating them together and shaping it with some 100 grit sand paper. After getting the shape pretty close to what I wanted I switched to 400 grit paper. I decided to leave a gap in-between the top of the wheal stem and the fuselage just behind the barring. This is to allow the wheal to have a bit of spring to it. I used a piece of hard balsa on the inside of the fuselage to give something to support the wire as it passes through the fuselage and up to the rudder. Iíll leave the wire straight until final assembly.
Well I think next Iíll work on installing the aileron servo and control wires.
I have been looking for a motor for this plane and found this combo at Hobby City that seams like it would be good for this. (TowerPro BM2408-21T / 18A BEC / 9x3.8 Prop Combo) http://www.hobbycity.com/hobbycity/s...idProduct=4853
I would be running it on 2c lipo and Iíd want to use a steeply pitched 7Ēprop (not sure if it woud be a SF or E prop). What do you guys think? Would this work? Any other suggestions?
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Old Apr 12, 2008, 02:58 PM
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Xpress..'s Avatar
United States, CA, Alpine
Joined Oct 2007
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Jaw droppingly clean!!

If it's speed you want, I suggest a lil' screamers park jet, or super park jet. both can swing 5" props at high speeds, to give you that "afterburner" speed you need.

Equip the plane right, and it will scream vertically like no other

I'm awaiting to see this little beauty fly.
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Old Apr 12, 2008, 11:32 PM
Registered User
Portland, Oregon, USA
Joined Mar 2007
80 Posts
Thanks Xpress.., I checked out the lil' screamers they look like a realy good motor but it might be a little out of my price range unless I can finde one used. I might look for one with simaler kv and amps.
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Old Apr 13, 2008, 01:36 PM
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Portland, Oregon, USA
Joined Mar 2007
80 Posts
Ok last night I got to work making the mount for the aileron servo and the control connections. I had already carved a channel in either side of the wings to accept the torque rods and a filler strip of 1/16Ē balsa (look in previous pics for that). The construction for the servo mount is pretty self explanatory from the pics. I made little brass tabs that I drilled and soldered to the torque rods to make the connection to the servo push roods. Those little brass tabs where by far the most frustrating thing about this build, so far. First, I didnít have a drill bit of the appropriate size so I made one out of a piece of pushrod wire that I cut a sharp angel on and mounted the other end in a hard stick of balsa so it would fit in my drill. That actually went through the brass pretty well and then I used an old x-acto blade to bore out the hole and clean it up. But the worst part was trying to solder those things to the wires and getting them in the same spot! This really made me wish I had a third arm. Anyway I donít recommend this method.
So, now I really need to figure out what motor I'm going to use so I can get started on making the cowling.

edit: I just reweighed the plane with everything I listed the in the first post and it came out at 9.95 oz
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Last edited by natedavis; Apr 13, 2008 at 01:45 PM.
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Old Apr 14, 2008, 12:18 PM
Registered User
Portland, Oregon, USA
Joined Mar 2007
80 Posts
In search of a motor for my plane I did some calculations to determine the watt range Iím looking for. According to the PDF fount on E-Fliteís web sight (http://www.e-fliterc.com/ProdInfo/Fi...equirement.pdf)
110-130 watts per pound is the range for advanced aerobatic and high-sped models.
So estimating a generous flight ready weight of 13.5 Oz I calculated that to be .84375 Lbs witch gives me a watt range of 92.8 Ė 109.6. Assuming this looks right to everyone dose anyone have any recommendations for a motor thatís in that range of watts when powered by a 2 cell LiPo? Preferably something under $40. Iíll keep looking but I would really appreciate your input too. Iím getting anxious to fly my creation.
Thanks.
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