Simple BModel Delta - Scratch Build

This is a highlight of the scratch build design I came up with. (photos and a quick flight video are at the bottom of the article)

When I started out scratch building an RC plane, simple was good for me. It was a simple design that allowed me to get in the air quicker than I expected. It's a great confidence booster and gives a person a chance to learn.

My first design is a delta wing pusher prop model. Simple and effective. I found some plans online and decided to scale down one of them that I found interesting. Since that first build, I've come up with my own design.

And so it began.

Print out...cut out...tape...cut again...fit...glue...re-think...glue some more...attach the hardware...fly it like I stole it! I might have missed the step that was a talented mixture of bandages and curse words. Also, I have to say that scratch building makes me feel alive. When the hot melt glue burns into my fingers, I start thinking "I'm alive!"

I worked through several different delta designs until I settled on one that I really like. I was using a CAD software package to create the templates for cutting the DTFB. I really wish I had a laser cutter but I can't afford one of those.

Simple ain't pretty but it works.

I got some of this special packing foam a few years ago. It was used for shipping the refurbished PCs we got for where I work. I didn't know what it was called but it was very light and very easy to cut. When I was thinking about my first build, the idea of using that foam popped into my head. I had saved some of it. I've found it for sale since then but I have enough that I don't need to buy any.

My first designs were the raw paper on the foamboard. Now, I wrap all of the surfaces in clear shipping tape before I assemble the plane. I put the striping on last so that I could peel it off if I want to change it.

The Specs:

MODEL TYPE: delta wing pusher w/ elevon mixing

WINGSPAN: 600mm (24 inches)

LENGTH: 540mm (21 inches)

ALL UP WEIGHT: 405grams (14.3 oz)

MOTOR: 2826 2200kv brushless

ESC: 30A brushless

BATTERY: 3s 1300mah

PROPELLER W/ MEASURED THRUST: 6x4R (approx thrust 850grams = 30.0 oz)

ALTERNATE PROPELLER: 6x3 (approx thrust 720grams = 25.4 oz)

MEASURED MAXIMUM POWER DRAW: 24A with 6x4 prop / 18A with 6x3 prop

RADIO SYSTEM: 3 channel required

SERVOS: (2) standard 9g micro (recommend 400mm leads = 12 inch)

APPROXIMATE CALCULATED AIRSPEED: 70+ mph with 6x4 prop / 55+ mph with 6x3 prop

LANDING GEAR: no (belly lander)

NOTES:

- motor mount firewall can be made from any thin durable plastic or from balsa

- motor mount backstop is made from built-up foam board that is laminated together with hot melt glue

- alternate propeller allows for longer flight times at sacrifice of speed

- the ESC could be reduce to 20A for 6x3 prop

- 30mm (1 1/8") Fastcap Kaizen foam for fuselage

- 5/16" wood dowels for spars to reinforce the wing

Pictures are worth a thousand words.  Unfortunately, I didn't take any photos during the build process.

The video was shot with a Mobius stuck onto my hat.  I'm using the 6x3 prop but the wind was keeping me from getting a good flight.  I know, excuses don't count.