SonexBuilders.net

Hello to all. Can anyone recommend which piece to start building first? I am just starting the construction of a Sonex and would like to begin with something small to boost my confidence. If I started with the rudder, what method/tool does one use to cut the end of the pre-formed skin? What device do you use to measure something four feet long with 1/64" accuracy? Any potential problems to watch out for?

Thanks,
Gunther

Gunther,
I generally measure to a 64th, shoot for a 32nd, am happy with a 16th. At the workshop they say about as much.

Use either snips or a cutoff wheel, cut just outside the line, then clean up with a file or belt sander. Whatever works for you. The rudder is a fine place to start. I started with my stabilizers.

Hello Gunther

So far you have received good advice. May I add to that?

Have you turned the crating you received your Sonex in, into a bench? My advice is to start making parts. It will help to teach your hands and your brain to be accurate. Everybody will immediately start of asking where is the aeroplane? Resist the temptation. Start off with the Z parts. They are easy to cut and work with. Then progress to the aluminum parts. The longerons first and there after the smaller parts. The thrill is to see material turn into useful parts.

This is if your are not accustomed to work with your hands. If you are, it will be easy to make parts and assemble strait off

Hannes Vorster
#1135

Gunther wrote:what method/tool does one use to cut the end of the pre-formed skin? What device do you use to measure something four feet long with 1/64" accuracy?

Thanks,
Gunther

To get a long, accurate measurement, I'll typically start the measurement with one of my longer rulers (48" in this case), then lay my 12" steel rule (with 1/64" markings) on top of the longer rule, lining them up at the inch markings, essentially providing me with 1/64" markings on my long ruler. Then To get an extra-accurate measurement, instead of placing the end of the ruler at the edge of the material to be measured, instead start at one of the painted inch markings. The ruler ends often have a little bit of error as compared to the actual painted scale.

As for where to start, I assume you're familiar with how the Sonex drawing system works, and how to read the drawing tree. I'd suggest starting at the bottom of any of the 3 main structural branches (fuselage, wings, or tail). Most people that I know of started with the tail, which is what I did also, beginning with the substructure. The tail takes shape rather quickly and is a nice confidence booster.

Did you order the pre-fabricated angle component upgrade? If not, making some of these parts isn't a bad way to begin either, as Hannes suggested.

I liked to use a 4" cutoff wheel to make my skin cuts, but this is better performed with 2 people. Snips will suffice if you're alone. Get used to a lot of filing!

Lastly, I invite you to view my blog (link is in my signature below). I've tried to write it in a manner than could be comprehended by laymen and/or new builders (like myself), and could be useful to you as a narrative on how I've approached the project.

I started with the flaps. A little easier than the rudder and bigger. It's a nice piece to have finished to show off.

Measure to the 64th as best you can, but don't sweat the tiny errors. Remember, you are going to use a blue sharpie to make all your markings, not exactly the most precise marking instrument. I had a four foot straight edge scale from home depot that measured fine against my 24" rule.

I just marked all the cuts in the flaps, rudder etc. and used snips to cut them. Cut just outside the line. Clean up with a file and Scotchbrite pads and you're done.

I started with the vertical stabilizer. It was the first sequence page of the tail section...

But get to know your plans, how to read them, and yes get your workshop in order and complete the inventory first!

It goes pretty quickly if you have ever done metal work before.

What did you order in terms of any pre-cut angles or pre-made spars?

The new kits don't require any cutting of the channel stock. It's all laser cut and matched hole.

n982sx wrote:I started with the flaps. A little easier than the rudder and bigger. It's a nice piece to have finished to show off.

Measure to the 64th as best you can, but don't sweat the tiny errors. Remember, you are going to use a blue sharpie to make all your markings, not exactly the most precise marking instrument. I had a four foot straight edge scale from home depot that measured fine against my 24" rule.

I just marked all the cuts in the flaps, rudder etc. and used snips to cut them. Cut just outside the line. Clean up with a file and Scotchbrite pads and you're done.

I would second this advice. The control surfaces are probably the easiest assembly to fabricate and if you screw it up, won't cost you a lot to replace.
Do yourself a big favor and fabricate a hinge drilling jig (look on EAA tips video) from a metal yard stick. Make sure you do it real straight and with the holes equally the same distance from the edge. You will use the jig throughout your build.