Prebuilt Spars worth the expense?

[OnAirCreative]

Hey Guys,

After 10 years working on my fuse...yes ten years 0 : I'm on the brink of purchasing the wing sub-kit for my Legacy Sonex.
I'm purchasing the extruded angle option but the pre-built spar is pretty steep. Any thoughts on the merit of spending $2200 extra
to have the spar ship pre-assembled.

Thanks for the help

Kevin
#1439 Sonex Builder

[Rofomoto]

My opinion is no. Didn’t take that long to build. Took me three weeks working off and on after I made all the pieces . Bolt and hammer technique. Billy

[Sonex1517]

My opinion is yes.

Anything that sped up the build time was worth it to me. My two cents.

[racaldwell]

My opinion would be to spend that money on something nice for the panel. I built Xenos spars and they were the easiest part of the wing, well nothing was hard, just tedious and time consuming. They went together like they should, no surprises. I used a rivet gun and bucking bar with the spar web vertical and held straight with clamps while riveting.

Rick Caldwell
Xenos 0057

[NWade]

Kevin -

If it helps, I built my fuselage last and it took me the better part of 5 years. It’s definitely the slowest part of the build, what with all of the wiring and cockpit details and FWF stuff to deal with.

As for the pre-built spars: What’s about 120 hours worth to you? That’s how long it took me to do the spars. All yourself how much your labor is worth, and how many months or years it takes you to get ~100 hours of time in the workshop (plus a little, to practice the solid rivet driving before doing it on the spar for real).
It would’ve been closer to 100 hours for me, but I misread the plans and put about 200 driven rivets in from the wrong side and had to drill them all out and re-rivet it all again. (And it disheartened me enough that I took a whole year off from building) :-P

The bolt & hammer method works best if you are working solo. A 3x gun is faster, if you have a buddy or partner to help buck the rivets.

Take care and best of luck with your project no matter which way you go!

—Noel
Sonex #1339

[Rynoth]

Just to give a little context into how long the spars take to build vs the rest of the plane, here's my timelapse video.

https://youtu.be/Q8QTd2HoyAM

So, I setup the camera and started filming that video about 270 hours into the build. The VERY beginning of the timelapse is me starting work on my right wing spar (the left was already completed at this point.) As you can see, that work flashes by in under 4 seconds. Then, another 2.5 minutes pass before I moved the plane to the hanger (still had a LOT of work to go from there to get the plane airworthy.) The time I spent building the spars myself was a tiny blip in the context of the whole project. I logged 50 hours to build and mate the spars (not including angle fabrications, but I don't think those are part of the spar kit upgrade, rather the extruded angle upgrade), and logged 1377 total hours until my airworthiness certificate.

If I did it again I would seriously consider the extruded angle upgrade, but definitely wouldn't bother with purchasing the pre-built spars.

Edit: I just found another, slower video of building my right wing spar. This is 18.5 hours of work in 1 minute 14 seconds. I still had about 4 hours of work to go at the end of this video before the spar was done.

https://youtu.be/VMyZrScejgk

To put it another way, if the prebuilt spars are $2200 and it took me 50 hours, I paid myself $44/hour to do it myself. I'll take that.

[Bryan Cotton]

I went with prebuilt spars because I was building with my kid. Otherwise I would have skipped them.

[mbean]

I agree with Robbie, they are worth it to speed up the process.
I purchased them for this reason. Finishing left wing assembly this week.
Feels a bit like cheating but nice to have everything exactly as it should be with solid rivets done and pilot holes drilled by the factory.
Mike

[Sonerai13]

One word - YES. :)

[avee8r]

In general, I have the problem of coming up with a spare $2200. Back in 2010 or so when I build mine I didn't have the extra either. I found using the hammer and bolt method very satisfying both in the execution and results. Many people stopped by and marveled at the simplicity of the process. It was like playing a piano, you could hear the pitch change with each strike of the hammer, almost to the point of not needing to use a rivet "go / no go" tool to check them.

My advise FWIW... Take the time to make the spars yourself, enjoy the build, it'll be over too soon, and use the go/no go tool just to be sure!

Happy Landings
John
N50NX