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pre-built spars

PostPosted: Mon Jan 01, 2018 7:29 pm
by EdW
Are they worth the extra $2700.00? I see a lot of 'precision' hammering going on with the home-built version. Is this instead of regular rivet upsetting, or is there another reason for the bolt/hammer procedure? What have others done? Pluses/negatives?

I wouldn't say I'm cheap, but my picture IS listed beside 'frugal' in the dictionary. That doesn't mean I wouldn't go for it if it's worth the investment.

Ed

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 7:34 pm
by Bryan Cotton
It was more like $2000 when I got my kit. Mainly I went that route because I was building with a 12 year old. Of course he was more like 14 when we were at that point.

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 7:58 pm
by mike.smith
EdW wrote:Are they worth the extra $2700.00? I see a lot of 'precision' hammering going on with the home-built version. Is this instead of regular rivet upsetting, or is there another reason for the bolt/hammer procedure? What have others done? Pluses/negatives?


I scratch built my plane, including the spars. It's not difficult, or even time consuming. Getting the right stacking order is actually the toughest thing. It took me 80.75 hours to assemble BOTH wing spars. No way in Hades would it have been worth the $2,700 for me. That would have covered 3/4 of the cost of all my avionics. But everyone has different needs.

The bolt and hammer is for at least two reasons: 1) it's cheap! and 2) Some of the rivets are located in difficult or impossible locations for traditional riveting tools (the spar flanges get in the way). With a bolt you can carve out a recess in the side of the bolt to clear the spar. 2 or 3 wacks gets you a good rivet set. I had to drill out very few.

http://www.mykitlog.com/users/category. ... egory=4821
Assembly started on 5/23/10.

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 8:08 pm
by rizzz
mike.smith wrote:
EdW wrote:Are they worth the extra $2700.00? I see a lot of 'precision' hammering going on with the home-built version. Is this instead of regular rivet upsetting, or is there another reason for the bolt/hammer procedure? What have others done? Pluses/negatives?


I scratch built my plane, including the spars. It's not difficult, or even time consuming. Getting the right stacking order is actually the toughest thing. It took me 80.75 hours to assemble BOTH wing spars. No way in Hades would it have been worth the $2,700 for me. That would have covered 3/4 of the cost of all my avionics. But everyone has different needs.

The bolt and hammer is for at least two reasons: 1) it's cheap! and 2) Some of the rivets are located in difficult or impossible locations for traditional riveting tools (the spar flanges get in the way). With a bolt you can carve out a recess in the side of the bolt to clear the spar. 2 or 3 wacks gets you a good rivet set. I had to drill out very few.

http://www.mykitlog.com/users/category. ... egory=4821
Assembly started on 5/23/10.


Same here, it's not hard to do or very time consuming in the grand scheme of things. If I were to do it again, I'd still build them myself.
Might I also add that I found it one of the most fun and satisfying phases of the build.

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 8:23 pm
by daleandee
EdW wrote:Are they worth the extra $2700.00? I see a lot of 'precision' hammering going on with the home-built version. Is this instead of regular rivet upsetting, or is there another reason for the bolt/hammer procedure? What have others done? Pluses/negatives?

I wouldn't say I'm cheap, but my picture IS listed beside 'frugal' in the dictionary. That doesn't mean I wouldn't go for it if it's worth the investment.


The kit I built Myunn from came with pre-built spars with "JTM" scribbled on them. 8~)

If you were going to do your own spars perhaps making a tool such as Dan Weseman uses at SPA would be worth considering ...

https://www.youtube.com/watch?v=frLcrJvSSa4

I'm not cheap either ... but I have been known to squeak when I walk!

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
166.7 hours / Status - Flying
Member # 109 - Florida Sonex Association
Image

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 9:44 pm
by MichaelFarley56
I agree with the Mike’s on this one. The spars are fairly easy to build, using either the bolt and hammer method or a rivet gun if you want.

It’s not my money but to save time, personally I’d purchase the completed angle kits over the spars. I think that saves more time. Just my two cents of course!

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 9:49 pm
by Bryan Cotton
If I was not building with my kid I would have definitely skipped the prebuilt spars. The hobby is about building. I scratch built the spars for my Hummelbird.

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 10:07 pm
by Brett
Buy the whole Quick build kit.... that way you get out of the canopy fun too and wing rigging :) Then again the Sonex is my second build and I wanted to skip those bits this time

Re: pre-built spars

PostPosted: Mon Jan 01, 2018 10:24 pm
by Sonex570
I'm scratch building mine, although I did order the .032 web to use as a template, I agree with the previous post, take your time and MAKE SURE you have it stacked correctly for their is no work around if you screw it up........enjoy?
Beware of the condition known as Analysis Paralysis Ive been a victim of it many of times during my build! Each area of the build presents rewards and challenges!
If you have money to burn or maybe your time is more valuable than the cost of the premade spar then by all means go ahead and take the plunge!

Re: pre-built spars

PostPosted: Tue Jan 02, 2018 1:40 am
by wlarson861
I built my spars from the kit in about 76 hours. I already had a "C-Frame" for riveting and dimpling (Avery c-frame) and used that to back rivet with a 3x gun. If I was doing it over i would get at least a 4x gun. At $2700 you can get a 4x gun and c frame and still save a lot of money. You will spend at least 70 to 80 hours putting them together. I enjoyed the work and smiled at saving, at that time, $2000. I probably spent close to 300 hours cutting and finishing all the angles. Doing another kit that is where I would spend my money. However: doing another build I would probably just do it the same way but with a Jabiru 3300.