I’m constructing the two wings together, so over the past few days I’ve brought the right wing up to the same construction step as the left wing. Both are now ready for match drilling of the rear spar assemblies.
Sooner or later I have to build a wing stand, so now seemed as good a time as any. Nothing original about it, the design has been floating around on the Internet for years, so credit to whoever came up with the original design.
For now, there are a couple of support rails for the outer part of the wing spar, these will get removed and replaced with a piece of hanging carpet once the leading edge assemblies are installed on the wings.
I got to use my ancient radial arm saw, another piece of my late father’s amazingly dangerous equipment that I grew up using around fifty years ago. Everything about this saw, including the castings and electric motor, was manufactured in Australia. Nothing has ever failed or had to be replaced. Could you imagine getting this sort of service out of a modern day “Made in China” saw?
I’ve decided to go a bit out-of-order with the wing construction, by preparing more assemblies before tearing it all down and priming the ribs. Just can’t get enough of all that de-burring.
For the left wing only, I match drilled all the rib front flange holes and bolt holes for attachment to the main spar. Took it apart, de-burred all that and re-installed the ribs. I then cut and de-burred the left aileron brackets, match drilled the various rear spar doublers, and de-burred all of the rear spar assembly. Cleco’d the rear spar assembly in place with no problems. After all that de-burring, it seems like I’ve made little progress because now I have to turn around and do it all again – for the right wing.
The never-ending job of de-burring, fluting and scuffing wing ribs seems to have ended. I’ve now got thirty wing ribs, ready to cleco onto the two main spars and match drill. Soon I’ll need to build a wing stand.
Tip: To trim the flange of the outboard spars, get a 3 inch die grinder cutting wheel, and mount it in a drill press. Wind the speed up as high as it’ll go – my top speed is 4000 rpm. Carefully feed the rib in as shown in the picture – the complete cut only takes a few seconds.
Eighteen down, twelve to go…
I completed the wing spars. You do a lot of work on the wing spars, and when it is all done, they don’t look much different than when you started. But there are a zillion plate nuts riveted in place, and a similar number of holes countersunk.
Tip: there are two rivets in each wing root (for fuel tank plate nuts) that are very close to the stepped bars on the front of the spars. A rivet gun mushroom head doesn’t really work in this tight space. So … insert the rivet, find the special RV-10 empennage bucking bar, and lay it flat on the stepped bar, so that it covers the rivet head. Clamp the bar tight against the spar, and then back rivet the offending rivet.
After completing this section, you end up with just a couple of parts to prime. It isn’t worth setting up the spray booth to deal with these, so I’m just going to continue on and catch up with these parts when I have all the wing ribs to prime.
After a long delay due to other commitments, I’ve finally started on the wings.
The main work items in preparing the wing spars are to drill wing box J stiffeners using the spar flanges as drill templates, countersink a lot of holes in each spar flange, and mount a large number of plate nuts on the spar flanges (for fuel tank mounting and inspection panels).
I completed the “bottom” flanges of each spar today. It was straightforward, repetitive work, and I get to do the same tomorrow on the top flanges. A few new items helped this job. I recently bought some single flute countersink bits, similar to these and I really like them. No chatter, swarf comes free mainly in one large piece and doesn’t build up inside the countersink cage, and the resulting quality and consistency is better than regular 3 flute countersinks. I also bought some NAS1097 rivets, and I’m sold on them for use with plate nuts.
I used an Alodine pen over the drilled and countersunk holes on each flange prior to fitting the plate nuts. I’ll do the same again after the #8 and #6 holes are countersunk.