Hanging Carlo's Wings on His Patrol

[SpruceForest]

Spent a toasty Sunday at Frederick Airport getting Carlo's wings on. Clock is ticking on this one, as the owner of the hanger next to Carlo's (very full hanger) is out for a few more weeks (Cirrus jet touring Europe). Usual conversations on this stuff as shown in the video screen grabs. Once struts are on, final welding on the fuse, final prime and paint, and the engine gets hung/firewall forward stuff. Sept 2023 purchase of plans for Carlo, so a pretty decent speed-of-build. Should mention Carlo spent the winter getting the panel and all the wiring harness, windows, and cockpit interior build out, so further along that it might seem.

We used a couple laser levels (the Takamine four line is shown on tripod - good option of you don't want to sink over $500 on a Bosch three line) plus some calibrated digital levels for incidence, fuse leveling, etc. The platforms are pretty rudimentary, but using an almost empty hanger has its benefits, as once set, unlikely to be disturbed.

Carlo Wing Fuse Mate 1.jpg Carlo Wing Fuse Mate 2.jpg

[spinningwrench]

I found digital levels to be surprisingly inaccurate and not repeatable. Ultimately the water level was the most accurate. laser is an interesting option.

[Utah-Jay]

I had several water levels going on the day I hung my wings
1) fuselage
2) root to tip on each wing, so 2
3) wingtip to wingtip Yep it was about 45’ long

Worked like a charm

[SpruceForest]

The lasers were surprisingly accurate for mass-produced tools - the biggest issue was line width and brightness at longer distances. Closing the hanger door addressed the brightness issue, and the 1/16" apparent line width just required consistency in use. I did cal on my shorter (24") digital level using a larger leveled surface plate in the lab, and shims showed a consistent flip to the next tenth. At angles around 45 degrees from horizontal and vertical, we saw closer to .2 variation when flipped, but that could have been my plywood and rare earth magnet rig! Carlo got things closer the next day and did a final check with water level before doing the intermediate ream to AN3.

One thing to consider is that 1/10th of a degree is about 0.3" vertical change on a 15' span between mount and the outward vertical measurement point - a water level should get you to at least 0.1 inch accuracy, so another good reason to use a water level as a final check/tweak.

What really surprised me was just how square and true the fuse was off the jig, as well as how straight the wings were. What became apparent as the fuse was leveled was that time and care in building out a rock-solid jig def paid off, to include the uniformity in timber size (trued on jointer two-adjacent-edges, then sawn to width and final-sanded to consistent dimension), a modular leveler design, and seasoning the wood a bit to get it to ambient for Maryland in Oct-Nov.



IMG_1014.jpg

[Bcone1381]

See post #7. I read a water level to 1/2 mm (0.5mm = .020") with 3x reading glasses when I drilled my wings.

https://bearhawkforums.com/forum/bearhawk-patrol-quickbuild/38544-drilling-the-wings

One other consideration. Where on the wing's span should the level reference be measured at? Wing root? Wing tip? I never asked that question when I drilled my wings. But I think it was Paul Johnson who suggested to set the wing incidence by referencing an outboard area like in the middle of the aileron area rather than the root like I did. There is more leverage out there to induce a roll force, so if things are off a little bit then focus on getting the aileron area set right.

[SpruceForest]

We used the aileron and flap rigging templates for setting incidence - rigged just outboard of the inboard aileron hinge. But should not be an issue, given how dead flat all our wing panels are (in our dreams)