As mentioned in a previous post, the spars are
long and the weight is not evenly distributed because the spar keeps getting thicker
and thicker towards the inboard end. Add
to that the RV-12 spar extends to the far opposite side of the fuselage which
means there is a lot of metal extending beyond the area of the wing that is
skinned, I’m guessing around 43” or so. After bringing the left spar out of the
shipping crate, I quickly realized the inboard end of the spar would require
more support than I had planned on. As a result, thought it best to move the big
square wing crate yet again, and push the assembly workbench further back so a
portion of the spar would extend slightly into the shed. A sling was made to
offer support to the end of the spar which will help stabilize the spar on the
workbench.
Left spar on the workbench with the heavy inboard end
in a sling to help hold the weight.
Didn’t proceed with any assembly today because
of a late afternoon start due to family commitments … but after sparing with
the spar I wasn’t motivated enough to be drilling holes. I think the spar won
today’s session but it will be drilled and tapped into submission tomorrow.
One of the first steps in the plans calls for
the drilling and taping of the AEX tie down extrusion. Interestingly, the plans
call for tapping both ends (meaning upper and lower wing sides) and the drawing
shows the left and right spar sharing a detail calling for drilling and tapping
both ends of the AEX extrusion. I questioned that … as logic would dictate,
only the lower portion of the wing needs a tie down ring. I called Van’s for
clarification and was told yes, the tie down is really only needed on the
bottom side of the wing. However, because of the removable nature of the RV-12’s
wings, Van’s has offered the builder the ability to secure both sides of the wing
for trailer transport. The upper wing skin has a small hole above the AEX tie
down so it can be drilled out to accommodate a tie down ring should the need
arise.
AEX tie down extrusion before drilling and
tapping.
Guess I will go ahead with drilling and taping
both ends of the AEX extrusion even though there are no plans to have the RV-12
as a trailer stored aircraft. I’ll just place a pop rivet in the small hole in
the upper wing skin and should I need a tie down on the upper side of the wing,
will only need to drill out a rivet and enlarge the hole in the skin a bit.