Caution: long, rambling post about structure and tedious building processesFrank,
Yea, the jig is nice. If I ever get around to it, I have steel replacement upright pieces partially machined. The thing I don't like with the aluminium ones is that you are constantly checking for squareness of the pieces. I have a dozen or more than what you see here. Occasionally I have to put them into a sort of jig for the jig to get them square again. That's a pain. Some just won't come back and are tossed on the cut pile and replaced with a backup. The steel ones shouldn't be as much of a problem with that and maintain dimensional stability over time better.
You do spend a bit of time leveling the jig base. I also use a laser leveler to get the bottom chocks straight. If I'm happy with the flatness of the jig base, I can use some set blocks to set up the lower chocks, but I usually use the laser doohickey.
I set up the jig and put the leading and trailing edges in. In this case, the leading and trailing edges are compound structures. I also usually glue the wing tips in at this point. This should include the leadout adjuster and possibly tip weight box. I've been using a tube for the tip weight box, but may do it differently on this one. Once those are in, you mark the leading and trailing edges for ribs. I usually put a template on the jig base for this and use a small square to mark the rib locations. Then drop the full length strip ribs on, flip the wing over and do it again. This can be challenging if the inboard and outboard wing have significant chord asymmetry, but that usually isn't the case. If you have that, there are somethings that can be done, but I don't usually use much asymmetry so it's seldom something I have to deal with. This wing does have a half inch of asymmetry. Once that's done, I glue in the top and bottom pieces of the main spar. In this case, they were 1/8" x 1/4" "C" grain 7lb stock. You can glue some carbon fiber on these pieces before they go in if you want to, but it's been my experience that you only really need that if you use really light balsa for this. This is a very good use of the 7-10lb stock you have laying around and takes away the need for CF. One nice thing about this sort of structure is, you can use relatively heavy (7-10lb) wood (other than the sheeting). Makes for a pretty strong structure without having to use up your light wood and the wing is still very light.
Once the top and bottom of the spar are glued in, I go back with the same stuff and put in the truss supports. I've done them both parallel and perpendicular (the 1/4" dimension of the piece either in parallel with the top and bottom pieces of the spar or perpendicular to them). I seem to get better resistance to twisting the way shown in the pictures and better vertical flexion the other way. It's a crap shoot. It's one of the areas I'm still experimenting with.
Once that's done and whatever extra bracing that I want to put in, like the center section for the bellcrank and center support, I usually I put the controls in. This time I decided to go ahead and build the rear spar first. I was sort of in a groove with spar building. Doesn't really matter, though. This is also when you put in the gear blocks if you are using wing mounted gear. This one will have that, but I haven't got there yet. Once the controls and rear spar are completed, I drop on the half ribs for LE sheeting support and flip the wing again to put the half ribs on the other side. When that's done, I use a 36" long sanding block to level the ribs. Be careful at this point not to alter the airfoil (easy to do). Once that's done, flip the wing and sand the other side. This has to be done in the jig to keep things honest. When it's all nice and level (rib to rib), you can start putting sheeting on. This one is going to have pretty minimal sheeting. It will have about a half inch wide TE sheeting and the LE sheeting will also be pretty minimal with a more substantial center sheeted section. Then the capstrips go on and some block sanding can be done (in the jig).
Anyway, when that's all done, I pop it out of the jig, cut the jig tabs off the leading and trailing edge and do the final sanding and shaping and it's ready to go into the new jig with the fuselage and stab for assembly.
As I've said before, this process creates a very light and straight wing, even using somewhat heavier wood. But it is just tedious as heck to build. Lots and lots of little parts hopefully working in some kind of harmony. But I like building them. I find it relaxing. I'm weird that way.