Well, all the pieces exist, just now got to get them all assembled. These pics show the spar attach brackets all fitted, the four ribs located and in place and the trailing and nose ribs. Soooo close. The metal rods between the spars are 4130 tubular compression ribs.
You will notice the front spar has the bushings installed (in gray) with the half inch bolts already placed. The front spar is missing the sway wire attach brackets, but otherwise complete. The rear spar has the bushings inserted with bolts and landing wire attach brackets. I will still need to cut the holes in the ribs to fit them, but otherwise its complete.
Some time in the next month or so I will cut and form the grab rail at the back and fit.
Would have to say the Steen CAD plans for this component are pretty good. There is an error on the way the rebates are cut out on the front spar nail strips – they are shown in reverse, otherwise, perfect.
I have found through this phase of the build you can never have too many clamps. This pic is the clamps used to attach and glue the front spar nail strip (it is only ever glued) used to hold the leading edge on.
Once the front nail strips are on, then its time to get to nose ribs glued into place. I tried to get the centre section of the ribs themselves routed out. Got one done and it took forever….gave up and will put up with the incremental weight. Wont be much though.
Ok, due to lack of forward planning I am waiting for my metal brackets to be welded and media blasted. They are currently off getting done so work has slowed. All the pieces other than ply are cut and ready for final fitment. I can glue the trailing ribs in, so here they are. You can never have too many clamps in the shop.
With the spars front and back complete, its now time to glue them together. The way that I thought would be best to approach it is to glue the widest two ribs together. This hopefully will ensure once set that I can maintain straightness and squareness.
Using a spirit level, laser level, trammel points and a tape measure I got the spars within .5mm comparing opposite corners to opposite corners, whilst keeping everything vertical where required. Pics show the clamps, laser level lines and centre lines of spars. Good to get this job done. No going back if I got it wrong!!
Work has begun on the rear spar. It is profiled, doublers trimmed and I have started on glueing them on. On the front spar I had dramas getting the doublers staying in position even when clamped. This time I am doing the front and will glue the back separately. This has made it much more stable. Takes longer, but they are staying in place nicely whilst drying.
While I have been doing this in between times I have completed the outside shape of the front nose ribs. There are seven of them but the outboard two are a different size (same profile) as they mount from on the attach bracket.
Below – I used a jig and trimmer bit on the router to form the outside shape of the nose rib. Picture is part way through trimming. Needs a sand too.
Above – 5 of the best. Nose ribs for the front of the centre section. Blessed to be able to pick up a set of upper wing ribs from an Australian builder. Came in handy as I was able to use a rib as a guide to ensure the profile is the same as the outer sections of the upper wing.
Left is how I have profiled the spars. Aluminium straight edge and trimmer. RHS doublers ready to go
Building continues on the front spar. I have finished the bevelling of the front spar to 10 degrees. (Rear is 8 degrees). This required a 1/8″ checkout for the spar attach bracket but as you can see from the pics, they fit just perfectly.
Once the spar attaches were mounted on the spar, next task was to drill the holes through the spar. These are all done and I have cut, fitted and drilled the aluminium right angle that fits against the attach brackets for the outboard nose and trailing ribs.
Left picture with the right front spar bracket attached. Fit is just right. Did have to sand a bit off the front and rear doublers as my glueing was not quiet tight enough. Right side, spar nice and level. Centre line bolts lined up on both sides and if you rotate the laser level the outside tips of the attaches are nicely lined up.
Once I give the doublers some wood sealer and get the brackets welded (need to add the cabane attach fittings) then it will be paint for all of the metal work and it can be re-assembled.
Next task…. Rear spar. Repeat.