Month: July 2016
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.