Dave's Sonex Builders Log

Work progressed today on the nose ribs. They have all been deburred. I did this using a file and Scotch Brite pads. First I filed the edges to smooth them out. Next a chainsaw file was used in the tight radii to remove burrs. Finally, the Scotch Bright pad was used to remove any scratches along the edges left from the cutting process. This also helped to remove burrs from the edges. All of the parts were tested with my fingers to ensure no sharp edges remained. The next step was to stack all of the blanks and drill the tooling holes and the center hole for the fly cutter. The blanks were then unclamped and a large (1/2") drill bit was used to deburr these holes. I then setup the drill press for the 4" lightening hole with the fly cutter and began to cut these holes.

Today I finished cutting out the nose ribs. I completed all of the relief holes, marked up the -01,-02,-03, & -04 ribs and cut them out as well. I also started deburing.

I cut out the remaining rib blanks. I picked up another sheet of 0.025 from Triangle Specialty Metals in Cambridge for this. The blanks were rough cut. I started to drill the relief holes. I’ll try to finish them tomorrow.

Today I made the template for the ribs. SNX-W16-06. I used the same process as the previous entry. I also layed out a number of both ribs on my sheet of 0.025 aluminium. I rough cut out all of the blanks that I had material for and started to work on the finish cutting.

I worked on the forming template for the nose rib. The template that I made in AutoCAD was glued to a piece of MDF. Next a second piece of MDF was cut out and clamped to the first one. I drilled the tooling holes and counter sunk them. The two pieces were then bolted together and the finished shape was cut on the bandsaw. I used the bench sander to finish the parts. Next I seperated the two pieces and used a router to put a round edge on one of the pieces. The band saw as set to 10 degrees and a fence installed. I then cut the forming block to provide a 10 degree relief to allow forming to the full 90 degrees. Finally, I transferred the flute positions from the plans to the forming block and then, using the drill press and a rasp bit, I cut the flute locations into the blocks.

Tonight I cutout the first rib (SNX-W15-05). I used a set of Andy Snips. These worked amazingly well. In the past I have use either left or right hand aviation snips and these would leave serations along the edges. This meant that I had to cut the blank a considerable amount oversize and then file it to size to remove the serations. The Andy Snips leave no serations to be cleaned up. A quick file and the cutout blank was ready to go. I drilled the two tooling holes and then setup my fly cutter. I am not happy with the pilot bit in the fly cutter. It seems to be off center slightly. I guess that’s what I get for buying the cutter at home depot. In anycase, the 3" lightening hole was easy to cut. I can now see why everyone else works in a batch mode. It makes sense to cut out the blanks then setup for the lightening holes and drill them all at once with the setup still in the drill. I plan to finish the current rib and then start working on a batch.

Today I cut out the templates for the nose ribs. Next, I need to decide whether to try a router to cut the aluminium or to use the snips. If I go with the snips I’ll need to glue the templates to bristle board and then use bristle board as the template. If I decide to use the router I need to cut out two pieces of MDF to sandwich the aluminium between and then use as a guide for the laminate trimmer bit.

Again tonight I worked on my templates for the wing ribs. This time I created the Aft Rib SNX-W16-06.

Tonight I started working on the wing rib templates. Using AutoCad and the coordinate table contained in the Sonex plans I drew up the forward rib, SNX-W15-05. I created two versions of the template. One with the flanges to be used as a pattern for the aluminium blank and one without the flanges to be used for the forming blocks.