Hi,
Just a quick update.
I spent today finalising the formers which will be used to lay the Cedar strips to form the fuselage. All 20 formers are cut perfectly on the CNC machine to very tight tolerances out of 9mm plywood. They are then threaded onto a 75mm x 25mm aluminium tube (called a “Strongback”). The strongback is mounted on a low trestle bench, so that the work height is comfortable, and is then secured in place. Once everything lines up perfectly the real fun begins. There are cut into the sides of each former a 5mm notch at the “waterline” and the first Cedar strip is laid against this. Nothing is left to chance – CNC is our friend here.
The Cedar strips are glued to the (permanent) nose and tail bulkheads with wood glue, and hot glued to each former. Then the first strip is laid on the other side. It only takes about 15 minutes or so for the wood glue to set sufficiently for the next strip to be laid above it. The second strip is glued to the fore and aft permanent bulkheads, and hot glued to the rest of the formers. Each strip is glued to the one underneath it, and held securely in place with masking tape. In this way, one can strip the entire bottom of the fuselage in a day. Let’s say two. Make that three (in case the wife wants you to pop down to the shops on an errand).
But back to reality…
You are probably asking “What will this fuselage weigh?” You would be surprised. The entire fuselage weighs just over 7kg. And that’s with a light glass fibre cloth sandwich. Bear in mind, of course, that this is an extremely small airplane. From nose to tail the fuselage is only 2684mm long. And that’s not big.
Anyway, here is what the formers on the Strongback will look like:
Of course, the bottom is stripped first. So the build table will look like this:
Well, that’s it for now. The CNC is *almost* finished, and once I make my wife her two barcelona chairs, and I cut the trestle bench pictured above, I can start CUTTING WOOD! Ta-daaa!
Duncan
Auckland
01/05/2025