Originally posted by xviper
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It's not a huge job, but precision is important.
The oval shape of the blank was marked by putting the cut end of the cockpit end on the foam and marking around it. The ends that slide into the fuselage are shaped by trial and error.
I marked the cut line using a piece of light cardboard wrapped round the fuse just in front of the wing recess. By bringing the ends together, a 'straight' line is drawn around the fuselage, and I cut the glass fuselage using a fine hacksaw blade, rolling the fuselage as I went so that I was always cutting down and into the fuselage, and not from one side to the other, which would probably result in chipping because the glass is so thin. A Dremel with a cutting disc is not necessary, although could just as easily be used.
I'll glue the blank into each piece of the fuselage, wrapping a piece of 1/16 balsa around the bottom half and securing it with rubber bands, and getting the alignment right by using the red stripes. I'll also wrap the visible part of the blank, that between the two fuse halves, in sellotape so that the fiberglass doesn't stick to the foam, making it easier to get the foam out. Most of that should come out by breaking it up, and the residue will melt out using acetone.
My question above regarding the type of resin used in the original layup may have been solved, but I'd still like confirmation from somebody who has actually done fiberglass work on the fuselage. When I cut it, it had a distinctive polyester resin smell to it, quite different from that of epoxy, but not the green/ish tinge that poly normally has. I have plenty of epoxy and cloth of varying weights here, but need to pickup some poly resin, probably tomorrow, so I can get on with the project.
Ben Jones, owner of rcairmods.com the guy who specializes in BoT mods, uses epoxy to attach his nose section mods, and says he hasn't had any difficulties, separations, etc., in spite of some heavy landings.
I'm going to use a 42 mm spinner, and make my bulkhead of three thicknesses of 1/16 marine ply, glued in. The diameter of the motor is critical, and I'll probably use one of Ben's recommendations, a Cobra 2826 which should easily fit if the bulkhead is about 45 mm across. Because of the oval shape of the fuselage, there will be an 'overhang' top, or bottom, or both. I'll sand that to fair it into the spinner, and may even have an air inlet top and bottom, a very small crescent shaped opening.
I'll post more as the project proceeds.
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