How to cut out for muffler

[Jack_K]

I have a kit I bought on eBay that has me scratching my head. There's a square chuck of balsa cut out for the engine's muffler. The muffler doesn't quite fit in that cutout and I don't want a square cutout anyway.

So, how do I go about filling in the square cutout and then making a nice tunnel-shaped cutout for the muffler?

[Hippie 64]

RE: How to cut out for muffler

Jack have you thought about building the side walls out of some balsa ? Cut and sand to fit then epoxy into place . Like building a wall on the outside to give the tunnel your talking of . Not sure just a thought ..






  Bryan

[Jack_K]

RE: How to cut out for muffler

Jack have you thought about building the side walls out of some balsa ? Cut and sand to fit then epoxy into place . Like building a wall on the outside to give the tunnel your talking of . Not sure just a thought ..
  Bryan

That's what I was thinking, too.

[WintrSol]

RE: How to cut out for muffler

Jack have you thought about building the side walls out of some balsa ? Cut and sand to fit then epoxy into place . Like building a wall on the outside to give the tunnel your talking of . Not sure just a thought ..
  Bryan

That's what I was thinking, too.

If all you need to do is extend the side of the fuselage down, but leave the empty space for the muffler, you could get a fairly thick balsa board, then put pegs or dowels into it that fit into complementary holes drilled into the wall of the fuse, to provide some strength to the joint. Round toothpicks should do. I would push two or more pegs vertically, then carve a groove along the bottom edge, so I could glue one into the wall of the fuse in the aft direction, and glue into the channel at the same time. If your skills are good enough, you could put them in diagonally, so you could have pegs in both edges that slide into holes in the walls of the fuse in one go.

[Jack_K]

RE: How to cut out for muffler

If all you need to do is extend the side of the fuselage down, but leave the empty space for the muffler, you could get a fairly thick balsa board, then put pegs or dowels into it that fit into complementary holes drilled into the wall of the fuse, to provide some strength to the joint. Round toothpicks should do. I would push two or more pegs vertically, then carve a groove along the bottom edge, so I could glue one into the wall of the fuse in the aft direction, and glue into the channel at the same time. If your skills are good enough, you could put them in diagonally, so you could have pegs in both edges that slide into holes in the walls of the fuse in one go.

Sorry, but you totally lost me on that.

[WintrSol]

RE: How to cut out for muffler

If all you need to do is extend the side of the fuselage down, but leave the empty space for the muffler, you could get a fairly thick balsa board, then put pegs or dowels into it that fit into complementary holes drilled into the wall of the fuse, to provide some strength to the joint. Round toothpicks should do. I would push two or more pegs vertically, then carve a groove along the bottom edge, so I could glue one into the wall of the fuse in the aft direction, and glue into the channel at the same time. If your skills are good enough, you could put them in diagonally, so you could have pegs in both edges that slide into holes in the walls of the fuse in one go.

Sorry, but you totally lost me on that.

You said you didn't like the notch as is, but want to retain a space for the muffler. I suggest restoring the wall of the fuselage, so the notch is not as visible from the side, and to do this, a replacement wall is needed. You could just glue in a piece of wood, but it won't be strong enough, so some strengthening dowels inserted into the new piece of wall that fit into holes made in the existing structure are needed. You would need these in both sides of the new wall, both into the upper side of the structure, and towards the rear, and there are a couple of ways to accomplish this.