HELP

[Bigstik]

I mentioned awhile back that I was building the Spectra amphibian. I'm having all sorts of problems keeping the fuse straight and true. Started two fuses, had to scrap both due to the fuse being crooked.

Anyone have any simple fuse jig solutions?

Bigstik

[piker]

Assuming that we're talking about a sheet sided fuselage, I would suggest you start with two sheets that are very similar in stiffness/weight.  That way when you bring the two sides together at the nose and trail, one side (the stiffer side) isn't over powering the other.

[Frank v B]

Al,

Drink beers in even numbers.

I have a permanent datum line drawn on my building board with a black magic marker.  Whenever I build a fuselage, I mark the center of each former and pin them onto the board at the datum line, then pull the fuselage sides together.  Make sure you draw both sides together at the same time.  Do not sheet one side and then the other side.

Also, if the sheets are slightly bent or warped, make sure you put them on in mirror image  )(  or ()  but not (( or )).

If the problem persists, attach a small stringers (3/16 sq) to each side by cutting a notch into the formers or bulkheads.

If you wish, post a photo of the hull and it would be much easier to comment.

Rob's answer of equal weight/stiffness balsa is critical.

Happy building in Guelph.

Regards,

Frank

[Bigstik]

Thanks Rob, Frank

I've already destroyed the fuse and will start another soon. I plan to use a base with flexible fuse holders. I have pictures, but can't get them to attach.

Bigstik

[Bigstik]

Whoa. It's magic! They attached!

[electroflyer]

Alan, you can also sheet the fuselage using strips of wood as opposed to sheets. This would allow more control of the straightness. A balsa stripper would make it cost effective.
Glenn

[Bigstik]

Thanks Glenn.

I like the the strips idea. One of the things I considered was to make the basic fuse of 1/4 sq and then cover with sheet balsa, but the strips, say 1" wide would do the trick too. May possibly add a little strength too.

Bigstik

[Bigstik]

Started another, #3, fuse for the Spectra. I think I have it licked this time.
I used a 1/4" balsa jig. I recall that Jim Ryan used the idea on some of his planes.
The jig doesn't run the length of the fuse, just the last half that was giving me problems.

I have my fingers crossed, but it looks good this time

Bigstik

[Papa]

Look's good Al. I admire your patience.


Jack.

[Bigstik]

Thanks Jack. Seems it's true that one mellows with age.

Bigstik

[Papa]

I tried to hide my surprise but did not succeed.


Looking forward to the build blog.


Jack.

[piker]

I'm glad you're getting it straightened out, Alan (pun intended  )  Get that plane built so you can join us for some float flying!