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Author Topic: Stab above fuse sides  (Read 518 times)

Offline Mike Ferguson

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Stab above fuse sides
« on: January 29, 2019, 10:43:51 AM »
Iím building an older design that has the stab well above the thrust line- itís higher than the fuse sides, and basically is mounted in the top block. Any recommendations for the best way to mount a stab like this, and ensure itís aligned properly? Aside from cut holes in the top block sides and do endless fitting and fiddling?


Online Tim Wescott

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Re: Stab above fuse sides
« Reply #1 on: January 29, 2019, 10:51:13 AM »
Is it slotted into the top block, or does it fit on top?  Is it some nice even number like 1/4 or 3/8, then make your top block in two pieces and use the wood as-milled to establish level with the fuselage.  You're going to have to fit and fiddle no matter what.

I'd be tempted to figure out some way of tying things more firmly into the fuselage structure than just using a top block out of the Lightest Possible Wood, but that sort of thinking is probably why I build heavy.
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Online Brett Buck

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Re: Stab above fuse sides
« Reply #2 on: January 29, 2019, 11:00:22 AM »
Iím building an older design that has the stab well above the thrust line- itís higher than the fuse sides, and basically is mounted in the top block. Any recommendations for the best way to mount a stab like this, and ensure itís aligned properly? Aside from cut holes in the top block sides and do endless fitting and fiddling?

    Add something to the top of the fuselage side so that it projects enough to align it properly.

     Brett

Offline Mike Ferguson

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Re: Stab above fuse sides
« Reply #3 on: January 30, 2019, 12:42:22 PM »
Is it slotted into the top block, or does it fit on top?  Is it some nice even number like 1/4 or 3/8, then make your top block in two pieces and use the wood as-milled to establish level with the fuselage.  You're going to have to fit and fiddle no matter what.

I'd be tempted to figure out some way of tying things more firmly into the fuselage structure than just using a top block out of the Lightest Possible Wood, but that sort of thinking is probably why I build heavy.

Itís shown as slotted into the top block. Iím thinks that it may work to cut a mock foam top block, then cut out the appropriate stab cutout. That should align everything near perfect. Iím also trying to figure how best to brace it, though.

Online Tim Wescott

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Re: Stab above fuse sides
« Reply #4 on: January 30, 2019, 09:46:44 PM »
But then you're left with a foam top block instead of a balsa one (??).

Brett and I are telling you two versions of the same thing: extend the fuselage side up with something that you can easily make to have parallel sides, and build the rest to that.  He wants you to use an extender (not a bad idea, IMHO), I want you build the top block itself from multiple pieces.

If I'm visualizing your plans right, doing your foam thing still leaves you with the problem of cutting an accurate slot in a balsa top block.
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Offline Mike Ferguson

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Re: Stab above fuse sides
« Reply #5 on: January 31, 2019, 06:34:25 AM »
But then you're left with a foam top block instead of a balsa one (??).

Brett and I are telling you two versions of the same thing: extend the fuselage side up with something that you can easily make to have parallel sides, and build the rest to that.  He wants you to use an extender (not a bad idea, IMHO), I want you build the top block itself from multiple pieces.

If I'm visualizing your plans right, doing your foam thing still leaves you with the problem of cutting an accurate slot in a balsa top block.

Iím probably not explaining myself well. I mean using the foam as a molding buck for a balsa shell. Have one mold with a cutout for the stab, to use as an accurate cutout for the stab.

Thanks to you and Brett for responding. Iíll get this figured out.

Online Brett Buck

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Re: Stab above fuse sides
« Reply #6 on: January 31, 2019, 09:22:59 AM »
In any case, you need the top block in place before you mount and align the stab, because if you glue the stab on to the fuselage without it there, you are almost certain to disturb the alignment when you finally put it on.

    Brett


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