Mast

[WHY]

John

I can't claim credit for that, I'm not sure but I think maybe Chuck said that.

Tony

[Penguin]

I still haven't heard a compelling reason to bond the redundant mast.

[04 Marine]

If you are really looking for a compelling reason, try this on for size. When you wash your gyro, water will migrate into the space between the two halfs. If you live near the ocean, include salt air into the mix. When bonded together, these potential corrosive elements are prevented from entering the area between the masts. beyond that it will make the mast substantially stronger.

[Earthboundmisft]

I'd rather let the two halves 'work', or move.
If I WAS to bond, I would choose a more elastic adhesive,
like B-1/2, aircraft fuel tank sealant.
JB Weld is too brittle.

[Earthboundmisft]

P.S. don't ever 'wash' your gyro with water.
Mine ain't never been wet.
Purple Polish...

[WHY]

What about the aircraft builders friend ----T-88

Tony

[Alan_Cheatham]

From this post: http://www.rotaryforum.com/forum/sho...60&postcount=2

Originally Posted by C. Beaty

Double 1 x 2 is 21% stiffer in fore-aft bending than 2 x 2.

46% as stiff in lateral bending.

68% as stiff in torsion.

147% stronger in tension.

That’s treating the double 1 x 2s as separate members. Stiffness in torsion and lateral bending depend upon how the two pieces are connected together. Structurally bonded or riveted and bolted at close intervals will get back to single 2 x 2 stiffness.

Most rotor shake problems are caused by using double 1 x 2 masts. Gets the resonant frequency of the mast/rotor system down to the periodic aerodynamic input. From a rotor shake viewpoint, it would be better to align the 1 x 2s crosswise.

[Stan V]

How about pro-seal, or is that what the T-88 stuff is ?

[Redbaron]

Originally Posted by Stan V

How about pro-seal, or is that what the T-88 stuff is ?

http://www.aircraftspruce.com/menus/wp/glues_t88.html

T88 is a structural epoxy adhesive that a lot of home builders use.

[papagyro]

That’s treating the double 1 x 2s as separate members. Stiffness in torsion and lateral bending depend upon how the two pieces are connected together. Structurally bonded or riveted and bolted at close intervals will get back to single 2 x 2 stiffness.

Most rotor shake problems are caused by using double 1 x 2 masts. Gets the resonant frequency of the mast/rotor system down to the periodic aerodynamic input. From a rotor shake viewpoint, it would be better to align the 1 x 2s crosswise.

Is there any real studys to prove any of this?

[gyromike]

Originally Posted by Stan V

How about pro-seal, or is that what the T-88 stuff is ?

Pro-seal is what Mike Hughes was talking about a few posts ago when he mentioned B-1/2. It cures to a rubbery texture.