On Friday, September 20, 2013 12:03:50 PM UTC-7, Tim Wescott wrote:
This is out of curiosity:



How good of a bond can one achieve with epoxy to aluminum? How good can

one achieve with epoxy that ordinary folks can mail-order, vs. what folks

who have the ear of a Locktite sales rep and applications engineer can

achieve? How good can one achieve with JB Weld?



An Internet acquaintance has a scale model airplane that needs a

driveshaft driven by an 049 engine (that's a bitty one that swings a 5"

prop, not a humongous one that swings a 12" prop -- 1/20th cubic inch,

not 1/2). His current driveshaft uses a solid aluminum rod, and is

heavier than he'd like.



Because of the way the plane balances with the current shaft, every gram

he takes out of the shaft takes out more than two grams from the plane,

because he's currently got a buttload of weight in the nose.



I'm thinking that one could machine ends out of aluminum, then plug them

into a thin-wall (.035"), 1/2" or 5/8" diameter tube made of 2024. I'm

also thinking that bonding everything with epoxy would be a valid way to

go -- but I'm not so sure about the epoxy in a part that's going to be

subject to lots of vibration in at least eight of the six available

degrees of freedom.



Threading such thin wall tubing makes me think that it'll just break.



Welding makes me think it'll never happen.



Soldering???



--



Tim Wescott

Wescott Design Services

http://www.wescottdesign.com

A little late but I would go with 6061 and have the assembly
dip brazed. Maybe too costly...