[ARC5] Brass Tubing

[Kenneth G. Gordon]

On 26 Aug 2014 at 17:22, Robert  Eleazer wrote:

> Only bad thing about that K&S tubing is that it is very thin

Well, that is actually an advantage here...

> Probably better to take the next larger size and crimp it a bit rather than to
> try to spread open smaller stuff.

Not in my experience. Please believe me: I've tried ALL the tricks.
 
> I just checked my small stock of K&S brass tubing and found that 1/4 inch is a
> bit too small for an ARC-5 receiver spline

Correct. The ARC-5 receiver tuning spline is almost exactly 1/4" OD.

> and the next size, 9/32 is a bit too
> large.

Correct: I already tried all this a year or two ago.

>  So it's either swage open the 1/4 inch

By slotting the ends for 1/4" or so with a VERY thin cutter, the brass will then 
"spring" open enough to get it started onto the spline, then by vigorous 
tapping with a small ball-pien hammer on the knob, the brass swages open 
just a bit and grips tightly. I tap on the knob so I don't expand the end of the 
brass by hammering on it. I have yet to mark a knob.

> or probably better, to crimp down
> on the 9/32.

I have had ZERO luck trying to do that...

>  Maybe some solder inside a 9/32 tubing would do the job

I've also tried THAT. I have photos to prove it. It makes for a loose fitting 
adapter.

Believe me, what I have detailed here on this subject was the only thing I 
came up with that worked, was reliable, easy to do, cheap, and results in 
ZERO backlash.

I am a very firm believer in the KISS principle.

Go ahead and try all that: I've already invented "the wheel"... I don't suppose 
it will hurt for someone else to do it too... ;-)

Ken W7EKB