[ARC5] Tachometer Cables

[Mike Hanz]

On 3/26/2013 7:06 PM, Robert Eleazer wrote:
> The catalog says standard aircraft tach cables have ends that are 7/8-18 on one end and 5/8-18 on the other. The engine end is the one that is 7/8.  That sounds a lot larger than for an ARC-5 coupling nuts.

Yes, they definitely are larger.  The command set coupling nuts have a 
thread of 1/2"-27.  But I have to admit that I'm a little fuzzy on the 
point you are trying to make.  The coupling nut sizes are somewhat 
unrelated to the sheath size, since they are matched with ferrules of 
the appropriate size.  One could easily match a 1/4" OD drive cable with 
a 7/8"-18 coupling nut if the torque requirement was small enough.

> The old one that I took out of the airplane is hiding in my hangar somewhere, but one I took out of my Toyota some years ago seems to have the exact same size couplings as given in the aircraft catalog. Ah, the wonders of standardization!

Yup.  Nice how that works out! :-)

> And the old Toyota cable outer body is 0.4 in in diameter, which would make it somewhat smaller than the ARC-5 cables.  It is a rubber-type material, rather than metal.

Wait.....what?  The OD of the command set cable sheath is .335"...

     73,
  - Mike