[TenTec] Jupiter Solid Aluminum Main Tuning Dial

[Dr. Gerald N. Johnson]

I like the aluminum knob I made for the PTO on my Corsair II. My lathe 
is too light to do a good job knurling so I don't offer it for 
production. Perhaps if I had a sturdier lathe, or made a knob to take 
the rubber sleeve. I would rather go hire a machine shop to make a 
bucket of them though. I might own a sturdier lathe in a year or two.

Alternatives I see, McMaster-Carr offers aluminum and steel knobs 
without cranks in 2" diamter 1-1/8" standoff from the panel, not drilled 
for shaft or set screw 6077K14 for under $15 in my vintage catalog and 
in stainless steel 6077K42 for less than $25. These would be fairly 
weighty. Or they offer a 2" diameter knob (material not listed) with a 
finger tip spinner for a quarter inch shaft with set screw, 7354K13 for 
under $4.

Mouser offers from Alcoswitch, machined aluminum knobs 1-3/4" diameter 
for quarter inch shaft with set screw with finger spinner, natural 
finish for $24.24 black for $21.50 in my lat 2008 catalog that is handy 
to the computer. 506-KN1751AS1/4 or 506-KN1751BS1/4. Or from Eagle 
Plastics with dual set screws and a crank knob 1-3/4" diameter, 450-1755 
for $8.55.

73, Jerry, K0CQ

On 4/12/2010 1:36 PM, David Goncalves wrote:
> You have it right...compared to the forces applied to the encoder from
> the user (hanging your hand on the knob waiting for the other guy to
> stop sending CQ, cranking through the band using one finger, etc) the
> additional forces from the aluminum knob. I made a quick measurement
> here with something similar, and got numbers within 50-80% of the
> loading specifications. I wouldn't have a problem replacing the plastic
> with the metal one, as long as it looked nice enough.
> Not an experience I have enjoyed yet - all my TenTec stuff is either
> computer control or PTO. I'm saving up my pennies, though!
> David Goncalves
> W1EUJ
>
> On Mon, Apr 12, 2010 at 10:45 AM, Dr. Gerald N. Johnson
> <geraldj at weather.net <mailto:geraldj at weather.net>> wrote:
>
>     I'd think that the side thrust from running a finger just under the knob
>     could be greater...
>