[Amps] Proof of idiocy

[Will Matney]

See, that's a shame. If I recall, those vernier dials are 8 revolutions per turn of 360 deg., and dial counters are set up for 10 turns used on ten turn pots. The old National verniers, I cant recall what ratio they were as they had the knob type, and the one with the large blank scale and pointer. It looks to me though like you'd be hard pressed to find anything that would come out right ratio wise. One might try to cheat it with belts, sprockets or gears, but that's a big mess to get into. To convert 23 to 20 turns, you'd need a gear ratio of 1.15:1 or for 10 turns into 23, 2.3:1. That 2.3 or 1.15 being an odd number, is impossible to get in off the shelf components. In gears and sprockets you'd need say an 12 tooth and a 13.8 tooth (for 1.15) which is an impossible thing. The only way left would be use pulleys and they can slip bigtime. Timing belts wont work as they have teeth like a gear. To me, what they done is about the absolute dumbest thing any engineer could have thought of. At least they could have used a ratio without an odd number, say 1/4"-25. Then using a 12 tooth gear or sprocket which is about the smallest, you'd need a 15 tooth to match it. 25 / 20 = 1.25. 12 x 1.25 = 15. Then you would get 20 turns to the inch. I forget what the maximum movement is for the piston in those for a dial to work for full count. That would be the only way to do it is use belts and machine custom pulleys.

Best,

Will


*********** REPLY SEPARATOR  ***********

On 3/13/06 at 2:40 PM HAROLD B MANDEL wrote:

>Jerry at Economy says Jennings did this just to prevent easy fixes
>that might void any warranty and to make the equipment
>expensive to repair.
>
>Hal
>On Mon, 13 Mar 2006 13:38:15 -0500 "Will Matney" <craxd1 at verizon.net>
>writes:
>> Custom stuff is highly expensive. Thing is, 
>> Jennings had to pay extra too just to use an odd-ball size.
>>