Tool Talk

What's-It Forum => What's-It Forum => Topic started by: stanley62 on July 19, 2011, 10:31:56 AM

Title: What do I measure
Post by: stanley62 on July 19, 2011, 10:31:56 AM

I should know what this is, but I don't.  My guess is to measure RPM.  Anyone know for sure???

Title: Re: What do I measure
Post by: jimwrench on July 19, 2011, 10:34:11 AM

 Rpm is the right answer.

Title: Re: What do I measure
Post by: rusty on July 19, 2011, 04:31:32 PM

Yup, rpm. It is really just a counter tho, it counts how many times a shaft goes around. To measure speed, you also need a watch to time how long it took to go around that many times...

Title: Re: What do I measure
Post by: lzenglish on July 19, 2011, 05:04:24 PM

I have 3 of them, but none have the needed rubber ends to allow them touch the shaft with. What brand is yours?

Wayne

Title: Re: What do I measure
Post by: anglesmith on July 19, 2011, 05:38:26 PM

Most of them have a friction "cluch" , the early starrets didn't (pre 1905?) You line up the "dimples" and hold down on the top one. apply to speeding shaft, when ready release pressure and time for one minute. Whala! you should have your shaft speed?
Graeme

Title: Re: What do I measure
Post by: rusty on July 19, 2011, 06:38:56 PM

>the needed rubber ends

Pencil eraser : )

Title: Re: What do I measure
Post by: stanley62 on July 20, 2011, 10:43:52 AM

This one is a Starrett.  It does look like it has a pencil eraser retrofit, at least the metal crimp that holds the eraser.  The end that touches the shaft is black rubber.
 Jim