What's a speed indicator used for?

[Ebel440]

I got an old starrett improved speed indicator number 106 I think. It has no model number but looking in an old catalog that's what it looks like. I have never seen one before and no one at my work knows what it is. What's it used for? Is it just to check rpm on a lathe?

 

[Alan Douglas]

Perhaps it's from the days of overhead line shafts and belts, where there would be no way of knowing the speed except to measure it.

 

[dgehricke]

The 104 and the 107 speed indicators are model numbers from Starrett tools. They were used to measure the speed of machine spindles ,shafts, wheels and other rotating applications. the 104 was good for RPMs up to 2000 rpm and the 107 was good for 5000rpms.
hope this helps.
regards
dgehricke

 

[Ebel440]

I found the model 106 improved speed indicator in a 1915 catalog and the one I found seems to resemble the 106 the most. It has a patent on the tool from 1897. I saw a 104 for sale the same day and it was a little different.

 

[Bill Gruby]

It is an early form of hand held tachometer. It measures speed in RPM's.

"Billy G"

 

[Vladymere]

Knowing the spindle RPM and the diameter of your stock you can then determine the stocks surface feet per minute which is used to determine the depth of cut.



Vlad

 

[pebbleworm]

I have one and it is fun to use. And definitely the cheapest speed indicator you can find, if not that precise. I like it.

 

[kd4gij]

I have one. What are thay used for?:thinking: Well thay are fun to play with. Everybody should have one.

 

[Ebel440]

I played with it a little but didn't try it on my lathe yet. I'm guessing you need to time it for a minute and that's your rpm?

 

[kd4gij]

Yes it is real hi tec. You just need a watch to use it. ATime it for 1 min or a half min to get your RPM's And then turn it back to "0" by hand.:roflmao: