What Is It??????

[ovrszd]

Lost my neighbor to Cancer two years ago. Was helping his widow clean out his Machine Shed and found this. Thought it a very interesting item. First one I've ever saw. Thought it might be interesting and entertaining to discuss it and confirm what it is.

I'll start by offering these pics.

 

[Reb954]

Tachometer

 

[ovrszd]

Tachometer

Okay, so how is it used and driven? What is it measuring?

 

[Reb954]

It measurers rpm. Press the rubber tip against the center of a spinning shaft so it can show how fast the shaft is spinning. Im on my phone so I can稚 see it very good but thats what it looks like to me.

 

[K5lwq]

I believe it came with some attachments. Did you find anything else with it? It will work like that for one application.

 

[coolreinfarm]

It’s a AC Delco rpm test gauge for auto mechanics

 

[kirkawilson]

Used to use a similar device to tach fan speeds. The end of the fan shafts had a small centered indention that the rubber point of the tachometer rested in. Now they use digital tachometers with lasers. There's even a phone app for tach work. My, how things change!

 

[ovrszd]

All very good responses. Perks interest doesn't it.

For some reason I have it in my head the AC is representing Allis Chalmers? Maybe used on old AC tractors prior to tachometers to set governor speed???

It's spring loaded and centers back to zero. If I twist it quickly I can make the indicator bounce back and forth. Appears to be maxxed out at 4,000 rpm. I'll try it on a drill and check that.

 

[ovrszd]

Here's a couple pics to give you size relevance.

 

[geblackwell]

WE used it in the "old days" to check pto rpm and then mark the throttle setting with paint or pencil to know where the proper setting should be. Back be fore tachometers were on a tractor.
I don't think it had anything to do with Allis Chalmers.