What is this used this for?

[Twincam]

Any ideas what this would be used for?
it counts revolutions, one revolution of the shaft is one division on the scale.

 

[SmithDoor]

Any ideas what this would be used for?
it counts revolutions, one revolution of the shaft is one division on the scale.View attachment 153304View attachment 153305View attachment 153306

Old fashion way of finding RPM.

Dave

 

[indian]

As its a revolution counter it could be used for coil winding or anything that needs a specific rev count.

 

[SmithDoor]

As its a revolution counter it could be used for coil winding or anything that needs a specific rev count.

You watch second hand and time . Then read the dial for RPM
It around for long time and see in some books how use it.
Still can be use today.
I think still sold in the 1970's

You probably find a app that would easer to use today.


Dave

 

[timo_gross]

Amazing how things change. I remember they printed colourful pictures on big paper sheets. Couples would take those pictures with them when their mood was too good, they would just look at the picture shout at each other and become "normal grumpy" again.

 

[Jonathan Coates]

I remember those map measuring things from school, if fact I may still have one somewhere that I picked up from a used equipment store. Anyone else remember those weird pantograph things that measured areas of things by some analogue magic?

 

[JimBrandon]

I found a nice little article on these.
https://americanhistory.si.edu/collections/nmah_690549

 

[trlvn]

Keith Rucker made a video demonstrating how to use either a Starrett or Brown & Sharpe speed indicator:



(Maybe skip the first 3 minutes of intro.)

I believe there is supposed to be a conical rubber tip on the end of the stem of the indicator to make it easier to engage with the rotating shaft.

AIUI, these also came with another flat, rubber disk that could slide onto the end of the stem. This disk had a known diameter (1 inch?) so it could be used to measure surface feet per minute. For example, check the SFPM of the bandsaw blade by holding the disk against the moving blade for a certain amount of time.

Craig

 

[L98fiero]

I remember those map measuring things from school, if fact I may still have one somewhere that I picked up from a used equipment store. Anyone else remember those weird pantograph things that measured areas of things by some analogue magic?

A polar planimeter, I used one for a few months to measure road building cross sections during winter when the ground was frozen too hard to survey.

 

[rickhann]

A polar planimeter, I used one for a few months to measure road building cross sections during winter when the ground was frozen too hard to survey.

A polar planimeter is a different animal. A planimeter measures area. The map measuring device shown measures distance. As for the RPM counter, I vividly remember my father using the exact same type of RPM counter to set the optimum speed to run a threshing machine (some people called them grain separators). If you ran them too slow, they would not separate the oats from the straw and too fast would waste grain. This was in the early 50's before modern combines took over. Good times to grow up on a farm. Rick

 

[L98fiero]

A polar planimeter is a different animal. A planimeter measures area. The map measuring device shown measures distance. As for the RPM counter, I vividly remember my father using the exact same type of RPM counter to set the optimum speed to run a threshing machine (some people called them grain separators). If you ran them too slow, they would not separate the oats from the straw and too fast would waste grain. This was in the early 50's before modern combines took over. Good times to grow up on a farm. Rick

He did say, 'weird pantograph things that measured areas'.

 

[Larry G.]

A planimeter was used as the source of data for my freshman statistics course. Each student was given instructions on how to build a minimal one out of a wire coat hanger.
1 Take a convenient length (8") and bend two equal length legs (1") parallel to each other
2 Beat one of the ends to a knife edge parallel to the main section
3 Make a rounded point on the other end
4 Draw an arbitrary closed figure on graph paper and count the enclosed squares
5 Draw an arbitrary line through the figure
6 Place the rounded point on the intersection of the line and the perimeter of the figure
7 Place the knife edge on the arbitrary line
8 Trace the figure with the rounded point, being careful not to bump the other leg or the beam
9 When arriving at the starting point again, measure the perpendicular distance from the arbitrary line to the knife edge
10 Multiply the length of the beam by the perpendicular distance. The result is the area of the arbitrary figure.

The difference between the counted squares an the planimeter result became the topic of discussion for experimental error, process variability, instrument calibration, etc.

 

[NelsonTaylor]

A planimeter was used as the source of data for my freshman statistics course. Each student was given instructions on how to build a minimal one out of a wire coat hanger.
1 Take a convenient length (8") and bend two equal length legs (1") parallel to each other
2 Beat one of the ends to a knife edge parallel to the main section
3 Make a rounded point on the other end
4 Draw an arbitrary closed figure on graph paper and count the enclosed squares
5 Draw an arbitrary line through the figure
6 Place the rounded point on the intersection of the line and the perimeter of the figure
7 Place the knife edge on the arbitrary line
8 Trace the figure with the rounded point, being careful not to bump the other leg or the beam
9 When arriving at the starting point again, measure the perpendicular distance from the arbitrary line to the knife edge
10 Multiply the length of the beam by the perpendicular distance. The result is the area of the arbitrary figure.

The difference between the counted squares an the planimeter result became the topic of discussion for experimental error, process variability, instrument calibration, etc.

Thank you for explaining. I appreciate you for giving us your time.

 

[metalmangler]

Amazing how things change. I remember they printed colourful pictures on big paper sheets. Couples would take those pictures with them when their mood was too good, they would just look at the picture shout at each other and become "normal grumpy" again. View attachment 153316

I have one of those in my desk, which I use regularly on UK OS maps to see how far we walked the dog - much quicker than measuring it out on Google Earth.

 

[DKGrimm]

Nostalgia strikes again. I put a lot of miles on a planimeter measuring crop acreages an aerial photos for the Wells County Agriculture Stabilization Committee during summers when I was in high school. We had a quality control process where we essentially had to measure each field three times and fill in a computation form to validate the results.

 

[SmithDoor]

It great in day.
Today I have app on phone that does better job.

I just sold some drafting equipment that top of line in its day. That did not use since 1996 and sad day for me for to see go.

It had day

Dave

 

[Nikhil Bhale]

We still use planimeter all the time. To calculate area under the indicator diagram for measuring power of ships main engines.
Now electronic versions of power measurement are common but old planimeter is still found onboard.

 

[ShopShoe]

Partially Off-Topic Question for DKGrimm:

Perhaps you can answer a question about a device that was auctioned along with some surveying equipment several years ago.

It was manufacturer-tagged as a goniometer, which I can find described and defined as an elaborate protractor-type device for use with maps and drawings, but it was a large piece of precision engineering in a fancy wooden case that had lots of spirit levels and two telescopes and came with a tripod. How would that device be used in comparison to a theolodite?

--ShopShoe

 

[L98fiero]

Partially Off-Topic Question for DKGrimm:

Perhaps you can answer a question about a device that was auctioned along with some surveying equipment several years ago.

It was manufacturer-tagged as a goniometer, which I can find described and defined as an elaborate protractor-type device for use with maps and drawings, but it was a large piece of precision engineering in a fancy wooden case that had lots of spirit levels and two telescopes and came with a tripod. How would that device be used in comparison to a theolodite?

--ShopShoe

Goniometers are basically specialized transits for finding/producing precise angles.

 

[DKGrimm]

Partially Off-Topic Question for DKGrimm:

Perhaps you can answer a question about a device that was auctioned along with some surveying equipment several years ago.

It was manufacturer-tagged as a goniometer, which I can find described and defined as an elaborate protractor-type device for use with maps and drawings, but it was a large piece of precision engineering in a fancy wooden case that had lots of spirit levels and two telescopes and came with a tripod. How would that device be used in comparison to a theolodite?

--ShopShoe

Your question takes me way outside my field. I'm sure others can give a better answer. My read on what I googled on the subject is that a theodolite is an optical goniometer that can measure angles between visible objects in both the horizontal plane and can also measure elevation angles. A transit is a goniometer that can measure angles between visible objects in a horizontal plane only. ( . . . I think.)

DKG