Need Extra Large Calipers?

[leehljp]

https://www.homemadetools.net/forum/122-inch-caliper-photos-97570?utm_source=newsletter&utm_medium=email&utm_campaign=07-05-23&utm_content=07-05-23-225455&fi=225455#post225455

[Jim Frye]

Interesting, but the length of the arms seems to limit its usefulness to measuring rectangular objects. I've used my shop made trammel points to measure inline distances. Unfortunately, mine only goes to 8'. Need to get a longer bar.

[cwsmith]

Interesting, but it does seem a bit impracticable. I worked more than thirty years in, what once was. the largest compressor factory in the world and I never saw a manual caliper even close to that size.

Nice craftsmanship though.

CWS

[LCHIEN]

Images from Hank's original post embedded for posterity
I'm impressed by the protective case.

[Jim Frye]

I wonder if it was custom made for a company for production use on a specific type or class of product?

[leehljp]

I wonder if it was custom made for a company for production use on a specific type or class of product?

Jim, that was my thought. But it did start me to thinking about how measurements were done on huge industrial parts. I have never given that a thought. I have participated in a house layout and even staked and measured the layout for a large cotton gin (roughly 80 ft by 150 ft) but those are done by large tape measures.

[capncarl]

I do remember some really large machinists tools in our tool crib that were used on a 16’ engine lathe. (That’s a big lathe for a maintenance shop to have). To be used successfully it would would take 3 people to hold it.

[cwsmith]

I'll have to ask one of my old friends to see if he knows. I worked at Ingersoll-Rand's Painted Post facility, which back in the 80's and before was the largest compressor plant in the world. There we made compressors from small enough to hold in your arms (special government project) to big enough that they had to be loaded a flat car and shipped in pieces by rail. I'll have to look in my photo library for some examples.

We had several large gauge labs located around the plant, but I don't recall seeing any caliper nearing that size. (After highschool and a decade before I went to work at the Rand, I had a short stent as an electro-mechanical inspector at a local industry here in Binghamton. I still have the vernier caliper I bought for that job.) Ingersoll-Rand hired me because I was a technical illustrator and writer and had conrtracted work to write and illustrate their instruction and parts manuals. I spent almost eight years doing that before being hired direct and during that time I visited there, on average, every two weeks and was hired in 1973 and left in 2003.

Unless I had a project that tied me to my desk, I was usually on the factory floor several times a week. I was under the impression that length measurements were done on the machines, which were constantly calibrated, Whatever, I don't think there was any operation that would have relied on calipers of any great length.

CWS

[Jim Frye]

My Son works for a Tier1 automotive supplier and does measurements on truck axels and assemblies. They currently use CMM technology, but he's been there since 1989. Next time he's over, I 'll ask him if he knows how they measured these before CMM.