Lathe Tool Height Gage

[metric_taper]

Wow, a 24" Mitutoyo caliper! That must have been a pricey bit of kit to buy initially. Since most hobbyists couldn't afford it or have the space to store it for that matter, I'm glad I mentioned the height gauge approach. Future readers may not think of it so a written reminder is in order.

The height gauge can be used to check conventional as well as cylinder squares for orthogonality. Angle plates too. With its accurate measurement of height, one can mathematically verify shallow angles as well.

It does often require some sort of protruding foot on the base of the gauge to space it a fixed distance from the object to be checked but that's a lot less work than making a purpose-built device.

It is a monstrous size item to store, very heavy. It came with it's original Styrofoam packaging, that used to have a cardboard sleeve, thus making it larger to store, but it acts as a dust shield. It's buried on a shelf over the lathe, under bore gauges and Clover brand lapping compound cans. Clearly not a very often used item in the shop. I have a 500mm digital caliper (Harbor Freight) that is typically what I use for large measurements, as I can hold it in one hand.

It's a mindset change to use the height gage. Thinking about it, it is a caliper that measures from an inside edge (surface plate, angle plate; reference datum) to an outside edge.

I purchased the granite square to calibrate a test indicator setup for measuring orthogonality.

My company (former Collins Radio and where I got the caliper from) had a world class manufacturing shop. They produced everything in house during the moon mission. They have sold off most of the machinery, long before I retired, to where engr. prototypes had long lead times. It's all outsourced CNC shops now. I never could get my hands on a large lathe (16X60) when they were being auctioned off. There were rows of them. They all went to a Chicago machinery dealer. The machines were in pristine condition from only running aluminum their whole life. That was in 96, and $15K was out of my budget. I recall LeBlonde and other mainstay manufacturing names. they all had DROs. They were mid 50s to 60s age.

[mklotz]

It's a mindset change to use the height gage. Thinking about it, it is a caliper that measures from an inside edge (surface plate, angle plate; reference datum) to an outside edge.

Indeed. And mindset changes are what "thinking outside the box" is all about.

Little mental exercises such as thinking of a linkage as a device to hold two holes a fixed distance apart can really help to develop the sort of mental flexibility needed to originate new and improved tools.