The Home Machinist!

Gage blocks and sine bars are really for reference set up, layout and measurement, not for use, machining on the mill. If you need something set in a vise and milled at an angle, use a angle block. If you can't achieve the correct angle with an off the shelf angle block, it's time for accurate layout and the use of a planer gage or height gage to see that it's clamped parallel to the table or the access of travel. Just because you can buy a cheap sine bar and so called "shop blocx", doesn't make it the proper use (abuse) for those tools.

To Inspector - Now you know what a Cadillac Gage looks like. Sure it was introduced in the 70's but I have not seen anything that can replace gage blocks, Cadilac gage, surface plate and a good indicator when it comes to tool and die work. CMM's may be state of the art but are of no or only limited use for a tool and die maker. Juergen

While I'm not privy to the introduction date, Cadillac Pla Chek has been around much longer. I started at Sperry as a trainee in '57, and left in '65. They were in use (there) then, so they date back earlier than the 70's.

Harold

_________________
Wise people talk because they have something to say. Fools talk because they have to say something.

Here's the 12" Starrett No.258 Digi-Chek sitting atop the No.258R 10" riser, flanked on the left by a "left handed" Brown & Sharpe 26" height gauge, and on the right by a "right handed" Mitutoyo 12" height gauge. Total expenditure for all 3 pieces: $85. Toolroom grade 24" x36" x 4" granite surface plate, $275. Being able to measure or layout almost anything under 26".....priceless!

We are not a tool and die shop but we do have a Mitutoyo height master (with 6' and 12" risers too) that looks similar to your Cadillac gauge (heavier though) that we use for calibration of height gauges, inside micrometers etc.. We also have a 20 year old Mitutoyo CMM that is on her last legs and is going to be replaced with an LK evolution (that will make 2), LK Ultima, a Faro Larser Tracker and an 8' Faro Arm. I can see how a standard CMM might not be of much use to you, but an arm could be.

I am sure that names in common usage for tools vary in different regions of the continent and a "Cadillac gauge" is one.

I just got a couple height gauges from work that were going to be tossed, both 24 inch Mitutoyos. One is the big brother to the one Pixman showed and the second is a twin beam electronic that probably was knocked over by an operator/machinist that bumped the top and misaligned the beams. Loosening the screws at the top and retightening them should make it usable for my home shop. I already have an electronic indicator and display that was never used and was tossed. When the old CMM is replaced I am going after the granite beam across the top. It will work nicely as a surface plate. A set of gauge blocks will satisfy all my measurement needs for most anything I can think of making at home. Mind you if the Faro Arm is going to be tossed.....

Pete

A client had a Faro arm, and output some data from it for us...... I was not impressed.....

I expected fairly decent data, and instead we got an almost unusable "data cloud"..... with no definite points. The variance in positions measured was several thou, on measurements we wanted pretty tight. We ended up not getting squat from it, and went and measured the old-school way with inside mic, etc. Our way worked.

Did they simply not know what they were doing? or does one take the data cloud and boil it down?

Our measuring is usually done to a cad model or to drawings. If there is an out of tolerance feature we make sure it wasn't our error, usually repeating the measurement. We don't do reverse engineering so can't say if it is a problem with the data or if it was with the operators technique in collecting it. Not in full contact with the part or probe out of calibration for instance. The Arm is like any measuring tool in that you must be sure that it is used correctly and if encountering something unexpected you need to verify what has happened, sometimes with another tool and sometimes confirming with a gauge block.

Pete

The articulated Faro arm is great for many data points (with a mechanical probe) or tons of data points (with a scanner). But, as you've found the arm mechanism with its many degrees of freedom isn't particularly accurate compared to, say, a CMM or gage blocks. Want to measure a sculpted surface or see if lots of points are in the ballpark? A Faro arm is a good choice. Want to measure from one well defined feature to the next? Something like a digital height gage is likely better.

Some folks do initial surveys with something like a scanner and then measure critical to function tolerances and anything that looks out by other means.

It also does take some skill to properly use the scanners as well as good software to turn the point cloud (sometimes millions of points) into something usable.