All draughtsmen/design engineers should spend some time in a machine shop. Not to become expert machinist, but to become familiar with what machines can do. The modern practice of having drawings done by one company to be made by another also takes the foreman out of the loop. The first DO I worked in had a doorway into the machine shop. When a fierce looking guy in a white coat appeared with a drawing in his hand, a hush would descend, wondering who was going to get blasted with ‘how the **** am I supposed to make that’.
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There’s always the possibility that the foreman is the problem! Quite often a senior man, experienced, but out-of-date. This is the guy who can’t cope with metric and sees no value in computers or anything else requiring an old-dog to learn new tricks. Whereas the Drawing Office blights the company with poor designs, a bad foreman brings his employer down by insisting everything be made using only the methods he understands. May not entirely be his fault because the dreaded Account-Ant may have spent his entire career discouraging investment in new technology because it costs money! And even if the accountant was agreeable, absentee owners often blew the profits on Horse Racing, the Stock Exchange, and their playboy lifestyles!
Watched a Youtube video a while ago. It was about a Canadian factory making shells for WW1 circa 1917. I was struck by the almost total absence of general-purpose lathes and milling machines. Mills and lathes were present in considerable numbers, but they had all been modified to perform one particular specialised function. The workers were mostly semi-skilled, or unskilled. For example, a lathe with a hydraulic chuck had a powered cross-slide purpose made to cut a zig-zag groove around the shell to stop the copper driving band slipping when forced into the gun’s rifling during firing. Presumably the zig-zag cut was driven by cams under the cover. The driving band, apparently impossible to fit, was squeezed into place with a large hydraulic-press, details not shown, possibly a trade-secret.
Another striking machine was a multi-head drill purpose made to drill 5 accurately placed holes simultaneously. This machine would be utterly useless without the necessary jig, itself held in a designer clamp, and only then if a new user needed exactly the same pattern of 5 holes. I guess a Production Engineer had this drill designed to his specification by the Drawing Office, and then the foreman was told how to manage it on the shop-floor. A small operation might combine the Foreman and Production Engineer roles, but this is quite dangerous because the jobs require different skills, and both are time-consuming.
By the by, I don’t know how to model a zig-zag slot running around a cylinder in 3DCAD! Sketching the zig-zag is easy but I don’t think FreeCAD will let me wrap a plane sketch around a curved face. I think SolidEdge can do it, not tried yet.
Here’s the shell, the zig-zag slot is cut around the inside of the groove highlighted in green:
Nothing difficult about making the shell body on my manual lathe apart from the zig-zag, but I think a CNC machine would cut one without much bother if only I could draw it!
Dave