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Comment by metalman | Hacker News Reader

this wont have much effect, as the origins of "shop class" was to introduce kids to power tools and modern equipment, who were living with all kinds of basic hand tools and work shops as the basic backgound of a world with a large percentage of hand made things. That background is gone, and with it the ability to tinker and practice, scrounge, and build stuff. Out in the country, you might still find plenty of that, but they dont need shop class, as there is any amount of tools, for free, or cheap, cheap ,cheap, building cars or anything from parts. bumper sticker says "built not bought" old timer told me that you used to have to watch your tools, and put them away, lest they go missing, now they are perfectly safe anywhere, presumably because tools have a negative conotation

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Using tools is a skill. Wood lathes, for instance, are extremely simple pieces of equipment - they hold a piece of wood and spin it. You can see and understand how they work in about 30 seconds. But even with years of practice you'll generally find yourself far less capable than a master lathe worker who seem to have this ability to take any piece of wood and chisel it into seemingly anything imaginable with a few strokes. Shop class is about teaching these skills, which are also highly transferrable.

And everything, at some fundamental level, is hand built. Think about the building you're in right now, or the road you're driving on. Or whatever else. Even for things where processes can have some high degree of automation when they break or need customization - it's back to a guy and his tools. For that matter on the factory line those machines need regular maintenance and repair once again from a guy and his tools.

And no, tool boxes are prime time theft targets in highly urban areas - probably more so than rural. Thieves don't usually steal things to use them (with such skills they wouldn't be thieves in the first place!), they steal them to sell them. And tools, especially high quality, are relatively expensive and one of the most resellable things in existence because good tools last practically forever - many feature lifetime warranties in any case.

Was going to say. I graduated high school 33 years ago. Was one of the last cohorts that had wood shop and metal shop. It was fun, but even back then the tools and presses we used hadn't been relevant to industry for awhile. If you want shop to be relevant to modern industry you would need to teach robotics, CAD/CAM, CNC, 3D printing, etc.

> If you want shop to be relevant to modern industry you would need to teach robotics, CAD/CAM, CNC, 3D printing, etc.

Uhh.. what? A CNC mill is, fundamentally, a mill. A CNC lathe is a lathe. You're not absolved from knowing how to use a manual lathe or a manual mill even if you use CNC machines all day long. Where do you develop an intuition for feeds, speeds, finishes, tolerances, etc if not by spending hours and hours doing it by hand?

A classic machinist apprentice task is to take a rough steel cube and make the sides flat and smooth using a hand file. That teaches you how steel behaves and can be worked. Life was slower a century ago.

High school students can learn CNC with smaller machine tools. There are little desktop CNC machines in the US$1000 range. You can cut aluminum, brass, and plastics, but not steel. They talk the same G-code as the big machines. You design jobs for them the same way you do for the big machines. At that scale you can usually avoid coolant, oily rags, oily chip disposal, and the general mess of a real machine shop.

Taking that lesson to its extreme you realize there's a rounding effect where seemingly no matter how carefully you hold the file, the edges of the face are cut down more than the center. To combat this you might discover you can use the end of the file (like the last tooth) as a scraper. You can use a gauge block and some blue ink to discover the high spots and repeatedly work them until it's flat. Congratulations! You've just discovered how to make a lathe bed.

I tried to learn machining on a CNC mill. it went ok, I guess. but I ruined a lot of tools, had to do a lot of polishing passes, and didn't really understand why my tolerances were so off. things like the flycutter mystified me, and using the boring head was deeply frustrating since it didn't have a tiny little servo. aligning the vice was something I dreaded, took me a good hour for some reason. 4 jaw chuck? maybe you use that if you need to drill off center or work on square stock.

couple of decades later I only use manual machines (with power feeds and DROs), and I'm really a lot faster and more consistent.

CNC is cool, and you can do some pretty amazing things e.g. with a 4 or 5 axis machine, but ultimately the value is in repeatably churning out the same part over and over again. The industrial utility is obvious, but there's not a lot of pedagogical utility and to a hobbyist or prototyper it's generally just not worth the overhead.

I learned CNC by hand writing G code. I think it was valuable.

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