Making machine parts vs paying top $ for factory built...

[MychesterCNC]

I wonder about this ALL the time, a lot of times on Ebay there are small lathe parts, such as cross slides and milling attatchments for small Levin style lathes and smaller, even watchmaker lathes... that go for MANY hundreds of dollars... and it's not always a collector or brand name thing, because often it's also no-name units that are not mint but simply functional that bring tons of money, and to me it seems crazy that people dont build thier own instead.

I'm wondering what are the reasons that people dont make copies of this stuff, even here in the USA in basement shops...? Is it that these parts use an expensive type of steel? Or is milling that time consuming? Maybe there's an obvious reason, but I cant see it, and I would love for someone to point it/them out... I'm absolutely new to machinging, but I've so far been shocked with how much you can do and how much you can learn to do with just a little research online (such as this forum) and a piece of equipment.

Just as an example, this little milling attachement is already up to $1,000 on Ebay, and the auction isnt even over yet. Thanks for your input guys!

[Cmailco]

Well, I can't possibly speak for every hobby shop guy or gal out there but my guess is that they don't have the capabilities to produce such items.

Looking at most of the mills geared towards the "hobbyist", there don't seem to be many capable of working with mild steels, never mind tool steels or tougher alloys needed for building long-lasting tool components.

[jalessi]

MychesterCNC,

It is possible that some of those parts look a lot like collectible European or old American brand components.

Some people get too caught up in the auction experience.


Jeff...

[RICHARD ZASTROW]

Or the pieces you are looking at are truly highly precise geometrically and very accurate dimensionally. Often they must be interchangeable and assembled with other such components. Plus quality material and finish grinding.

I just disassembled a Swiss made Gear Hobber. That little machine is made of very finely made components. Since it was made to produce watch/clock type workpieces, it was made equal to its mission.

Replacement parts are quite pricey I imagine.

Dick Z

[Cmailco]

Yeah, those gear hobbers are quite amazing!

There are always those things that make you wonder, "How in the hell did they do that" but the one that still sticks clearly in my mind is the old pre-WW2 Gleason bevel gear cutting machine an ex employer of mine had in their gear shop. Fully mechanical... designed before computers with a slide rule... and still running like a top after all those years. Our forefathers were some amazing designers and craftsman. I know many an engineer who'd have a tough time designing a similar machine WITH CAD...

... my apologies for the tangent.