Thursday, November 19, 2009

subcontracting and machine tools

Well, it seems I won't be able to use my lathe or my steady rest to machine the housing and liner for the micro-Marx after all. The work won't fit in my steady rest, and I can't do the work without using a steady rest.

I am in the process of modifying my steady rest so that it will take slightly larger diameter work, but there is only so far I can go before the functionality of the rest is affected. I think I can get about 1/4" larger diameter from it.

The mechanical design for the mico-Marx is approaching the point where I will need the exact final dimensions of certain parts. For example, the length of the liner - which is shorter than the length of 4" copper pipe which will form its housing - constrains the maximum length of the Marx generator, which must have room for N stages of capacitors, spark gaps, and connection straps.

I will talk later today to a friend who owns a small machine shop business, and who allows me to occasionally bribe him with good beer to use his better quality facilities. Perhaps one of his lathes can handle these things.

I've finally admitted to myself that buying the lathe I did was a mistake. Given the information that I and my adviser had at the time, it seemed like a decent deal, but since then, I've found out just how much easier it is to work with a quality machine tool.

my shop, lathe area

Even the Chinese lathes (which mine is) that are being sold now are 10X higher quality than the one I have, which appears to have been made in the 1970s.

There are companies (I've read that Grizzly Industrial is one) who have good working relationships with a factory in Taiwan, and that after receiving the machines in the states, they do a lot of finishing, tweaking, and adjusting in large regional plants. According to some, this results in a pretty good quality machine for much less money than you would pay for something made in the USA or Europe. They also add a premium over the apparently identical machines sold by Harbor Freight, Enco, MSC, and McMaster-Carr - their prices are about 5% - 10% higher for identical machines.

I think when I can afford it (which may be a very long time from now) I will buy a Grizzly lathe (complete with all the accessories mine was missing, dammit) and sell the one I have.

In the mean time, I will muddle along with the lathe I have, making occasional upgrades where possible (as I have already begun doing) so that it will fetch a reasonable price when I sell it.

Besides, I really need a band saw and a 3-in-1 metalworking machine much more than I need a higher quality lathe, and I can get by with the lathe I have for quite a few years.

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