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Doug Ayen

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Lathe work [Aug. 21st, 2007|08:39 pm]
Doug Ayen
Well, got something done today in the workshop, albeit minimal.

I'd cut down a dead Hickory tree earlier, and while weilding the chainsaw cut out a couple of nice pieces of crotch. While I haven't written much about it, I used to do a fair amount of lathe work, mostly making sawdust and toothpicks, but occasionally making something interesting.

So, I grabbed one of the crotch pieces and went to the bandsaw to trim it up. Since it had a fine-cut blade in it, and I wanted to rough cut the excess wood off for a better balance and to reduce the amount of work required, I changed to a larger blade. Or, rather, I tried to.

Now, one of the blade guides had broken earlier, and I'd fixd it by replacing the pot-metal (why are zinc alloys called pot metal, I'd think zinc would make a horrible pot) set screw holder for the upper blade guide with a bit of steel. So I shouldn't have been surprised and depressed when the pot-metal bracket that held the (cast iron) blade tensioning frob turns out to have sheared. I suppose I could fix it, but I'm thinking that there's enough broken bits on it (the aforementioned blade guide, one of the lower guides, and now the tensioning adjustment) that it's time to admit defeat and buy a new one.

Fortunately, I have other saws, and a couple of cuts later I had a semi-balanced and trimmed piee of stock. Into the lathe. Slow speed, a roughing gouge, and patience until the piece is rounded and smoothed. Then on with the power, higher speed, a bit more force on the gouge while I start to rough in the shape . . . and the tool rest breaks. To judge by the coarse grain, the lack of deformation, the dark grey color, and the sand inclusions, it must have been made from the lowest grade pig iron. When it snapped, at the tensioning nut that held it onto the bed, it of course got sucked into the work, jammed between the wood and the bed, and ripped the ~15 lb log off the spurs and into my stomach hard enough to knock me back several feet. Fortunately, I'm well padded and was wearing a leather apron, so I just have a bruise to remind me of a close call.

Please note that this piece broke, as near as I can tell, purely from the force I was exerting from using it as a fulcrum while turning wood. I wasn't leaning into it, so it couldn't have been a whole lot of force.

Again, do I replace the obviously too-cheap tool? A master craftsman doesn't blame his tools, but this is getting very frustrating. While I didn't buy the highest-end stuff when I bought the lathe and bandsaw, tey weren't the cheapest either (mid-list Grizzly both of them). I could fix the lathe pretty easily, since all I really need to do is make a new flat piece with a 3/8" slot in it for the bed attachment and a hole in one end for the rest -- but what is going to break on it next?

What I'd realy like to do is go find some good used, but not too heavily used, industrial equipment. Something designed to be *used*, not just look pretty. Sadly, those few bits I've found have either been so heavily used as to be unusable, or priced far out of my hobbyist budget.

--doug
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Comments:
[User Picture]From: ramblingheritic
2007-08-22 02:01 am (UTC)

tried craigslist?

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[User Picture]From: gfish
2007-08-22 02:29 am (UTC)
I've always assumed 'pot metal' refered to its source, not its use. As in, it's whatever random low-temp alloy was in the pot on the stove when you did the casting.
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[User Picture]From: cz_unit
2007-08-22 02:56 am (UTC)
Hm. You might want to look for >30 year old tools. I have some drills from my grandfather that basically will drill post holes to the center of the earth if you leave the switch on.

Same with the hand tools. My guess is your stuff is made from China steel. These are the same people who made "steel" in the 50's by cooking down tableware in sand pots.

It hasn't gotten much better. But if you go back 30-40 years you should find tools with burned out brushes (which of course can be replaced) that are made out of real metal.

Sorry you got whacked; come to Burgerfest.

CZ
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[User Picture]From: cz_unit
2007-08-22 02:58 am (UTC)
PS: While a master craftsman doesn't blame his tools per se, it's a fact that crappy tools are not worth the time. I find this with socket wrenches; the Snap-on double-square ones will last forever; the cheap-o ones will snap and tear your arm.

CZ
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From: celtic_anya
2007-08-22 01:16 pm (UTC)
I knew I should have gotten that book about the medicinal uses of leeches. I'm kidding. I'm glad you're not hurt too badly.
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[User Picture]From: ceo
2007-08-22 02:07 pm (UTC)
First thing I'd do is talk to Grizzly. Their customer service is reputed to be pretty decent. Not least, they should know about failures like that for QA reasons.
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