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Jim Wilkins[_2_] Jim Wilkins[_2_] is offline
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Default Carriage lock screw - Any reason not to

"Bob La Londe" wrote in message
...
I've got a 1440 Chinese lathe from Precision Mathews. Its not the
cats meow, but its still better than any other lathe I have. Often
when taking facing cuts or parting cuts I like to lock the carriage.
The bolt for that is a recessed socket head screw. It works ok, but
it seems I am always looking around for the hex key when I want to
release it and move the tool away from the stock. Unless I am
holding it in my hand the whole time it always takes me a couple
seconds longer than I would like to locate where I set it down.

I've been thinking about about making a taller head replacement
bolt, drilling it for a small vise handle. I've got a bit of 4140QT
shaft on hand and a bit of 1/4" 1144 rod. Making it should be no
big deal. Any reason why I shouldn't. I'd keep it as low as
possible, and make the handle about half the difference in length
between a short arm and a long arm hex key that size.

Speaking of such I'd also like to lock the cross slide from time to
time. There isn't a lock on it, but it does have a tapered gibb
that's easily adjustable with a screw at each end. Usually I just
keep the gibb adjusted a little bit tighter than is perfectly
comfortable to spin the hand wheel, but on heavy roughing cuts it
can still back off on longer pieces of stock. I wind up standing
there with my hand on the hand wheel and my eye on the DRO the whole
time. Is that just the best way to do it?


I bought several 'vintage' box wrenches for square-headed bolts and
made replacements for missing lock and clamp screws on my 1965 South
Bend to fit them. There's been no problem with the square head
carriage lock.

When not trying to match a style and period I make as many fasteners
as possible on home made machinery fit the same pocketable gear
wrench, normally 9/16" for 3/8" bolt heads.

The SB has a Threading Stop which is a bar that locks into the
dovetail and limits in or outfeed, so the cross slide can be retracted
to quickly move the carriage and then run back against the stop for
the cut. It serves the same function you are looking for without
messing with the gib adjustment.
https://www.ebay.com/itm/South-Bend-...-/123733462898