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Jim Wilkins[_2_] Jim Wilkins[_2_] is offline
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Default hydraulic valve - opens on set pressure, closes no pressure

"Richard Smith" wrote in message ...

It's known that high pressure oil seals work if done right, so I'd bin
that with the minor issues that can be solved later by throwing enough
money at them, ...

I'd wish - but lots of slightly different sizes - and you are going to
be able to find a seal for each diameter?

Maybe one could get a list of stock seal diameters, and find that yes,
the pressure and therefore test force you'd end up with would be just
fine - sits just where it needs to be to plot the S-N curve for
fatigue performance. Throwing aside minor vanities like getting the
stress which should mean the mean-average sample break is at exactly
250k cycles, etc.

Rich S


This is a US company selling inch-sized products, but it shows what to look

When I needed new seals for leaky used Porta-Power-type cylinders I went to
a pump rebuilder who found seals that were close enough in the catalog of a
supplier I don't remember. My cheaply made Chinese cylinders were somewhat
non-standard so I had to machine the pistons a bit. I've been told they are
typical of import hydraulics that can't be repaired (without remachining).

The cylinders were $10 and $15 each and the right very compact size for my
bucket loader design so they were worth the trouble.

I suspect that seals are available for all cataloged sizes of chromed and
polished hydraulic rod stock, a part I can't make. Then you only need to
make (or buy) the packing gland that adapts the seal to the cylinder end
cap, and a crosshead to keep the piston running straight, both fairly easy
on a thread-cutting lathe. They could be combined into one part. Instead of
machining a hex you can drill two holes for a pin spanner wrench to tighten

Last night the air cleaner cover latch on the Chinese engine of my sawmill
broke off so I made a stainless sheet metal replacement. I've stopped
hunting for spare parts that are difficult or impossible to find and no
better than the originals.

A -good- lathe is an investment that may appreciate. Collectors restore the
better examples of mine, like classic cars.
"Too funny! You bought a great lathe, and with all of those vintage Rovers
you better learn to make parts quick! Thanks for the note!"