Subject: Re: Brass bearings

From: [email-masked] (Gene Olson and Chris Wilson)
Date: Fri, 16 Aug 1996 22:49:12 -0400 (EDT)

>>Don't bother, just go buy some scrap brass angle at your local nonferris guy.
>>Mike Wolfe
>>
>>
>>At 09:29 AM 8/15/96 -0400, you wrote:
>>>I'm building a air hammer from the Abana plains, and i'm haveing
>>>trouble bending the brass for the side guides. I think it may be
>>>360 brass, can anyone help with this?
>>>
>>>Thanks,
>>>Travis
>>>
>>>
>
>Don't bother with the brass at all. Make it steel on steel and keep it
>juicy. It will probably outlast you.
>
>Bob

For many, many years the bearing of choice in DIACRO sheet metal shears was
a piece of oak with couple holes in it and a grease groove sliced into the
surface. I wasn't until the mid seventies that an acceptable (not necc.
better) but percieved better alternative was found. I don't think it would
be appropriate for the air hammer but for something like  a hydraulic ram
guide it would probably be ideal and cheap. Oak lattice or door stop at the
lumber yard.

Gene

 The Studios of Gene Olson and Chris Wilson  Metals, Stone, Mixed Media
  8600 NE O'DEAN AVE, ELK RIVER, MN 55330
  URL: http://www.concentric.net/~mettlewk/

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From: [email-masked]
Date: Sat, 17 Aug 1996 23:01:10 -0400

In many types of applications, the brass acts as a "sacrifice", so
theoretically, the harder to machine steel would not wear out and the brass
could be easily replaced.  Something else I have seen before is the tendency
of like materials to "gall" so similar grades of steel on steel might end up
with scored surfaces (especially if they get hot).  Toolmakers commonly use
different grades of tool steel if bearing contact is a requirement, e.g., S7
and H13, both hardened to 48 Rc or the same grade at different hardnesses
(maybe 52Rc and 46Rc).  If you are going to the trouble to build a hammer, I
would definitely install some sort of wear plate - I don't think you will
regret it.

Hollis

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From: [email-masked]
Date: Mon, 19 Aug 1996 23:05:45 -0400

I agree with your comments.  I work in the injection molding business and the
molds are often designed for over 1 million cycles, so most of the parts are
hardened steel.  They also have bronze leader bushings to help keep the mold
in alignment.  Quite often, there will be steel on steel for sliding
applications but bronze is also used except where it would fail prematurely.

I have a Beaudry hammer which has the ram riding against the frame casting on
the left and a bronze V-way on the right side.  The bronze is tapered so you
can adjust for wear.  The trouble is that it didn't wear evenly over the
years - so, I can adjust it until the ram sticks and the bottom of the guide
is still loose.  It needs a trip to the machine shop to be trued up.  To
summarize, I think your suggestion of steel for guides would work fine.  If
they wear, you can put shim stock under them.

hollis