Volume 8, No 10 - October 2003

Statement of Purpose

Regular Meeting

Collier Library, Houston Texas, 1:00 p.m., September 13, 2003.

The Sept. meeting featured the various kinds of lathe radius attachments used by club members. For the October meeting we will be having a FLY CUTTER ROUND-UP. So, bring them to the meeting, preferably with pictures of their use.

Member News

You know, the older we get the more we know, and understand the vile work of the dark specter. John's good work will live on, in his children, and his dreams. Each time we meet, we celebrate ideas and the love of the craft that John knew so well.  What John helped create is a living thing, and the unmeasured success of what we now enjoy is tribute to John's vision and dedication. As a former President of the club, I interacted with John on many occasions, and can surely say that John had a passion for the club and it's success.  We will miss him, but once a month, on the second Saturday, we will talk the talk he loved to hear, recount the experiences he too lived, and relish the gift he left us. - Vance Burns

Business Meeting

Minutes are sent via email or regular mail to club members.

Presentation

Show and Tell

Metal Casting SIG

Ed Gladkowski brought the silicon bronze casting, drag plate and core pattern for a pulley for a model steam engine he is building.

Editor Note: Oops!  This picture was left out of the September newsletter.
 Computer Numerical Control SIG

The CNC SIG looked at Dennis Cranston's Sherline CNC Machining Center. The unit is based on a CNC ready Sherline and 187 oz-in steppers and a Xylotex driver. It used a Mini-ITX PC Mother board running XP Pro. The control program is currently MACH1. - Dennis Cranston
Novice Sig

The Novice Sig worked on hole drilling. They brought a desktop drill press and practiced drilling holes in the metal plates that they scribed and center punched during the Sept. meeting. Some of the drill types that they discussed were: Silver & Demming (reduced shank), Center Drills, Counter Sinks, Spur Point (sheet metal drills).

Featured Articles

Remember to bring your FLY CUTTERs to the next meeting's tool roundup!

Radius Grinding Fixture
J. R. Williams - HMSC member

The project was to machine a quantity of special hinge bolts, for a WWI replica airplane, with a uniform 1/4 inch radius on the ends of the bolts.   The first idea was to hand grind the radius to a scribed line, but I soon gave up on that idea and went for the fixture in the photo.  I used a base of 3/4 inch aluminum bar stock and drilled a hole thru and reamed a little over half way for a 3/16 diameter dowel pin that was pressed in place.  To grind the radius, I used my 1 inch wide belt sander.  The part on the fixture was pressed up against the belt and the part was rotated while holding the fixture steady.  The result was a uniform radius on the parts.  The radius part of the project was the easy part of the project.  The large part, with the two sections, was made from a 1-1/4 inch diameter bar stock of 4130 steel with the threaded section 1/4 inch in diameter. Fabricating a fixture to machine a radius does not have to be complicated.
 

A Sea Story
by an anonymous HMSC member

A few wars ago in 1968, my old destroyer was back in the south China sea off Vietnam after some quick repairs in the Subic Bay (Philippines) shipyard, when a little problem came up. The steam turbine-driven main condenser water circulating pump in the forward engine room wasn’t working too good (to put it mildly). The pump end had a water-lubricated split bronze sleeve bearing about 14 inches long, 3 inches ID by 4 inches OD . The 1/2-inch thick bearing walls were perforated with a bunch of 3/8-inch holes for water to cool and lube the shaft. The two halves of the split bearing were aligned by four dowel pins in the mating faces.

Maybe because things were kind of busy then, the shipyard workers had reassembled the bearing with only two dowels engaged, so that each half of the sleeve overhung the other by about three inches on each end.  Somehow, they managed to get it back in the pump bearing housing which was also split, put the cover on, and slug up the nuts.

When the pump finally quit, it was torn apart and the mangled bearing found. When it had been bolted up, about 3 inches of each half had been bent diagonally outward by almost an inch.  Since we had no spare bearings on board, it was fix it or leave our duty station and limp back to the yard.

Fletcher-class destroyers had a 16 inch lathe, a drill press, and a small workbench with a good heavy bench vise.  The way we fixed the bearing was as follows:

The pump shaft was “miked” and a piece of brass bar stock turned between centers .004 inches oversize for running clearance, using the old rule of thumb “.001 inch of clearance per inch of shaft diameter  plus .001 for luck.

Each bearing half was held in soft jaws in the bench vise and beat back into something like the original shape using the biggest (about 5 pound) rawhide mallet we had in the ship.  Sounds extreme, but there was nothing to lose; it was no good as it was.

The two bearing halves were then fitted to the .004 inch oversize bar using Prussian blue, half-round files and finally scrapers.  When it was as good as we could get it on the bore, the outside diameter was fitted into the pump housing again using blue, files and scrapers, while hanging upside down in the bilge through a hole in the engine room deck plates.

Not much more to add – the pump was reassembled (this time with all four bearing dowel pins aligned!), lit off and put on the line.  It ran fine until we got back to the U.S.A. about six months later.

Maybe the moral is, you don’t always need elaborate equipment to do a job if it really has to be done.

The next meeting will be held on Saturday October 11, 2003 at the Collier Library 6200 Pinemont, Houston, TX at 1:00 p.m. Bring along a work in progress to show. Visit Our Web Site homemetalshopclub.org

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