I need BX-28J344-01 MMP 8 on!

I've been arriving at the office a couple hours early each day this week trying to get things repaired from the storm we had last Friday evening. The temporary "prevent further damage" repairs have been completed as well as the cleanup of the yard debris. The grass needs cutting and I need to call (why?) the insurance company to see if they received the paperwork I faxed over to them yesterday morning. On the fax cover sheet was a note saying "please call me when you get this" and my phone number and I'm still waiting for it...

One day this past week, the phone rang in the early hours of the morning, and when I answered with sleep still in my voice, "Hullo?" I heard my dad rattle off, "I need BX-28J344-01 MMP 8 on!"

After I got a bit of paper and a pencil, I asked him to repeat himself. I sometimes think the powers-that-be in our Government might be listening in and wondering what the secret code is...and half expect a visit from the FBI.

But it's nothing sinister. Down in the basement of the office, fondly referred to as the dungeons, is the rack.


The rack holds the production tooling from my dad's business. When he closed the foundry down, he and I spent hours selecting out about hundred of these from literally thousands trying to find those that were still in use. In the trade, they are called patterns, and function somewhat like dress patterns do for a dressmaker.

The production tooling ranges from rather expensive to simple, depending primarily on how intricate it is, and how many of the final items are to be produced. A high volume run of tens of thousands usually requires metal patterns and as many duplicates that can be put in a manageable package.

A one-off job might entail a simple wood pattern with no other tooling.

Here is BX-28J344-01 MMP 8 on!


There are eight of what looks like toilet flush handles on a Metal Match Plate (MMP). The magnesium tooling is liberally covered with talc parting powder. The item made by this tooling is a yellow-colored, bronze "handle" that I've no idea what is used for or what it does. I know that the finished handles look like "toggles," are quite hefty (about 2 pounds apiece) and fit my hand nicely.

The tooling can be simple but elegant.


This pattern is made from hard mahogany wood. The fellow that crafted it is a pure genius when it comes to wood shop tools. The beautiful wood is sadly covered with a grey paint that has special 'non-stick' qualities that permit the pattern to be pulled freely from a sand mold. You can see the sand mold process here part 1 and part 2. The first minute or two of part two is the most explanatory if you are short for time.

Again, I've no real idea what the finished metal item is used for - it looks like some sort of mixer that is mounted on a steel pipe.


This is the pattern for part of a metal lecture hall chair... the kind with the wooden arm that swings up and across your lap. This is reproduction of the ones used at Princeton University and were used when they refurbished McCosh Hall. You can see a picture of the finished chairs here.

I quote the last paragraph from the website linked to above:

The lecture hall McCosh 50 has played host to visits by dozens of prominent figures in politics, science, literature and the arts. Most notably, Albert Einstein gave his renowned Stafford Little lectures on the theory of relativity in McCosh 50 in 1921, the year before he received the Nobel Prize. Scientists from all over the country packed the room for the five lectures, which were compiled and published under the title "The Meaning of Relativity." Recent speakers have included novelist Chinua Achebe, comedian Steve Martin, political activist and class of 1955 member Ralph Nader, architect Cesar Pelli, actress Meryl Streep, Marina Mahathir, an activist for HIV/AIDS awareness, and Elie Wiesel, who won the Nobel Peace Prize in 1986.

This is the stuff my father, his father, and on back to 1850's make and made.

Next time - a little about the math involved...