Jan. 2018

Unfortunately, the meeting was rather poorly attended with only 8 of us present. It seemed to be a combination of iffy weather (snow) and several people suffering from colds etc. Our Treasurer was one of those absent so there was no report on our finances.

There was some discussion about obtaining small wrenches. Bruce Mannerow has some bolts on his howitzer chassis that are very difficult to reach. A few people talked about the ignition wrenches that used to be available from Sears. You are obviously out of luck with Sears Canada but checking their American website, they still offer these in both inch and metric sizes.

He has also been looking at measuring the large end of an internal taper. Getting an accurate measurement with digital callipers is really not feasible. However, if the hole is large enough and long enough to get the internal measurement part of the calipers inside, and you know the taper angle, it is then possible to take a measurement with the calipers (at the depth of the internal measuring part) and calculate the diameter at the outer end. (See the diagram later.) There was also some discussion about using an appropriately sized ball to carry out the measurement. The use of 2 balls was also talked about: Thinking about this; if appropriately sized balls are available, the approach can be used to measure the taper angle as well as the diameter at the end. (Again, more later.)

The geometry/trigonometry associated with the internal calliper technique is fairly simple but when one starts using balls for measurement it gets more complicated. Someone commented that it is possible to find all sorts of math related stuff on the web but that a lot of what comes up is erroneous.

The next item up for discussion was "Forged in Fire" as shown on the History Channel. Alan Olsen got involved in the discussion and there was general admiration for the techniques that were evolved in fairly early times to get the right combination of hardness at the cutting edge of a sword to hold that edge while maintaining sufficient ductility in the rest of

the blade so that it does not break during use. (I never cease to be amazed at the ingenuity and enormous effort that mankind has devoted to killing his fellow man.)

One other item Bruce came up with was the recent discovery of an underground factory created by Rover during WWII to enable them to escape destruction by the Luftwaffe. One asks how this could have remained secret for so long but a few years ago a lot of information started to become available about the Bletchley Park code breaking facility and one aspect which came to light was that people who worked there were sworn to secrecy on pain of very serious consequences. That secrecy was well respected and so it is not surprizing that many secret wartime activities have remained that way. (Just Google "Rover underground factory WWII" and all sorts of interesting stuff comes up.)