Showing posts with label heat treatment. Show all posts
Showing posts with label heat treatment. Show all posts

Tuesday, May 8, 2018

Early PM Shop Notes Files Preview

So as mentioned before I am working on some early (pre 1930) PM shop notes files in my spare time. For example J. V. Romig, the D. Gingery of his time ( maybe that should be stated the other way around since Romig came first) produced a large number of small hobby shop sized machine plans for publication in Popular Mechanics and Popular Science from 1921 to 1925. That file is now over 75 pages of some of the more interesting plans he produced.

There is another file of short plans and ideas from these early shop notes that I am working on. These all come from the 26 volumes of early shop notes reprinted by Algrove Publishing. Here is a preview of a few short articles from this file.

The first one deals with heat treatment, hardening, and annealing. It is not a well known fact but when heat treatable steel reaches the right temp for hardening it looses it's magnetic qualities. A metal worker who does heat treatment all the time can easily judge by color but someone who only does it occasionally will find this tool very helpful.


This short article is an interesting method of casting brass worm gears. The second article is another plan for cutting circular work. There are lots of plans for this type of fly cutter, I have posted a few. For very thin sheet metal this is probably a better idea since it incorporates a shearing action with less chance of grabbing and damaging the work.


In addition to the many plans Mr. Romig authored, he also produced many articles for publication in the "Popular" magazines of the day. Here is one on making "no casting" machine slides for the hobbyist who would rather avoid setting up a small foundry.
  


Saturday, April 14, 2018

More "Mechanical Details"

So here are a few more pages from "Mechanical Details For Product Design" Proper spur gear design can get confusing without an understanding of the terms and formulas used in there design. The first page is a clear layout of the terms and formulas used in designing spur gears.


Next is a couple of pages on designing for easier machining. Some are obvious,some not so much. Taking the time at the design stage can save time and frustration with less than great set-ups later.



For parts that will need heat treating, many of the rules used in castings also apply. Rounding internal and external corners and avoiding quick changes in section thicknesses will go a long way to preventing cracks and shrinkage problems such as warping.




So back to my breakfast, nothing special just some extra old, crumbly Canadian cheddar, on overly buttered whole wheat toast, washed down with a couple of cups of strong coffee, mmmmmmh. Cheers.