Popular Mechanics has it¡¯s full archive on Google Books free to read, and their indexes are pretty good:?
You cannot download articles, but I have a big monitor, so going full screen and blowing up each page of an article I take a screen shot and piece them together. (I have a Mac¡you can set the default screen capture to pdf and set the default location, and the Preview app lets you drag one page into another preview sindow to assemble a multi page pdf. ?I¡¯ve gotten a ton of useful articles from them
An example, apropos of tapping:?
Or an interesting knurling tool that might be useful for a mini-lathe:
I¡±ve spent a lot of time just going through them; for metal working there¡¯s a wealth of information; particularly during the ¡¯40¡¯s, when there¡¯s a number of good articles on machining basics.
It¡¯s interesting to see the trends as you go through the decades. Home-built boats were really big in the ¡®30s, home built aircraft in the ¡¯60¡¯s.
On Mar 17, 2024, at 2:06 PM, Charles Kinzer <
ckinzer@...> wrote:
There were several references to a "Popular Mechanics" magazine issue with am EDM DIY article even in YouTube comments.? One comment said 1963.? One said 1969.? One said 50's or 60's.? I spent a LOT of time looking for it but came up empty.? It doesn't mean it isn't there, but people may be misremembering.
I finally was able to find an EDM DIY article in the March 1968 issue of "Popular Science" magazine on page 149 titled "EDM:? Space-Age Machining in Your Home Shop."? Sound about right?
Here is a link to that magazine - but it won't help.? You can see the article listed on the contents page, but pages 149 through 154 are MISSING.
I have a sneaking suspicion that the design might have been so hazardous that by some means somebody had it excised.? But if you can get your hands on a physical issue (there are copies on eBay right now and often will be), or find somewhere it is scanned complete, that may be the article people are thinking about.
Charles E. "Chuck" Kinzer
On Sunday, March 17, 2024 at 12:14:47 PM PDT, Bill Williams <
bwmsbldr1@...> wrote:
I read it about 40 years ago in the CC library in Colorado Springs! I am not even?sure of the date! Try google say" DIY EDM Cheap"? Bill
In my home hobby projects, I've usually only tapped holes in the range from 6-32? up to 1/4-20. The smaller 6-32 and 8-32 taps still make me nervous, even when tapping aluminum. Even when using a guide or tap follower to keep things straight, and using tapping lube, my biggest question has always been "how much torque should I be applying, and how much is too much?" Like many hobbyists, I started out with one of those large sets of "tungsten steel" taps and dies. The taps are typically plug taps, so I find the cut is quite aggressive. I will start off with a hole drilled with the recommended number drill, but more often than not, the tap will not start properly, even if I chamfer the opening of the hole. So, I go up to the next-larger number drill, and try that. Often I have to go up two drill sizes to get the tap to start. I know I'm giving up some thread engagement by doing this, but the results have been acceptable for my projects.
But, this past week, I bought a set of HSS taper taps, from 6-32 to 3/8, from an industrial supplier. I'm hoping that the less-aggressive taper taps will give me more luck in starting the tapping, and less anxiety? when trying to decide how hard to twist the tap wrench.
--?
Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
