Showing posts with label engineering magazines. Show all posts
Showing posts with label engineering magazines. Show all posts

Monday, October 8, 2018

Regulating Speed Mechanically

Man we are sure making up for the rain we did not get this summer. I was in the middle of putting up firewood today when the clouds opened up, looks like I am inside for a few days again.

So here is another article from the engineering magazines, that I scanned the other day. This one is from the March 1978 "Machine Design" magazine.

Regulating speed mechanically has taken a big hit with the advancements being made in AC and DC speed regulation in electrically driven equipment. For all other powered drives there is mechanical speed regulation. This article gives a quick description of the most used forms of these methods of speed regulation.

Of greatest interest to the "I can build it myself" workshop addict is the Traction and Variable-Pitch methods. The Hydrostatic method is used in things like your garden tractor, though much larger equipment has been run with Hydrostatic transmissions. Variable stroke is used mostly in manufacturing processes, the torque converter in your car operates on the Hydrokinetic principle and the Hydroviscious method can handle huge amounts of HP and is mostly used in large industrial applications.

Traction, the first of the two methods more common to the home diy'er, has been around for a long time. It saw use in the days of steam, though you don't often see it anymore. It is relatively easy to construct and can give good control of things that require quickly changing feed rates and disengagements. Here is a picture from Fine Woodworking # 17, of a circular sawmill build, that uses this method to control the carriage. Two handles control the start, stop, speed, and direction.


Variable-Pitch is the other more common method of speed control for the home diy'er. I have never followed up to see who the inventor was, but they used to be called Reeves Drives and many units were manufactured under that name for light duty to very heavy industrial applications. They may have been the original inventors, however when the patent ran out it was adapted to a larger variety of applications. It is used to run drill presses, in the picture below, the Shopsmith combination woodworking machine, snow machines use this method, and even automobiles have been built using this method of speed regulation. In 1959 the Dutch sold a car in North America called the DAF, (maybe this is where the term DAFT came from, lol, just kidding), that ran on a Variable-Pitch drive.


So enough about what I know, here is what "Machine Design" knows.







Hope you enjoyed this little read.

Wednesday, October 3, 2018

Engineering Magazines


If you love fries like I do, (who doesn't) then the above picture is just what it was ment to be , click bait, ha,ha. Man did they get those fries right or what? They are probably just a plastic advertising prop, but boy did they get it right, I salivate just looking at them, ha, ha. This advertisement for air cylinders was in "Machine Design".

Back in 1997 I filled in for a year operating the power house at Orenda Aerospace while they converted the power house to low volume flash boilers. I used to call them "pop cans" because they were built small enough to avoid the Pressure Vessels Act requirements for licensed operators, and they were light duty, with a fraction of the life of a conventional water tube boiler.

While I was there, Orenda Aerospace, an aircraft engine developer and jet engine rebuilder, ran out of space in their huge reference library. They culled there shelves of most of their  older engineering industry magazines, an amount that filled two dumpsters. So, I went dumpster diving, ha ha. I had competition from a interested co-worker on another shift,  but I managed to set aside close to 800 issues of over a dozen different titles that caught my interest.

Below is an example of some of the titles I managed to collect. I got between 40 and 50 issues of most titles.







Most are probably familiar with "Machine Design" and maybe "Canadian Machinery" if your in Canada. If your here then much of the content in these magazines are of interest to most, more or less.

There are many informative articles, they are written for industry, but much of the information is just as valid for the home hobbyist, working in wood and metal to build his own machines. Check out the next post for a couple of articles on the proper care and installation of bearings.