Category: General

Different Differential

 

head-pic

Get the gear

I am basically tipping my hat to the hobby engineers out there. Somewhere along the way I needed a ‘universal joint’ but research efforts far outweighed practical knowledge. This post acknowledges those that inhabit the world of, wait for it… gears.

Hypothetical gear config @ 60 degrees:

60-degree-alt

and a nice write up on gears:

http://www.explainthatstuff.com/gears.html

To bevel or not to bevel

In my research I came across some confusion in terminology (or probably my own). While mitre gears (or miter) fall into the category of bevel gears – gears of various angles – the term denotes a motion transfer of 90 degrees.

bevel-and-mitre

Some instances of rotation require antithetical movement such as counter rotation.

So what is the application for this type of gearing I hear you ask ?

Well, as Beatty Robotics outlined, NASA employs a similar setup for their Mars Rover to enable mobility over rocky terrain (beatty-robotics.com). And check out Beatty’s own fab counter rotation differential.

So here is my build for a similar axle. Needing a prototype setup to try things out I used adjustable parts such as bearings mounts, spacers, collars etc before constructing the 3 geared version. Casings, blocks and collars are aluminium.

Alien Messages

messages from space

The media is littered with eye witness accounts of extraterrestrial encounters and while some seem genuine enough a vast number are discredited.

Of the plethora of sightings two distinctly different recorded accounts are worth mentioning here. Both are especially revealing.

Alphanumerical sequence

On August 15, 1977, an alphanumerical sequence 6EQUJ5 was recorded at the Big Ear radio observatory at the Ohio Sate University. The sequence, emanating from the constellation Sagittarius is regarded as the most persuasive evidence of extraterrestrial communication. A volunteer researcher named Jerry Ehman working at the observatory at the time, circled the sequence with a red pen and wrote ‘Wow’ in the margin. Observatory director John Krauss confirmed the finding and was astonished at the discovery. Lasting approximately 72 seconds the radio signal is known as the ‘Wow Signal’.

Continue reading Alien Messages