My Favorite Irrational Number

I have always been interested in numbers, especially special numbers like Pi (3.1415. . . ).

Normal whole numbers, like 1, 2, 3, etc (and their negative counter parts) are amazing when you consider there is no end to how far you can go to find a larger number, just by adding one. Within that very large range of numbers, there are many numbers which have their own special properties, for example the "Prime Numbers". As with all whole numbers, there is no Largest Prime Number, there is always a larger one to be found.

The whole numbers (plus/minus) and fractions that can be written using them are known a "Rational Numbers" - meaning that they can be written as a ratio (a fraction), for example:  1/1, 1/2, 1/3, etc.

But there is another class of numbers that can NOT be written as a ratio of two whole numbers, they are called "Irrational Numbers", for example the value of "Pi".  Pi can be written with many-many non-repeating digits without end, but Pi could never be written as an exact fraction (a ratio) of two whole numbers. There are many such "Irrational Numbers", many are used in science and found in Nature.

My favorite Irrational Number can be computed as simple as: (1+sqrt(5))/2

This can be computed with as many digits that you like with a simple Unix command (change that scale as desired for the number of digits):

        echo "scale=1000; (1+sqrt(5))/2" | bc

This is a very special number known as "phi".

A very interesting property of phi is:  1/phi = phi-1

No other number has this simple property.

Phi is found in many places in Nature, for example it is the way seeds are arranged withing a Sun Flower, the size of chambers of the Nautilus fish,  etc.

Phi is the name given to what is also called the "Golden Ratio" or "Golden Rectangle".

Here are the first 1000 digits of Phi:

1.618033988749894848204586834365638117720309179805762862135448622705
26046281890244970720720418939113748475408807538689175212663386222353
69317931800607667263544333890865959395829056383226613199282902678806
75208766892501711696207032221043216269548626296313614438149758701220
34080588795445474924618569536486444924104432077134494704956584678850
98743394422125448770664780915884607499887124007652170575179788341662
56249407589069704000281210427621771117778053153171410117046665991466
97987317613560067087480710131795236894275219484353056783002287856997
82977834784587822891109762500302696156170025046433824377648610283831
26833037242926752631165339247316711121158818638513316203840052221657
91286675294654906811317159934323597349498509040947621322298101726107
05961164562990981629055520852479035240602017279974717534277759277862
56194320827505131218156285512224809394712341451702237358057727861600
86883829523045926478780178899219902707769038953219681986151437803149
97411069260886742962267575605231727775203536139362



-- Home Page: https://WA0UWH.blogspot.com

Hands Free Jig

UPDATED:
Added Details and Links


In the past I successfully have used "Hands Free Soldering Jigs", but I wanted more functionality.

I found on ebay Machinist Magnetic Indicator Dial Gauge Holders, with a little 3D Printer Designed Adaptor they could be used as a Hands Free Soldering Jig.

A single Knob adjust and locks all three major joints.

In this case, the yellow alligator clip adapter was 3D Printed.

Also, another adapter (black) was printed, and a "Hat Pin" heated and inserted. This makes for a very nice PCB probe, an Oscilloscope probe can be attached to the top of the pin.

Once adjusted, these Dial Indicator Holders are "Rock Solid", once positioned they stay put, allowing for precise probing.  I use tape to hold board under test to the bench (thanks, Jeff - KO7M).

If used, the Magnet Base needs a stable steel attachment point, in my case, my bench edge is metal and provides as necessary.   The Magnet Base could be abandoned for something that could be attached to a wooden bench.

-- Home Page: https://WA0UWH.blogspot.com

Test Lead Rack - For my eShop

In my Electronics Shop, space and organization is always a challenge.  The following 3D Printed Test Lead Rack will help.

An Interactive Link To The Design

I designed the Test Lead Rack with Fusion 360 as one of my efforts to learn this new (to me) software.  I had been using Sketchup for most of my previous projects, but the lure of Parametric Design is to great to NOT switch to Fusion 360.  Also, a lot of public available designed parts are available from Fusion 360.

Now 6.5 hours later after design, the 3D Printer provides the Results:

And now, it is in use:

-- Home Page: https://WA0UWH.blogspot.com

3D Printer - MY Noob Mistakes

As posted before, I have been playing with a new TEVO Little Monster 3D Printer, I have made a LOT of Noob mistakes that could have been avoided if I had only knew.

The following are notes to myself.

o. Do not turn off the power to the 3D Printer unless you are certain that the Hot-End has cooled down. if not, removing power to the 3D Printer will cause the filament to melt within the Cold-End and then a complicated repair method will be required to fix the problem.

o. Remember, 3D Printing is very SLOW, it is much slower than waiting for paint to dry.

o. Remember the hot-end is VERY HOT, I have several burns to remind me.

o. Learn how to set the Z zero Height to within a paper thickness of the print bed, or nothing will work correctly until you do, no mater how hard you try.

o. Buy several sets of Print Head replacement parts, for the; Cold-End, Thermal Break, and Hot-End.

o. Consider buying some Tetrahydrofuran (THF) , it is the only effective thing that will dissolve PLA (for Hot-End  clean and repair), and it can be used to glue PLA parts together. Or at least that is what google suggests.

o. Note, MOST often Hot-End repair work will be done while it is HOT (about 210 C, or more), other wise PLA will be hard and not easily removed.

o. For my use, Blue Painter Tape works best for the Printer Bed, it has some texture that will show up on the printed part, but PLA stick very good to it. A roles of Blue Painters Tape (10 inches wide) are available on-line for about $50, and worth every penny, it makes bed prep very easy.

o. If the Hot-End is disassembled, for cleaning or repair, remember it has to be re-assembled and tightened while at intended operating temperature, for me that is about 215C.  If not, it WILL leak.


Note: I will add to this list as I learn more.


-- Home Page: https://WA0UWH.blogspot.com