Wednesday, September 20, 2017

Reduction Gears

Sorry, this is not an Amateur Radio post.

After many months of working with a 3D Printer, I have finally successfully created a working set of interlocking reduction gears, each section provides a 7:1 reduction. This device is about 2 inches in diameter, the total reduction is 14:1.

The original Ring Gear from Thingiverse was modified to create this multi-stage Reduction Gear. My contribution was to modify it as necessary and join two sets together.

Sketchup Model
The transfer plates (with the connecting pins) were assembled by adding the center HEX pin after printing.  Each of the two Reduction Cluster were printer as an assembled single object on the printer. No cleanup or filing was necessary.

Silicon grease is used for lube.

I may increase the size (and with other modification) this could be used as a Light Weight Field Day Antenna Rotor.

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Wednesday, May 3, 2017

Lost Friends

This week has not been a good week, very sad, two of my Ham Radio Friends have passed away.

Doug Phillips - W7RDP  (SK) a good friend from the local Pacific QRP Group (pQRP).

Don Sehulster - K7QYP / W7LSC  (SK) - a very good Navy Buddy (1968-1972).

73 - My Friends . . .  K

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Sunday, April 30, 2017

First 3D Printer

I purchased a 3D Printer, and just now learning how to use it, there is a lot to learn.

After many trials and failures, I have successfully printed the equivalent of "Hello World" for 3D Printers, which is the "3DBenchy". This online part was designed to be a torture test for a 3D Printer, with many under-cuts, over-hangs and fills, that are somewhat difficult. This part is about 2.5 inches long.

My Printed 3DBenchy Results
3DBenchy was actually about my 10th attempt at print anything, the first few parts went horribly wrong.

Here are a few of my initial prints of a part of my own design, obviously I did not know what I was doing.

Things got better with practice and understanding of the 3D Print process and control parameters.

The above is a replacement part for an Orbital Sander, this part is no longer available from the manufacture, it will eventually be printed with Black ABS Plastic, which is similar to the original. I designed this part with FreeCAD and used Slic3r for the G-Code output for the 3D Printer.  For me, FreeCAD has a steep learning curve.

And, then . . .

On the next part, a Cable Chain of my own design, I must have lost the magic !!

But finally, things got better with practice.

Cable Chain Links
The First Two Links of a Cable Chain.
I am currently printing four Cable Links with newer/better design, I will report the results. For these link design, I have used Sketchup and Slic3r. For simple designs Sketchup is easy to use, as long as you only need "Union" style of object creation, that is, objects that touch are automatically joined together (union'd) when exported as an STL file. STL files are needed by Slic3r.

Four Cable Chain Links
About 2/3 Complete

This is fun, I think I am going to enjoy my new 3D Printer.

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Tuesday, March 7, 2017

Esp8266 WebServer Farm - Again

After several long months, I have reactivated my Esp8266 WebServer Farm.

Use this links to all of my Esp8366 project blog posts.

Esp8266 WebServer Farm

Currently, one of my WebServers can be accessed as:

The main reason that it has be off-line, is lack of interest, and recently, I could only get the code to compile on the old Arduino IDE (Rev 1.6.x).  The code is quite large and I took advantage of many "tabs" for code fragments, which are concatenated before presented to the compiler.  The new Arduino IDE Revision (1.8.1) is much more strict regarding Header Files, code files, and program structure. There were just TOO MANY errors to correct to keep my interest in solving the problem.

Once started to solve the problems and not getting much accomplished, my Friend Jeff - Ko7m, suggest another IDE, he suggested "PlatformIO IDE".

With little work, I found and installed PlatformIO, but alas, I found similar problems and concerns with it.  But little-by-little after much on-line reading, Jeff and I worked out the best file structures that worked with PlatformIO.

I have not moved the new code structure to GitHub, but maybe soon.

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Saturday, January 14, 2017

My Soldering TIP #1

Several years ago my trusty Weller Soldering Iron failed, knowing that most of my projects were going to use small SMD parts, I ordered a fancy replacement, a Hakko FX-888 Soldering Station (about $90.00) with several assorted tips, some really small tips for SMDs. The tracking information, revealed that it would be in my hands in about three weeks.

But, I needed a replacement Iron NOW, to finish a project. I went to Frys, and found a cheapy Iron that I thought I could use (about $29.00), it was a Hakko Presto 980-V12/P. It had only one smallish chisel tip, but I thought it could be used for some larger SMDs.

Well, now several years later, the expensive Hakko FX-888 with its small tips is VERY seldom used (maybe about 3%), while the cheap Hakko Presto 980-V12/P is used for most (if not all) of my projects, and I am still using the original TIP. If you have seen my projects (typically on a 0.5in x 0.7in PCB boards) you might think the FX-888 would be more appropriate, but I fould it is not.

The following are some of my projects where the Hakko Presto 980-V12/P was used:

HomeBrew Double Sided
Si570 Board
HomeBrew Double Sided Project
These are 0805 Caps, and SOT-223 Voltage Reg
I like and use the Hakko 980-V12/P, it has "Two Temps, 20W normal, and 130W push button switch", very seldom have I used the 130W button.

I have recently purchased a second Hakko 980-V12/P for my tool box.

Today I think the Hakko 980-V12/P is priced about $60.00, if you are interested in online purchase, google is your friend. see:

I think you will like it.

BTW: I use a "wall outlet timer" to supply power to my soldering irons, if I forget, the timer turns off power to them after about 45 minutes, which saves the soldering TIPs.

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Wednesday, December 7, 2016

A Small Experimental Receiver Circuit

I have finally found some time to "melt some solder" at my new location and new eShop bench. The bench is not finished yet, but I needed a Solder FIX.

This, like all of my project, is an attempt to make projects as small as my abilities allow.

New eShop Bench
The project that I am working on is some boards I just received back from OSH Park. The boards are a small and part of an experimental HF Receiver. The boards edge connectors are "Castellated" to allow them to be used within a larger PCB circuit, and with attached Headers, they can be used with/on a Solderless Proto Board.

The size of these boards are:
Left: 0.8x1.0 inch,
Right: 0.5x1.0 inch

This is my experimental design, it is a circuit that contain the:  HF VFO Mixer, Band Pass Filter (BPF, 40MHz), and BFO Mixer.

The bigger boards on the left are similar to those on the right, except they also contains the Oscillators for both the VFO and the BFO, along with the voltage regulator for the oscillator chip.

The components on the lower half are installed
Ready for some testing
Unpopulated is the VFO/BFO and Voltage Regulator
LTSpice suggests this circuit will work, but assessing the actual performance is the real reason for building this experimental circuit.

Additional circuits will be needed, to make this a real receiver, like: Band Select Filters, Automatic Gain Control, Audio Circuit, a Microcontroller, and Display. Likewise, I will make each as small as I can.

Testing will start when I have some (more) time.

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Sunday, November 20, 2016

My new eShop

UPDATED: 11/21/2016

I have NOT posted anything for several (6) months, my life has been in somewhat of turmoil (maybe, I am getting too old for this), but now, maybe things are starting to get back to normal.

Regardless, I have been thinking of many HomeBrew projects that I want to build and blog. But first I have to set up my eShop in this new (and better) location.

This is the beginnings of my new eShop setup:

My new eShop Bench
I just finished building the wooden shelves. My previous eShop shelves were about the same but fixed, these shelves are movable, and therefore this setup should be more effective for varying sized electronic equipment.

Adjacent to that,  is my current MS 10 WorkStation, Raspberry Pi, and Orange Pi set ups:

Computer Workstation
The three bottom screens are connected to the MS WorkStation, and the three uppers are for the PI's.

Note: and the refrigerator is only about 15 feet away, hihi.

Unfortunately, I have not started my Ham Station and Antenna System yet.

I have some small Ham Radio related PC boards out for manufacturing at OSH Park, if they works as expected, I may be blogging about those, soon.


The day after installing my shelves and turning on the Oscope for the first time in a long while, the (calibration) trace is going bonkers, with a short bright spot at the beginning of the trace. Trace INTEN has little control.  DANG, now something else to repair.

Tuesday, May 3, 2016

FORD Rant - Oil Cooler Bypass Valve - is a non replaceable part.

UPDATED: Tue May 17 11:19:46 PDT 2016

This is post not about Electronics, it is a RANT about FORD.

For the last few weeks, my Son and I have been working on his F350 6.0L Diesel Engine, to replace; the Exhaust Gas Recirculation (EGR) Heat Exchanger, and the Oil Cooler. This work is a pain because most of the top of the engine, including the Turbo Charger has to be removed to get to the parts being replaced. There are several good Youtube video showing the details.

We ordered parts and gaskets bases on information available. This repair is somewhat of a difficult task due to engine compartment large size and the long reaches necessary to access everything.  There is one very dirty mess when the Oil Cooler cover is removed, where about a quart of oil spills over the engine valley, but that cleanup marked the beginning of the actual part replacement and rebuild.

Most of the previously dis-assembled parts where replaced in the order they were removed without difficulty.

But Then

FORD Failed
Oil Drain Back and Oil Cooler Bypass Valve Assemble
On top of the Oil Cooler Cover there is a small assemble which is held in place with two screws within the Oil Filter Case (Can). This small assemble is about 3 inches wide.

This small assemble holds two valves; one to Drain Back oil from the Oil Filter Case (helpful during oil and filter changes), and the other is the Oil Cooler Bypass Value (OCBV) which opens in case the Oil Cooler get clogged up. These two valves are very simple; the first is held shut by gravity and can pressure; the other is a spring loaded Brass Plunger with a small flat plastic/rubber (of some sort) washer (flapper) that opens at 25lbs of Oil Cooler pressure.

Spring Loaded Oil Cooler Bypass Value
The Brass Plunger shows scoring
The Wood Chip holds open the washer at the failure.

The Problem

According to FORD, these two small values are NOT replaceable parts !!

And therefore, normal Auto Parts stores do not have the parts, nor does FORD.

Our OCBV plastic/rubber seal is damaged, and the Brass Plunger is scored showing that it had failed long ago.

The values can only be replaced with a NEW Oil Cooler Cover, which is about $180.00, the plastic/rubber part, if available, should only cost about $2.00, even though it is about $0.10 worth of plastic/rubber.

My Conjecture

I suspect that the OCBV failure contributed to the EGR Cooler failure and therefore the need to repair this engine - it is a $0.10 part ?

Our Planned Fix

Google searches provided very little help or suggestions of a solution.

Our current plan is to create a new Teflon washer (value flapper). A Teflon rod is now on order. Experiments with different on-hand materials failed to hold up in a gas/oil environment.  Teflon appears to have the right properties; inert and high temperature resistant.

Thanks FORD, my Son's truck has be on blocks for about three weeks now, while finding a workable solution.

End Rant

If this works as planned, I will be selling Teflon washer, and or Teflon Plunger with integrated Teflon Value seat, . . . soon :-).

Teflon Washer
The engine has now been running with the new Teflon Value Seat for several weeks, when the oil is changed it will be removed and inspected for ware.

Here is a photo of the Bypass Valve Assembly reinstalled ( I had forgotten I took this photo). The Oil Filter Tower and Canister have not been reinstall yet, as can be seen, two screws hold the assembly in place. Inspection for ware at the next oil change, will be easy.


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Monday, February 1, 2016

ASCII Strings within the Largest Known Prime Number

Someone on the Youtube Numberphile Channel was wondering if after converting the Largest Prime Number  to base 26 (see previous post) would there be any interesting ASCII strings within the Number.

I think I have created a Unix Function that will do the conversion.

( echo "obase=16;"; echo "obase=26; 2^74207281-1" | bc | tr -d '\n\\' | sed 's/ /;65+/g' ) | bc | xxd -r -p

This will take a while (maybe several hours, or days), but if I find something interesting, I will report the results.

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Friday, January 22, 2016

The New Largest Prime Number Found

Added Details and Links

Recently (Jan 7. 2016) the next and Largest Prime Number has be found (so far), it has about 22 Million Digits long, See, YouTube at:

The number can be expressed as a small-simple math function, that is: "2^74207281-1"

The previous Large Prime Number (17 Million Digits) was found about 3 years ago on Jan 25, 2013, see:

Hopefully, and if history hold true, we will see the next Largest Prime sometime within the next 3 to 5 years.

Just for fun, I decided to see how long it would take my 3.4GHz Workstation to perform the calculation and print the full 22 Million Digits to the screen - it took about 154 minutes - it was like watching paint dry.  :-)

Note: To verify that it "is actually prime" would probably take several months (or more actually several years) on my computer.

Here is the linux command that I used to print this New Prime, and a few of the Beginning and Ending Digits of the results:

$ time echo "2^74207281-1" | bc

 .  ( 22 Million More Digits )


real 153m50.931s
user 92m34.588s
sys 0m13.496s

Note: To capture the number on the screen, a large display buffer of more than 22 Meg Bytes (of RAM) was necessary.

I need to check with YouTube and/or Numberphile to see if my calculated number is correct  :-)

My computer is current checking four large numbers to see if they are Prime, this consumes about 100% of the Quad Core CPU, but it runs at a very low priority so it does not effect my use of the computer. Each is expected to finish at different times, Below shows the number being tested, and number of days until I should have the results:
As you may have expected, . . . I am a fan of Very Large Numbers !

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