Saturday, July 4, 2015

Renew Old Pencil Erasers

I'm old school, and still draw with pencils.  Something that irks me about pencil erasers is they become oxidized, and hard, don't work no more...  Through some experimentation I found that this oxidized layer is maybe 50 mils thick, and once it is removed the eraser is supple again, and can be use effectively on paper once again.  The process is to uniformly scrum off the oxidization with a moderate grit sand paper, and the eraser is happy again.  I have hundreds of old pencils that are useful again...

Friday, July 3, 2015

Renew NiCad Batteries

Don't toss those weak NiCad batteries...  OK, we have all experienced the NiCad Battery memory effect.  That cordless drill or saw begins to loose its vigor, doesn't last as long, and this can be maddening when you have a job to do.  My Ryobi 14.4 Volt cordless drill would drive 3 inch screws all day long when it was new.  But after a while it starts getting weaker, doesn't last as long.  A while later the thing is useless, and you have to buy new batteries, or at least the manufacturer wants you to...

What is happening to your NiCad batteries is there are microscopic shorts that form between the electrodes in the battery, and the short out parts of the battery.  This is a drawback of the Nickel Cadmium battery architecture.  These microscopic shorts form, and it creates the "memory effect" where the battery looses capacity over time, and is eventually worthless.  There are a lot of people that have worked around this problem with various techniques.  There are various ways to use high current pulses to annihilate the dendrites that short out the electrodes in the battery.  What I found through research is that you can use the battery's charger itself to do this for you.
This case is the Ryobi 14.4 Volt series, a strong battery, and device when its new, but when the dendrites grow in the battery it quickly becomes worthless.  When the battery get internally shorted out the green, and yellow lights on the charger come on together, and this indicates that the battery needs to be replaced.  You can find many people on the internet (You Tube) that have figured this out, and developed a work around to annihilate the dendrites.  Basically they use the inrush current of plugging the charger into the AC Voltage to generate high current pulses to the battery.
Plug the battery into the battery charger, then you will see the green, and yellow light come on simultaneously, indicating a not chargeable state.  At this point unplug, and replug the charger from the AC outlet, allowing the inrush current from the AC to generate higher than normal current pulses that hit the battery, annihilating those damn annoying dendrites.  The basic NiCad charging circuit could be redesigned with a pulsed high current technique that would make the dendrites, and the memory effect history.  I am putting this theoretical technique to the test now...
 The next morning I developed this into a process.  I'm lining up the batteries, and run all of them through the process several times.  When one gets the green light I'll pull it off, and put the next one in line on the charger.  Then cycle the AC power 10 times.  I think the process is working because they are charging longer, and getting stronger.  There was one battery that was dead dead, nuthin', and now its running the drill at full power.  The real test will come when the Sun comes up, and I can start using the power tools...

Saturday, March 21, 2015

WOPR succeeds XPC

Ah technology, that thing we have been acclimated to adopt as literally an extension of our mind, and now find we cannot live without.  I struggled to save the XPC for months.  XPC died in early January, and I have been replacing various pieces, and parts over the last couple months.  Finally I had to accept that my XPC was dead, and I have to move on.  However the spirit (software) of XPC will live on in a new host, WOPR.  WOPR is an AMD A-10 processor with integrated Radeon Graphics Processor, a much better physical representation indeed.
I was amazed at the speed of integration.  Everything worked the first time, and installed with amazing speed.  I had none of the hassles that I had become so accustomed to.  The operating system installed in less than 30 minutes, with no driver headaches.  I was able to restore my archived data easily, and now less than 12 hours later all of my software tools are installed, and usable.  Plus they all run much faster.  I should have done this a couple years ago when XPC suffered its first hard drive crash.  The part I was most worried about was my CAD software.  I was able to install it in 15 minutes, again no driver headaches, and it ran the first time.  XPCs spirit (software) lives in WOPR now... 

Wednesday, March 18, 2015

Mike's Solder Smoke Suckers

This began as a plan to make something useful out of scrapped parts that serves a useful purpose.  I work in a shop that mandates the use of no clean solder flux which is very irritating on the mucus membranes, and there is a need to keep this smoke away from you.  Scrapped computer fans do this very efficiently.  I then built a motley set of very scrappy looking Solder Smoke Suckers.  But then after building a dozen fans I ran out of scrapped components, and had to source parts.  This is when I went to the surplus electronics store, and bought surplus components to build the Solder Smoke Suckers.
Now rather that relying on what I could scavenge out of the scrap bins, I could specify parts, and literally design a product.  These look much better than the early Smoke Suckers on blocks of wood.  This also let me redesign in a way that minimized the foot print, and noise.  I chose a ball bearing fan that is extremely quiet.  The base has been reduced to a piece of Aluminum sheeting with silicone rubber feet.  The speed control potentiometer also has a power switch now, and I added a nice blue LED for the power on indicator.  I can build one of these with surplus components for less than $20.
Tanner Electronics also had some nice chrome plated fan screens that look cool.  I picked the right size stainless steel hardware, and nylon insert lock nuts to hold the mechanical pieces together.  If I was to source the parts to build these fans with new parts they would still probably less than $40.  Eventually I will run out of surplus parts, and have to build them from new parts.  I've been sourcing new parts, and building the bill of materials to build a new Solder Smoke Sucker, which eventually I'll offer for sale here.
Maybe eventually this will be my little hobby thing that turned into a business...

Saturday, February 28, 2015

The Saga of the XPC

My Super Computer, the Shuttle XPC, Pentium 4, Liquid Cooled, state of the art Machine in 2005, has died.  I bought it almost 10 years ago exactly.  It had its troubles through the years, but kept going.  The Mutha Board is that which quit.  Every other component works...
A fortunate event happened that gave me posession of a Dell B110 chassis, Muthaboard, and a Celeron, no memory, or drive.  Turns out this is a socket 478 Mutha board that will support my Pentium 4, and DDR2 memory.  So my system has reincarnated in a drab Dell body, and doesn't like it very much.
 This system was built in the XP era, but won't load XP because Microsoft ended its support.  The only option was to install 7, but now the machine is handicapped because Dell never developed drivers for 7, and never will.  This machine is ripe for a Linux install...  Hello Professor Falken...

Tuesday, February 10, 2015

Solder Exhaust Fans

This is scraptacular...  I've been building Solder Exhaust Fans from scrapped components.  At work I have a large scrap heap, and there are a lot of base materials, and some complex devices, like computers.  I take the CPU Cooling Fan out of the computers, and use it as a Solder Exhaust Fan.  I need to add some things to it like screens to keep the fingers out, and a base to keep it from cruising around the table.  Here is the latest set, minimized to take up as little space as possible.
This started with my Fan Controller from another project, and got simplified into an extremely cheap product.  The early models were mounted on a block of wood.  Then I moved on to a aluminum box, and now  its just a plate of aluminum with rubber feet.  The speed control is a LM317 Variable Voltage Regulator mounted on the top.  I use a switched potentiometer to provide On/Off control on the speed control knob.  Here is a shot of some "Classic" Solder Exhaust Fans...

Tuesday, January 27, 2015

Magnetic Stirrer 3

We finally got all the pieces in the same place, and were able to test the Magnetic Stirrer.  Looks like its working good.  The motor I picked is considerably overpowered.  I can trim the power level when I design the next generation Magnetic Stirrer.

Sunday, January 4, 2015

Magnetic Stirrer 2

Back in the Metal Shop, my favorite place, I am building the mounting system for the Magnetic Stirrer.  I decided to use 0.125 Aluminum sheeting to build the frame pieces.  Its locally available at Turner Hardware.  The closest piece I could get to the size I wanted was 12" x 18", so first I had to reduce the sheet to the 8" x 8" squares I want.  Then I can mark the parts, and start cutting.
I draw lines on the part with a carbide scribe so they are durable during the cutting process.  First thing is making the holes that hold everything together during the cutting process.  The I can clamp the two pieces together so all the cuts are the same on both pieces.  Then I'll clamp the whole jig onto the Mini Mill, and make the round cuts first with an endmill.
I jam a bolt into the table, and through a T Nut to make an axis.  Then line up the part, and nibble out the circle part.  Once I found the process to do this, it makes round cuts easy, and precise.  There are some select parts I don't want to cut like this, so when I get to those parts I have to disassemble the jig, then put it back together with only the parts I want to cut.  Next is cutting the straight lines.
This is a hacksaw job, a good challenge to make straight lines.  Cut wide, and grind into tolerance, LOL!  No, I'm pretty good at making straight lines.  After this I will make the ventilation slots, and mount holes for the motor.  The bottom piece will have a clearance hole in the middle for the body of the motor, but no motor contact.  Then also on the bottom piece there is a shelf for the motor Speed Control.
I've got a little more machine work on the bottom piece, then I can do a test fit.  There is one more piece which is the shelf on top where the stir vessel is placed.  It will be 1/4" plexiglass, and I'm not sure how I want to cut it...

3D Printing

We got the 3D Printer printing last week.  Finally had some time off to work on it.  There were problems with the Extruder Head feed mechanism, too much tension.  Also the feed motor was binding.  We re-adjusted the tension on the screws that hold the feed motor to the extruder to free up its motion.  Also we disassembled the filament path into the extruder, and found some obstructions, then cleared them.  We had to coax it along a bit, but we finally made some printed pieces.
Here is a little bit of video to show the thing in action.  It takes a long time to make a part.  The large Tron took an hour , and fifteen minutes...