making a heavy workbench mobile

making a heavy workbench mobile
movable workbench
Had a big bench/cabinet that was in my battery room become surplus because of the large battery rack for the off grid batteries.
The bench weighs about 150 lbs and is very difficult to move even with 2 people because of the size. we moved it outside and started using it while getting ready for solarfest, and found that it was a great workbench.
I did some digging in my wheel box, and found some big plastic wheels. I built a simple lift assembly that lets me lift the bench onto the two wheels so I can move it my self. The long handle gives plenty of mechanical advantage so the empty bench is easy for me to raise and lower, and the central location of the wheels lets me rotate the bench in place for easy positioning. When the bench is lowered,the wheels retract completely so the bench is solid and stable. Now I need to put a durable top on it, and give it a good paint job and I will have a great workbench that I will be able to use when I get older.

making a ducted blower from a computer fan

making a ducted blower from a computer fan
DIY in line ducted fan
I need a battery box vent for my solar batteries enclosure. Many people sell fans that can be installed in PVC piping, but they are expensive.
I have a bunch assorted fans from 2" to 4" from the MIT swap meet, so I set out to make a ducted fan assembly for them.
I found that the white PVC reducers were just the right size, so I took some white expanded PVC foam board, and using a 4" hole saw bade a simple flange. I glued the flange to the reducer, and used some long 6-32 screws and now have a nice ducted fan that can be inserted into the 1.5" PVC vent line. Made another for a 2.5" fan.

Where do you find high quality alligator clips?

Where do you find high quality alligator clips?
beefing up some clips for high current
I wanted a quantity of alligator clips that could handle currents in the 10 A range, and bought some nice looking ones with # 18 wire. As I usually do with chinese made products, I always want to see if the product is made well or if some shortcuts have been taken in materials or workmanship.
I removed one end with a trick I learned many years ago.
You put a large diameter shaft (phillips driver) into the clip, which makes the shape like a ramp, so the insulating cover can be slid off, and then back on.
In this case, I used some long nose pliers to force the jaws open, so I could grab the jaws to pull off the cover. The deeper you go with the pliers the better the ramp and the easier the covers slides back.
One look at the connection, and I knew that this clip, despite the nice wire and tough clip, was not going to pass the current that the wire should comfortably handle. The bare copper was not crimped metal to metal, instead they crimped it with the rubber, which while capable of handling an amp or so, if we start passing 5- 10 A, the joint would rapidly heat up and soften the wire insulation, and thus decrease the clamping force, which would raise the joint resistance, which would raise the temperature in a death spiral that would end with fire.
My investment would be wasted if I did not fix this only weakness in an otherwise good product for a fair price.
I carefully pried open the two clamp pins
Cut of the mangled end of the wire and make a new strip.
twist the fine strands, pass through the hole from the inside
Solder the wire to the clip with a heavy iron so the heat does not have time to heat the spring in the clip and soften it
The solder joint wants to present a smooth surface to the insulating cover, so flow in enough solder to form that surface
After the clip cools (blow on it to speed the process) bend the two clamps back over the insulation
Using the Phillips driver to create the ramp. slide the cover back into position,and you have a first rate alligator clip that can handle some high currents, and will last.

Measuring resistance of less than 1 ohm

Measuring resistance of less than 1 ohm
measuring less than 1 ohm accurately
Having some issues with the resistance of a db-25 cable, and need to compare the end to end resistance of several brands to find the lowest resistance.
Unfortunately when using most DVM's, the sub ohm accuracy and resolution is pretty poor.
Special sub ohm testers usually use a 4 connection meter. two leads apply a constant current, and two pick up the developed voltage.
I used my adjustable constant current lab supply, set to produce 1A CC.
This current through the sub ohm cable wires will develop 1V/ohm, so the cables actual resistance can be measured with 0.001ohm accuracy. The voltmeter will read 220mV for the 0.220 ohms.
Since the current is constant, and the current connections are separate from the measuring connections, the accuracy is very good.

Broken gas can cap

Broken gas can cap
Fixing a broken gas cap
New England weather can get nasty, so having a generator and some gas is almost a necessity.
I bought several 6 gal cans a few years ago, and one of the plastic caps split, and would not seal.
I went on a quest to buy a replacement cap, but as was my experience in the past, they seem to keep changing the threads and size, and none of the replacements would work.
I bought a new gas can last time, but hate to trash a perfectly good gas can for lack of a working cover.
I washed the broken gas cap in alcohol to get any residue off. Then cut some small strips of my favorite aluminum tape, and carefully taped the cracked cover back in the correct shape.
The type of plastic they use does not glue well, and there is a lot of stress on the cap when tight, so I got out my trusty epoxy putty, and mixed up enough to totally cover the cap.
I rough sanded the plastic cap, and made some light saw cuts to give the epoxy something to attach to,
and I made sure to get some under the bottom lip of the cap, so the broken cap was totally encased in the putty. The epoxy cured overnight, and the cap now works just like new, and I expect that this cap may last longer than the virgin ones.

Lifting the battery safely

Lifting the battery safely
Some insight battery pack lifting options
As anyone that has pulled the battery pack on their insight can tell you, it is just heavy enough to hurt your back, and it requires you to lift in a very awkward position. Honda has a special lifting frame that the techs use, so I thought that with the requirement that one pulls the Insight pack to do a clean grid charger install,it was time to see if a quick and dirty version of the lifting frame could be fabricated.
Randall sent me a photo of one he made, using some handles, and a piece of plywood.

I made one with long handles, that allow comfortable lifting angles, and full control of the pack while removing or installing.

Using digital caliper to measure hole center to center distance

Using digital caliper to measure hole center to center distance
direct center to center hole measurements
The digital caliper is a great tool that no self respecting home tinkerer should be without.
A simple technique allows accurate hole center to center measurements.
First set caliper to measure the hole diameter, but instead of reading the diameter, zero the caliper.
Now the hole diameter will be subtracted from any subsequent readings. Use the caliper to read the outer edge to outer edge of the two holes you want to measure, and the hole diameter will be subtracted from the measurement yielding the true center to center distance.

Seprating the cells for reuse

Seprating the cells for reuse
Deconstructing the subpack
Ok I can test the subpacks down to the cell level, so the bad cells can be identified, now how do we get the cell replaced. Grabbing the stick with plastic strips in the milling machine vice, I milled off the welds being careful to not machine into the stainless steel case. Once the welds were removed, the cup just slid off the underlying case with hardly any force required. The case only needed a light sanding to make it like new. The two end caps also were quite easy to remove and they were left in a reusable condition.
All of this is good news. With a proper fixture to hold the sticks, I could separate the end caps and cells on a whole stick with everything ready to become part of another subpack.
No new parts required.
Time to get on the welding machine.

Soldering iorn degausser

Soldering iorn degausser
Another use for your soldering gun
Having a magnetized screwdriver can be a life saver for getting a screw into a tight place, but that same screwdriver when used to nudge a small component around for soldering, or when it falls into a floor with steel chips that stick to it.
We learned in science class that we can magnetize the driver buy sticking a magnet to it and dragging it off the tip, but how to remove it is a bit more difficult.
Your trusty weller transformer type soldering gun makes a quick degausser.
The high ac currents flowing through the soldering iron tip makes a strong AC magnetic field. If the gun is turned on, and the screwdriver is placed in the gap and them smoothly pulled out to at least 6 inches, all magnetism will be removed.While in the gap it is getting magnetized north south 60 times a second, as it is slowly removed this reversing field gets gradually weaker and weaker until it has erased all trace of the original field.
Need it magnetized again, just grab the magnet.

Back hoe log splitter

Back hoe log splitter
Splitting wood with a backhoe
I built a log splitter for my backhoe with 1/2" steel plate. A local steel yard cut the pieces for me, so All I had to do was weld it together. I remove the bucket and use the bucket curl cylinder to push the ram.
It works quite well, and has enough power for pretty much everything that I have tried to split.
To make it operable by one person, I rigged up a rope and pulley system that lets me operate the valve from the splitter end.

weed whacker motor converted to bicycle motor

weed whacker motor converted to bicycle motor
Bicycle drive
About 12 years ago, I decided to build a powered bicycle, so I dismantled my seldom used weed whacker and built a three speed drive system that attached to the motor. I put it on the front wheel of a bike, with a hand shifter so I could move it through the gears. It worked pretty well as far as pushing the bike, with top speed being faster than I felt comfortable going. I could not stand the noise and fumes, so I removed it.
I just ran into the motor/drive when looking for something else, so I figured I would snap a few photos in case someone else wants to play with a similar concept.

aluminum tape again

aluminum tape again
Re-Sealing that can
I needed to varnish a piece of wood, and as usual, the cover of the can was stuck so strongly (had been previously opened) that I had to damage the seal to get the cover off. Faced with loosing the rest of the mostly full gallon of varnish, I pulled out the roll of aluminum tape again, and was able to seal the top.
I opened the can three weeks after sealing it, and the varnish was perfect, with no skin on the surface.Looks like it works.

Handy use for Aluminum tape.

Need to make a template for a bracket? Aluminum tape works pretty good.
Thanks to Randall Burkhalter for this tip.
Remove the backing and fold sticky side to sticky side. A little stiff, holds its shape fairly well and flattens back out so a pattern can be transfered to the desired material. It can be cut with scissors, and when you get it into place, small mounting holes can be outlined by slightly pressing the aluminum tape around the edges of the hole or sticking a pointed object through the tape into the hole.

It worked very well for the bracket shown, as there wasn't a real good way to measure distances between the 3 mounting holes.
Handy use for Aluminum tape.
Making a pattern out of aluminum tape.

Motorizing a snow blower chute

Motorizing a snow blower chute
remote chute operator
Tired of cranking the chute with one hand while trying to control your snow blower with the other.
If you have a 12V light on the blower, this will work with no batteries. Cover the motors with a small plastic grocery bag when using.
The chute raise/lower motor is mounted to the chute with a bracket, and uses a square steel bar for the actuator. The bar is attached to the motor shaft with a setscrew.
The chute rotation motor is coupled to the chute rotation screw with a simple dual set screw coupling. The motor floats free, with an aluminum fork to stop the rotation. This type of attachment allows lots of slop and misalignment, and is easy to make. This has been part of my snowblower for the past 5 years.

Some uses of laser pointers

We all should have a couple of laser pointers sitting in the "used to be cool toy box" There are many uses for those lasers other than the usual pointer application.
Detecting things:
I have used them for generating an electrical signal when detecting things. I needed a flow meter to detect the flow rate of the heat exchanger for my solar heating system. To buy a unit with high accuracy, and a readout, was in the several hundred dollar range. I found this cute German made home water meter for less than $100. It only had one pulse output for every gallon, which was not sufficiently accurate to measure the sub gallon per minute rates that were sometmes necessary. I mounted a laser pointer so that it shined through the notches on the rotating disk that was right on the flow turbine, so it turned hundreds of times to each gallon of flow, and gave multiple puldes per revolution. I mounted a photodetector in a blackened tube, and glued a lens on the front of the tube. The detector assembly was focused on the notches of the rotating disk. and was able to generate a pulse stream for each rotation. This pulse was buffered, amplified and converted to a digital pulse that was read by the controlling computer to regulate the speed of the pump to produce a constant flow rate.

Some uses of laser pointers
Detecting a rotating disk