Building a one-ton linear servo

one_ton_servo_jack

A while back, [Windell] from Evil Mad Scientist Laboratories wrote up an article for Make Magazine detailing how he built a one-ton, servo-controlled scissor jack for under $100. He dropped us a line to let us know that the project details have been released for free at Make Projects, so we stopped by to take a look.

The project starts out by pulling apart an electronic scissor jack to get access to the solder pads for the up and down buttons. Once wires are added there, a servo is the next victim. [Windell] recommends using an old servo with a busted motor, but you can use a good one just the same. The servo’s pots are replaced with 10 turn pots, and then wired up to a controller board, to which the jack is also connected. Then, to provide feedback to the servo, a string is looped around the top of the jack, which is used to turn the pots added in the previous step.

[Windell] says that the setup works quite well, though we imagine the duty cycle might be a bit short before adjustments are required. Regardless, it’s a quick way to get a heavy load lifted with servo precision.

DIY high voltage electric field detector

electric_field_detector

Who needs a Fluke high voltage detector when you’ve got one of these things?

Actually, we still recommend a professional high voltage detector for serious work, but you’ve got to like this electric field detector that [Alessandro] recently put together.

The detector works by using a JFET to detect the high impedance electric fields that are generated by high voltage lines. The JFET amplifies the signal while dropping the impedance in order to drive a pair of NPN transistors which are used as a threshold amplifier. Once the voltage hits 3V, an LED is lit, indicating the presence of high voltage near the detector’s probe. A wire-wrapped resistor does double-duty serving as the probe while providing a high impedance path to ground, ensuring that stray charge does not accumulate on the JFET’s gate, causing false readings.

It’s a neat project, and something that can be constructed in no time, making it perfect for beginner electronics classes.

Keep reading to see a quick video of the HV detector in action.

[Read more...]

PC casemod-inspired benchtop PSU

benchtop_psu

[Will] had a cheap power supply sitting around, and decided to turn it into a full-featured benchtop PSU. Inspired by some of the other benchtop supplies we have featured in the past, he decided that he wanted his PSU to be more than just a simple-looking box sitting on his work bench. Taking some cues from PC case modding, he put together a unit that is not only very useful, but also quite sharp looking.

The frame of the case was crafted from aluminum angle, while all of the other flat surfaces were made using black polycarbonate. He installed the standard 12v, 3.3v, and 5v terminals you would expect from any benchtop PSU, complete with an LCD display showing the voltages provided by each rail as measured by an Arduino stationed inside the case. Additionally, he installed a variable terminal capable of providing 1.3v-30v, along with its own LCD display. The most unique feature is the multimeter embedded in the front of the case, which makes it virtually impossible to lose.

The case is finished off as you might expect, if you have seen any of his previous work. It features LED lighting on the inside, large fans on either side of the case for optimal air flow, and a pair of machined aluminum handles.

Be sure to check out the quick video below of the PSU being powered on.

[Read more...]

Hacking strippers to do your bidding

wire_strippers

[Alex] knows his strippers.

By his estimation, he has stripped millions of wires over the years, and he has seen his fair share of wire strippers come and go. That cheap set of wire strippers you have with the graduated holes, or that adjustable stripper you squeeze as you pull the wire through? They just stress the insulation as well as the wires you are trying to strip – he says you might as well just use them in your tackle box.

His favorite style of wire stripper is the automatic kind that grip the wire, then cut and remove the insulation just by squeezing the handles. His issue with this particular tool is that it’s difficult to get a uniform length of stripped wire when working in volume.

Since [Alex] needs uniformity in his line of work, he modified a set of automatic wire strippers to include an adjustable wire stop. He determines the length of wire he needs, adds or removes some washers from his wire stop, and off he goes. It’s a very simple yet very useful hack, depending on your application. We bet it is probably one of the most accurate ways to get uniform length, this side of a fully automatic wire stripper.

Easy to build rig prevents reflow soldering mishaps

reflow_soldering_rig

[Erich aka VK5HSE] performs quite a bit of solder reflow work, but has always been concerned about bumping his circuit boards once the solder has liquified and is ready to be removed from the heat source. He says that removing workpieces from toaster ovens often results in the unintentional jarring of a circuit board full of components sitting on molten solder, and he wanted to find a solution.

Using some off-the shelf components from a local hardware store, he built a rig that fits on top of a hot plate, allowing him to move hot circuit boards away from the heat source in a smooth controlled motion. The rig is pretty simple, not only preventing unwanted workpiece movement, but also making it easy to regulate the amount of time a circuit board is allowed to heat.

He suggests that his design is not absolutely ideal, and that it can easily be improved upon in several ways without adding significant cost to the project.

Shovel…guitar?

We didn’t believe this hack at all when we saw it, or rather heard it. Surly a guitar made out of a shovel couldn’t sound decent. But the video (after the jump, skip to 2:40 for the jam) to our untrained ears sounded pretty rad. Could be the supremely well done wood work, proper use of tools, high tech pickups, or maybe Russian magic, we don’t know.

In fact, if you continue the video it doesn’t stop there. The creators also made a 2 string bass and a few other instruments from shovels. Do I smell a new shovel hero?

Related: Guitars made out of things that should not be guitars.

[Thanks Paul]

[Read more...]

Bus Pirate preorder 2 update

bp-unbox-0

A few weeks ago we held a preorder for the Bus Pirate universal serial interface tool. We split the preorder into two parts due to a shortage of PIC 24FJ64GA002-I/SO chips. The first preorder is arriving worldwide now, the second preorder has a longer lead time. Here’s everything we currently know about preorder 2, it’s subject to change, but we wanted to keep you up to date.

Preorder 2 contains orders for 563 Bus Pirates. Seeed Studio noticed an error in our quality control testing routine that misclassified about 50 preorder 1 Bus Pirates as defective. We updated the test and passing units will ship immediately to preorder 2 participants on a first come, first serve basis. Another 500 PICs are scheduled to arrive after August 1, which should take care of most remaining orders.

[Read more...]

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