Hacking Amazing Soldering Features Into The Already Great Weller WMRP

May 11, 2015 by Anool Mahidharia 35 Comments

Weller, the German soldering tools manufacturer, has a nice range of micro soldering irons (pencils) designated as the WMRP series. These are 12V, 40 W or 55W units with a 3 second heat up time, and allow quick tip exchange without needing any tools. [FlyGlas] built a neat soldering station / controller for the WMRP series based around an ATMega microcontroller running Arduino.

It’s packed with most of the features you see in a professional rig.

low offset op amp for soldering tip temperature measurement with type c thermocouple
cold junction compensation using the PTC (KTY82-210) included in the WMRP soldering pencil
input voltage measurement
soldering pencil current measurement
recognizing if the soldering pencil rests in the stand (–> standby)
3 buttons to save and recall temperature values
rotary encoder to set soldering temperature
illuminated 16×2 character LCD module
USB for debugging and firmware update
4mm safety socket for +12V power input and a protective earth socket for connection to ESD protection

A PWM signal from the microcontroller controls the load current using a MOSFET. Load current is measured using a Hall Effect-Based Linear Current Sensor – ACS712. The corresponding linear output voltage is buffered and slightly amplified using AD8552 zero drift, single supply, RRIO Dual Op Amp before being sent to the microcontroller ADC input. To ensure ADC measurements are accurate and stable, a low noise precision voltage reference – ADR392 is used. Another precision resistive voltage divider allows input voltage measurement. The supply input has over-current and reverse voltage protection. A set of buttons and a rotary encoder are connected to the microcontroller to allow settings and adjustments. An analog section measures the thermocouple voltage from the soldering pencil as well as the stand-by switch status. The handle has an embedded reed switch that is activated by a magnet in the support stand which puts it into stand-by mode. Another analog section performs cold junction compensation using the PTC sensor within the soldering pencil.

The Git repo contains the initial Arduino code which is still a work in progress. While the hardware source files are not available, the repo does have the pdf’s, gerbers and BOM list, if you want to take a shot at building it. Check a demo video after the break. Thanks [Martin] for sending in the tip.

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DIY Concrete Mixing Wheelbarrow Made From Recycled Parts

May 11, 2015 by Rich Bremer 18 Comments

[Dan] had a bunch of concrete mixing to do. Sure, it was possible to stand there and mix concrete and water in a wheelbarrow for hours and hours but that sounds like a tedious task. Instead, [Dan] looked around the shop to see if he had parts available to make a concrete mixer. As you may have guessed, he did. Instead of stopping at just a concrete mixer, he decided to make a concrete mixing wheelbarrow!

The frame is built out of plywood left over from a past canoe project. The frame holds a mixing barrel that was also hanging around the shop. From the photo, the drive system looks simple but it is not. First, the small motor pulley spins a larger pulley that is in-line with the barrel. Gearing down the drive this way increases torque available to spin the barrel, and that gear reduction is necessary to spin the heavy concrete slowly. What you can’t see is a planetary gear system that gears down the drive train again. The gears are cut out of plywood and were designed in this Gear Generator program. The sun (center) gear of the planetary setup is supported by another scavenged part, a wheel bearing from a Chevy minivan.

Now [Dan] can mix all the concrete he wants, wheel it over and dump it wherever he needs it. With the exception of the drive belt and some miscellaneous hardware, all the parts were recycled.

New Cross Bladed Axe Not For Cosplay Or Larping

May 9, 2015 by Rich Bremer 51 Comments

Firewood aficionado and general axing enthusiast [KH4] likes to cut and split his own fire wood. To burn a tree trunk sized piece of wood efficiently, it has to be split into 4 smaller pieces. [KH4] does this with 3 axe swings, the first splitting the main log in 2, then splitting each half in half again. Although he likes swinging the mighty axe, he still would like to increase the efficiency of each swing.

Well he’s done it! This is accomplished by making a Cross Bladed Axe that has an X-shaped head. Each axe swing should split a log into 4 pieces. That results in 66% less swings for the same amount of wood split!

This projected started with two spare axe heads. One was cut in half with an angle grinder. The two axe head halves were then ground down so that they match the contour of the original axe head. Once the fit was good, the welder was broken out and all 3 axe head pieces were combined into one beastly mass.

After the new head was polished and sharpened, it was re-assembled a new hickory handle. We have to say, the end product looks pretty awesome. There’s a video after the break of this axe in action. Check it out!

Have you ever seen how these axe heads used to be manufactured?

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Printed Tentacles For PCB Probing

May 9, 2015 by Anool Mahidharia 15 Comments

Every hacker workbench has one or more of those “helping hand” devices to aid in soldering and assembly. When it comes to testing and debugging though, it could get tricky if you have to start handling test probes while looking at the meter display or fiddling with knobs on the oscilloscope. Sometimes one has to test a board that has just pads for test points. Or maybe you need to directly probe pins on an IC. Checking multiple signals on I2C, SPI, Serial or USB is not too easy with just two hands. [Giuseppe Finizia] is an electronic engineer at the Scientific Investigations Department of the Carabinieri in Italy. He works as a senior analyst in the Electronic Forensics Unit and deal’s with technical investigations on seized electronic devices. To help him in his investigative work, he designed and built a 3D printed PCB workstation with octopus-like tentacles that provides all the additional fingers needed.

The tool is basically a base with adjustable clamps where the test PCB can be fixed. Around the base, up to twelve articulated “tentacles” can be fixed. Various test accessories are attached to the ends of these tentacles – Alligator Clips for holding electronic parts, IC Hook Clip Grabbers, Micro SMD Grabber Test Clips and some others that he is still working on. [Giuseppe] used MOI 3D modeling software to design his device, and the files are available on Thingiverse for download. He does warn that printing all the parts, specially the tentacle units, can be quite tricky on a regular 3D printer. He used a ZORTRAX M200 printer in high resolution mode and Z-HIPS filament. However, it may be easier to just use machine shop flexible coolant pipe for the tentacles. This may require some sort of modification to the base mounts and the business end of the tentacles though.

Thanks to [CFTechno] for sending in this tip.

Portable Workbench Is Solid And Space Saving

May 8, 2015 by George Graves 28 Comments

Last week we covered the topic of electronic work benches. But we know that there’s more to life than soldering irons and tiny components. Sometimes to pull off a hack, you need to get your hands dirty, and get some sawdust in your hair. If you’re limited on space, or need to be able to move to different locations quickly, this shop workbench may just be what you’re looking for.

First, let us preface that this project is not open source. Now before you “boo!” too loudly, the designer [Ron Paulk] only charges $10 for the plans. We think that is a small price to pay for how much though has gone into the design. But hey, if you’re a bit crafty, we bet you could easily reverse engineer the build just from the pictures alone. Personally, we think there are times when it’s a good thing to support a project like this.

The basic design allows the workbench to be very rigid, but light weight. And if you don’t have room for it to be permanently set up, it tears down and stores away nicely. It seems like the plans are well done, but if you need a bit more guidance, there is also a 15 part video series that will guide you along the way (here is the youtube playlist.) Also, there is an overview video after the break. So what are you waiting for? Go out and make something!

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Router Jig Makes Quick Work Of Flattening Irregular Shaped Wood

May 6, 2015 by Rich Bremer 27 Comments

[Nick Offerman] is a pretty serious wood worker. He likes to make crazy stuff including organic looking tables out of huge chunks of wood. Clearly, the wood doesn’t come out of the ground shaped like the above photo, it has to be intensely worked. [Nick] doesn’t have a huge saw or belt sander that can handle these massive blocks of wood so he built something that could. It’s a jig that allows him to use a standard wood router to shave each side down flat.

The process starts by taking a piece of tree trunk and roughing it into shape with a chainsaw. Once it is flat enough to not roll around, it’s put into a large jig with 4 posts. Horizontal beams are clamped to the posts and support a wooden tray which a wood router can slide back and forth in. The router’s cutting bit sticks out the bottom of the tray and slowly nibbles the surface flat. Once one side is flat, the block is rotated and the flat side is used as a reference to make all the other sides square to the first. After flattening, sanding and finishing the block results in a pretty sweet piece of functional artwork.

DIY Hydraulic Clamp Saves The Day

May 4, 2015 by James Hobson 33 Comments

[Elton] wrote in to tell us about a little excitement they had after this year’s ridiculous winter. Their pool froze and as luck would have it, crumpled the edge of the liner. They asked around and their pool company said they’d better involve their insurance company because it would not be easy to repair — so they decided to try fixing it themselves.

Now since the pool liner is a fairly heavy gauge sheet metal, they wouldn’t be able to simply hammer it back into shape — so they started brainstorming ways to make their very own hydraulic clamp. What they came up with is a very clever application of physics. And all it cost was about $2 in hardware plus some scrap lumber and a bottle jack they had lying around.

Some of their first ideas included a scissor style clamp, and even a monkey wrench-like vice, but in the end, the following design was chosen — and worked.

Ideally the hydraulic jack would be farther from the fulcrum, but since it’s rated for 2 tons it ended up being more than strong enough. To avoid scratching the liner, they also threw some socks on the end of the lumber. Still rather unwieldy, it was a two person job to pop it out. But once they got the major dents out, they were able to use a rubber mallet to finish the job off. Hooray for fluid power!

If you’re looking for the link, there isn’t one. [Elton] sent us his pictures and told us the story directly.