PID Controlled Glue Gun

Internals of a glue gun controlled with a PID controller

Hot glue falls into the same category of duct tape and zip ties as a versatile material for fixing anything that needs to be stuck together. [Ed]’s Bosch glue gun served him well, but after a couple of years the temperature regulation stopped working. Rather than buying a new one, he decided to rip it apart.

With the old temperature regulation circuit cooked, [Ed] looked around for something better on eBay. He came across a cheap PID temperature controller, and the Frankengluegun was born.

A thermocouple, affixed with some kapton tape and thermal paste, was used to measure the temperature of the barrel. Power for the glue gun was routed through the PID controller, which uses PWM to accurately controller the temperature. All the wiring could even be routed through the original cord grips for a clean build.

Quality glue guns with accurate temperature control are quite pricey. This solution can be added on to a glue gun for less than $30, and the final product looks just as good.

Using Surface Mount Devices On A Breadboard

[Czar] was working on a project with the Raspberry Pi using the MCP3008 analog to digital converter. The surface mount SOIC version of this chip was slightly cheaper, and there’s always a way to make that work (Portuguese, Google Translation). How [Czar] did it is fairly impressive, as it’s a bit more flexible for breadboard designs than a through-hole version, and done correctly, is an extremely sturdy hack.

A few new leads needed to be soldered onto the SOIC package, and for this [Czar] chose jumper wires. This makes each pin easy to plug into a solderless breadboard, and since [Czar] was extremely clever, all the wires for power, ground, analog, and SPI are color coded.

Simply soldering a few jumper wires onto a chip won’t last for very long. To solve this problem, [Czar] potted the entire chip and its connections with hot glue. Probably not the best solution, and a heavy-duty epoxy would have been better, but the current build is more than enough to stand up to the relatively minor abuse it will receive on the workbench.

Injection Molding With Hot Glue

Injection molding is simply forcing a melted thermoplastic into a mold of some sort, letting it cool, and then prying the mold apart to get to the finished piece. Hot glue guns are basically handheld thermoplastic extruders, so when [scorch] dug up some old injection molds he had sitting around, it didn’t take long to put two and two together.

Injection molds aren’t something any normal person has sitting around, but a few years ago [scorch] found two books published by Gingery, the same people who have published instructions on how to build a metalshop from scrap. [scorch] created his molds on a small CNC mill – a Sieg X3 – and his initial experiments with injection molded plastic were fairly successful, even if the molds were made from self-cast billets.

After molding a few hot glue LEGO parts with his equipment, [scorch] had a look around the Internet and noticed this was nothing new. One company even sells a hot glue gun-based injection molding kit using polyethylene glue sticks. Their demo video (seen below) seems much more complicated than [scorch]’s efforts, so  we’ll say he came out ahead on this one.

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Hackaday Links: February 9, 2014

hackaday-links-chain

Here’s a quick tip to extend the usefulness of your multimeter. It’s a set of mini test hooks soldered to alligator clips with a short hunk of stranded wire in between. You can buy mini test hooks that go right on the metal probes of your meter, but the weight and bulk of the meter probes and cords sometimes get in the way. This rig allows more flexibility because of that wire.

Staying on the theme of test equipment tips, here’s a simple way to make a Y-connector for logic analyzers. [Thomas] uses a dual-row pin header, shorting each pair of pins so that both rows are connected. When this is plugged into a pin socket it leave two pins for connecting your test equipment and the rest of the project hardware.

After seeing our feature of a 3-wire Character LCD [Chad] wrote in to mention he built a 1-wire version using an ATmega328.

If you’re going to be in Anaheim this week you can stop by the ATX-West expo and see a 3D printer with a 1m x 1m x 0.5m printing area. [Thanks Martin]

Speaking of 3D printers, here’s a big delta robot (seven feet tall) outfitted for alternative material printing. It’s printing a CT scan of ribs and a heart in hot glue. This seems to be a popular material for more artistic uses. We just saw a hexapod which deposits hot glue as it roams.

The weaponized quadcopter post from Tuesday was a controversial one. The really bad part of it was the laser, which strapped to anything is extremely dangerous. But the other hack may have just been poorly executed. Hackaday alum [Jeremy Cook] wrote in to mention that fireworks and quadcopters can be used more responsibly. He strapped a sparkler to his quadro and used it to make light graffiti. You may remember that [Jeremy] wrote an introduction to light graffiti for us back in November.

Is A LEGO 3D Printer By Definition Self-replicating?

lego-3d-printer

LEGO parts are plastic. 3D printers make parts out of plastic. So the transitive property tells us that a LEGO 3D printer should be able to recreate itself. This one’s not quite there yet, mostly because it doesn’t use plastic filament as a printing medium. Look close and you’ll probably recognize that extruder as the tip of a hot glue gun. If all else fails you can use the machine as a precision hot glue applicator.

The instructions to make your own version include the design reference and a few ideas for getting the most out of the glue dispenser. For the design phase [Matstermind] used LEGO Digital Designer. It’s basically CAD with the entire library of LEGO parts available as building blocks. from there he assembled the machine which is controlled by an NXT brick. He goes on to link to a few different printing mediums. There’s instructions for using crayons to make colored glue sticks, as well as a method of printing in sugar using the hot glue extruder.

We remember seeing one other LEGO 3D printer. That one didn’t use an extruder either. It placed blocks based on the design to be printed.

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Tearing Apart A Hot Glue Gun For A 3D Printer

If you’re building a 3D printer, the most complicated part is the extruder. This part uses a series of gears to pull plastic filament off of a spool, heats it up, and squirts it out in a manner precise enough to build objects one layer at a time. [Chris] made his own extruder out of a hot glue gun and made it so simple we’re surprised we haven’t seen this build before.

The basic operations of a plastic extruder – pushing a rod of plastic through a heated nozzle – already exists in a hot glue gun available for $3 at WalMart. To build his printer, [Chris] tor apart the hot glue gun and mounted the nozzle on a piece of plywood. The hot glue sticks are fed into the nozzle with the help of a 3D printed gear and a stepper motor driver.

After the break, you can see [Chris]’s hot glue gun RepRap printing a 10cm cube. It’s not fast, but the quality is exceptional, especially considering he made it out of a hot glue gun.

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Climbing Robot Glues It’s Own Feet To The Wall

The problem of gripping all surfaces has always plagued the field of climbing robotics. But if you don’t care about damaging the wall, why not just let the robot glue its feet to the surface. That’s exactly how this robot does it, using a couple of climbing feet in conjunction with a hot melt glue gun wielding arm. It seems to be a predecessor of the hot glue 3D printing robot which we saw last week.

Check out the video to get a full overview of the climbing process, but here’s the gist of it. The legs and arm are able to pivot around the central axis of the robot, parallel to the climbing surface. Once one leg is glued in place the robot swivels around it so that the body is directly above that leg. From there it reaches up with the arm to deposit some glue on the wall, then moves it out of the way so the other foot can be pressed against the hot adhesive. When the newly attached foot has cooled sufficiently, the lower foot is reheated to free it from the wall. At this point the whole process repeats.

We’re still fond of vacuum-based climbers like this parachute-equipped robot. But the design of the hot-glue arm on this guy is something that might make it into one of our own projects someday.

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