Auto-Trickler Gently Doles Out Powder To Assist Reloading

May 2, 2019 by Dan Maloney 41 Comments

Do you even trickle?

[Eric] does, and like everything else about reloading, trickling is serious business. Getting an exact charge of powder to add to a cartridge is not a simple task, and very tedious when done manually. This smartphone-controlled auto-trickler is intended to make the job easier, safer, and more precise.

Reloading ammunition is a great way for shooters to save money and recycle the brass casings that pile up at the end of a long day at the range. It can be a fairly simple process of cleaning the casings, replacing the spent primers, adding the correct powder charge, and seating a new bullet. It’s all pretty straightforward, but the devil is in the details, especially with the powder charge. A little too much can be a big problem, so tricklers were invented to allow the reloader to sneak up on the proper charge. [Eric]’s auto-trickler interfaces to a digital powder scale and uses a standard cell phone vibration motor to gently coax single kernels of powder from a hopper until the proper charge has accumulated. It’s easier to understand by watching the video below.

The hardware behind the trickler is pretty standard — just a Raspberry Pi Zero to talk to the smartphone UI via Bluetooth, and to monitor and control the scale via USB. [Eric] has made all the code open source so that anyone can build their own auto-trickler, which we applaud; he did the same thing with his rifle-mounted accelerometer. This project might have applications far beyond reloading where precision dispensing is required.

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Fire Extinguisher Ball Mill Destined To Grind Kitty Litter

March 2, 2018 by Dan Maloney 15 Comments

Nothing says hack like a tool quickly assembled from a few scrap-heap parts. For [Turbo Conquering Mega Eagle], his junkyard finds were a fire extinguisher, an old office fan, and a few scraps of plywood; the result was a quick and easy ball mill.

There’s very little mention of what said ball mill will be for — [TCME] said something about milling bentonite clay, AKA kitty litter — but that’s hardly the point. Having previously fabricated a much smaller version of this ball mill that could chuck up in his lathe, he scaled this one up considerably. The spent fire extinguisher was relieved of the valve and some external bits to create the mill’s drum. Plywood was used for a quick frame to support rollers and to turn a couple of pulleys for the running gear. The fan motor proved barely capable of performing, though, even with the mechanical advantage of the pulleys and an improvised drive belt. The motor just didn’t have the oomph to turn the drum when loaded with ceramic balls, but a quick adjustment to the drive train did the trick. The video below shows the whole build process, which couldn’t have taken much more than a couple of hours.

It looks like a sand casting project may be on deck for [TCME]’s milled bentonite, so we’ll look forward to that. Perhaps his other recent fire extinguisher build will make an appearance in that video too.

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A quick brush over the part with some sand paper and it quickly transforms from obviously plastic to metallic.

Learn Resin Casting Techniques: Cold Casting

July 14, 2016 by Gerrit Coetzee 36 Comments

Sometimes we need the look, feel, and weight of a metal part in a project, but not the metal itself. Maybe you’re going for that retro look. Maybe you’re restoring an old radio and you have one brass piece but not another. It’s possible to get a very metal like part without all of the expense and heat required in casting or the long hours in the metal fabrication shop.

Before investing in the materials for cold casting, it’s best to have practical expectations. A cold cast part will not take a high polish very well, but for brushed and satin it can be nearly indistinguishable from a cast part. The cold cast part will have a metal weight to it, but it clinks like ceramic. It will feel cool and transfers heat fairly well, but I don’t have numbers for you. Parts made with brass, copper, and iron dust will patina accordingly. If you want them to hold a bright shine they will need to be treated with shellac or an equivalent coating afterward; luckily the thermoset resins are usually pretty inert so any coating used on metal for the same purpose will do.

It is best to think of the material as behaving more or less like a glass filled nylon such as the kind used for the casing of a power tool. It will be stiff. It will flex a relatively short distance before crazing and then cracking at the stress points. It will be significantly stronger than a 3D printed part, weaker than a pure resin part, and depending on the metal; weaker than the metal it is meant to imitate.

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DIY Powder Coating

October 25, 2015 by Brian Benchoff 65 Comments

If you don’t yet have a toaster oven you can’t use with food, here’s yet another reason: DIY powder coating. Powder coating is much harder and more durable than paint – a property imbued to it by the fact that it’s baked on to a part. [Thomas] had a go at powder coating some skateboard trucks, and with the right tools, found the process downright easy.

[Thomas] only needed a few things to powder coat his parts, the first and most important being a powder coat gun. A few years ago, Craftsman produced a powder coat gun that’s still available on Amazon and eBay for about $50. Powders are plentiful and cheap in small quantities. The only other tools needed were an N95 or better respirator, some high temperature tape for masking off the part and a toaster oven. If you want to coat big parts, there are DIY oven options for that.

After the part was sandblasted down to bare metal, [Thomas] masked off all the holes and threads of the part with polyimide tape. Any tape that’s capable of withstanding high temperatures will do, and most of us have a roll of Kapton sitting next to a 3D printer, anyway.

The part is coated with powder via an electrostatic charge, and this means attaching a ground lead from the gun to the part. After that, it’s just filling the gun with powder, putting it in the oven set at 450°F, and letting the powder liquefy.

In the video below, you can see [Thomas] sandblasting, powdering, and baking a set of aluminum skateboard trucks using his method. Compared to other methods of finishing metal parts – anodizing or plating, for instance, powder coating is remarkably easy and something anyone can do in a garage.

Thanks [Tyler] for sending this one in.

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Hackaday Links: January 25, 2015

January 25, 2015 by Brian Benchoff 24 Comments

Misumi is doing something pretty interesting with their huge catalog of aluminum extrusions, rods, bolts, and nuts. They’re putting up BOMs for 3D printers. If you’ve ever built a printer with instructions you’ve somehow found on the RepRap wiki, you know how much of a pain it is to go through McMaster or Misumi to find the right parts. Right now they have three builds, one with linear guides, one with a linear shaft, and one with V-wheels.

So you’re finally looking at those fancy SLA or powder printers. If you’re printing an objet d’arte like the Stanford bunny or the Utah teapot and don’t want to waste material, you’re obviously going to print a thin shell of material. That thin shell isn’t very strong, so how do you infill it? Spheres, of course. By importing an object into Meshmixer, you can build a 3D honeycomb inside a printed object. Just be sure to put a hole in the bottom to let the extra resin or powder out.

Remember that episode of The Simpsons where Homer invented an automatic hammer? It’s been reinvented using a custom aluminum linkage, a freaking huge battery, and a solenoid. Next up is the makeup shotgun, and a reclining toilet.

[Jan] built a digitally controlled analog synth. We’ve seen a few of his ~~FM synths~~ VA synths built from an LPC-810 ARM chip before, but this is the first one that could reasonably be called an analog synth. He’s using a digital filter based on the Cypress PSoC-4.

The hip thing to do with 3D printers is low-poly Pokemon. I don’t know how it started, it’s just what the kids are doing these days. Those of us who were around for Gen 1 the first time it was released should notice a huge oversight by the entire 3D printing and Pokemon communities when it comes to low-poly Pokemon. I have corrected this oversight. I’ll work on a pure OpenSCAD model (thus ‘made completely out of programming code’) when I’m sufficiently bored.

*cough**bullshit* A camera that can see through walls *cough**bullshit* Seriously, what do you make of this?

Conductive Ink Circuit Experiments

May 18, 2012 by Mike Szczys 12 Comments

This glowing LED is proof that the experiments [Nvermeer] is doing with conductive ink are working. We’re filing this one as a chemistry hack because you need to hit the lab ahead of time in order to get the conductivity necessary for success. He reports that this technique uses a copper powder suspended in an epoxy intended for spray painting. Before mixing the two he etched the powder in ammonium persulfate, then washed it in deionized water which made it a much better conductor.

We gather that the ink was applied with the brush seen in the photo. But since this uses that spray paint friendly solution to host the copper powder we wonder about stenciling with something like masking tape in order to spray the circuit paths onto the substrate.

There’s not too much info up yet, but [Nvermeer] does link to one of our other favorite conductive ink projects.

Zinc Sulfide Glow Power At Home

October 3, 2010 by Mike Szczys 40 Comments

Further solidifying her mad-scientist persona, [Jeri Ellsworth] is making glow powder with household chemicals. When we saw the title of the video we though it would be fun to try it ourselves, but the first few minutes scared that out of us.

To gather the raw materials she puts some pennies in a bench motor and files them into powder. From there it’s trial and error with different cleaners and tools to create just the right dangerous reaction to get the chemical properties she’s looking for.

Check out her experiments after the break. And if you find you’re wanting more, go back and take a look at her EL wire fabrication process.

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