Add CNC to your…Propane Tank??!?

It’s starting to be that time of year again; the Halloween-themed hacks are rolling in.

[John Lauer] needed a propane-powered flame effect for his backyard ICBM “crash site”. Rather than pony up for an expensive, electronically-controlled propane
valve, he made a custom bracket to connect a stepper motor to the propane burner’s existing valve.

With the stepper motor connected up, a TinyG stepper motor controller and [John's] own graphical interface, ChiliPeppr, take care of the rest.

The hack is almost certainly a case of “everything looks like a nail when you have a hammer” but you have to admit that it works well and probably didn’t take [John] all that much time to whip up. Maybe everyone should have a couple spare stepper motors with driver circuitry just lying around ready to go? You know, just in case.

All the details of the build are in the video. If you’re done watching the flames, skip to around 2:50 where we see the adapter in action and then [John] steps us through its construction.

You may have seen coverage of the TinyG motor controller here before.

Additional thanks to [Alden Hart] for the tip.

Sound Isolation Box Makes Living Room Based CNC Routing Tolerable

CNC Machines can be loud, especially if they are equipped with a high-speed router spindle. Unfortunately, such a loud racket could be a problem for the apartment dwellers out there. Fear Not! [Petteri] has come up with a solution. It’s a sound isolation enclosure for his mini CNC Router that doubles as furniture. It keeps the sound and dust in while pumping out some cool parts….. in his living room.

What may just look like a box with an upholstered top actually had a lot of thought put into the design. The front MDF panel folds down to lay flat on the floor so that the user can kneel on it to access the machine without putting unnecessary stress on the door hinges. The top also is hinged to allow some top-down access or permit a quick peek on the status of a job. All of the internal corners of the box were caulked to be air tight, even a little air passageway would allow sound and dust to escape. Two-centimeter thick sound insulation lines the entire interior of the box and the two access lids have rubber sealing strips to ensure an air tight seal when closed.

With stepper motors, the spindle motor and control electronics all running inside an enclosed box, there is some concern over heat build up. [Petteri] hasn’t had any problems with that so far but he still installed an over-temp power cutoff made from a GFCI outlet and a thermostat temperature switch. This unit will cut the mains power if the temperature gets over 50º C by intentionally tripping the GFCI outlet. None of the internal parts will ignite under 300º C, so there is quite a safety buffer.

Although the isolation box came out pretty good, [Petteri] admits there is room for improvement; when cutting wood or aluminum, the noise level is kind of annoying. If he had to do it again, he would use thicker MDF, 20mm instead of 5mm. However, during general use while cutting plastic, the router is still quieter than his dishwasher.

Video below.

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The TinyG Motion Controller

When you go to a trade show of any kind, you’re expecting cool demos in the booths. At Maker Faire, there were plenty, but one of the most hypnotic was a robot built around Synthetos’ TinyG motion controller.

The demo was simply a large CNC gantry moving a ball bearing around on a string. The gantry moved in the X and Y axes, and the miniature wrecking ball was spooled and unspooled in the Z axis. The ball move around the space, coming to a complete stop without any swaying. There were even a few clear plastic tubes that the ball fell in, and popped out of without raising or lowering the string. It’s the height of motion controller coolness, all made possible with the TinyG.

The TinyG was one of a few motion control and CNC boards found at the faire. In its base configuration, it has 6 axes of motion control, RS485 to network several boards for crazy machine configurations, and a suitably powerful processor to do everything correctly.

A Folding Laser Cutter

Want a laser cutter, but don’t have the space for one? How about a portable machine to engrave and cut wood and plastics? A folding laser cutter solves these problems, and that’s exactly what Red Ant Lasers was showing off last weekend at Maker Faire.

Inside the team’s Origami laser cutter is a 40 Watt CO2 tube, shooting its beam along an entirely enclosed beam path. The beam travels through the body of the machine, out into the folding arm of the machine, and down to whatever material you’ve placed the Origami on. It’s a 40 Watt laser so it will cut plywood and plastics, and as shown in the video above, does a fine job at engraving plywood.

This is a Class 4 laser device operating without any safety glass, but from the short time I spent with the Red Ant team, this is a reasonably safe device. You will need safety glasses if you’re within five feet, but after that, everything (according to OSHA, I think) is safe and not dangerous. Either way, it’s a tool just like a table saw. You don’t see commentors on the Internet complaining about how a spinning metal blade is dangerous all the time, do you?

The Red Ant guys are currently running a Kickstarter for their project, with a complete unit going for $4200. It’s pricier than a lot of other lasers, but not being constrained by the size of a laser cutters enclosure does open up a few interesting possibilities. You could conceivably cut a 4×8 sheet of plywood with this thing, and exceptionally large engravings start looking easy when you have a portable laser cutter.

Cryogenic Machining: Custom Rubber Parts

Fashioning a custom, one-off rubber part for your project isn’t usually an option, but [Ben Krasnow] has an alternative to injection molding and casting: machining frozen rubber.

As [Ben] points out, you can’t exactly pop a sheet of rubber on your mill and CNC the needed shape; the bit will push the material around rather than cut it. Freezing the rubber first, however, allows you to carve into the now-hardened material.

His initial setup consisted of a sheet of aluminum with water drizzled on top, a square of neoprene placed on the water, and a steady stream of -60 to -80C alcohol flowing directly onto the rubber. The water underneath freezes, holding the neoprene in place. This proved problematic as the ice-clamp gives way before the milling is complete. [Ben] later adds some bolts to clamp the pieces down, allowing the milling process finish as planned.

A small plastic tray sits underneath this assembly to capture the alcohol as it runs off, feeding it back with some tubing. [Ben] recommends against a submersible aquarium pump—his initial choice—because the pump stopped working after a few minutes immersed in the chilly alcohol. An external, magnetically-driven pump solved the problem although it does require manual priming.

Stick around after the jump for the video and check out some of [Ben's] other projects, like his quest for the perfect cookie, or CT scanning a turkey.

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THP Semifinalist: Farmbot

The FarmBot team has been pretty busy with their CNC Farming and Gathering machine. The idea is to automate the farming process with precise deployment of tools: plows, seed injection, watering, sensors, etc. An Arduino with an added RAMPS handles the movement, and a Raspi provides internet connectivity. Their prototype has already experienced four major iterations: the first revision addressed bigger issues such as frame/track stability and simplification of parts. Now they’re locking down the specifics on internet-of-things integration and coding for advanced movement functions.

The most recent upgrade provides a significant improvement by overhauling the implementation of the tools. Originally, the team envisioned a single, multi-function tool head design that carried everything around all the time. Problem is, the tool that’s in-use probably works best if it’s lower than the others, and piling them all onto one piece spells trouble. The solution? a universal tool mounting system, of course. You can see them testing their design in a video after the break.

If the FarmBot progress isn’t impressive enough—and admittedly we’d have called project lead [Rory Aronson] crazy for attempting to pull this off…but he did it—the FarmBot crew started and successfully funded an entire sub-project through Kickstarter. OpenFarm is an open-source database set to become the go-to wiki for all things farming and gardening. It’s the result of [Rory] encountering an overwhelming amount of generic, poorly written advice on plant growing, so he just crowdsourced a solution. You know, no sweat.


SpaceWrencherThe project featured in this post is a semifinalist in The Hackaday Prize.

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USB to DB25 Adapter Uses GRBL For Parallel Port CNC Communication

With the continuing manufacture of new computers, there is a clear and obvious trend of the parallel port becoming less and less common. For our younger readers; the parallel port is an interface standard used for bi-directional communication between a computer and a variety of peripherals. The parallel port’s demise is partially due to the invention of the USB standard.

If tinkering with CNC Machines is one of your hobbies then you are familiar with the parallel port interface being fairly popular for CNC control board connections. So what do you do if your new fancy computer doesn’t have a parallel port but you still want to run your CNC Machine? Well, you are certainly not stuck as [Bray] has come up with a USB to Parallel Port Adapter solution specifically for CNC use.

A cheap off-the-shelf USB to DB25 adapter may look like a good idea at first glance but they won’t work for a CNC application. [Bray's] adapter is Arduino-based and runs GRBL. The GRBL code is responsible for taking the g-code commands sent from the computer, storing them in a buffer until they are ready to be converted to step and direction signals and sent to the CNC controller by way of the parallel port DB25 connector. This is a great solution for people needing to control a CNC Machine but do not have a parallel port available.

[Bray] is using a Raspberry Pi running GRBLweb to control his adapter board. However, there are other programs you can use to communicate with GRBL such as Universal G-Code Sender and GRBL Controller.

The board has been created in Eagle PCB Software and milled out using [Bray's] CNC Router. The design is single-sided which is great for home-brew PCBs. He’s even made a daughter board for Start, Hold and Reset input buttons. As all great DIYers, [Bray] has made his board and schematic files available for others to download.