New Cooling for the Laser Cutter – Part 1

Last Thursday, Ben and Kevin started experimenting with a proper closed loop cooling system for the laser cutter. This is something we’ve wanted to do for some time, as it’ll make the laser easier to move and less likely to spill coolant all over the floor (again). The big push now is that the existing coolant pump is getting noisy, so it’s an ergonomic consideration ūüôā

Most of the parts for this build were sourced from the junk pile, including the reservoir, fan and pump. We bought a cheap ebay radiator and a bunch of plastic fittings.

At this point, we’ve got a few slow drips to chase down, and need to figure out how to enclose the system, but as evidenced in the picture, it cools pretty well. Ben is using a blowtorch on that piece of copper tube (our stand-in laser tube), and it’s cool to the touch immediately after removing the fire.

Toner Transfer Testing


My wife ask about me lasercutting a sign for some friends, but at the time she ask, our laser was still down for repairs. I remembered Ben doing a toner transfer project several years ago, so I googled it up, and it turned out to be easier than I remembered.

This isn’t intended to be a tutorial, but the general steps are as follows:

  • Print Design on a laser printer (mirrored)
  • Sand wooden surface (I bought a prefab plaque at Michaels 40% off)
  • Tape paper to surface so it doesn’t move around
  • Apply acetone (a little goes a long way)
  • Remove paper before toner bleeds everywhere.
  • Apply clear finish

This was my first try at toner transfer ever, and the photo below wasn’t my final product. The toner doesn’t soak in very deep, so it’s easily sanded off for another attempt.¬† I ended up resanding and transferring 3 times, due to incomplete transfer or smudging (as below).

Lighter weight paper seemed to work better (the paper at OMG was quite a bit lighter than what I had at home, and worked great) as it didn’t want to soak up so much acetone, and transferred more completely as a result.

Once I was satisfied with the transfer results, a quick coat of spray lacquer finished the project.  Setup, drying and cleanup took the majority of the time and effort here. Total hands-on time was about 15 minutes.

Spice Rack

This is just a quick and dirty spice rack I put together for my wife. It’s a piece of plywood (supported at an angle by a chunk of 2×4) with some maple cleats glued and stapled to the front. Figuring out the size and placement of the cleats took the longest (Thanks Ben and Eric), but the entire project only took an hour or so. I wasn’t originally going for a documented tutorial, so the pictures are just of the finished product. Someone else’s measurements would vary anyhow, given the sizes of their cupboard and its contents. It’s the thought that counts, right?

New Ryobi Tool Center

It’s been a few months now, but I’m finally getting to documenting the tool storage wall we built. I found a plan online to build some PVC drill/driver hangers, and adapted it to carry the grinder, glue gun and angle drill by their battery holders.

All the tools in one place!

The slanted pipes below the drills are some spare PVC cemented to a piece of Sintra (which is also PVC, so I used pipe solvent). These tubes, which have since been labeled, hold cylindrical tools, such as our rotary and oscillating multitools and apparently a caulk gun.

If you’re in the market for some drill hangers for yourself, we have a fancy jig built (for 3″ pipe, but 4″ works too), so c’mon down and build some for yourself!

Raspberry Pi NES Build

Over the years I’ve played around with the Raspberry Pi to see what I can get it to do. I have limited programming skills and rely heavily on the opensource community and how-to documents.

The most successful projects I’ve done with the Raspberry Pi have revolved around using them as DNS and VPN servers. I also have them running with a monitor and wireless keyboard/trackpad combo in the basement utility room and garage. The screen on my phone to look up something in those rooms gets to be a little small and I’m usually using the phone as a flashlight so having a full sized monitor comes in very handy.

One of the things I’ve wanted to do for a while is build a portable gaming machine. Something that could easily go in luggage and look decent to the TSA as it gets scanned. I tried putting something together in 2013 with a Raspberry Pi B first gen, but struggled with lag and the controller setup. As luck would have it, I’ve had an extra Raspberry Pi 3 Model B sitting around I’ve been trying different projects with, but haven’t found the one until I read about RetroPie again.

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Robots!

This past Tuesday, Jeff Jensen, a long time friend of OMG was at our regular meeting to get some help with mechanical assembly and soldering of a dozen CEENBoT units. Jeff is part of a program that develops the CEENBoT robots for education and the program has been so successful that Jeff is overloaded with requests for new robots, so several OMG members jumped in to help out.

We had several other visitors, including first-time guest Chris, who promptly jumped in to help out. This really embodies the spirit of OMG, creating an environment where folks feel comfortable getting involved in whatever’s going on.

Thanks to everyone who helped out on Tuesday!

Banker’s Box Storage Plans


For years, our makerspace has used a hodgepodge of solutions for storing members’ projects in progress and other personal belongings. ¬†Most recently, we’ve used a dozen or so plastic totes. ¬†The totes worked great, but were limited in quantity (they were industrial waste, and no more matching totes were available) so that not everyone could have one. ¬†Additionally, these totes were slightly trapezoidal, which wasted quite a bit of space between them.

To that end, Ben and Kevin undertook a project to convert personal storage to standard Letter/Legal Banker’s Boxes, which are readily available and pack more densely. ¬†They are a bit smaller than the totes we were using, but most members totes weren’t full, and we can store twice as many boxes in the same space.

Read on for full plans and assembly instructions.

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LiPo Battery Ruggedized Power Module

A while back, we decided that we needed a 24v power source for various “testing” applications. This source needed to be durable enough for daily use by a wide variety of people without becoming damaged. It also needed to protect the device being powered, and be easy to maintain.

Given that tall list, Ben suggested a HobbyKing LiPo pack, 6S, 5Ah. With that start, we decided that it should have volt and amp meters for monitoring, as well as a circuit breaker to provide√ā¬†positive√ā¬†power disconnect, and protect the battery (easily capable of 150A into a dead short).Meters were ordered from Ebay and the breaker was something out of an old UPS.

The blue enclosure is a waterproof storage box from Walmart, modified to pass through various connectors. √ā¬†It’s not waterproof at this point, but we’re more after the durability of the polycarbonate than the waterproof aspect anyhow.

Internally, there’s quite a bit going on. √ā¬†The battery is packed into a foamed-off area, while the other side contains the electronics, including the circuit breaker,ammeter shunt and all the connectors.

Charging is accomplished via a modified ATX connector (which re-presents the balance plug and main power leads), with a fuse to protect against abuse. The idea is that it’s virtually impossible to charge the battery improperly, or to break a relatively fragile balance connector.

Overall, it was a pretty straight-forward build, and cost around $90, including the battery and all the connectors.

Microscope Photography – Integrated Circuits

On Tuesday night, we were disassembling some old printers, and salvaged some large ROM chips. Patrick got the idea to use the mill to remove the top layer of the case, and expose the IC inside. √ā¬†Here are some photos we took of the chip’s insides with a microscope. Magnifications range between 4x and 40x, thought the 40x were pretty difficult to illuminate properly, because the lens obscures most of the light. As for the cameras, we √ā¬†used a little point and shoot and a cell phone camera, both just held up to the microscope’s eyepiece.