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 🙂

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.

Gingerbread Teaser

While we’re waiting on the “good photos” from Garrick, enjoy these two less good photos I snapped of some our members’ handiwork.  As always, we had quite the turnout for this event, with several members bringing friends and family to play along.

A special thanks to Sarah and Jeff for helping make it go off without a hitch, particularly in the processing and emergency procurement of our frosting supply.

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!

“Gingerbread” “House” Event – 12/19/2017

Hey gang, it’s time again for OMG’s annual Gingerbread House event. Note that this event has no actual gingerbread (we use graham crackers) and few, if any, “houses” in the traditional sense. In the past, we’ve seen locomotives, hobbit holes and skyscrapers.

This years’s event coincides with the regular meeting on December 19th. As usual, doors open around 5:30pm and people are usually around until 9 or 10pm. The start time is nominally 6pm, but realistically people will arrive and work on their construction whenever on that evening.

Frosting “mortar” and whatever decorations leftover from last year will be provided, but please consider bringing a box of crackers and some things to decorate with.

This is traditionally an “open house” sort of event, with folks bringing friends and family. The holidays are for group gatherings, after all.

Hope to see everyone there!

Coming Soon – Drill Torture Tests

Just a sneak preview of an upcoming “project” at OMG… Member Ben found a great old drill at Habitat ReStore, and it spawned a conversation about torture testing various drills under extreme circumstances.  As a test, we pitted Ben’s drill against one of our cordless Ryobis… More “sciencey testing” to follow.

Remember, these sorts of things aren’t really planned or scheduled in advance; the best way to get involved is to show up a the space on our regular Tuesday meeting nights (along with off-week Thursdays, like tomorrow night).  Doors typically open around 5:30, and you’re invited!


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!

Oscilloscope Music

A few weeks back, I caught a video on AvE’s YouTube channel of graphics drawn on an oscilloscope, given an audio input. Last week, Ben, Garrick and I decided to give it a try at OMG.

According to Garrick’s research earlier that week, “older scopes” do better with this sort of thing, and OMG’s scope is plenty old. We had to do some tinkering with the settings, and the phase, eventually arriving with the left channel on Input 2, alternating vertical and External trigger (ch2). It worked best if the laptop volume was turned clear up, as it gave the best signal to noise ratio.

We’d initially hooked the scope directly to a laptop headphone jack (through a spaghetti of cables), but as Eric pointed out “To be music, there’s gotta be…music”, and no devices we had would play on the headphone jack AND the internal speakers at the same time.  We ended up hacking up a powered speaker to give us a stereo output and play both channels on a single speaker. This gives us something to feed the oscilloscope AND lets folks hear what the audio actually sounds like. In addition, it had a lot less noise than our initial mess of wires.

As for what we played, we just searched YouTube for “Oscilloscope Music”.  Someone who works with Jeff mentioned Aphex twins “windowlicker” and “songs about my cat” by Venetian Snares as two examples of spectrographic songs.