This isn’t a blog post about modular synthesizers. This is a blog post about a wooden box. The wooden box pictured above is one of the first projects I’ve worked on at the Makerspace, and it’s the first wood project I’ve worked on since making a wooden trinket in shop class in high school. If I actually used a table saw back then (or any power tools), I have no recollection of it. I’ve always been more adept with a keyboard, mouse, or soldering iron than power tools, but I have been trying to expand my horizons over the years. Still, this was a more ambitious project for me than soldering together the electronic modules contained within.

The plan

Designing the box
Armed with a little bit of knowledge from the woodshop training (Thanks Steve!) and some mounting hardware to define the inner dimensions of the box to be, I went to work. I fumbled around with the “rails” which the modules eventually are mounted to, lining them up with some scrap plywood, marking things, measuring, deciding how the pieces will have to align so the front and sides look clean and consistent. I drew a diagram. A really bad diagram, but a diagram nonetheless. This diagram contained all the information I wasn’t going to rely on myself to remember. It’s pretty scrappy, and reviewing it now barely makes sense, but at the time it was enough to convince me that I was ready to start cutting wood.

Cutting the wood
I’m not going to lie, the prospect of using the table saw for the first time was a little out of my comfort zone. I once again put some time into watching videos and learning more about safe table saw operation. It probably looked silly, but with the saw powered off I rehearsed the movements I would need to make to cut my plywood to size. After a few such rehearsals, adjustments, and different configurations of where to hold and push the board to achieve the movement I needed, I was feeling pretty good about my first cut. I am typing now with all 10 fingers, success! By cut 3 or 4, I was cutting with confidence. The compound miter saw made the rest of the cuts after I had my plywood at the correct height for the 4 sides of the box.

Checking the dimensions

I aligned all the pieces of my box, tested that my hardware would fit, and to my surprise everything lined up… approximately. I made a few minor adjustments, tested, and knew it was now time to attach everything together.

Pocket hole details

Joining the box
I watched some videos a couple of years ago about pocket hole joinery, and thought maybe it would work for this project. It has the benefits of leaving the exterior faces of the box clean from screws, and also creates a very strong joint. What appealed to me the most about the process though is the involvement of a pocket hole jig. The pocket hole jig allows you to clamp your wood in place, and then helps guide a drill bit into the face of the wood to make holes for screws. Once the holes are drilled, you simply clamp two pieces of wood together and put a couple of screw through them. This was great for a beginner since everything I needed came with the jig kit, the appropriate drill bit, screws, and instructions. I did a few tests on some scrap wood and found that going very slowly was the key to getting a clean screw hole in the plywood. The process was pretty fool proof since the jig ensured screwing at the correct depth and angle. It made very short work of joining the box together.

The enclosure and the pocket hole jig.

Finishing the box
At this point, I considered the box to be mostly done and was ready to write off my first wood shop test as a success. I was happily noodling around with my electronics, and I built a little confidence in myself to make bigger and better things down the road. After a couple of days with the enclosure I started to notice the plywood chipping at the ends and that it was awkward to carry around. I decided to finish the box to protect the wood and add a handle to make it easier to carry. The faux-leather handle was easy to source on ebay by searching for “guitar amp handle,” but similar to cutting and joining wood the concept of applying a wood finish was foreign to me.

Left side: unfinished plywood. Right side: Danish Oil (Medium Walnut)

I did some searching for beginner friendly wood finishes and found a general consensus that Danish oil is a very easy to apply and attractive finish. Danish oil can be applied rather haphazardly, a couple of times if necessary until you reach your desired color, and doesn’t require any additional sealing. I watched a couple of videos, but ultimately just went with the instructions on the Watco cannister I bought at Home Depot.

Staining in the paint room

I sanded the box by hand and then brought it into the paint room to apply the oil. I did a quick test on the inside of the box, and determined I was OK with how the oil interacted with my plywood. I did a couple of applications on the rest of the box and when I was happy with the look I wiped it dry with some rags I bought from the same section of Home Depot that I found the stain. 24 hours later, the box was dry. A few holes in the top with the drill press and the handle was on in no time!

Conclusions
I hope to build a bigger enclosure for my synthesizer, since this one is already full! It only took a few days to complete the enclosure, and I’m sure I could recreate it with half the effort using what I learned during the process. Sure, I could have spent some time at the belt sander to get everything flush, and if I would have finished the piece right away before carrying it around without a handle I might not have ended up with chipped edges, but overall I’m very happy with the final result! I’ll definitely be making more things out of wood in the future.

Being able to acquire skills that help you push your interests into new directions is one great thing about the Makerspace. I never would have attempted this project without having access to the equipment in an environment where I could work through things at my own pace whenever I could find the time or inspiration struck me. There are always other people around willing to offer advice if you get stuck on something, and since everyone is there to learn and build things, everyone benefits from helping each other out with whatever knowledge they bring into the space.

Around 25 members have hopped in the new Milwaukee Makerspace Theater after the last two Tuesday meetings.  Its up and running in a “no hearing protection required” way!  The bass still goes way down to subsonic tones, but its being powered by a small & sensible surround sound amp.   Its a very immersive audio experience, and likely sounds much better than any 5.1 system you’ve heard because there’s only one seat!  The sound has been optimized for the single theater-goer: You!  The theater is hooked up to a DVD player, and is available 24/7  for any member to watch a movie in: no check-out required.   Note that any video source you have can be hooked up via the HDMI cable.  Alternately, you can follow the lead of JasonH, who used the theater with a portable audio player to rock out while he worked on his own project near by. See the photos below for the simple instructions on how you can start up the theater, and feel free to take a break from making by using the theater!

The request went out on the message board. Pete P., Shane T., and I all expressed interest, but life got in the way and it soon became a matter of whomever got to it first would be the one to make it. I ended up devoting the better part of last weekend to this project (much more time than I anticipated) but I can honestly say I’m pretty happy with the result.

The goal was fairly straight-forward: make an enclosure for the switch Tom had already provided. It was a color-coded, 4-button, mechanical switch that had been wired to provide four settings: OFF, LOW, MEDIUM, and HIGH. The more laser cutters in use, the more air you’d need and the higher the setting you should choose. There’s four duct connections available for the three laser cutters we currently have.

There’s a saying: “Better is the enemy of done.” Truer words have never been spoken in a makerspace.

At first I wanted to build the enclosure out of acrylic. Then I remembered this awesome plastic bending technique that Tony W. and some others told me about. I found a video on the Tested website and got inspired. (If you don’t know about Tested, please go check it out. You’ll thank me later.) Unfortunately, my bends kept breaking and melting through, so after a few hours of tinkering I moved on.

Thankfully, we have a small cache of plastic and metal project enclosures on our our Hack Rack. I managed to find a clear plastic, vandal-proof thermostat guard. It looked workable.

I tried laser cutting it, but the moment I saw the plastic yellow and smoke, I knew there was probably some nasty, toxic stuff in it, so I moved to the CNC router. About an hour later I had my holes cut.

Then came the wiring. Up until this point I had been focused on the control box itself. Now I wanted to add a light!

No, two lights! Yeah!

One light to tell you when everything was off, and another that lit whenever the fan was in use. People could look at the lights from outside the room and instantly know if the fan had been left on. (It should be noted that the new fan, despite being twice as powerful than our last, is actually much quieter. Tom added a homemade muffler to the inlet of the blower and shrouded the whole contraption in 3″ fiberglass batt insulation. The best way to know if the fan is running is to open a slide gate damper and hear air being sucked in.)

OK, I totally got this.

Draw myself a ladder diagram and get out the wire connectors… Remember that I need to isolate the signals from each other so any button doesn’t call for 100% fan… A few more relays… Some testing… and done!

Wait a second… the motor drive doesn’t have a ground for the control signal.

Hmm.

Guess I can’t power it from the drive. I’ll just tie into the drive’s ground. Nope, that didn’t work.

I’ll read the motor drive manual. OK, it has a set of “run status” contacts I can monitor.
….and they’re putting out a steady 0.4 volts DC. That’s enough to light up a single LED! …except, no. It’s not lighting. Doesn’t seem to be any real current.

I’ll just use a transistor! That’s the whole point of a transistor!
….well nothing I tried worked.

I’ll build a voltage multiplier circuit!
….and this isn’t working either.

On Day 3 of this “little project” Ron B. made a comment about using a pressure switch of some kind.

Wait.

We have a Hack Rack full of junk and I know there’s this old bunch of gas furnace parts. It couldn’t be that easy…

Yeah. So, three days (and a few frustrating epiphanies) later, this all came together. Press the beige button, get some air. Press the other buttons, get some more air. Any time there’s suction, the red light comes on. The indicator light is powered by its own 24 volt DC wall pack. The pressure switch has both normally open (N.O.) and normally closed (N.C.) contacts so it would be totally feasible to add another light at some point. The controller could display “OFF” or “SAFE” or whatever as well as “ON” or “FAN IN USE” or whatever. The text is just a red piece of paper with words printed on it, then holes laser-cut out to fit. We can trade it out with different words or graphics if we ever feel the need. I was just glad to have it done, so I called it. Better is the enemy of done, indeed.

You can learn more about the evolution of our laser cutter venting system on our wiki!

Simply put, the Humorously Maniacal Milwaukee Makerspace Multimedia Machine (HMMMMMM) is a personal sized movie theater, with 5.16 surround sound.  That’s right, this theater is like a conventional 5.1 home theater, but with 15 extra subwoofers to delight the senses. While the bass in a live concert can be felt in your chest, the bass in the HMMMMMM can be felt in your soul(!).  In addition altering listener’s consciousness, the HMMMMMM will soon be used to screen our yet-to-be-filmed Milwaukee Makerspace orientation video as an integral part of our onboarding process for all new members. The HMMMMMM measures about 7 feet long and about 4 feet wide.  An eager movie-goer can simply climb up the integral stairs (shown on the left) and jump in through the 27” diameter escape hatch in the top of the HMMMMMM. Despite its crazy appearance, the HMMMMMM offers a surprisingly comfortable reclining position, much like that of a lazy-boy.  Check out this photo of the HMMMMMM under construction for a better idea of the ergonomic internal layout: There is a pillow for one’s head, and ones feet extend to the right.  The 27” display is mounted to the angled portion on the top surface, about 24” from the viewer.  Eventually, two 24″ monitors will expand the visual experience into the periphery.

The audio portion of the HMMMMMM is a 5.16 system.  The high frequencies are played by 5 uninteresting Swan/HiVi speakers that are arranged in a properly boring 5 channel surround configuration.  The more exciting portion of the audio system is the subwoofer – well, the 16 (Sixteen) 10″ high efficiency subwoofers that provide that TrueBass sensation the masses crave.  Its clear from the use of 16 subwoofers that one object of the HMMMMMM was to create an audio system that plays low bass.  Playback of really low bass typically requires an extremely large speaker box, and still notes as low as 20 Hz are rarely audible.  However, inside any speaker box the bass response is naturally flat to much lower (subsonic) pitches.  For more on the sound pressure level inside and outside speaker boxes, check out this link.  The graph below is a measurement of the SPL or sound pressure level (how loud it is) versus frequency (pitch) at the listener’s ears in the HMMMMMM.

The graph shows that with a sine wave input, the SPL inside the HMMMMMM is 148.6dB at 40 Hz.  That means the acoustic pressure on the 27” diameter escape hatch is 45 pounds.  Excellent.  Note that earplugs in addition to earmuff style hearing protectors are mandatory to safely experience the TrueBass.   To understand this strict hearing protection requirement, lets compare the sound pressure level inside the HMMMMMM to other audio systems that may be more familiar.  Note that the loudness of these other audio systems are not visible in the graph above, because essentially all other audio systems (including yours) are inferior.  Adjusting the margins of the graph a bit produces the following graph:

The plot shows how loud typical audio systems are, and how low they play.  For example, cellphone speakers play only a bit below 1khz, and are ~90 dB if they’re 40cm from you.  When a Jambox-type bluetooth speaker is about 60cm from you, it plays ~10 dB louder, and another 1.5 octaves lower, to 200 Hz.  Typical bookshelf speakers can get another 5 dB louder if you’re 1.5 meters from them, but only play down another octave to 100 Hz.  OEM installed car stereos are a big improvement, but they’re still not in the same league as the HMMMMMM.  Yes, the IASCA record holding car is louder than this, but it plays only from 50 Hz to 60 Hz, which isn’t even really bass.

Note that the difference in loudness between a cellphone and a car is 20 dB, while the HMMMMMM is 30 dB louder than a high-performing car stereo.  Also note that the frequency range of a piano, with its 88 keys, is about the same as a bookshelf speaker – a bit over 7 octaves.  Surprisingly, the subwoofer portion of the HMMMMMM has a 6 octave bandwidth, but it plays the 6 octaves you’ve never heard before!  The HMMMMMM plays 6 octaves below what your bookshelf speaker or Jambox calls bass. The HMMMMMM has a +/- 6 dB passband extending down to 2 Hz, with the output at 1 Hz being nearly still above the 120 dB “threshold of pain.”

Disclaimers: For safety, the big 2000 Watt amplifier that drives the HMMMMMM to its full potential is not available when the author is not present.  Ironically, the author has taught 75-100 people, the eager early HMMMMMM listeners, how to properly insert earplugs, meaning that the HMMMMMM is actually a learning tool for hearing safety! Finally, the author has some hesitancy in having the HMMMMMM reproduce recordings with 5 Hz content at 140 dB, because typical hearing protection has little effect at these unnaturally low frequencies.

PS:  Please don’t hesitate to contact me if you’d like to help with the video scripting, filming or editing.

I made two VIDEOS about the snow-globe. The first is just a brief video showing the finished project. The second video is a longer “How-To” which includes some video, but is mostly a photo slide-show of all the steps I took to create the project.

For an in-depth step-by-step of how I built the project, check out the info I posted on Instructables. http://www.instructables.com/id/Custom-Singing-Snow-Globe/

-Ben

The MESSSSS (Makersace Eight Speaker Super Surround Sound System) that we debuted at Bay View Gallery Night Friday went over pretty well, but could use some work.  We ran it off of 3 stereo receivers and 4 android phones coordinated by the PBST (Push the Buttons at the Same Time) protocol and want something a bit more controlled.  Also, the levels on our pieces were very different so we had super subtle things followed by ear-splitting shrieks.  While i’m personally into that kind of thing, it didn’t make for a terribly cohesive whole.  

We left the meeting with 3 main actions:

1. rebuild a spare PC I have with an 8 channel audio card to be the new brains of MESSSSS.
2. Start on an android app to control playback from multiple devices at once.
3. Kevin and I are going to spend some serious time learning max/msp. I have done a couple of things with it but they are ugly and hacky and i only made them work by pushing things together really hard.

If we can get the new MESSSSS brains up and running, we are going to refocus the music club meetings on performance and recording.