Shortcuts Rarely Save Time

After I added lighting to my broom closet, the unfinished shoe rack started to bug me. It wasn’t only that the saw marks and colors caught my eye, more than once I scraped fingers when grabbing a pair of shoes since I never sanded the edges. My time-saving shortcuts only ended up causing more work in the long run because now I had to disassemble the other shelving a second time in order to get the rack out and finish it.

I sanded the edges and used white spray paint. I also painted the piece of wood holding up the other shelves.

Much better!

Sound Card Oscilloscope

Earlier this year I came across an old Make post about building your own oscilloscope. I messed around with it a little bit at the time, but I didn’t have the necessary potentiometers, so I set it aside. Then the topic came up again when the tutorials accompanying HackerBox #0018 made use a 3.5mm audio breakout module and some PC oscope software. So in my next Digi-Key order, I got the pots I needed and I picked up some cheap test leads on Amazon. It’s several months later, but I got around to building my own sound card oscilloscope.

First, a couple of notes…

You’ll definitely want to read through the Make post to get familiar with the project. As mentioned in their guide, there really isn’t any good oscope software for the Mac like there is for the PC. With Audacity, which is what I used, at least you can see the signals in wave form.

I spliced an old audio cable. There are several different styles of 3.5mm connectors, but if you’re doing 2 channels, you’ll want to make sure you your cable has the tip, ring, and sleeve.

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Source: blog.audio-technica.com

A lot of MacBooks only do mono microphone input. Several Mac bummers in this build! It wasn’t easy, but I found a USB adapter on Amazon that does stereo mic input (most of them only do mono). It’s pricey at almost $30 for something I’m not even sure I’ll use after this build.

Enough of that, on to the build…

I added the LEDs to my build as a visual reference a signal was coming through, but they can be left out, just like in the Make build. If you’re interested in the Fritzing I showed in the video, head over to sound-card-oscilloscope on GitHub. Whenever I’m soldering up a final project I prefer to have the Fritzing for reference instead of looking at my prototype, which typically has a lot of extra wires hanging around. Having a nice clean diagram helps me from making mistakes.

I also found another guide on a site called Home DIY Electronics, which I didn’t end up following.

If you have any questions or build your own version of this, let me know in the comments.

RBT 1911 Pull Back

I’ve always wanted a rubberband gun, so when I saw awesome kits by Rubberband Tech at Maker Faire Detroit I had to get one. I could have a sweet gun and build it myself. The 1911 immediately got my attention because of the slide action and the functional clip. The hardwood version (I picked zebrawood) of the kit was an extra $10 to make it $30 and a big bag of extra rubberbands was $5.

The build, spread over several days, took about 7 or 8 hours, which was much longer and harder than expected. A lot of difficulties were from the instructions being short on details. They tell you to sand several pieces but don’t get into how much sanding is required (A lot and then a lot more!), especially to get the trigger mechanism working properly.

I tried to video the entire process, ending up with over 140 GB of footage! On a first pass through iMovie at 20x fast forward the video was way too long, so I exported and ran it back through at 8x more. At the end of the video is a demo at normal speed showing the gun in action.

The stain I used on the zebrawood pieces was called Espresso and the one I used on the rest of the gun was an English Chestnut. I finished it off with 2 coats of a finishing wax. As mentioned in the video, I’m not happy with the end result of the staining. I wish I had done a second coat of the espresso stain on the hardwood pieces, or gotten a little lighter stain for the rest of the gun, or even both.

Now I need to make some targets. I have some ideas involving electronics for timing and scoring.

DIY Overhead Camera Rig

I’ve been recording more videos at my hobby desk and hanging a GoPro from my LED desk lamp via a Gorillapod wasn’t cutting it. Having to run GoPro’s Capture app on my iPhone connected over a WiFi network broadcast by the GoPro in order to see a preview of the camera view was also a pain point in my setup. I think I’ve even mentioned wanting to get a new camera in other posts.

My friend Casey was looking for a GoPro for his 5-year-old son, so it was perfect timing to get rid of my GoPro HERO3 Black Edition. I figured I’d just upgrade to the HERO5 Black, but it’s $400 for just the camera. After doing a little reading, I decided to get a YI 4K Action Camera with Selfie Stick, 2 spare batteries + charger, and an accessory kit. All of that ended up being $100+ cheaper than the GoPro HERO5 Black itself!

I had also been looking at a lot of videos and tutorials for building my own overhead camera rig. Then I remembered I had this lamp stashed away in a storage closet…

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I took the whole thing apart.

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I started putting things back together, using only the pieces I needed. I immediately noticed an issue. The swing arm would go up to about 20 degrees shy of vertical, but it wouldn’t go down more than this…

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I tried to get a decent picture showing how this joint works, but it’s hard to see in the photo below. There is a slot carved out of the edge and then a screw that hits the edges of the slot.

Here’s a better picture at just the notch…

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I needed to extend one side of the notch, which was quick work for my Dremel.

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After the adjustment, the arm can swing down to about 45 degrees.

The next problem I faced was needing some type of bracket where the light bulb used to be connected so I could attach the camera. I found this old ceiling light fixture bracket in my box of goodies. The threaded hole in the middle was a perfect match to the bolt on the end of the stand.

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I didn’t need the entire thing so I cut off one side with my Dremel.

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I found another part (the long arm type piece you see below) in my goodie box, which fit perfectly in the camera mount pieces. I had to use a couple of mount pieces from the accessory kit to get the camera oriented in the correct position relative to the stand. There was one trip to Home Depot for the wingnut, thumb screw, and small washers (definitely needed a few for spaces with the camera bracket at the bottom). Here is everything laid out before assembly.

Of course I had to test it out right away, especially since I hadn’t even turned on my new camera yet. I grabbed a couple of fidget spinners and adjusted the rig.

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I may need to create a cover or paint the base due to the reflection, which won’t be ideal for lighting.

Being able to frame the shot immediately with the camera LCD is amazing compared to the shit show I used to do with the GoPro.

Check out the video…

In case you weren’t keeping track, blue spun for 1:38 and black went 4:58!

Did you notice the shaking at the beginning of the video when I started up the spinners? Not good. I thought it would be super stable because the base of the stand is quite heavy (reminds me of the sand filled base of a moveable basketball hoop). Most of the movement seemed to be coming from the bracket I cut. An unused dead bolt bracket from my goodie box matched up well enough in size after making one of the holes bigger. This allowed me to double up the thickness, which does seem to help.

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I’ll have to do some testing while working on a project on the desk, because if this rig shakes the camera every time the desk moves a little bit it won’t be good.

As a bonus, there are some really useful parts of the lamp left. Maybe I can come up with a neat DIY lamp some day. The foot switch is also neat and could be used for a lot of things.

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