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It’s a QWERTY Keyboard

QWERTY Keyboard Rendering

I’ve always been fascinated by typewriters. I find them to be curious machines, and their history is no less interesting. (Go on, take a look!) Of course I’m also fascinated by digital technology, and how it empowers people to creating things. Above is a rendering of a QWERTY keyboard, and below is an actual QWERTY keyboard I created using digital fabrication and a tiny computer called a microcontroller functioning as the “brain”.

QWERTY Keyboard

The keyboard is fully-functional. Plug it into the USB port of your laptop or desktop computer and you can start typing. Of course you can only type the letters Q, W, E, R, T and Y… but it does work. Like all of the things we use, it has limitations. Like all of our technology, it doesn’t do quite all of what we’d like it to do.

QWERTY Keyboard

The QWERTY Keyboard is made from wood. (Just like the early prototype of the Sholes, Glidden & Soule typewriter seen below.) My father was good at working with wood, and his father before him was probably even better at it. I am not that good at working with wood, but I am good at creating things digitally. There is perhaps an inverse skill scale at work here. Are we losing the ability to craft real-world objects in exchange for creating digital objects? Maybe digital fabrication is the answer, bridging the gap between the two.

Sholes, Glidden & Soule typewriter

The Sholes, Glidden & Soule typewriter is a weird looking device, as is my QWERTY keyboard. I think there’s a place in the world for both of them, and perhaps a place where the two can meet.

QWERTY Keyboard

For more information on this piece, visit the QWERTY Keyboard project page. There are more thoughts and more photos, and as always, I welcome your comments.

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Turntable Lathe(ing!)

Lathe

Just a quick follow-up to the previous shaft post… I cut the shaft to length on the horizontal band saw, and then chucked it in the lathe (and had Frankie do a quick check before I started) and then cut down the other end so the bearing would fit. It’s not perfect, but close enough. I’ve still got some of the shaft left if I need to make another one. The main thing is, I got some good experience using the lathe, which will come in handy if I end up turning my own knobs to fit on the potentiometers.

Shaft

One bad thing… we had thought the shaft was steel and would work well for the magnets I plan to use, but… it’s not magnetic! I’ll probably end up drilling (er, lathing) a hole in the shaft to thread a steel bolt into so I’ve got some material I can stick the magnet to.

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Turntable Electronics

Electronics

I finally got the electronics for my Turntable Drawing Machine working. It wasn’t easy…

I decided to use a DC gearmotor controlled by an Arduino and potentiometer for the speed. I did a quick test of this with a Leonardo and a DRV8835 Dual Motor Driver Shield for Arduino. It worked fine for controlling the speed of the motor, but I didn’t really want to use the shield, so I used a DRV8835 Dual Motor Driver Carrier I had on hand. (Since I’m only using one DC motor, I probably could have used a DRV8838 Single Brushed DC Motor Driver Carrier.)

Pololu has an easy-to-use Arduino library for the DRV8835 Dual Motor Driver Shield which worked fine for the shield, but doesn’t (I mean didn’t) work with the DRV8835 Dual Motor Driver Carrier. I ended up hacking the library a bit to make it work. All was well until I added a servo. Since the Arduino library for the shield is hard-coded to use pins 7, 8, 9 and 10 there’s an issue because the default Arduino servo library disables PWM control on pins 9 and 10. I then changed the library to not use pins 9 and 10, but that still didn’t quite work… Seems that the servo library and the motor control library both need to use timers, so there’s some weirdness there…

I ended up digging through the forums and eventually found some useful posts and a link to ServoTimer2.zip. (It’s worth noting that there are a number of ServoTimer2 libraries, but I tried this one and it worked.)

Once I had the ServoTimer2 library in place, getting it to work with the my hacked ‘DRV8835DualDriver’ library was simple. (I’m saying “simple” but it took a few hours of screwing around with things that should have worked but didn’t) If I had used one of the Arduino Megas I had lying around, I probably could have avoided some of the issues the Servo library causes.

Alright, well… electronics seem good! Next step is to build things, and get the turntable portion constructed to test if the DC gearbox will work out. I think it will, as it’s got plenty of torque, and there shouldn’t be much resistance.

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#TeamArduinoCC

Arduino.cc

In accordance with a request from organizations and people I respect, here’s a photo take on 2015-04-19 showing the packaging from an Arduino UNO I purchased from Adafruit Industries (in the United States of America) on 2010-10-19 showing the text “Manufactured under license from Arduino by SMART PROJECTS S.r.l.”.

Adafruit / Arduino.cc

Here is the order information from that purchase. For more info, see the Hackaday post Your Arduino Packaging Could Sway a Court Case and the Adafruit post Please post old Arduino packaging that says “Manufactured under license from Arduino” #TeamArduinoCC.

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Turntable Shaft

Platter System

For my turntable drawing machine I’ll need the platter to spin. In a “real” turntable (the kind used for vinyl albums) there are three methods, idler-wheel, direct drive, and belt-drive. The illustration above shows my original idea for direct-drive, which I quickly abandoned in favor of belt-drive, on the bottom.

Rod & Bearing

Typically I use 8mm rod for things because, well, I have it handy, and lots of 608 bearings as well. For this turntable shaft, Frankie gave me some 6003Z bearings, which have an inside diameter of 17mm. I found some 17mm steel rod from McMaster-Carr, but I didn’t need very much, so I asked Chad about making a piece on the lathe. He said it should be easy if we had some stock just a bit larger, and well… Frankie did indeed have something! (Oh, if I used 17mm rod I would have added shaft collars… luckily by machining the part, we won’t need them.)

Frankie gave me a crash course in the metal lathe. (I last use a lathe back in the 1980s, and it was a wood lathe!) I learned how to face off the material, and then he showed me how to narrow it down to size. We got it to a perfect fit for the bearing!

Plastic pulley

I also had some plastic pulleys on hand from when MakerBot sold off all their old Cupcake CNC parts… I knew they’d come in handy someday! We managed to drill out the center on the lathe so it fits tight over the steel shaft. I may need to add a set screw or some locking collars, but it’s a nice tight fit right now.

Parts

Here’s the shaft, bearing, and pulley all properly sized. Once I determine the length of the shaft we’ll put it on the lathe, cut it down, and then get the other side to the right size. I’ll make some pieces that hold the bearings by either laser cutting some material, or 3D printing something, or maybe via the CNC router.

Perfect Fit!