Tag Archives: cnc

Fish for all the family!

As a welcome distraction from CNC machining of HDPE, I made a whole lot of little fish for a colleague of mine.

Can you spot the difference?

Fishes: cut out of 13mm red oak and “flap-sanded” smooth

Each of the fish is about 65mm (2 1/2″) long by 45mm (1 3/4″) tall with a through-hole eye and a small detail cut to a depth of 25%.

As these little beasts will get a lot of rough handling, I cut them from 13mm red oak, with the grain oriented along the body to protect the tail from breaking off. I sanded the faces and flap-sanded the profiles so that they were all nice a smooth.

In use they will be painted and used as clues to solve some part of an escape game… To keep the mystery, I won’t say moire than that!

Fishes: close-up-detail

Fishes: close-up detail

… And it’s not even Friday!

seXY Machine: Now sporting a new head!

I designed a new head for the seXY Machine to raise and lower a pen or stylus, under software command.

seXY Machine: The new head to raise and lower a pen or stylus

My friend, Doug Commons (a real electronics whiz), built a new controller board for the seXY Machine that runs GRBL software so that the machine can execute gCode directly from my CAD/CAM applications. In real English, it means that the seXY Machine can now be controlled using standard software that is widely supported by most computer-controlled design tools.

So it was time to give it a head!

The new head comprises of a modified end cheek that pockets the travel rods and a new face plate housing two brass rods and a metal-gear servo motor. These rods align with holes in a pen holder assembly to allow it to slide up and down. Two simple 6mm thick pen holders clamp the pen or stylus to the slide assembly using M3 screws.

A spring on the end of the servo horn lifts and lowers the assembly. The alignment of the servo is such that when it is in the lowered position, there is light downward pressure on the pen to keep it in contact with the drawing surface.

seXY Machine:showing adjustable pen / stylus holder

seXY Machine: showing servo motor and spring connection to the pen/stylus slide

All of the pieces of the head were cut on my CNC machine out of 12mm and 6mm HDPE and assembled using 3mm brass rod and M3 stainless steel hardware.

seXY Machine: closeup of the pen/stylus slide in its lowest position

Now, to do some drawing with it…

Surround Sound: The latest edition to the Simpler Simon series

Introducing Surround Sound, the latest member of the Simpler Simon interactive games.

Surround Sound:Sporting bubble lines and large arcade-style illuminated buttons.

One of the comments from users of the original Simpler Simon was that the sound effects were not loud enough. In addition, those users who had some musical background, found the “circular” sound aspect of the game somewhat confusing. They were more used to the idea of keys and corresponding notes being presented in a linear fashion; much like a piano keyboard…

So, voila!

The Surround Sound offers a new look and feel, with large illuminated arcade-style buttons that can take a lot of pounding, and up to 4 watts of sound for those with the hardest of hearing. And, there is a simple-to-use volume control built in!

As my recreologist friend noted…

“The staff in my activity department tried the new and improved Simpler Simon…. The longer design allowed the device to rest on the lap comfortably.  The volunteers tried it too.  It is a hit!  “

All the great games of the Simpler Simon with a new look-and-feel – jumbo buttons and lots of volume for game-play sound effects.

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“Dimmer Not Dumber IV” – the fader continues

The “Dimmer Not Dumber” fader saga has not closed. In the spirit of invention being the mother of invention, introducing “Dimmer Not Dumber IV“, for a customer who wants to control slide dimmers.

Here the “Dimmer Not Dumber IV” is going through its “homing” sequence. The stutter near the top allows the dimmer to travel beyond the proximity detection to reach maximum brightness.   Once homed, the dimmers drop to the OFF “rest” state. The dimmers are programmed to move through a specific light sequence when triggered by the external control signals.

Dimmer Not Dumber IV: with pair of electrical light slide dimmers and control unit

Where the original Dimmer Not Dumber II” design used servo-motor to control a residential rotary dimmer, the new design (and its failed predecessor, “Dimmer Not Dumber III“) uses a stepper motor to control a slide dimmer.

Talk about a hammer to crack a nut. This design uses a NEMA17 stepper coupled to a 1/4” 20 screw upon which a slide assembly that captures a corresponding nut rides. The end-stop, necessary to establish a “home” position for the steppers, uses an inductive proximity detector that is activated by the presence of a machine screw embedded in the slide assembly.

Dimmer No Dumber IV: showing fader base, motor mount, proximity mount, and slide assembly.

The pieces are cut from 12mmm and 6mm HDPE and connected using M3 machine screws. The whole assembly screws to the slide dimmer using the normal fascia mount.

Dimmer No Dumber IV: closeup of the 2-part slider assembly that captures the nut that rides on the screw. The countersink-head machine screw on the left triggers the inductive proximity detector at a distance of ~ 5mm.

The control software consists of an Arduino Nano and a pair of DRV8825 stepper motor drivers. The electronics, steppers and proximity detectors are powered through a 12v connection, and 24v control signals are conditioned to lower voltages for the Nano. Screw terminals are used to make the electrical connections for power, control signals (reset and trigger) and each detector.  The entire electronics assembly is housed in a small enclosure created with from a 12mm HDPE base and 6mm HDPE top plate.

Neater, huh!



seXY – computer-controlled mechanism for a new clock

s e X Y

Computer-controlled mechanism for a new clock

seXY is a motorized mechanism that under computer control can move a carriage slide in two separate axes: up to 380mm (15″) in the X-axis (side to side) and 350mm (13.5″) in the Y-axis (front to back). A huge “design space” to play with! My intention is to mount a head to the slider equipped with a servo that engages either a pen or an eraser… More to come on that front!

In the following video, the left and right steppers are being controlled by the micro-controller which is just moving the slide to and fro the X and Y axis, and the four diagonals.

seXY: Stepper-driven X-Y mechanism

So, this weekend CNC project was largely inspired by an interesting product called AxiDraw,  that is described as “the personal writing and drawing machine that mixes the precision of robotics with the warmth of a hand-drawn note.”  I was primarily fascinated by the control belt arrangement that allowed the two steppers to be stationary. This avoids all the complications of creating wiring harnesses that have to flex with the machine movements.

It appeared from the video and other similar designs that the two steppers are fixed at either end of the x-axis and that axis movement is achieved by moving BOTH. This belt arrangement has an interesting effect. When both steppers turn in the same direction, the carriage slide moves along the x-axis. When the steppers move in opposite directions, the carriage slide moves along the y-axis. If either stepper is stopped, the carriage slide moves along a diagonal.

Neat, huh.

So I decided to design and build one.

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Pop-UP Clock… now in colour!

The Pop-Up Clock described in a recent post “Pop-Up Clock and Flipper Clock – Magnetic Digit Elements” is a work-in-progress proof of concept as I develop a full 4-digit clock (complete with flashing colon).

So far, the design displays the time on this single digit display in a sequential manner: two digits for the hour, then a dash (“-“) followed by two digits for the minutes.

Wishing to increase the illumination of the display and the contrast of the segments between ON and OFF (or IN and OUT) states, I made some changes. I added a strip of addressable WS2812 LEDs around the periphery of the display and blacked-out the rear of each segment so that little light passes into the HDPE when it is extended (OUT).  When retracted (IN), light from the LEDs shines into the elements and illuminates them.  In the software I reversed the direction of the segments so that when it is ON, it is retracted (IN).  Here’s a video that shows the effect.

This test shows considerable light bleed from the LED strip, and this shall be rectified when there is a fully enclosed baffle between the front plate and servo mount plate… In addition, I shall also increase the contrast of the segments with a better light seal.

As with many of my clocks, the accurate time is obtained from an NTP request to the US National Institute of Science and Technology (NIST) atomic clock server, using an ESP8266 WeMost D1 Mini WiFi module.  WiFi channel access parameters, local time relative to GMT, daylight savings active, and duration between display updates (minutes) are entered on its web server and subsequently stored in EEPROM when the unit is powered on for the first time, or if it fails to connect to the local WiFi channel.

Oh yes, and just for Lise, the display its blue!


SHAPE SHIFTER – A shapely game for the elderly

Introducing “SHAPE SHIFTER”, a tactile and visually stimulating shapes and colours game

SHAPE SHIFTER sports large shaped illuminated tactile buttons and a big illuminated display. The bright and vibrant colours and playful melodies make this an engaging game for all ages.

Shape Shifter

Shape Shifter

Aimed primarily at the elderly and people with cognitive challenges, the current version of the SHAPE SHIFTER sports five games – “Follow Me” (simple and blink), “Memory Pairs”, and “Memory Sequence” (slow and speedy). Similar to the SIMPLER SIMON, the games are accompanied by musical tones and melodies.

The games of the SHAPE SHIFTER are selected upon start-up by pressing one of the shaped buttons. The details of each game are as follows:

  1. TRIANGLE: “Follow Me (simple)” game encourages the player to press the randomly illuminated button. In this  simplest version of the game, the button to be pressed remains illuminated until pressed
  2. CROSS: “Follow Me (flash)” is a slightly more challenging variant of the game as it just flashes the colour that is to be pressed.
  3. CIRCLE: “Memory Pairs” game shows a sequence of two random buttons, that encourages the user to press the correct buttons in the same sequence.
  4. PLUS: “Memory Sequence (slow)” game encourages the player to replay a random sequence of illuminated buttons. After each successful replay, the sequence is repeated slowly and lengthened by one. This game repeats the sequence slowly allowing plenty of time for the user to see and hear each button of the sequence.
  5. SQUARE: “Memory Sequence (fast)” game is for more advanced Memory Sequence game players, as the speed of the sequence increases with the length of the sequence.

For each of the games, play is accompanied with button tones and action melodies that include initial start-up; game selection, level start, level completion, and player error.

The game to be played is selected after the power-up routine by pressing on one of the five shaped illuminated buttons.

Game play encourages the player to stay engaged through multiple modes of feedback. Successful completion of each game level is accompanied by a rousing melody and the length of the number of rounds in the level is incremented. In addition, the tone of each button is also raised one semitone to indicate that the player is playing a progressively harder round. Successful completion of 10 rounds advances the player to the next SHAPE SHIFTER game.

More images to come…