Thursday, October 16, 2014

Making Toothless and a Turtle

Halloween is coming up and this year, I decided to start early with the costumes for the kids.  I wanted to do something that the kids wanted.  Little did I know, my oldest was still in love with How to Train your Dragon.

She said she wanted to be Toothless.  And my younger daughter wanted to be a turtle.
There are different levels of costumes for Toothless out there and turtles.  I wanted to do something that they would be excited about and also learn a little bit about making.
So Toothless and the Turtle it was.
The first thing I thought I would work on was the wings.  But the wings, for me, needed to be able to expand and contract, articulate a bit.  So, I looked up some ideas and found an articulating wing design on Instructables.  I found this one  by a user named Rachel and proceeded to hack away at it.
The main issue I had was that I did not have a frame for a backpack for a seven year old.  The other issue was, Toothless has legs and arms so the costume couldn't attach the arms to the wings or else I'd have to make fake legs for Toothless.

So first, I sketched out some dimensions and played with some LEGO's to get the articulation going.  Then, instead of a frame, I used a pice of 4mm plywood as the back.  This of course doesn't allow the wings to flap but we wanted them to just open and close.
So I got out the bandsaw and a marker and started drawing shapes and measuring hole spacings.
Soon, I came up with these.
My daughter with her dragon wings at different extensions.
Toothless however, had ribs going down the middle.  So I needed to figure out how to do that.
It took pieces of plastic rod and hot glued wire connectors on the ends of them, and then just bolted them on to the top bolt of the wing rib.

On this picture, you will notice that I have placed bicycle brake wires in the center to pull down and actuate the wings.  See the video below for them opening and closing.


The only issue is that the wings are rather heavy and difficult for my 7 year old to squeeze the brake handle.  I hope to fix this with a linear actuator if I get it in time.

So I continued with covering the wings with a spandex like fabric.
They definitely look like bat wings here.  I covered the front side and mounted backpack straps with a piece of contoured foam I cut on my bandsaw so it would fit my daughters back.

It loses a bit of the coolness when you cover the structure so I may just paint the frame black and not cover it.  We'll see what my daughter says.

The Head
When I started to think about the head I had the plan to sculpt it out of clay, cast it in some kind of resin, and then paint it up.  that would give some great details but then, it became clear that wasn't going to happen just because of the timing and the lack of materials I had on hand.
So I decided to just sculpt the thing from foam. So again with the bandsaw, I cut away pieces that didn't look like the dragon and made the head.
The process was done with scissors, razor blades, and hot glue and it turned out okay I think.
I of course, wanted my daughter to see through the eyes so I cut through the foam and came up with the idea to create some eyes using vacuum forming.
I took a styrofoam egg, cut it in half and saw that that fit okay.  So I proceeded to make a vacuum forming machine with some extra wood I had lying around.
Unfortunately, I was so excited to get the vacuum forming done I forgot to cover the  pieces of styrofoam with aluminum foil so the styrofoam fused to the plastic.  :(
Next time, I make them out of plaster and cast them.
A second round of work and the first set of eyes came out.  I got some testers paint and tried to match the colors of the eyes as much as possible.

For the mouth I got a piece of cardboard, attached it to another piece of foam and covered it with fabric.  The teeth were cut out of foam and hot glued on to the colored cardboard.  
The ears were two pieces of fabric sewn together by my wife then pulled over the top, nice and snug.  
Something was missing though and I realized it was the scales of toothless.  So my daughter and I proceeded to paint on the scales with some latex paint to give it some texture.
So the final step for the head will be to add two blue LED's inside with an activation switch in a glove that my daughter will hold.  Some more stuff coming up too.

The mouth is attached on the bottom with a fabric hinge and articulates with the chin of of the user.
The Turtle Shell
My youngest daughter wanted something simpler, to be a turtle.  So I proceeded to make her a turtle shell out of foam.  Using a razor blade and some scissors, I cut out different shapes on the foam.

This was then covered with a sparkly green fabric my daughter had chosen, and glued down.


I put hot glue in the grooves and pressed the fabric into it.


So far, so good.  We'll see if I get all my parts before Halloween so I can finish this thing.  :)

Thanks for reading!

Miguel

Friday, November 22, 2013

Stepper Motor Music

I recently came upon a small project by accident.  I was working with a bipolar stepper motor and an Arduino, trying to program the steps individually without using the stepper motor class.  I finally succeeded, wasn't too hard but noticed I was getting some interesting beat sounds coming from the clicking of the stepper motor as it resonated on my table top.
So I wanted to amplify this sound but could not find my piezo amplifier so I decided to use the guitar pickups on my daughters pink mini strat.
By placing the stepper motor on the strings and running different sets of intervals between the steps on the stepper motor, I produced some crazy sounds.
You can listen to them here on my Sound Cloud account.
https://soundcloud.com/migsmixs/sets/stepper-motors

The basic setup is an H-Bridge with an arduino.
You can find the example here.
http://arduino.cc/en/Tutorial/MotorKnob

Rather then using the code in the stepper class, I just started sending values to the pins at different intervals.

Here's a video of it working.
https://www.youtube.com/watch?v=eIfX5nt4FPQ




Here's the code for the arduino.
#####
int mo1 = 8;  //These are the different pins connected to the H-Bridge
int mo2 = 9;
int mo3 = 10;
int mo4 = 11;
int BeatDelay=20;



void setup() {              
  // initialize the digital pin as an output.
  pinMode(mo1, OUTPUT);
 pinMode(mo2, OUTPUT);
 pinMode(mo3, OUTPUT);
 pinMode(mo4, OUTPUT);
}

void loop() {




myBeat7();




}

//This is a function that takes in different intervals.
void stepMyMotor(int mySpeed){
  digitalWrite(mo1, HIGH);   // turn the Motor on (HIGH is the voltage level)
  delay(mySpeed);               // wait for a delay
  digitalWrite(mo1, LOW);   // turn the Motor off (HIGH is the voltage level)
  delay(mySpeed);
    digitalWrite(mo4, HIGH);
  delay(mySpeed);            
  digitalWrite(mo4, LOW);
  delay(mySpeed);
    digitalWrite(mo2, HIGH);
  delay(mySpeed);            
  digitalWrite(mo2, LOW);
  delay(mySpeed);
      digitalWrite(mo3, HIGH);
  delay(mySpeed);            
  digitalWrite(mo3, LOW);
  delay(mySpeed);
  }

//These are the different beats
void myBeat1(){
stepMyMotor(1);
stepMyMotor(100);
stepMyMotor(10);
stepMyMotor(100);
stepMyMotor(10);
stepMyMotor(200);
  }


  void myBeat2(){
stepMyMotor(1);
stepMyMotor(1);

  }

  void myBeat3(){
stepMyMotor(1);
stepMyMotor(40);

  }



    void myBeat4(){
stepMyMotor(1);
stepMyMotor(120);

  }

//To keep the beats within the same intervals, the delays are divisors of each other 80, 160.
      void myBeat6(){
stepMyMotor(1);
stepMyMotor(80);
stepMyMotor(1);
stepMyMotor(160);

  }


      void myBeat5(){
stepMyMotor(1);
stepMyMotor(120);
stepMyMotor(1);
stepMyMotor(30);
stepMyMotor(30);
stepMyMotor(30);
stepMyMotor(30);

  }

  void rev(){
   int i=0;
   while (i<50 p="">     stepMyMotor(i);
     i++;
     }
    }
 
          void myBeat7(){
stepMyMotor(1);
stepMyMotor(120);
stepMyMotor(1);
stepMyMotor(60);
stepMyMotor(60);


  }

Tuesday, April 2, 2013

April Fools Make Cover

I took an old picture that I had and made it into a fake cover for Make Magazines April Fools Cover Contest.
I went with a Star Wars theme and added some wordings to the cover and viola, there you have it.
Enjoy!

Monday, February 25, 2013

LEGO Peristaltic Syrup Pump

As part of Project PancakeBot, I created a peristaltic pump that dispenses syrup onto the pancakes.
The pump is made up of round pieces of LEGO, some electric tape and some surgical tubing.  A bottle sits in the back and the syrup is sucked up and dispensed onto the plate below.
It's quiet a simple contraption but it takes a bit of effort to get the tube to sit in the right place while the rollers squeeze it through.
Instructions will be available as part of the PancakeBot instruction set through IndieGoGo.com/pancakebot2013

Sunday, September 9, 2012

LEGO Pancake Bot @ New York World Maker Faire

Woo hoo! I'm really excited to announce that the Pancake Bot will be making its debut at the World Maker Faire in NYC!  Woo Hoo!


The cool thing was, I was interviewed by Goli Mohammadi of Make Magazine!  How cool is that?
Here's a link to the interview.

http://blog.makezine.com/2012/09/08/maker-faire-new-york-lego-pancake-bot-interview/

So what is up the Pancake Bot these days?  Here's the scoop, or I guess you can say the flip.

The Pancake Bot took a break as we've been really busy with moving into our new house, starting a new job and well, enjoying the summer in Norway.  I learned that Norwegians have a tendency to stop whatever they are doing when the sun comes out!  Well, sort of.  At least for summer.

I've also been helping out at the DevotekBank1 Lab at the Konbsgerg public library.  They got a new 3D printer and CNC machine that I'm anxious to start helping out with and they've agreed to open up the lab after hours for a Maker Space!  More details on that to come later!  The most exciting thing is, the staff Hilde and Bjørn are coming out to New York for the faire and helping out with the exhibit.

So after a summer of fishing, making, building, inventing, destroying and finishing our rental unit #1 at your house, I finally got around to updating the Pancake Bot to make it a bit easier to control.

Still sporting only one LEGO NXT unit and a bunch of pneumatics, the new Pancake Bot now has a dual pump/vacuum capability.  This allows better batter control.  It also integrates the NXT controller into the gantry and uses a centralized NXT motor connected to two long axles and a drive on both sides of the gantry so that gear slipping is reduced to a minimum.
Notice how the motor shaft in the center now drives gears on both sides of the unit.  There's also some additional touch sensors to calibrate the location of the pancake bot.

The Batter dispenser unit now incorporates a pressure gauge, a vacuum and extra compression tanks.


Something about the camera really gets the kids to act funny.  

We'll also be posting up the video of Pancake Bot 2.0 and let's see what shapes I can come up with!

Cheers for now and remember to follow me on twitter @migpics for some cool announcements coming soon.

Anyhow, check us out at the World Maker Faire in NYC on September 29th and 30th.

http://makerfairenyc.eventbrite.com/

I'll do my best to make you some good tasting pancakes!

Mig


Thursday, April 26, 2012

Makerbot visit!

On my way back to Norway from San Diego I had a 27 hour lay over (planned on purpose) in New York City.  While there I took advantage of the time and jetted on over to Brooklyn where I was able to meet Greg Shutack and Bre Pettis from MakerBot Industries.
It was rather a fluke actually because I got this stupid idea to jet on over to Brooklyn from Hoboken New Jersey and meet someone from the MakerBot there.  While trying to find the building I bumbed into this guy on the street with three spindles of ABS plastic and asked him if he could help me with meeting someone there.  it was Greg Shutack the Executive Administrator for MakerBot Industries and he gave me a quick tour of the operations.
While there I was able to meet Bre Pettis and I embarrassingly flagged him down and said hi and told him about my Pancake Bot.
Here is a photo of me and Bre.
 Wow, either I'm really short or he's really tall.
Behind us are loads of Makerbots printing lots of things getting ready for the Maker Faire in San Mateo California.

What is so cool about this is the fact that these guys took a few minutes out of their busy time to say hi and had no problem encouraging me about my projects and chatting for a second.

Thanks Maker Bot Industries!

Sunday, June 26, 2011

How the Pancake Bot Works


The Pancake Bot (PB) is basically a 3 axis CNC made that uses the Z coordinate as the Pancake Batter Dispenser Control. This one just happens to be made out of LEGO.
The Pancake Bot is made up of the following parts:

1.  A set of linked base plates with 3 parallel tracks snapped on.  One track has a bunch of Technic, Gear Racks (1 x 4) riding along top which makes up the X axis.


2.  A moveable bridge that holds one NXT motor on one side and has free rolling wheels on the other.  The top of the bridge uses two tracks covered with gear racks that holds the Pancake Batter Dispenser Unit (BDU).  The track allows for Y Axis Control.


3.  A carrier gantry on top of the moveable bridge that rides on the gear racks and holds the PDU.

4.  The PDU consists of two ketchup bottles cut in half and glued together so you have two open ends.  This allows you to change the nozzle size on the bottom and allows for input of compressed air on top.


5.  Compressed Air Dispersal Apparatus (CADA) consists of an NXT Motor, two Pneumatic Cylinders, a tank and a bi-directional flexible switch.


The bi-directional flexible switch allows for the switch to be flipped based upon which direction the NXT motor turns.  If you notice in the video, on the close up of the motors turning, the cam is switching the flexible switch every time it rotates.  In the initial turn, the switch is flipped and stops and then continues to flex out of the way of the rotating cam.  When the motor turns the other way, the cam catches the switch, flips it back and changes the direction of the airflow.  It continues to flex as the cam passes over it.  This allows for air to be compressed when the motor turns clockwise, and then the air to be released when the motor turns counter-clockwise.
The reason I did this is because I only have 3NXT motors and needed to a way to change the direction of the air flow while at the same time, still compressing air.

The Program
Originally, the goal was to control this with Python NXT, an open source programming interface developed by Marcus Warner and the Python NXT group.  It worked like a charm at first but for some reason, I could no longer communicate with the brick, so I went back to using the less flexible LEGO Mindstorms programming.

The program itself is a variant of the the Etch-A-NXT program found in Extreme NXT, by By Michael Gasperi, Philippe E. Hurbain, and Isabelle L. Hurbain.  The original program just controlled two motors using an external text file.  I modified the program by adding the third motor.

The text file needed to draw with the Pancake Bot uses three coordinates, each with a character return afterwards.

360
2400
-500

This tells the NXT to rotate Motor A 360 degrees, Motor B 2400 degrees, and Motor C 500 degrees conterclockwise.  Depending on which gears you choose, one rotation can equal different numbers of units of movement.
I used the 8 tooth gear which with one rotation, moves 4 standard LEGO units.
Depending on the size of your electric griddle, you can calibrate how big you want your drawings.
A simple program in XL converts the LEGO units into degrees and outputs the text file.

Motor C in this case is the Z axis which controls the BDU.  It also acts as a timer for discharging the batter.

The parts that are exposed to the heat of the griddle are covered with a sheet of aluminum foil during cooking.  This reduces the chance of parts melting.

Making the batter.

The batter is made using Martha Stewart's Basic Pancake Recipe as the base.   I sometimes add cinnamon or different berries for flavors or color.
Once the batter is made it goes through a strainer and all the clumps are removed.  This makes the batter smooth and allows for continuous flow of the batter from the BDU.

Things to work on!
The BDU is not the best design but other attempts were not as successful for batter delivery.  I attempted using a standard RCX motor with a corkscrew that went to a funnel but the corkscrew was not as effective as using air pressure.
A corkscrew discharge would allow for controlled amount of flow vs. the air pressure discharge (10 turns equals 20cc's of pancake batter.  When you use the air pressure discharge you have the additional variable of batter viscosity and so any slight changes in batter recipe modifies the flow speed.
The advantage of the air pressure solution is that you don't need a mechanical means to extrude the batter, so even using a aquarium pump (thanks Bruce Shapiro from Egg-Bot) could be used to control the flow of the batter.