I watched an interesting youtube video on the numberphile channel:

https://www.youtube.com/watch?v=ZfKTD5lvToE

about "perfect" numbers. I was thinking that nobody really sits around trying to calculate these things do they?

Anyway I thought it might be cool to practice my arduino programming skills to replicate the results. It took about 4 hours but I learned a lot about how to manipulate arrays. Here are the results:





















and here's the code I came up with:


unsigned int number = 2;         //the number being tested
unsigned int divisor = 1;        //divisor to find factors
int r = 0;                       //remainder
int f = 0;                       //test factor
int fCount = 0;                  //interger for storing array values
int factors[32];                 //array to store the factors
int sum = 0;                     //sum of factor interger
int lim = 10000;                 //highest number to check
int i = 0;


void setup() {
  Serial.begin(9600);
}

void loop() {
  while(number < lim){
    //Serial.print("number:");
    //Serial.print("\t");
    //Serial.println(number);
    //Serial.print("factors:");
    //Serial.print("\t");
    while(divisor <= number){
      r = number % divisor;
      f = number / divisor;
      if(r == 0){
        factors[fCount] = f;
        fCount++;
      }
      divisor++;
    }
    for(i = 0; i < fCount; i = i + 1){
      //Serial.print(factors[i]);
      //Serial.print("\t");
    }
    //Serial.println();
    for(i = 1; i <fCount; i = i + 1){
      sum = sum + factors[i];
    }
    //Serial.print("sum:");
    //Serial.print("\t");
    //Serial.println(sum);
    if(sum == number){
      Serial.print("Found one!");
      Serial.print("\t");
      Serial.println(number);
      Serial.print("The factors are:");
      Serial.print("\t");
      for(i = 1; i < fCount; i = i + 1){
        Serial.print(factors[i]);
        Serial.print("\t");
      }
      Serial.println();
      Serial.print("Found at:");
      Serial.print("\t");
      Serial.print(millis());
      Serial.println(" milliseconds");
      Serial.println();  
    }
    //Serial.println();
    sum = 0;
    fCount = 0;
    divisor = 1;
    number = number + 2;
  }
  if(number == lim){
    Serial.println("Done!");
    delay(60000);
  }
}



It could probably be optimized a lot more. I told the program to ignore odd numbers to speed it up but I'm sure it could use it's information to ignore more numbers by the looks of it. There's a bunch of commented out lines for debugging but it works. It was more of a learning tool for me than anything. Arrays are no-longer a mystery!

Little free library plans for "Amish Shed"

Ryan asked me to do a little free library workshop because there has been a bunch of demand for it at the tool library. I went searching for plans but there weren't any for the one that I liked. So I made my own.


I've uploaded a copy of the PDF plans to dropbox if anyone else wants to use them.

https://www.dropbox.com/s/dwmhl01mmemhzy4/Little%20free%20library%20amish%20shed.PDF?dl=0
Living up to my name,

Makerbot fixing Pt1:

The Breakerbot was broken again (surprise surprise). I managed to fix it in 2 hours, for $4 with only local materials. Here's the rundown:

The issue was that the filament was melting in the extruder tube above the heatsink, just below the hobbed pulley. This allowed it to expand to the point where it couldn't be pushed into the tube. Eet was two big. Ryan pulled it apart for me to put back together.

Here's what I found:




The fan that cools the heatsink which in turn cools the aluminum cooling block; was missing some fins. How'd the fins get borked? I dunno but the were definitely borked.

So I realized after some research that 24V 40mm * 10mm fans aren't that common in local computer shops. Although they do carry the 12V version.


So how do you make a 12V fan work in place of a 24V fan? Easy! You replace what's borked! The fan blades were the issue here, so that's what i fixed. I removed the rotor portion of both fans:

Borked:


12V:

I had to remove the plastic snap-ring from the 12V fan to remove the rotor. You can see it in the bottom right of the last pic.

I then installed the new rotor in the 24V stator.


The rotors are stunningly identical, all the way down to the small bronze bushing that keeps it running true. The only difference is in the coil windings of the brush-less motor.

I re-assembled the extruder and added some washers so that the fan wouldn't be crushed. Surprise, it all worked!


I tested the extruder before bolting it back on the machine. Far too many times I've re-assembled something thinking it would would work without actually seeing it work.

Now it works again so I can print out some X-mas gifts.


Post the first,

There's a lot of catching up to do! The date is December17 2013 and I'm taking over the blog that was started for me by my good friend barb.

First some history.

In 2010 I started participating in the reprap project. I bought my first set of parts from a guy in St. Catherine's and it took me a year and a half to start printing. That was back in 2010. The greatest challenge I faced was the extruder. I spent the last 3 years (among other things) building an extruder that can keep up with me. I'll give you more details later.

Aside from 3D printing, I also take part in sustainability projects in the community. The latest project is the Toronto tool library.





I helped construct and assist in running the 2 current locations of the Toronto tool library and Makerspace. My other origin stories include wikifarm, open source ecology, and the zeitgeist movement.

Fast forward to today. I'm currently the proud owner of a Prusa Mendel V2 with heavy modifications and my brand spankin' new water cooled hotend!


What to expect? Loads of 3D printing, some wood working, some survivalist, some home improvement, some future economy.

Who know's what the future knows? I sure don't but I can have a guess.

See you again soon.

-A

Welcome

Not sure what to do with that broken or non-functioning electronic bit of equipment? Have an old stereo that you'd love to reuse? Believe in fixing rather than throwing away? Adam is here to fix your broken electronics, electrical and mechanical devices, as well as build custom parts for your needs.

If you live in Toronto, contact Adam today for a quote at 647 379 1080