3D Printer – an aside

I’ve had a few discussions recently as to why I’m building a 3D printer using one of these collect the parts magazine rather than either a) buying one outright or b) getting a “proper” build-it-yourself kit from an online store.  Now seems like a reasonable time to address the reasons behind this.

If you’ve been following my 3D printing posts you’ll know I’ve subscribed to Eaglemoss’ 3D Create and Print magazine and am gradually building my own printer.  With the weekly cost of the magazine this will eventually cost me £650 and I won’t have a complete printer until the middle of next year.  While this is cheaper than buying one outright now, with the speed of change and improvement it’s likely that the printer will be out of date, and this is not the only argument:

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3D Printer Part 3: Y-axis motor and testing

Following from building the Y-axis assembly of my 3D printer, this post covers the fitting of the motor and the circuit boards to test, using the pieces in issues 7 to 10 of the 3D Create and Print magazine.  It’s a good job that, even though this is a “weekly” magazine, the issues arrive in sets of four as otherwise I imagine it could be very frustrating waiting, not able to add to the printer, until issue 10.

I don’t actually see why this stage was any different to the earlier steps – if the pieces had been delivered in a different order then there would have been no need to wait until the 10th issue before starting.  I can only assume that someone may have been tempted to power it all up before it was ready, which is why the motor itself is the last piece from this stage to arrive.  Continue reading 3D Printer Part 3: Y-axis motor and testing

3D Printer Part 2: Y-axis assembly

Today I finally started unwrapping the pieces of my 3D printer.  After the issues with getting the magazines into their binding, I have been putting this off until I had the time and space to work through it properly.  I have 15 pieces to work through and this includes several circuit boards and a plug.  This entry covers the first 6 issues of 3D Create and Print by Eaglemoss Publications where we create the y-axis assembly up to the point of being ready for the motor and power.

Parts 1 and 2 and the tool kit
Issues 1 and 2 and the tool kit

The last set of pieces also came with a handy tool kit with everything I need to build and maintain the printer – another reason that I hadn’t done this earlier – no matter how many screwdrivers or allen keys I’ve bought over the years, I can never find any when I need them.  The one thing the tool kit is missing is a sharp pair of scissors to break open the plastic packaging of the printer pieces, but you can’t have everything! Continue reading 3D Printer Part 2: Y-axis assembly

How Old Robot – Well played

How Old example
Example of How Old Robot doing its thing

So, a few days ago, the internet had a new toy: How Old Robot – a very simple website where you can upload a photograph and it will guess your age and gender.  For many people the guess was about right, but there were some howlers, with very similar images being uploaded and giving age results differing by (several) decades!

The site doesn’t hide the fact that it’s a learning tool based on Microsoft’s facial recognition technology and is built on the Azure platform as an example of how quickly it is to build and deploy sites using Azure.  What started off as a quick demo from the Build conference soon became viral, with people all over the world loading their photos into the app and sharing the results on social media.  This is exactly what Microsoft wanted and they’ve been oh so clever with this and here’s why.

Continue reading How Old Robot – Well played

Proof by Induction

In my last post I talked a little about logic as it applies to generic statements.  Now it’s time to think about more mathematics proofs and different techniques.  As part of MS221 there are two proof types that we need to consider: proof by exhaustion and proof by induction.  This all lays the foundations for building more and more complex mathematical statements so it’s important to get the basics right.

Dominoes
Wikipedia: Domino effect

Firstly, proof by exhaustion.  This simply means that we try every possible valid input and check that the result is true.  A single false result would disprove our proposition.  So let’s consider an example:  Continue reading Proof by Induction

Proof and logic

The final part of block D in MS221 of my OU Maths degree is all about mathematical proofs and deduction, which I find absolutely fascinating.  A big part of this block was clarity on some logical fallacies that we encounter all the time and that many people use to trick us into agreeing with their arguments.

XKCD: CorrelationXKCD: Correlation

With one week to go until the General Election in the UK it seems like a good time to revisit logic and proof from both the political and mathematical sides.

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Public-Private Keys

This morning I had a tutorial for module MS221 of my OU Maths degree.  In addition to complex numbers, groups, and proofs one of the topics we covered was RSA encryption and decryption.  As I’m a little behind in my study I’m going to use this post to explain how this type of encryption works (even though this is already covered elsewhere e.g. in wikipedia).   You’re going to need a little maths to follow this, but hopefully not too much!

Firstly, a quick recap.  Public-private key encryption means that you have a pair of keys – the public one you can give out without a care and anyone can use this to encrypt messages to you.  Without the private key to decrypt, it’s practically impossible to decipher the encrypted messages, so as long as you actually keep your private key private, everything is (relatively) safe.  As an aside, if your private key is obtained by someone else then they will be able to read your messages and you would never know.

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An academic professional

I’m three days in to my new role and, while there is some run of the mill development that I’m managing there’s also a very exciting project just starting that I’ll be taking from the very beginning based on a discussion I had with the CEO on my first day.

This new secret project means I’ve got to become an expert in Deep Learning and also all the changes in AI and since I wrote my own thesis.  I discovered very quickly that the way I knew was the “old way” and that machine learning has come on very considerably in a short space of time. So the past few days I’ve regressed into academic mode.

Continue reading An academic professional

3D Printer Part 1 – binding

So, today I decided to make a start on the 3D printer project.  I’ve got 15 parts now, enough to get started and also to get to a point where I can have something that moves I hope (I have a plug and circuit board in these issues).  The first 12 issues cover “stage 1” and that’s what I hoped to be covering in this first guide.

I had the mantra “read everything carefully before starting” ingrained as a child so I have a Pavlovian response when opening a  kit to read the instructions. In this case the instructions are spread across several magazines and the logical thing to do was to put them all in the binder first.  The binder takes 15 issues and looks like this:

The unfilled binder
The unfilled binder

This instructions say:

  1. Open the top and bottom flaps
  2. Remove all pegs and insert into the holes in the spine
  3. Close the top flap clipping into place
  4. Open the magazine in the centre and slip the first peg into the top of the  centre fold
  5. Do the same at the bottom, pulling the peg out slightly first
  6. Close the bottom flap, clipping into place.

Continue reading 3D Printer Part 1 – binding

But is it correct?

I love science.  My parents fostered a great sense of curiosity in me and the need to learn.  Part of this was the ability to question what was presented and come to my own conclusions as to whether it was correct or not.  It was okay to change my mind as new evidence was presented, included my own experiences and this is how we grow as individuals.

At university we were taught to go to the primary sources for information – not the summaries or reviews but read the original papers and decide whether the research was sound for ourselves.  Corrections are regularly published for papers (or retractions made) and these are not always referenced when the original paper is cited, perpetuating the error.  (I don’t want to get into a discussion of specific examples as this will detract from the point of this post).

Continue reading But is it correct?