Building Rostock 3D printer (Part 5  – Installing the extruder)

I found this to be the easiest part of the assembly process.   The extruder is the mechanical device that pushes the filament all the way down to the hot end.   The extruder proper is a simple stepper motor, attached to the top plate of the 3D printer and pushes the filament down a Bowden tube.

Here’s a picture of the extruder before I attached it to the top plate.

From the picture, you can see the motor and the extruder proper attached to the motor.  The filament is inserted at the top and is pushed at the bottom.

Here’s a picture of the extruder and the Bowden tube connected to the hot end. For display purposes, I have reversed the arms of the hot end.

That’s pretty much it for the extruder, quite easy.

Book Review: “How to build a billion dollar app”

A really great book. I found most of the advice in it to be highly practical. If I had had this book a few years ago, I probably would have made fewer mistakes in my selection of startups to work for and on my own startups. A couple of years ago, I read “The lean startup” from Eric Ries. I find that this book is a “practical” companion to Ries’ book. Where the Lean Startup is more on the theoretical side, this book is quite practical.

The book is divided into 5 parts (the million dollar app, the 10 million dollar app, the 100 million dollar app, the 500 million dollar app, and the billion dollar app). Each section covers the problems and solutions associated with that particular size. I have to admit to having being riveted for the first few parts but lost interest a little bit towards the end. The initial parts cover more of the mechanics of creating the app while the followup parts cover more the mechanics of running a large company. At the present time, I’m pretty far from having a billion dollar app but could see myself having a 1 million dollar app (rightly or wrongly) so it’s understandable that section 1 and 2 hold more interest to me.

The most enlightening part of the book is the importance of analytics. Obviously, it’s important but I never realized how important it is. Get Google analytics, get Mixpanel, and possibly others. You can have more than one analytics solutions. Mixpanel and Google analytics appear to be quite complimentary so start with those. Make sure you have a plan as to how you want to use analytics.

That being said, awesome book. Highly recommend it (4.5/5)

Here are some of my notes:

Part 1: The million dollar app

The first part of the book is about getting an idea, a proof of concept app, and a founding team in place. It also talks a little bit about getting some seed money.

  • You need to define which business model applies to your business. The author defines 5 of them:
    • Gaming
    • E-commerce
    • Consumer/Advertising
    • Software as a service
    • Enterprise
  • I am unsure as to the way the business models are broken up. It seems a little bit contrived but there’s no doubt that as an entrepreneur you should know where your revenues will come from.
  • It is possible to start a company by yourself but having a co-founder is a good idea to deal with complementary skill sets. The author recommends a number of ways to meet somebody (e.g. Developer meetups, startup weekends) and a number of online resources ( and
  • Online resources to find domain/company names:
  • You should build an iOS version and an Android version but do one at a time. Though the author does not state which one you should start with, all of the examples seem to point to iOS.
  • The author recommends doing MVP (minimum viable product) from Lean startup approach.
  • Metrics are immensely important. Make sure you have some.
  • The author divides metrics into 5 categories:
    • Acquisition
    • Activation
    • Retention
    • Referral
    • Revenue
  • You should understand these categories and understand how they map to actions and goals.

Part 2: The 10 million dollar app

This part of the book covers product-market fit (PMF) and series A funding.

  • It’s pretty simple, you need to build something that people like, or rather love. It’s easy to say, quite hard to do.
  • Analytics should help. Make sure they are present from the start. (Look into using more than one of them e.g. Google Analytics and Mixpanel)
  • Having analytics is key to finding Best PMF but also to get proper funding. If I have good analytics number concerning acquisition and retention, getting money is a lot easier.
  • Agile and continuous development recommended
  • CrunchBase is a free site that allows you to find valuation of companies that may be comparable to yours.
  • It takes time to get money. On average, in 2013, it took close to 600 days. This is awfully long when you have a team living on the initial seed money.
  • VCs will normally look for three things, the ability to maintain their ratio in the company, the ability to sell before anybody, sit on the board.

Part 3: The 100 million dollar app

Here we work on improving the business model. Fine tune revenues, start working on growth

  • Find head of marketing, get a marketing team in place
  • Look at Fiksu for marketing, seems interesting
  • Analytics still play a huge role here
  • On page 282, there’s an interesting equation to measure virality
  • User retention is important. Fred Wilson has this ratio (30:10:10). I am intrigued by these numbers. Need to find out more. Here’s the breakdown:
    • 30% use the app each month
    • 10% use the app daily
    • 10% of daily users represent a maximum number of users present at any time.
  • OKR (Object Key Results) method is a good way to focus a company. Every quarter goals are set, measure metrics are defined and results are obtained at the end of the quarter. Used by Google. Created at Intel.

Part 4: The 500 million dollar app

Hire well, might be time to find somebody who is used to managing/guiding a business of this size. Might want to take a backseat. (Paraphrasing here).

Part 5: The 1 billion dollar app

It’s all about people. Hire well.

Building Rostock 3D printer (Part 4 – Putting the towers in)

Ok, the base is built.  It’s a good start but it still doesn’t look like much of a 3D printer.  The next step consists in assembling the “towers”.  The towers are the metal rods on which the printing arm chariots are installed.  They also are used to carry the electric wires.  Each one of the towers carries part of these wires, there’s a lot of them and they do a lot of stuff:

  • supply power to the hot end
  • supply power to the extruder motor
  • supply power to the two fans used in the hot end assembly
  • carry stop end signal back to the controller
  • carry hot end temperature from the hot end to the controller

The towers are named X, Y, and Z.  Here’s what they look like once installed:

As to the chariots, version 4 of the Rostock Max V2 makes them look very very good using a transparent casing with blue rollers…

Things are starting to take shape!!!

Building Rostock 3D Printer (Part 3 – Assembling the base)

I did the prep work of both the heating plate and the heating element last week.  This week, I’ll do the initial assembly of the printer’s base.  On the Rostock model, the base contains the power supply, the motors, a cooling fan, and the power switch.  It also houses the computer but this won’t be dealt with for a little while longer.

The base is made out of melamine boards that need to be removed from the cut-out sheets.  There’s quite a bit of satisfaction in seeing the thing take shape.  Here’s what the base looks like once the boards are installed.  Note that at this time, the construction is a little bit flimsy, as nothing is glued in and the top board is not installed yet.

The Rostock kit contains four stepper motors.  Three of these are used to control the extruder (the last one is responsible for pushing the filament down…  More on this in a future post).   The three motors used here each require a casing and a gear to be glued on.  The casing is constructed out of some other melamine components.  Note that I initially installed that gear the wrong way… Thankfully, somebody made me realize this and the problem was easily corrected).  Here’s a picture of the three motors.

After this step, it’s back to the base assembly where the power supply and the stepper motors now need to be screwed in.  This brings some more robustness to the overall structure.   Note that there is still quite a bit of space left in the base, which is going to be filled up when we finally put the electronics in there.  Here is what the printer looks like after this part of the installation.

(Note that on this picture, the gears are still installed the wrong way).

The last step consists in closing off the base by putting the top melamine board.  Now, this sounds easy but it took a fair bit of work to correctly align everything.   In the end though, here’s what the whole thing looks like: 

Very happy with the result!  It’s solid and the wiring is decent.

Building Rostock 3D printer (part 2 – prep work)

After taking a cursory look at the instruction manual, I got the impression that for me, the assembly problems would be in the initial prep work.  More on this in a few paragraphs…

Prep work consists in assembling the hot end, heating plate and power supply.

First, the hot end assembly.  Technically, it could have been done later but since it needs a drying time (24 hours), it should be dealt with first.

Assembly consists in inserting a couple of resistors in specially made pockets and cover them with RTV paste.  It also involves gluing a thermistor on this element using the same RTV paste.

The RTV paste is a heat conductor and it ensures the best transfer of the resistor’s heat to the heating element.   You want to make sure that there are no air bubbles in the paste… It should be paste through and through so that there is the least amount of heat dissipation as possible.  Not sure what the best way is for this.  The way I did it was to put a lot of paste in,  I also spun the resistors when I put them in… My hope is that this will break any air bubble formation… might be wrong on this.  (I’m looking in getting a thermometer to verify if I did a good job with this)

You can see on the following picture the two resistors (the leads) on the edges of the hot end.  The thermistor is glued in the middle.

This is where things get a little bit tougher… It involves soldering… I’m a software guy… 😦   That being said, there’s nothing quite complex here.  Once again, there’s a thermistor to glue in the middle of the plate.  There’s a resistor and a led too.  The only thing that was a little bit more difficult was the plate’s connector themselves.  The heating plate is quite good a dissipating heat so “tinning” it was a little bit more difficult.  On a  recommendation from a colleague, I preheated the plate a little bit (put it in the oven at low heat)…  It seems to have helped but I’m unsure if I would recommend doing this.  In any case, after this step, the heating looked as follows:

The power supply assembly was quite easy.  I think that SeeMeCNC was previously using an ATX power supply.  You had to cut a few wires from it.  The new power supply is quite nice.  It has a back panel that’s easy to wire in… and no connectors to remove.   The power supply is low profile and seems sturdy enough.  Quite happy with it.

Building Rostock 3D printer (part 1 – first thoughts)

I took my first step in building my 3D printer last week.  I am far from being a hardware guy, this is a personal challenge… it’s pushing me out of my comfort zone, which is a good thing…

Reminder to myself:  I’m going to take my time building this.  I’ll follow the instructions and don’t rush things…

So opening the box, I get this:

Four things can be seen here (from top to bottom and left to right):

  • Laser cut melamine sheets (skeleton for the printer)
  • Power supply box
  • Electronics parts (Rambo controller, etc)
  • Other parts (screws, bearings, etc).

I got everything out of the boxes, inventoried the components and put them in containers.  Everything seems to be there.  It’s a good way to start.

Note that there are a number of things you need to get prior to starting the assembly.  Amongst these, you need Kapton tape and RTV paste, both of which were quite hard to find in my neck of the woods.  These are not sold at my local “Home Depot”.  I was lucky enough to have a work colleague who had both of these.

The instructions provided by SeeMeCNC are quite good. The instruction manual (139 pages) is quite detailed and has a number of helpful links to checkpoint videos that allow you to ensure that you are not screwing things up.  They basically take you by the hand and guide you through the process.

Let’s start building!

Book Review: “Show your work: 10 ways to share your creativity and get discovered”

Loved it! It’s a short book that can be summarized as “a manifesto for creative types”. The “be good enough, that they can’t ignore you” is simply not enough. You can’t stay in the consciousness of people if you only show the result of the creative process. You need to show how things get done. As the book states, people do care “how the sausage is made”. You need to participate!!

Highly recommend the book (4.5/5 stars)

Notes and comments:

  • Scenius: Under this model, great ideas are often birthed by a group of creative individuals—artists, curators, thinkers, theorists, and other tastemakers—who make up an “ecology of talent.”
  • Creativity is always, in some sense, a collaboration, the result of a mind connected to other minds. (Take Leonardo, he was a great creator but never forget that he was in apprenticeship for years before striking out on his own).
  • The best way to get started on the path to sharing your work is to think about what you want to learn and make a commitment to learning it in front of others.
  • Share what you love, and the people who love the same things will find you.
  • The only way to find your voice is to use it.
  • One day you’ll be dead. (I highlighted this, because first, it’s true, second start acting now!)
  • Become a documentarian of what you do. Start a work journal: Write your thoughts down in a notebook, or speak them into an audio recorder. Keep a scrapbook. Take a lot of photographs of your work at different stages in your process. Shoot video of you working. This isn’t about making art, it’s about simply keeping track of what’s going on around you. Take advantage of all the cheap, easy tools at your disposal—these days, most of us carry a fully functional multimedia studio around in our smartphones.
  • “Stock and flow” is an economic concept that writer Robin Sloan has adapted into a metaphor for media: “Flow is the feed. It’s the posts and the tweets. It’s the stream of daily and sub-daily updates that remind people you exist. Stock is the durable stuff. It’s the content you produce that’s as interesting in two months (or two years) as it is today. It’s what people discover via search. It’s what spreads slowly but surely, building fans over time.” (I love the idea of stock and flow)
  • A blog is an ideal machine for turning flow into stock: One little blog post is nothing on its own, but publish a thousand blog posts over a decade, and it turns into your life’s work.
  • Your website doesn’t have to look pretty; it just has to exist.
  • Whether you’re telling a finished or unfinished story, always keep your audience in mind. Speak to them directly in plain language. Value their time. Be brief. Learn to speak. Learn to write. Use spell-check. You’re never “keeping it real” with your lack of proofreading and punctuation, you’re keeping it unintelligible.

Building Rostock 3D printer (part 0 – off of bucket list!)

I’ve had this dream for about 3 years now.  I want a 3D printer!  Whenever my wife asks me “What do you want it for?”  I keep giving answers like:  “Ah, you’ll see…” or “It’s a secret…”.  The matter of fact though is that I don’t know really know what I want it for.  I do have a few ideas, but nothing concrete… and certainly not something that justifies spending that much money.  Here’s the thing though,  my dad bought an Apple IIe when I was a kid and I’m pretty sure he didn’t know what he was going to do with it either.  Ultimately, he found many reasons to use it, games, business, and even software development.  I’m pretty sure that he told my mom that this would be “good for the kids”.  Not sure he truly believed it but ultimately it did foster my interest in computers.

So why buy one now? I had put some conditions on me buying it.  The printer bought should:

  • Be of decent quality;
  • Be open source;
  • Cost less than $1000
  • Preferably be kit based

(The last condition I decided upon because I really want to understand the guts of the system.  A kit is the easiest way to truly “grok” how something works… it also decreases the overall price and therefore should allow for greater component quality)

In any case, those conditions were finally met with the Rostock Max V2 model.  It was voted by Make magazine as the best quality price 3D printer out there.  It is totally built from open source parts and on top of this can come either pre-assembled or as a kit.  The kit version of the system is quoted at $999.

So there you go.  Now, the building starts…

Here’s what it looks like now: