New Project, New tech

I’ve had a passing interest in 3D printing for some time, but even the basic kits have cost too much to justify buying what would be a fairly expensive toy. Recently however the cost has reduced and I found that the ethos behind some of the printers is one that is very similar to the open source software. RepRap is a project which is trying (successfully) to develop a minimal cost printer that can reproduce a quantity of the parts it is actually made of.

Adrian Bowyer is an academic (Engineer/Mathematician) who started the RepRap project, he describes the project as:

RepRap is about making self-replicating machines, and making them freely available for the benefit of everyone. We are using 3D printing to do this, but if you have other technologies that can copy themselves and that can be made freely available to all, then this is the place for you too.

It is a clever approach because (in theory) as each machine is able to reproduce at least part of its self it reduces the cost of making the next. This benefits everyone and leads to a knock-on reduction of the consumables as the community becomes larger. As more technologies are involved the machines will gradually be able to make more parts, further reducing costs hopefully.

The ability to create parts, coupled with the open source ethos and promotion of community contributions frames the project in evolutionary terms. This means that not only can a printer reproduce its self, the owner of the printer can redesign all or part of the machine and then release his plans into the community for adoption or extinction. This process has been in play for some time and there have been many iterations of the initial plans and numerous new machines so far.

If the only goal was this grand experiment then it would be pretty pointless, however the printer can make pretty much any shape that fits within the confines of its printbed. Whether these objects are useful in the real world depends on the application, after all plastic is not be suitable for every situation.

The plastic filament used to create the objects varies in cost and quality, but I have seen it from on sale from £10 including postage and packing. So long as I can get a reasonable number of small items out of a roll of filament I will gain a lot of flexibility and save money (just on postage and packing if nothing else)

Personally I want to use the printer for making enclosures for some electronics projects I want to do, to fix a few things around the house, and to gain some mechanical engineering knowledge.

Simplistically the printer plans all consist of a frame, the print head (hot end), extruder drive, rails or arms for supporting the hot end on, motors and electronics for actually moving the hot end/ arms extruder drive, a print bed, and the electronics for actually controlling the printer.

The controller is usually an arduino based microcontroller board which can take gcode and turn it into the head movements and extruder commands to build an object in the printer. The gcode is usually exported from software running on an external computer although because it is text based can be written directly!

I have dabbled in electronics and work in software development so from that point of view I am not a beginner. However I was under no illusions that the mechanics would be a challenge for me. If I had to do everything from scratch I’d just fail because I would not know how to begin. Luckily there are businesses that sell kits meaning that I just have to follow the instructions – adult lego :)

I decided to get a Fisher Delta printer kit from RepRapPro although they as a company decided to get out while they are ahead (too much competition in the market). Other designs are available as kits from many other sources so there are many options out there. When the kit arrived it was complete and contained a lot of parts. I had pre-read the instructions and made sure that I had the “required tools”. I just needed time to put it together.


Setting up.

This post is a place holder for setting up a Java development environment. It is intended for my son, but if useful to others then great. I will also be providing some basic information for Java as well. Note that many tutorials are geared to getting people using basic tools (notepad and command line) this will be using an IDE and hopefully more fun!

Before we start we need to set up a couple of things :

The last two of these are not entirely necessary but are a good practice and allow you to avoid mistakes, backtrack, backup and share your code if you want to.

Not much explanation at the moment, but a solid starting point. I’ll explain a couple of features in future posts but experimentation is the key to learning – try things and see what happens.


Modding again.

I dabbled a little in modding minecraft before, and now after some time I am getting into the whole thing again. Much has changed since 1.6/1.7 and I have had to relearn quite a few things that I thought I understood, but that’s the initial challenge.

I have a github repository now and unlike before I am going to use gradle properly for the setup and download of dependencies. I am also now using the jetbrains idea IDE which I have to say is much easier than eclipse to understand, although because of gradle, switching from one to the other is a simple operation.

In addition, I have looked into Kerbal modding and this is based on the Unity engine at its heart. Consequently this requires me to learn C# to write any mods. It’s not too far from Java and I am using Microsoft Tools at work but I have more ideas on what to do in Minecraft than Kerbal which is a whole different mindset. A Magic mod wouldn’t be too useful in kerbal 😀 although I did have one possible mod in mind. We’ll see…


The Trouble with Tourists

Dliny and Carte, socialites of the Kerbal aristocracy and looking for new thrills came to Kasa and asked us whether they could fly in one of our craft. They both wanted to be the first to take a selfie with the planet and then post it to MyKerbBook. We said no of course and they offered money and we decided to think again.

The big problem was that neither of them could fly and we needed them to survive to get paid. Werner suggested we get a good lawyer and just fire them into orbit, but or bad lawyer said that would cost more than getting them back and we had to think again.

Eventually the guy changing the light bulbs in the command centre realised that the remote controlled lighting and air-conditioning in the office could be modified to control a rocket! He was hired and started the electronics department. He added a nice range of lights to the mix too :)



The configuration that worked in the end was one in which two command modules were placed one on top of the other. The control system sat on-top of these so that the heat of re-entry wouldn’t fry it.


Dliny and Carte were ecstatic on their return, luckily they thought that the near disaster that happened after final separation was simply us keeping them closer together during their experience *phew*


They were down and we were back in the black. After waving them goodbye we found that there was a flood of requests to travel! Having a spare rocket we decided to do one more trip and Magda and Franbella were the 3rd and 4th tourists.


This time the final separation went much smoother and everyone breathed a sigh of relief as we cashed their cheque. All this media coverage had led to wannabe kerbinauts attempting to get into space by themselves. The problem is that none of them seemed to think about getting back – we were called on to so a rescue. Our tracking team plotted an orbit and we ran simulations.


We could get close, but our knowledge was lacking, the inclination and alignment was ok, but we never came close enough to transfer Debilian from his scrap ship to the Mun-Bus ™  (our tourist ship). We always seemed to run out of fuel before being able to correct the orbit.The planners needed to pull an all nighter to see how this could be done…





Fly me to the mun…

Ice cool Glendine Kerbal has moved from being the new girl in the space  centre to being the hero of Kerbin. Our first moon pass has been achieved without a hitch. Including and EVA during the pass by.


After a smooth transition to a low Kerbin Orbit, the tracking station plotted the course for the Mun.




Glendine executed the course to perfection and said good by to Kerbin for the long trip. She decided at that point to do the Kerbin Times crossword to kill a few minutes and sat back for the ride.



After drifting in the emptiness for what seemed like only a moment the Mun was near.



Glendine prepared the final approach, she poised her finders above the controls ready to correct any mistakes in the course, her fear visible as the pass was made. But it was perfect! Glendine saluted as she flew over the  peak on the mun where Valentine was likely to have died. It has been named Mt. Smear in her honour. Quickly she did the science experiments, and prepared for an EVA, this was the icing on the cake. 2015-05-15_00012

There was the chance to take measurements for some private companies, but there wasn’t enough fuel to enter a mun orbit. That would have to wait. Tracking contacted Glendine and relayed the course correction required to get back home.



This was going to be tricky, the only way back was straight down. She was about to fall from the Mun to kerbin. The tricky bit was stopping at the other end. She said her farewells to Mun vowing to return. and began her decent..


Glendine was hitting 2800m/s as she hit the atmosphere, although that quickly slowed, she just hoped enough to depoly the parachute!


Tracking lost contact for a moment at this point but our hero glendine survived. The chute did its job and she splashed down in the Kerbal Sea where her ship was recoved successfully a few hours later.


Planes before Manley…


The Kerbal engineers got to work and created a plane, they took their inspiration from a paper dart they created the week before. Amazingly the plane flew.





We had a contract to test the Weasley engine at certain height and speed. We reached 10k fairly easily but the speed was simply unobtainable even when diving straight down. We tried a few variants of this model in an effort to get the speed:



try4 try3

But it didn’t matter what we tried it just didn’t work. Then Werner had a brainwave. The contract didn’t say it had to be tested on a plane. We could test the engine on a rocket!

tester1 tester2

Job done! we got the cash and Werner realised that the windgs we made for the plane could be modified on a rocket allowing us to use the more powerful (and lighter) reliant engine and still steer. A stroke of genius…