So what's involved in supporting 3rd party filament on a printer that takes proprietary cartridges? Well as you can imagine I'm not the first to do this and there is solutions out there already. The problem is two fold......the first is how to get the filament to the extruder. The second is how to fool the printer into thinking it's using it's own filament. The physical side of using 3rd party filament itself has several options, firstly you can mount an spool holder on the back and feed the filament though a gap in the case, this design from DaakTwo demonstrates it well. You can see the filament enters the printer through the gap in the back of the case. This is were the standard cartridges are located so the filament uses the same guide path to the extruder.

DaVinci rear spool

Read more: Da Vinci 1.0A - 3rd Party Filament - Spool & Guilds

In my last update I said I got a new Da Vinci 1.0A and right out of the box it was awesome......well this has not changed but, as is my nature, I have started to tinker with it.


Read more: Welcome the Da Vinci 1.0A

I have always suffered from poor print quality with both Z-banding (bumpy side walls) and oval holes on my prints and thought that it was (at least in part) due to the badly printed x-axis idler that was delivered with my printer. I finally received replacement parts in metal.

Original X axis x axis metal

Read more: More printer updates

So the time has come to put auto bed leveling on my printer. While this is not really a requirement I do like the option of the system checking the bed before a print and mathematically adjusting for any miss alignment during the print and not just wrecking layer one if the bed is not 100% level.

There are many ways to do level checking on a bed but the simplest and the one I have parts for is the servo based one. ZennmasterM did a great overview of this process for the Makerfarm and was the inspiration for my own project.

Read more: Adding Auto-Bed Leveling

So those reading previous articles will know about my fuse issue with the GT2560 board and that I needed to completely swap out the electronics for my printer. Well the new kit arrived on Friday and I spent the afternoon retrofitting.

First was to assemble to Arduino Mega to the RAMPS board then add the step sticks. I decided to simply transfer over my existing stepper boards as they have already been tuned for my printer. I found this connection diagram most useful.....


.....only I have not used a relay for the bed but just hooked it up directly, since I'm using PID to control the temperature a relay is in appropriate.

Read more: Changing to Mega2560+RAMPS

I looked at many different methods of control and there are lots to choose from. However the Wii nunchuck came very high on this list for a few reasons. The nunchuck has 5 axis of control and 2 buttons in a very small package and some free space internally. This means I can do directional control, basic head control and trigger a couple of additional on/off functions all from a single controller.


Read more: Nunchuck as controller

My intention for Wall-E is to operate in two different modes. The first is a puppet mode for use when demonstrating Wall-E or where discrete interaction is required, the second is an autonomous mode where Wall-E does what he wants on his own.

To facilitate these two different control systems on one platform I decided to use a distributed control method that splits up the higher functions and the lower functions in much the same way as our own brains are meant to be working (does anyone really know?). This means that items such a motor control and head movement are not done directly by the main controller (brain) but by instruction to a lower level controller. For this the I2C bus (network) makes sense.

TWI two wire interface

Read more: Internal network design

So where do we start our Wall-E build? I decided the best thing here would be to start at what I saw as the most complex part, the track system. Joining the Wall-E Builders club and watching a YouTube video from showed me that it was possible but most people took an off-the-shelf approach to the track system.

Read more: Designing the track system - Pt1

My printer kit came with an all-in-one controller board from geetech called the GT2560 which combines the traditional Arduino Mega and RAMPS boards together and offers a smaller dedicated package. This seems like a great idea and for the first few prints is worked great. However moving to ABS and the higher temperatures required at the bed and hotend caused me a few issues.

700px GT2560 wiring

Read more: GT2560 fuse issues

When I decided to go back into robotics I wanted to build a platform for experimenting with autonomous robots. However I didn't just want a box on wheels or a couple of servos on a circuit board, I wanted something people could relate to. I made a short list of 3 which I would put to my wife and see what she thought.

First up we have Johnny 5 from the Short Circuit films and as my favorite robot of all time he made the list first.


Read more: Why build Wall-E

I decided when I started with 3D printing that my primary plastic would be ABS however my kit was supplied with a 1kg roll of PLA and as this would not be my plastic going forward I decided to use this to setup my printer. As a result I had to change out the plastic later.

So why did I choose to use ABS as my primary plastic? 

  1. ABS is a stronger plastic than PLA
  2. ABS can be solvent welded so joining ABS parts together in a strong way is easy to do
  3. ABS is heat resistant and as some of my robotic parts would get hot in normal use PLA is not suitable

What has to be considered when printing in ABS?

  1. You need a heated bed. This came with my kit so I was setup already. ABS requires a heated bed to ensure that the lower layers do not cool too quickly and therefore lift from the bed (curling)
  2. ABS requires a higher print temperature (typically 230C).
  3. ABS doesn't smell as sweet as PLA
  4. Finally and critically, ABS requires you to prepare a print bed to ensure it sticks during printing.

Well my printer has all the pre-requisites all I needed to do was find a way to ensure the print stuck to the bed. After reading much advice I settled on the hairspray option since this is easy to get hold of, smells better and is not too difficult to clean off the class if I need to.

Read more: Changing from PLA to ABS

One of the issues a ran into was the filament getting tangled off the roll before getting to the extruder. I printed a filament guide to help with this and this solved the problem. 

The guide I used is Prusa i3 Filament Guide from thingiverse. I customised this to suit my 5.5mm frame since my kit was not a standard 6mm frame. Printing was easy and installation even better.

Filament guide

My customised guide can be downloaded Prusa i3 Filament Guide 5.5mm

When I decided to get back into robotics I took a look at what caused me to stop doing it ~10 years ago. I came to the conclusion that I was most frustrated by the need to use pre-designed kits or re-purposed scrap parts to build things. In recent years this has changed with the introduction of 3D printers at affordable rates. Now I can get back into robotics with the ability to design my own parts.

So where did I start. I looked around ebay and associated on-line stores for the parts required to build a 3D printer. Yes I prefer to build than buy, it's my preference for most things where possible. I quickly discovered that it is more expensive to buy in parts than to by a printer kit so decided on a kit printer, a decision I would later regret.

Prusa i3


Read more: Building the printer