Sunday, October 20, 2013

Large Form Factor T-Slot Tantillus 

Build Blog Part #1- Introduction

This is my attempt to document the build process for the Ingentis, a large form factor t-slot Tantillus 3d printer I'm currently putting together.
Before I get into the specifics, I should point out that the design I am working off leans heavily on the efforts of Sublime with his original and very innovative Tantillus printer and the subsequent development of his design into a T-Slot variant by Goopyplastic. Links to the respective pages for these printers below:

Why am I building this?

I don't intend to go into any great detail as to how I've decided to take this particular route – I hope the results will speak for themselves. However, there are some key features to point out.
  • The design is a Overhead Gantry cartesian x/y solution, this means the build plate only moves in the Z axis, significantly mitigating the issues arising from build plate weight and print speeds with the popular Mendel/Prusa style bots.
  •  The drive mechanism for the x/y axis is very similar to an Ultimaker, with the notable inclusion of Spectra braided fishing line replacing timing belts and pulleys, an innovation from Sublime that really makes the Tantillus stand out as an original design and contributes to the excellent print quality it produces.
  • The gantry approach makes the use of Bowden tubes and fixed cold ends virtually mandatory. Although Bowden systems can be slightly more challenging to calibrate, the lighter x/y carriage allows for much faster print speeds and acceleration which is important when you have such a  large build volume.
  • The Z axis is a significant deviation from the original Tantillus design as it’s increased size warrants a more sturdy approach and I'm keen to see how belts can be used to avoid costly lead screws.
  • The current design allows for 2 extruders, at some stage I may increase this to 3. I will be using the excellent E3D all metal hot ends, I strongly recommend that you consider these as they are very much a leap forward from Jheads and their contemporaries .
  • I've tried as much as possible to apply the KISS and KIM principles to the design.
    • KISS (Keep It Simple Stupid) - The non printed parts for the Ingentis are all readily available from a number of online vendors. It uses standard 2020 T-slot aluminium, 10 and 8mm liner shafts, press-fit bronze bushings, and the usual NEMA stepper motors. I have tried to leverage existing, proven designs as much as possible and made as much of the bot as 'printable' as possible without compromising it's structural strength or accuracy. The one exception to this is the use of belts to drive the Z axis, I believe this will provide a better print quality than a lead-screw solution, However a more conventional screw driven option can be easilly retrofitted to the design.
    • KIM (Keep It Modular) - The  bot's design can be easily broken up into a number of modular sections with as little interdependance as practical. This should allow for plenty of room for future upgrades and improvements without needing to re-design every part.

Overview of the design

 The printer can be broken up into a number of functional units as follows, I'll link to relevant blog pages as I document this.

  • Frame 
  • Exterior Gantry supports
  • X/Y axis
  • Z Axis
  • Print Bed
  • Carriage and Hot ends
  • Exruders
  • Electronics
  • Reticulation and lighting.

 The Bill of materials showing the hardware I have sourced for this project is linked to below:

Please be aware that this BOM is a work in progress and that purchasing hardware from suppliers in China is something that requires a degree of consideration and thouhtfulness. In saying that, for the most part, the products I’ve purchased form China are  good quality and significantly cheaper than the locally sourced equivalents.

Source files for 3d printed parts and machined parts are kept on youmangine (link below) . I don't really agree with/trust Thingiverse and youmagine is still a bit clunky but the alternative would be github which really does my (non-coder) head in.