Prusa Part 1: Planning

By February 6, 2016RepRap

This is the first of many posts which will outline the construction of a customized Prusa i3. It is not intended as a complete manual, however will provide links to the relevant information required to complete a build, along with how to select parts, etc. You can read about the original Prusa here and the RepRap family tree here. For a very detailed guide, see here.

This is not intended as the “cheapest way to acquire a 3D printer”. Nor is it the fastest. While potentially cost-saving, it is intended as a hobby and self-educational tool, potentially leading to larger, more customised printers in the future. There are currently a wealth of new 3D printers, such as the Tiko, which is about to come into full production. Similarly, it will not be the most beautiful, as I am interested only in functionality, rather than aesthetic.

For this build, I was looking to lasercut as many components as possible, and hence reduce the amount of 3d printed components required. In the interests of reducing costs, I was also looking to lasercut MDF instead of metal or thick acrylic. This design hence comes heavily based off twelvepro’s model from 2013, which is based on 6mm lasercut components.

Prusa i3 Improved for laser cut
by twelvepro, published

I modified this design to further reduce the amount of 3d printed components, and reduced the amount of threaded rod. The significant advantage this model had compared to others, was that it was modelled in a NURBS CAD program, allowing easy editing and customizing.

The extruder I selected is a Greg’s Wade, slightly modified for compatibility, with a mount for the hot-end I’ll be using. Again – this is a fairly standard extruder model.

Greg’s Wade extruder for Prusa i3
by misan, published

For the electronics, I elected to use an Arduino Mega 2560 with RAMPS 1.4. There is a a comparison here. RAMPS isn’t the newest board, but it’s pretty standard and well documented, and will do everything that’s required for a first build.

There’s also a low-profile spool holder (also lasercut) based on the principle of this one.

Here are the relevant files (click image to download).


Most resources I looked at had long lists of tools that I’d need to be able to complete the project, however generally it seems that they are tools to make life easier, but not strictly requirements. For example, dupont crimps, thread-locking liquid, digital calipers. In this case the only tool that I’m acquiring that I didn’t already have is a cheap multimeter from ebay. I intend to manage with a soldering iron, hacksaw, and general toolkit.

I am getting almost all of these parts off ebay in a total of 20 or so shipments, with the following exceptions:

  • Vitamins (bolts, washers, nuts)
  • Threaded and Smooth rod (need to be high quality, and very straight)
  • Power supply (needs to be reasonable quality)

Almost all of the parts from ebay are shipped from Hong Kong or China, with the exception being when local parts are found cheaper, which was the case of the stepper motors, heat bed, and glass plate, which I got from an Australian ebay store, LearCNC.

I also bought a lot of spare (and optional) parts, particularly since many of the small parts come in large packs (ie. 100 LEDs for $1.20). I also made sure to buy plenty of spare bolts (aside from what I already had).

Some notes on selecting some of the more important parts:

And it’s also worth noting that I’m using a pre-assembled RAMPS board.

See below for links and cost spreadsheet as of Feb 2016. It ends up around $300 for primary hardware, $35 for vitamins, and $30 for material. If I’d used an old power supply it would’ve been $50 cheaper – and I also elected to go for a borosilicate glass bed, which I’d call a luxury at $25.

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