Project: FFF 3D Printer “Eta” Part 1

Hello Sunday!

So for the last 6 months I’ve wanted to build a 3D printer. It’s a good, challenging project, and will have utility for helping me prototype some of my more ambitious projects. So I spent the first five months planning and designing the printer, and then after I began acquiring the parts for my printer.

So, onto the juicy details of Eta. To start off with, the name is stands for the Greek character“H”, which stands for both Hephaestus, the god of smithing and craftsmanship, and also for H-bot, which is the name of the configuration of my drive train.

To summarize, my printer has the following specs-

  • CRS L profile frame
  • Approx. 29cm x 29cm x 25cm build volume
  • H-Bot mechanics
  • Bowden extruder 1.75mm
  • RAMPs 1.4
  • 300mm X 300mm heated build surface
  • Hot end moving in X & Y axis
  • Print surface moving in the Z axis


Let me just elaborate on a few of these points, to highlight the unique parts of my printer.

It’s a bit difficult to understand what a H-Bot system is without watching a few videos or seeing multiple images, but a quick search on the web should resolve any doubts. The main difference is that typical printer mechanics involve whats called “Serial Stacking” which means placing one axis of motion upon another, like how the Z axis of the Reprap Prusa i3 moves the X axis as well. The issue with serial stacking is that it requires the motors to move, which further increases issues related to cable management and most importantly increases weight.

By using H-Bot, which using a single long belt connected to two stepper motors, moving the heavy mass of the motor is eliminated, and the printer becomes faster and less prone to artifact creation in the print. To further reduce weight, I’m using the Bowden Extruder concept, which involves using a stepper at the end of a tube to feed filament into the hot end of the printer rather than directly bolting the stepper to the moving hot end, which would increase its mass.

The most obvious choice I’ve made is to go with L profiles instead of the standard 20X20mm aluminium extrusions. My main reason was that the L profiles were much cheaper & commonly found, reducing costs by approximately more than Rs. 2K. This comes at the cost of increased weight and difficulty in customization and fine adjustment.

The heat bed was difficult to procure, as 200mm is the standard size available, but I managed to find a site which sold 300mm beds in India.

Most of the joints and carriages are being manually made by me, primarily out of MDF and plywood. I’d prefer to have it milled out of aluminum or industrial plastics, but that would be prohibitively expensive. I may decide to ‘reprstrap’ my printer, which means to have a 3D printer print parts to upgrade itself, which might increase its final results.

There are a few other differences my printer would have, but I’ll talk about them later. For now, here is the current stage of construction of my printer.



I’ll be sure to keep you all updated on my progress as it happens. I’ve recently just recovered from a bout of dengue, so progress might be slightly slow, but I hope to finish the construction and calibration of printer in less than a month.

Thank you all,

Signing off,



4 thoughts on “Project: FFF 3D Printer “Eta” Part 1

  1. Pingback: Project: FFF 3D Printer “Eta” Part 2 | Adithyaa Designs

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