Fab Academy 2014 Machine Assignment

Full Size on-the-wall CNC Machine

A Fab Academy 2014 machine assignment by Francisco Sanchez from Fab Lab Sitges

The Problem (Why)

Full size CNC machines are still expensive. Fab labs cannot progress towards the next power of 10 (10k fab lab) if there is no way to make a cheap and reliable full size CNC machine. Apparently there is no reason for a 3 axis machine to be that expensive. But there are a few reasons why these machines cost that much:

  1. Due to the high spans, the machine requires a lot of stiffness in order to avoid deformations. That means more material and weight, and hence money
  2. This increase in weight requires more powerful motors and components, again more money
  3. Because of all of this weight, crating and shipping of these machines is expensive as well. And you cannot source parts locally because most of the vendors use custom frames not globally available

Actual reason:While all of the above is true, the absolute truth is that I would love to have a Shopbot in our Lab, but I still haven't managed to gather the funds.

The Goal (My expectations)

My goal this semester is to make a full size CNC machine attached to a wall. The wall has already a lot of stiffness and I want to take profit of this stiffness to make a much more lighter and cheaper machine. The main advantadges of this design are:

  1. Uses stiffness from the wall. Requires less material, cheaper motors and components
  2. Uses gravity as a natural dust collector
  3. Occupies virtually no space in the lab

Design Requirements (The needs)

Design requirements

Please find below the design requirements:

Parameter Minimum Value Desirable Value
X axis 244 cm 250 cm
Y axis 122 cm 150 cm
Z axis 15 cm 25 cm
Feedback Open loop steppers Closed loop system

The Materials (As cheap as possible)

To be continued...

About Me

My name is Francisco Sanchez Arroyo, I have a Civil Engineering educational background which brought me my passion for tall buildings and structural engineering. I took the Fab Academy course in Fablab Barcelona, but I live in Sitges, a very cute coast town 25 miles to the south of Barcelona that you should absolutely visit when you come to Fab10.

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About Beach Lab

Sitges Beach Fab Lab is a FabCafe and digital fabrication facility participant in the MIT Center for Bits and Atoms Fab Lab Network to be completed by fab10, the 10th International fab conference which will be held at Barcelona in July 2014.

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About Fab Academy

The Fab Academy is a Digital Fabrication Program directed and taught by Neil Gershenfeld, one of the world’s top 50 scientist and director of MIT’s Center For Bits and Atoms and based on MIT’s rapid prototyping course, MAS 863: How to Make (Almost) Anything.

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