18 September, 2012

A closer look at CNC Router number three

I have been asked a couple of times now what plans I used to build my current (at the time of writing) CNC router. Well I have perused, perused and did a bit more perusing of CNC router plans. I rejected all of them for various reasons. Suitability, cost of build, access to unusual materials, imperial measurements were a particular problem as I live in Europe where we have metric nuts, bolts and materials. Adjusting plans seemed like a lot of extra work. 

So I decided just to go ahead and build my own design but applying what I had learned from previous router projects and from perusing those other plans.

The layout is deliberately basic. I wanted to create a robust functional machine rather than something that would win a beauty contest, or be feature rich. This machine will eventually be used to create a larger CNC router, when I am in a position to need one. In the diagram below you can see the layout of the x-axis and y-axis. The y-axis comprising two beams sitting on two 'feet' and the x-axis comprising one longer beam fixed to two uprights. It should be noted that this design is a fixed gantry which is simpler to build and generally more robust than a moving gantry design at the expense of a larger machine. Please be aware that there is a small error in my layout diagrams. The two y-axis beams are shown accidentally rotated 90 degrees along their length.

A simplified layout diagram

Simplified layout with rails

Update on comments

For some reason known only to blogger, the replys I post to your interesting comments do not appear! :-/

I really enjoy reading your comments, so please don't stop commenting, or if you want a direct reply, please use my contact page.

I will add information that you request in your comments here:

@Dana, #3 cost me around £700 (£1000) to build, but I could have built it for just over half as much if I had used Acme rod and not the high precision leadscrew and anti-backlash nuts on each axis. The golden rule with the cost of homebuilt CNC is build as small as is practical. The cost rises exponentially with cutting area. Solsylva CNC has a great article for beginners on different leadscrew types and a host of other useful information.