Prototype #3: final prototype

This is insides of the Y axis prototype, Z axis is similar as well.  The build is rough as it is only used as a proof of concept.  The final material will be out of aluminum. As you can see the mechanics is simple: motor turns screw, screw turns nut, nut moves tray.





Here are pictures of the final proof-of-concept prototype model of Concept 3.  This is where I ended my first semester of my school project.  It is a fully functional 3 axis CNC machine.  It's setup at about 120 inch per minute, and an accuracy of about 0.015"  I used a floor engraver setup configuration as supposed to a typical desktop CNC configuration.  In this setup I am capable of doing CNC work on the surface below which I demonstrated during my end of semester presentation.  Built time: 1.5 weeks

Prototype #3: Materials Exploration

My original concept for prototype #3 was to make it as stiff and light as possible.  So I experimented with carbon fiber and kevlar combination as the main material.  Kevlar has great vibration dampening characteristics and is more inexpensive compared to carbon fiber. 

I did multiple experiments to see how many layers of kevlar I need and ways to make it stiffer without adding added weight.  By adding ribs or using sandwiching techniques, I was able to make it rigid and light.

Prototype #3: Introduction

By this time, I am starting my final year in my Industrial Design degree. Since I always wanted to update my CNC with better improvements I decided to use it as my grad/thesis project. My original intent for the project was a portable CNC that is multi-functional/transformable to allow CNC technology to progress (as I believed CNC technology has had very little progress in the past decade).

I ordered faster lead screws, this time using Acme 1/2" 8 start threads. This will be 8x faster than my old setup, going from 16 inch per minute to 120 inch per minute.  I ordered the Acme coupling to attach the motor to the screw instead of using a hose as per my earlier machines; less fuss and maintenance. Also got an end clamp for the other end of the Acme screw instead of having it free spinning; this reduces potential backlash and makes the screw more aligned all the time.

Bearings and slides are now all fully supported.  X and Y axis are using 24" Thompson bearings/slides while the Z axis is by another brand (bought separately). Motors and control boards are the same Xylotex setup from my old setup.

Parts & Resource List

Some parts I use on my CNC projects:

Xylotex: Electronics & Motors
-4 axis control board
-4x 269oz bipolar stepper motors


DumpsterCNC: Anti-Backlash parts

CNC Zone: forum for tech help

McMaster-Carr: misc parts (Acme screws, etc)

ebay for used bearings and slides