WorkingDevices

Bench Top CNC

By merc inari

I previously don't know much about building a CNC but it inevitably grabbed my interest to a point where I have to suffice my curiosity. CNC is very useful for machinists, hobbiests and the likes--without it would mean disastrous for any design engineer. CNC from the description of ATOMICA implies;

"A category of automated machine tools, such as drills and lathes, that operate from instructions in a program. Numerical control (NC) machines are used in manufacturing tasks, such as milling, turning, punching and drilling."

I recently built a CNC for myself because I like to do a lot of prototyping and machining. Although, I originally started this project for the company I work for, and I have to build one because they currently won�t approve a bill for a new bench top CNC(20K). I know it would help a whole lot if I have a CNC since it will machine the parts directly from computer image to an actual part. I would normally complete the parts by manually machining them on a Lathe or a manual Milling machine (Bridgeport). But thanks to the internet, I found all the information I need to build my own, with my modifications and at a very cheap price when compared to a turn key or new ones. Most of my parts were purchased at a local surplus dealers in my area and also at a local hardware stores.

As you can see on the picture below, my CNC is made out of oak veneer that was purchased at Home Depot. The worm gears, screws, bearings etc. were purchased at OSH. All in all, I probably spent less than $100 on this project keeping in mind that I have some of the little things in house and I am not charging myself for labor.

The cnc is a 3 axis stepper motor (70 oz) using a Dremel tool for its spindle. Obviously not for heavy duty use, but does what I ask to do. Most of the information on how to build this was available from the web, let me know if you need some information about this one. I made many design flaws when I was building this (which I can correct on my upcoming cnc.) however, the flaw does not affect the operation�it just makes it imperfect.

The hardware used for this cnc are not designed for heavy duty machining but it was sufficient for my applications. Surprisingly, the tolerance is excellent. Being my FIRST cnc that I built, I was astounded by the accuracy and the repeatability of this machine. I brought this cnc in my company lab and amused everyone that saw it running�it was very impressive.

Check out the first prototypes I built with this cnc below, it was crude at first but the next ones I built after this was really worth having.

Look at the 3D image of the globe on the front right and the flip phone prototype at the front left. The PCB on the background are machined off a one sided copper board while the one on the right is of a REN shape board, the traces on the board are schematic of the CNC stepper motor driver. Let me know if you are interested on this one--for more information, drop me a note!