Custom Built CNC – Part 1

Welcome everyone. To cover my past and current Computer Numeric Control (CNC) build will take a few posts. I will be breaking up the documentation and discussion into sizeable chunks. I will introduce the first few builds but avoid the deep details. The final build will be full of details as it is built using all of my lessons learned from the previous ones. So…

— The Evolution of my Machine —

A note on product links: From time to time in the following posts I will provide links to the products I bought to build this project.  Many of these items are from Amazon.  As an Amazon Associate I earn from qualifying purchases you make using these links.  It costs you nothing but provides a small commission from Amazon for me to use for hosting and upkeep.  Thank you for your understanding and support!

Build 1 – The Small Cheap Mill (2007-2008)

I’ve had the bug to build my own CNC router since 2001 when I first stepped into a professional machine shop at my University. I got a job in that machine shop just to have access to the machines after hours. When I graduated and finally had a place of my own, I began planning and tinkering. At the time the maker community did not have the large presence it does now online. My first attempt was humbler than the big CNC router I would end up with. In 2008 I took my first real attempt. I built V1 around a Harbor Freight 3 axis mill. I ran this machine off of an ebay bought motor driver that still used BIG POWER RESISTORS as current limiters. Those suckers got hot. I had limited success with this build.

The biggest problem proved to be with the x/y carriage. It was metal on metal and was next to impossible for me to calibrate and tune with the skills I had at the time. In the end I donated this machine to a local high school. There a senior took the machine and by the end of the semester got it working well for cutting things out of acrylic. I unfortunately have very little by way of documentation or pictures of this unit. In fact, the picture above is all I have to prove it existed.

Build 2 – Joe’s Original Wood CNC (2009-2012)

This is when I got serious. I was scheduled to depart on a Deployment in the spring of 2009. I was to be on the U.S.S. Abraham Lincoln for 10 months flying combat operations in support of Operations Iraqi Freedom and New Dawn. On the ship, internet connectivity would be sparse and down time ample. Before I left I went over to www.joescnc.com and bought into his site. With this purchase I gained access to Joe’s plans and his forum. This forum was truly awesome. I developed some great friends through this group and learned a ton. I would have spent the $100 just for forum access, it was that good. Over the next 10 months I studied the designs and began to build my Bill of Materials. For this build, I cannot share it with you online as it was heavily based on Joe’s work. Parts started to arrive in bulk back at my house and my wife, not expecting this, was left to just stack large boxes in our office for months on end. When I finally got home, I went on a building spree. Echo (Version 1’s name at the time) was built in 31 days during my post deployment leave. She was beautiful:

She featured a mobile wooden base constructed of plywood. The top was built as a torsion box from MDF and plywood. The rest of the build was per Joe’s plans, constructed out of 8020 aluminum extrusion and hand cut MDF parts. The torsion box was of particular interest. The box was 6ft by 5 ft and 6in thick. It started with a piece of 3/4 in MDF, then the ribs and finally a top of MDF like in the CAD drawing below:

This resulted in a super strong, rigid and relatively light tabletop. It was perfect but this build had one more trick up its sleeve. I built into the table top a touch screen. The touchscreen itself was a junk salvage unit and was circa 2001. Needless to say, it wasn’t very good, which is why you wont see it again in future builds:

Perhaps the area I learned the most from during this build was the electronics. I built the case out of MDF… Hand slap to forehead…. this was an awful idea. If you look closely you will see four Gecko Drivers (G251s), a parallel port breakout board and a 48V power supply. Version one of the wood box had electrical noise issues so I decided to get shielded cables and build the back and front of my case out of sheet aluminum. While making this upgrade, I shorted the ground to one of the drive pins of the driver and FLAMES EVERYWHERE. It is the only time I have really used a fire extinguisher. The only electronic part to survive was the power supply. The lesson to take away here is don’t for any reason build your electronics box out of wood. Just don’t do it, this isn’t the place to save a penny.

Learning from this almost catastrophic accident, I bought a case for my electronics. This time I found a 4u Rack Drawer for server racks. This case worked great. It was solid metal and lockable. I will post my source in the BOM of my final build (See later post)

In the pictures you should notice that I upgraded the burnt up G251 with a Gecko G540. I bought a package from www.cncrouterparts.com that included the motor cables and G540. This was one of the best buys I made. You may also notice that I added a contactor into the circuit to allow the two push buttons on the front (Red and Green Buttons) to turn the machine on and off. It was over kill but very satisfying. Finally, I added the much needed emergency stop mushroom latching button. This electronics setup would remain untouched for the next 10 years before being reworked. In the end, while cleaning my machine I unplugged the cables from the back of the G540 and one of the pins was melted. I was unable to clean the pin and never did get it to return to action. I’ll describe the new build when I get there. Bottom line though, I would not hesitate to recommend the G540! It was an easy and reliable controller.

Even though it was built of wood, I set fire to my electronics and it was my first real attempt, it built some great pieces for me:

After 3 years, as is the case in the military, I found myself moving again (Washington State to California). This was the beginning of the end of Echo. I took it apart and separated the two halves of the base. I designed it to do this but post move, she never really went back together the same. This led to me rebuilding the base to make it more mobile to be ready for the next move. Enter version 2 (Build 3).

Build 3 – Joe’s Evolution CNC (2013-2014)

Since my first go at Joe’s CNC he had released the Evolution design. Essentially this consisted of several cast aluminum plates to replace the Y and X carriages as well as a change from 4020 (4x2in 8020 extrusion) to 6030 (6x3in) for the X Axis. When I went to reassemble Echo, I decided to invest in the upgrades needed for the Evolution. I also, for some reason thought painting everything orange would be great.

This time the base was truly separable and all that was needed to move the machine was removal of the Y carriage and then the removal of the 6 hex bolts that held the CNC together. Unfortunately, this build ended up being even more short lived then the first and I consider it to be a failure (But I learned more). I really couldn’t get myself to love the base. I tried to build lighting in and even mounted the monitor to the vertical wall, but it just wasn’t very rigid and shook too much for my liking. This time when I had to take it apart to move from California to Maryland I decided to rebuild it properly. Goodbye version 2.

Build 4 – The final build (2015-Present)

See Next Post Here: www.replicantfx.com/Folding_CNC_Router

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