Family Bonding Over a Giant CNC Router Project

This heartwarming story appeared in my inbox recently, from Sean Fairburn, a father who built a big awesome CNC router in his shop with his kids. Growing up I’d heard of father son projects where the result was a restored hot-rod (I live on Route 66, it’s all cars here). My father and I tended to do more hiking than building, something I still value with my kids today. I hadn’t heard of a family bonding over the flashes of a welder and whir of stepper motors while building a giant CNC router!

Here’s Sean’s story.

My sons and I started building our advanced desk and electronics platform we call Gaming Thrones about four years ago, when my oldest son Caleb was 17, Joshua was 15, and Nathanael was 12 years old. The reason for building the thrones in the first place was to give me and my sons an amazingly comfortable, specifically designed collaboration workspace. Caleb designed the thrones and all their parts in Fusion 360; we hired cabinet shops with CNC routers to cut out the 89 separate pieces for each throne. Getting the design accurate was time consuming, and tooling all the parts with the usual modifications and changes was very difficult and really slowed down progress.

We decided to cut out templates from the parts for future thrones on a table router. That method worked great for two thrones, but each time we wanted to modify the design we would need a new template for each part. It also increased the time it took to cut all the parts out from 2.2 hours on a CNC to 4 days as every hole, cut, countersink, and roundover had to be done by hand.

At that point we decided we would need to understand and implement every aspect of the process to give us the flexibility needed to move forward. The main reason for doing this was to create a catalyst for the education of my kids, and give them a practical reason to learn what it takes to move through every aspect of a project and solve and understand each interrelated discipline:

• Designing the thrones in Fusion 360 allowed them to learn Fusion and 3D design

• Engineering the parts and following the design accurately brought in practical woodworking skills

• Finishing each part with sanding and painting created a sense of quality and craftsmanship

• Assembly put all the parts together and each aspect of each layer became real and appreciated.

The next step was to look at the cost and ability to manufacture products quickly and efficiently. If we got an order from a company for 12 thrones it would take three months to fulfill by hand. It became obvious that we needed to make our own CNC machine.

The boys already had the expertise to design this; together we set out to make something that would be large, stable, and provide a 4 ft x 8 ft cutting area. I also wanted to have it take up less floor space and manage dust collection better than conventional flat tables. We decided to make it very strong, with the ability to cut soft metal and hardwoods with ease. We researched each part, and if it could be purchased, like Nema 34 motors and mounts, we would purchase them. We designed the brackets, gantry, and table base to be made from 3x3x3/16″ steel square tube.

This opened up a whole new skill to be acquired: welding, including understanding the thermodynamics that make accuracy difficult as welds expand and contract while holding steel parts.

Welding up each and every part with the intent of a very flat, tight, level bed was arguably the toughest part of the entire project. The center ended up about 1/4″ higher than the corners over the 5 ft x 10 ft bed. I expected it to be worse..

Next up was the purchase of linear rail and blocks, which we got from Motion Constrained. Then the rack for the motor pulleys, which required a lot of patience as we had to, again, be very precise and deliberate in setting the pieces then drilling and tapping all the screw holes.

We designed and welded the gantry using parallel tubes to make one piece for strength, and for the flexibility to mount multiple spindles and tools. For this 88″ long steel gantry, we had to affix vertical lifts to the table rail blocks, then weld them precisely into place with no stress for a perfect fit. We maintained exact distance and parallel positioning by clamping wooden blocks between both ends 6 1/16″ apart, then tack-welding them very quickly to keep them from pulling or twisting apart.

We also designed a custom Z carriage to let us mount multiple tools, bolting them in at various heights so that the Z travel lead screw would not need to be so long. This worked great and it allowed us to precisely tram the tools to 90º of the table..

We decided to slant the table 65º so that the dust collection would be easier as gravity would pull chips down into the bottom where the collection port would be. This design also let us easily get to anywhere on a 4 ft x 5 ft sheet of material, as well as take up less space in the garage.

We installed the motors, power supplies, controllers and wiring, mapped out power, and assembled a custom 220v breaker box to run everything including the 4Kw spindle and VFD (variable frequency device), which is like an industrial size router with 6 hp of torque.

Caleb decided to gut an old G5 Mac Tower and use it as our controller box because it looked cool and you never see Mac stuff around CNC machines. We thought it would be quite funny for people to look at our rig and wonder if it all runs on an old Mac G5

Soldering became Nathanael’s job, putting male and female 4 pin connectors onto each cable for the motors for quick disconnect throughout the system. Measuring and testing became another important skill we learned as all the wires were checked for continuity and properly set to length to keep things tidy.

After all the parts were in place, we needed to do a distance calibration for all three axes, so that 12″ in the Mach3 software is 12″ actually cut. This is done in a motor tuning section of the program — you set the steps per inch for each axis’ motor, compare the actual distance traveled, and then make adjustments to get finer and finer accuracy. We used an X-acto knife in a drill chuck to mark the distance traveled repeatedly getting to 0.002″ at 96″ distance.

Caleb, now 21, freelances as a designer for hire with a 3D printing company in New Orleans. He previously worked at a high end cabinet shop running their CNC before returning to build our home CNC and work with me on the thrones, and the custom shop stools and tables we sell. When he was younger I would punish him by making him watch Photoshop tutorials. Now he goes right to the web to watch tutorials on anything he want to learn to do.

Joshua now works at the same cabinet shop making and installing cabinets and building door faces and drawer fronts. When he is not at work he is a wood turner and a very hands-on maker. He’s a huge fan of Jimmy DiResta. Joshua has no fear and can make anything.

Nathanael worked in finishing for a while, learning to sand and spray-finish cabinets. He loves this, and has a very good patience for it. He is also into wood carving and inlay work, as well as calligraphy. He learned Fusion 360 from his older brother Caleb, and teaches it to his younger brother Isaac instead of playing video games.

Even my 11 Year old Isaac has now designed a 10-1 scale 2×2 Lego brick in Fusion 360. He knows how to CAM the pieces, tool the parts, import the file to MACH3, load the bits, and cut the wood. He knows exactly what are the materials to use and how much time it takes to make each Lego. He is now gathering wood for making Christmas presents to sell to others, putting into practice everything he has learned. Makes me very proud.

Nowadays, I just get to be Dad, encouraging, supporting, and always watching over. Sometimes I’ll get things started then hand them off to the boys. I am retired, but being a cinematographer for 25 years and a US Marine combat vet, I encourage teamwork, good communication, and totally owning the information on the work you are doing — you gotta know your stuff. I stress for my boys to be in the moment and pay attention to the tools. I encourage testing and bold experimentation, especially with designs and finishes; failure is a mighty teacher.

Each project lets me hand more and more to my kids so that they ultimately handle each and every aspect and have an understanding of the total time and materials needed when bidding on a job or selling a product they’ve made. I am extremely proud of my kids — the time invested in them to become better makers, inventors and entrepreneurs has unlocked a wide range of capabilities in their future.

Our Home CNC’s Technical Specs:

• 5 ft x 10 ft bed for 4 ft x 8 ft cutting area (2 inch Lagniappe)

• 88″ gantry width with 3″ of floorspace used with a 65º bed angle.

• The Y axis can reach 512 ipm

• The X axis can reach 410 ipm

• The Z axis can reach 150 ipm (lead screw: Igus Drylin, with Energy Chain carrier)

• Spindle rotates from 8,000 to 18,000 RPM