Before I get too deep into building a new CNC router, I owe you the backstory. My first run with CNC machines was … let’s just say, an adventure. Mostly frustration, a little bit of success, and a lot of “what the hell am I doing?” moments. Honestly, about 90% of the headaches were my own fault. So before we jump into the new shiny stuff, let’s grab a magnifying glass and figure some sh*@ out.
How Not To Buy Your First CNC
As I stated in my previous post, I’d been doing woodworking for a while and noticed others using a CNC router to enhance and extend their creativity in the craft. Seeing some of their creations made my head explode with ideas. I wanted this!
To my detriment, I have a tendency to jump in without much thought when a new and exciting opportunity presents itself. I do the minimal research required to understand the concepts and hope for the best. And in keeping with tradition, I did this when I purchased my first CNC router. BIG MISTAKE.
I didn’t have a clear goal in mind other than not having to sell my kids to get one. I could already see myself making intricate inlays, custom signs, maybe even small detailed parts for my other woodworking projects. I figured that with a little patience and a few YouTube videos, I’d be cranking out masterpieces in no time.
Reality, as it turns out, had other plans.
Choose Your Poison
After making the decision that I would purchase a CNC router of some sorts, I started on a quest to find the perfect option. I looked at products such as the Shapeoko from Carbide 3D, Onefinity, Sainsmart, and others. Most of these machines were too big for my small garage shop and, more importantly, my budget. So, I started looking for a “desktop” size machine. That’s when I stumbled upon the 3018-style machines from China … there were tons of these clones out there for ~$250-300 at the time. After doing the conversion from metric to imperial measurements, I knew immediately this wouldn’t work … it was way too small.
After the 3018-style machines proved too small for my needs, I realized I needed to find something a little bigger, but still manageable in size and cost. That’s when I found the MillRight M3.
Enter MillRight CNC
In my internet search, I stumbled upon a company named MillRight CNC. They had comparable products to the ones mentioned above, but they also had an entry-level desktop model, the M3, that was a little bigger than the 3018 but still small enough (in size and price) to seem perfect for what I wanted. SOLD! That was all I needed to know. A few clicks of the mouse and one MillRight M3 was on the way!
About The M3
The MillRight M3 is a 3-axis desktop-sized CNC router that has a workable area of 10.25″ (260mm) x 10.25″ (260mm) x 2″ (50mm). It utilizes NEMA 17 stepper motors and a fiberglass-reinforced belt for motion and was billed as being able to cut not only wood, but also PCBs, plastics, and thin aluminum. The frame is made of coated MDF to allow use of lubrication when milling aluminum. The one that I received came with the Dewalt DWP611 palm router, but some of the later versions shipped with the Makita RT0701. Everything was nicely packaged in a decent-sized box… kudos to MillRight for protecting my $677 investment while in transit.
NOTE: MillRight has now discontinued production of the M3.
The M3: A Stepping Stone, Not a Stumbling Block
Before I could get started on this new journey, I had to first assemble the M3. Dear Lord! What had I gotten myself into? So many parts! Many of which were small and some seemed to be impossible at the time. But after a couple of days, I had everything together and it was time to introduce power for the first time. The assembly alone felt like a major accomplishment. Exciting stuff to say the least!
I found a couple of test files for the M3 online and was able to get it running and actually do some carving, albeit minimal and not very useful. So I decided to find something a little more personal to me and try carving that. I selected my personal logo since I had the vector files already and knew that I could import that into the CAD/CAM software I was using at the time. Even with not understanding the how and why of creating toolpaths, I was able to get the machine to carve my logo into a scrap piece of ¾” plywood. Booya! I got this!
The next few projects were geared towards learning how to use the software to create the files to use with the M3. For this, I purchased Vetric VCarve Desktop. This, it seemed, was the software that most of the other woodworkers were using. It took a couple of hours, but I was soon able to grasp the basics and felt comfortable with the software.
Lessons Learned the Hard Way
I was soon attempting to create more advanced projects with my new CNC router. That’s when things started going wrong. The electronics and Gcode were doing exactly what they were supposed to be doing. However, I was having some hardware issues that caused things to go to hell in a handbasket.
I would start running a new Gcode file after setting my zero on the CNC and things would be running along as expected. Then a few minutes into the carve, I’d hear the machine make a weird clicking noise and all of the sudden, I had cuts across the workpiece in the wrong location ruining the entire project. What did I do wrong? I tried and tried to reproduce the problem, but the next time I’d run the exact same Gcode on another piece of scrap, it would cut fine. WTF??
Looking back, I now know that there were several problems of my own design. First, I didn’t understand the CNC feeds and speeds. When I set up my file in VCarve Desktop, I left the material set to soft wood. Guess what, plywood doesn’t cut the same. There are variations in the plys that are more and less dense. And on the second run of the file, the scrap I used was a soft wood; yellow pine to be exact, that didn’t have any knots or other defects. Second, because of the variations in the plywood structure and the feeds and speeds that I was using, this caused the belts to skip which caused the machine to now be in a different position on the material than it thought it was in the Gcode.
The second problem has plagued me the entire time that I’ve had the machine which is going on five years now. Even after accounting for the material and speeds and feeds. Things would work fine one time, but I’d come back a few hours or the next day and run the same file again on the same material and here we go again … another piece of expensive firewood and a further bent ego.
My Eureka Moment!
I think I have finally identified the source of the belt skipping problem. I don’t use my CNC machine on a daily basis; just randomly when I need something for another project. I’ve looked back at the times where things worked, and where things didn’t. The one common variable that I can find is … wait for it … the weather! My shop was first in a two-car uninsulated garage and my current shop is a 20×20 uninsulated metal building. The commonality in both of these environments is extreme temperature differences; where I live in North Central Texas, it can be upwards of 110+ degrees in the summer and 20-30 degrees in the winter with the shop temps being +/- 5 degrees from the outside temps. I believe the temperature differences are causing the belt that drives the system to be either too stiff or too loose. On the days where I was able to successfully make something on the M3, temperatures seemed to be between 50* and 75* although I don’t have actual proof of that theory.
Conclusion
I’ve spent years and countless hours wrestling with this machine, but I’ve learned what works and what doesn’t. I should’ve done more research up front, but now, I’m ready to make something that’ll work right. In the next post, I’ll talk about the lessons I learned and the path forward with my new build.
Stay tuned. I’m about to figure some sh*@ out.