Following the publication of my latest update video about my DIY CNC Machine, I was delighted to observe the significant level of interest many of you expressed in this project. This endeavor has been a lengthy process due to the time I needed to invest in studying these machines and acquiring extensive knowledge about the necessary tooling and machining techniques required to construct such a tool. Below, I have detailed the specifications of the machine for your reference.
Expectations
Moving forward, I want to establish clear expectations for this machine. I have every confidence that it will be a valuable addition to my workshop. However, it's important to note that I'm not suggesting this machine will surpass or even equal the performance of an industry-standard machine with equivalent specifications. I'm under no illusions; since I'll be constructing this machine by hand, there will inevitably be some margin for human error. What I am conveying is that by building it myself, I can achieve performance that comes remarkably close to industry standards at a fraction of the cost.
Introduction
Specification & Hardware
DIY CNC Machine Specification:
Machine Footprint (L x W x H): 1200mm x 930mm x 620mm
Frame: Solid Aluminium Plate (Bolted Together)
Working Area (L x W x H): 935mm x 620mm x 115mm
HGH20CA Linear Rails
SFU1605 Ball Screws (BK / BF12 End Supports)
4 x NEMA 23 Closed Loop Motors
2.2kW 24000rpm Spindle (Water Cooled)
36V 800W Power Supply (Powers NEMA motors)
24V 125W Power Supply (Isolated Electronics)
8 x 'NPN NO' Proximity Switch.
M5, M6 & M8 Marine Grade Stainless Steel Bolts.
Mach 3 Breakout Board (For inital testing, may change).
CNC Frame Material
I grappled with the choice of materials to use for constructing the frame for quite some time. I aimed to select a material that offered solidity and could be easily machined using cost-effective tools. Affordability was a pivotal factor in this decision-making process, as I sought to keep expenses as low as possible.
Initially, I leaned toward 304 Stainless Steel due to its commendable mechanical properties and resistance to corrosion. However, its price tag left much to be desired. Ultimately, considering the substantial influence of cost on this project, I found myself torn between EN3B Bright Mild Steel and Aluminium 6082T6. Below, I've compared the characteristics of these two materials:
In conclusion, the choice of material ultimately hinges on individual preferences and the nature of work to be performed on the machine. EN3B Mild Steel proves advantageous if there's a possibility of machining both aluminium and mild steel in the future. However, it's worth noting that it's notably heavier and more challenging to machine manually. Additionally, it is susceptible to corrosion, necessitating the application of a high-quality paint like Hammerite. There is also the posibility that a steel gantry would require higher power NEMA motors.
In my case, the majority of my work will involve hard and soft woods, with future plans to experiment with machining materials such as brass, copper, and aluminium. Hence, I concluded that aluminium was the most suitable choice for my needs. Moreover, I encountered difficulties in sourcing the required sizes of mild steel in my local area.
DIY CNC Foundation
Another critical decision in this project revolved around the foundation for the machine. These machines, once assembled, become exceedingly heavy, making mobility a considerable challenge.
Typically, larger industrial CNC machines feature a solid steel frame to which the machine is welded. There's no denying that this setup offers the utmost stability, but it's a costly route and demands welding skills. As I mentioned from the outset, one of my primary goals for this project was to make it as accessible as possible and inspire others to embark on similar endeavors using basic workshop tools. This is why I opted to design the machine in a manner that allowed for assembly through bolting.
I maintained the same mindset when constructing the frame. The frame needed to possess exceptional strength and stability, yet remain easy to move. I chose to utilize 3x2 timber to construct a robust structure for the machine to rest upon, as depicted in the images below. The entire frame is equipped with castors, facilitating effortless movement around a workshop. This feature also proves highly advantageous if you plan to relocate the machine in the future. What's particularly noteworthy about this setup is that it provides ample storage space for stock materials underneath the workbench, thanks to the two shelves I've incorporated. I also later decided to add a piece of Oriented Strand Board (OSB) to the top of the workbench to act as a surface top, but this isn't mandatory.
DIY CNC Cost
Now, onto the big question: What will it cost to build this machine? As of the time of writing this blog post, the total cost stands at £2,330.54, encompassing all expenses. I was initially hesitant to divulge the list of materials at such an early stage because my intention was to construct the machine first, ensure its functionality, and then share the list. However, I've come to the decision that there's no harm in releasing it earlier, with the understanding that this list may undergo changes. It's possible that I may have overlooked something during the design phase, and any necessary adjustments might surface during the construction process. Consequently, I cannot assume responsibility if you choose to order an item that ends up not being used or replaced later in the project. Additionally, it's essential to take full responsibility for completing the build on your own, as I won't be providing comprehensive, step-by-step instructions. Instead, I plan to create update videos at various project milestones to assist you along the way.
Thank You for Reading!
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