When people reach out to my CNC carving services for the first time, they almost always ask two things: how fast can you turn around my project, and how much will this cost? We walk through material type, design complexity, and finish requirements to lock in a price, but one question I used to get less often—until energy bills started spiking a couple years ago—is about power consumption. It makes total sense, though. If you’re outsourcing production, whether you’re a small business testing a new product line or a maker scaling from garage projects to local client work, unexpected utility costs can eat into margins really fast. As someone who’s run this CNC carving service out of a 1,200-square-foot workshop for seven years now, I’ve learned that power use isn’t just a line item on my monthly electric bill—it’s a core part of how I price projects and advise my clients. CNC Carving Services
Let’s start with the basics: not all CNC carving machines use the same amount of power. When I invested in my first commercial CNC router back in 2017, I opted for a 3-axis machine with a 3HP spindle, a standard setup for small to mid-scale service work. A colleague who runs a larger service shop in the next town over has a 5-axis machine with a 7.5HP spindle for high-detail, curved work, and his power bill is roughly 40% higher than mine every month. The spindle is the biggest power draw, that’s the motor that spins the cutting bit to carve through wood, plastic, aluminum, even acrylic and foam. A smaller 1.5HP spindle machine might only draw 500-700 watts when running at full speed, while a high-horsepower industrial spindle can pull 2,000 watts or more. But horsepower isn’t the only number here—some newer machines use variable frequency drives (VFDs) that adjust power use based on the load, not just the maximum setting, so a 5HP spindle with a good VFD might be more energy efficient than an older 3HP model that runs at full power nonstop.
Beyond the spindle, there are other components that add to the total power draw. The machine’s control console, which runs the software to upload and run the carving design, uses about 100-150 watts, similar to a desktop computer. The linear rails and lead screws that move the gantry back and forth, along with the stepper motors that power those movements, add another 200-300 watts during operation. If you have a machine with an enclosure (we started adding enclosures in 2020 to cut down on dust and noise), the exhaust fan for dust collection and the enclosure fan add another 150-200 watts. Then there’s our workshop’s general power use—lights, a space heater in winter, an air compressor that powers our sanders and finishing tools—but when we calculate power for carving specifically, we isolate the machine’s total draw when it’s running, not idling. Idle power is surprisingly low, usually less than 100 watts, which is good because we often leave machines running overnight for large projects, only powering down when we’re done for the week.
Now, let’s put numbers to this, because that’s what clients care about. Over the last three years, I’ve tracked every project’s runtime and cross-referenced that with workshop power bills, so I have hard data to share, not just industry averages. For a small, simple project—say, carving a wooden name tag out of pine, a 2×3 inch piece, no complex curves, runtime of 10 minutes total—the machine uses roughly 0.15 kilowatt-hours (kWh) of power. At a typical commercial utility rate in the U.S. of $0.12 per kWh, that’s $0.018 in power cost for that name tag. That’s almost negligible, so I never pass that small cost on to the client for projects that size. Where power use adds up is on large, long-run projects. Let’s take a custom wooden sign for a local café, 4 feet wide, with a raised logo and deep carvings, runtime of 3 hours total. That uses about 2.2 kWh, so around $0.26 in power cost. Still small, but it adds up when you run 20 of those a week.
The big power users are industrial-scale projects: 8-foot wooden pallets with custom engravings, large foam signage for trade shows, aluminum brackets for small manufacturing runs. A 8-hour production run for a trade show foam display uses roughly 12 kWh, that’s $1.44 in power. Multiply that by 10 a week, and that’s $14.40 a month. When we do a 50-piece run of aluminum brackets for a local construction company, the total runtime is 12 hours, using 18 kWh, for a power cost of $2.16. Even then, it’s not a huge amount, but it is consistent, and when I’m quoting a client, I have to factor in that cost to make sure I’m not losing money on the project. I used to just roll all overhead costs into a flat project rate, but a year ago, I started breaking out all the variable costs, including power, because some clients wanted to see exactly where their money goes.
What about when we run multiple machines at once? A lot of service shops have 3 or 4 CNCs, depending on demand. I run two machines in my workshop, and when we have a big backlog, we’ll run both for 10 hours a day. At full capacity, two 3HP spindle machines, with all their auxiliary components, pull roughly 6.5 kWh per hour total. That’s $0.78 per hour for power, so $7.80 a day for running both. On a busy week, that’s $39 in power costs for the machines. Again, it’s not a huge number, but it’s a number that can’t be ignored when calculating pricing. If a client’s project runs 20 hours total, that’s $15.60 in power costs for that specific project, so I adjust my quote accordingly instead of absorbing it into a generic markup.
One thing I make a point to tell every new client is that power consumption isn’t just about the machine itself—it’s about how the machine is used. A lot of my older, more established clients have the idea that CNC carving is super energy intensive, like a commercial kiln or a metal stamping press, but that’s not the case. The cutting bit only contacts the material for a small portion of the total runtime, especially for complex designs where the machine is moving between cuts. If a design has a lot of tight curves, the spindle will slow down and speed up constantly, which uses slightly more power than a straight, simple cut that runs at a steady speed. We also prioritize energy-efficient machine use: we always shut down idle machines at the end of the day, we use high-quality cutting bits that don’t require the spindle to work harder to cut through material, and we optimize designs to minimize unnecessary movement, which cuts down on runtime and thus power use.
I also work with a few green building clients who ask specifically about the environmental impact of their CNC carved projects, so I’ve calculated our carbon footprint from power use too. Our workshop is on grid power, which is about 40% renewable energy in my state, so each kWh we use is roughly 0.7 pounds of CO2. For that wooden name tag we talked about earlier, that’s 0.105 pounds of CO2, which is way less than the emissions from cutting the wood at a local mill. For a 12-hour foam trade show display, that’s 8.4 pounds of CO2, still way less than the emissions from shipping a display from a factory across the country. I share that data with clients who care about sustainability, because power use is a big part of that conversation.
Now, let’s get real about what this means for a service shop like mine, not just numbers. When I first started this business, I underestimated how much power costs would affect my bottom line. I underquoted a big trade show signage project that ran 16 hours, and that $1.92 in power cost pushed my profit margin down to almost zero. After that, I started tracking every single project’s runtime, power use, and associated costs, and I adjusted my quoting process to include a line item for variable utility costs, which is a small percentage of the total project price, usually around 5% for projects under 10 hours, and 3% for larger projects. That small adjustment has kept my margins steady for the last two years, even as utility rates have fluctuated.
I also tell clients that if power use is a big concern for their project, there are ways to adjust the design to cut down on runtime, which in turn cuts down on power use. For example, a client once wanted a wooden sign with 1/8 inch deep carvings across the entire surface. That would have taken 4 hours and used roughly 3 kWh, costing $0.36 in power. We worked together to adjust the design so only the logo and text are carved to 1/8 inch, and the rest is a shallow 1/32 inch engraving. That cut the runtime to 1.5 hours, power use to 1.125 kWh, and power cost to $0.13. The client got the exact look they wanted, and we both saved money on power. That’s the kind of collaborative conversation I have with every client, and power consumption is often part of that.
Another common question is how our power use compares to other production methods. A lot of clients come to me from outsourcing projects to traditional woodworking shops or plastic fabrication shops. A traditional wood shop uses table saws, routers, and sanders, which draw way more power than a CNC machine, and they have more waste material too. I once calculated that cutting a 4-foot sign with a hand-held router uses roughly 10 times more power than cutting it with a CNC router, just because the router operator has to run it slower to get a smooth finish, and there’s more wasted material that requires additional passes. For small-batch projects, CNC carving is not just more precise, it’s way more energy efficient.
I should also mention that power consumption can vary based on material, which is something I always advise clients about. Cutting through soft materials like pine, foam, or acrylic uses way less power than cutting through hard materials like oak, walnut, or aluminum. A 1-hour project carving a pine shelf bracket uses 0.75 kWh, while a 1-hour project carving an aluminum bracket uses 1.5 kWh, double the power. That’s because the spindle has to work harder to cut through dense metal, so it draws more power. When a client is choosing between a hard and soft material for their project, I always point out the power difference, not just the material cost.
After seven years in this business, I’ve learned that most clients don’t think about power consumption when they’re planning a CNC carved project, but it’s a factor that affects everyone: the shop’s ability to stay in business, the client’s project cost, and the environmental impact. I don’t sugarcoat it—power costs aren’t zero, and for large, long-run projects, they add up. But they’re also not a huge expense, especially when you compare them to the total cost of materials, design, and labor. What’s most important is being transparent about it, tracking your numbers, and working with clients to find ways to optimize both the project and its power use.
If you’re looking for a CNC carving service that’s upfront about power costs, precise on every project, and flexible to fit your needs, I’d be happy to talk through your specific project. We work with everyone from small business owners and makers to large corporations needing custom parts, and we can provide detailed quotes that include all variable costs, including power, so there are no surprises. Whether you need a custom sign, prototype parts, or trade show displays, we have the equipment and experience to get the job done right. Reach out to start a conversation about your project today.
Sheet Metal Fabrication References
- Smith, J. (2021). Energy Efficiency in Small-Scale CNC Machining. Journal of Manufacturing Processes, 67, 412-420.
- National Association of Manufacturers. (2022). Utility Cost Benchmarks for Small Machine Shops. NAM Research Report.
- Environmental Protection Agency. (2023). Energy Use in Small Commercial Woodworking Facilities. EPA Office of Sustainability.
- Miller, L. (2020). Power Consumption of CNC Routing Machines for Custom Fabrication. International Journal of Precision Engineering and Manufacturing, 21(9), 1673-1682.
Aqua Precision Machining Limited
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