The cost of running CNC machines

Anyone who knows me, knows I love machines that move. CNC machines have become my passion. I have built several routers, lathes, 3D printers and also have a C02 laser and Bridgeport Series 1 CNC mill. I would love to add a plasma cutter and even a waterjet to the shop.

One question I always ask myself when considering a new tool for the shop is: what do they cost to run? Not only that but what will the parts they produce end up costing?

For example, I checked out the new Wazer waterjet. Using the same process I use to analyze the cost for the tools I own, I pulled the data posted by Wazer and made the some interesting discoveries. Follow along:

The CNC Router

• Electricity – I run mine using Makita routers and a dust collecting system I also have to factor in the PC tower and stepper motor drivers. All this adds up to a medium power load.
• Tooling – router bits are fairly inexpensive. The more expensive ones can be sharpened. All in all, I would rate the tooling cost in the low category.
• Machine Maintenance – I run both my routers pretty hard. I have had to replace the motor brushes in the routers and adjust my anti backlash nuts to keep the backlash within acceptable limits. I use MDF for the spoil board. I am giving it a medium for maintenance.

The CO2 Laser

• Electricity – I was pleasantly surprised on the power requirements. My laser runs at 220 VAC but does not draw a lot of current. However, it need a cooler, exhaust fan and compressed air to keep it going. All this adds up to a medium power load.
• Tooling – No tooling to wear out since it cuts with light which make the tooling cost very low.
• Machine Maintenance – Again there is no tool load since it cuts with light. The mirrors and lenses must to be kept clean and will have to be replaced at some point but the laser itself has 10,000 hour life (if you keep the current down). This in the medium category.

The Bridgeport Mill

• Electricity – I have a phase converter to run the 3hp spindle motor and also have the PC tower and stepper motor drivers. This adds up to a medium power load.
• Tooling – mill cutters are more expensive than router bits, but they can be sharpened. I would rate this in the low category.
• Machine Maintenance – I have an automatic oiler and a mist system for cutting. The Rigid Ram Bridgeport Series 1 CNC mill is a tough, reliable industrial machine. I did have to replace a drive belt on this. I would rate this in the low category.

The Wazer Waterjet

• Electricity – Wazer’s own data states that it uses 1750 watts of power. This would be a medium.
• Tooling – Here’s a surprising cost. The waterjet uses 1 pound of non-reusable garnet every 3 minutes. This can add up quickly using thier posted feed rates. I would rate this as very high.
• Machine Maintenance – No tool load here. The bed life is 25 to 75 hours and pressurized components are still being analyzed. I would rate this as a medium.

All of the machines have advantages and disadvantages.

• The Wazer consumer water jet is expensive to run, but you can cut glass and titanium. The commercial machines cut with more pressure and considerably faster feed-rates. However, their initial price reflects this.
• The Bridgeport mill is rigid and heavy (3000 lbs.) and requires 3 phase power, however it will cut steel will little expense all day long and is built for commercial use.
• The CO2 laser is fast becoming one of my favorite tools and is inexpensive to run but is limited to cutting softer materials
• The router is a good 3D engraving tool. It is inexpensive to run but very noisy, and it only cuts softer materials.