Let's look at an example of what type of production can be expected from a CNC, the time it will take to pay for the machine and how much production you need to make the machine worth the investment.
CNC machines will vary from model to model and from manufacturer to manufacturer. The following example is based on one of these machines and information from the manufacturer. I have also modified some of these figures based on my personnel experience with CNC operation and cost. Production rates and payback can be more or less.
Let's say you purchase a CNC for $210,000 and decide to lease it. Your lease payment will be somewhere around $4,200 per month. If the machine works for eight hours a day and 21 days a month, based on an average production rate of 14 lineal ft./hr. that translates to about 2,352 lineal ft. per month. Of course this is assuming that the machine is running constantly for eight hours a day. Loading and unloading the machine can take from 10 to 20 percent of the time, which would reduce the lineal feet per month to 1,881 lineal ft. at the 20 percent range.
In addition to the machine cost, you also need to calculate operator and tooling cost, as well as power, water, etc. For the purposes of our calculations let's assume that a set of tools for one profile costs $3,000. The life of these tools is approximately 2,500 lineal feet. This translates to a tooling cost of about $2,500 per month. CNC operator rates can vary considerably from state to state. I have seen rates as low as $16 per hour and as high as $40 per hour or more, plus 20 percent burden for benefits, etc. In addition you must calculate the labor rate for loading and unloading the machine. On the low end you are looking at about $3,300 per month on labor and on the high end about $8,064.
Now let's total this all up. Your cost to operate the CNC for one month based on 1,881 lineal ft. a month will range from $10,000 to $15,000 per month. Notice I did not include power and water consumption into the calculation or the labor involved for computer time, etc. The cost I will guarantee you will be higher than this calculation. But this will serve as a guide and a starting point to help you calculate your cost.
Basically you are looking at total cost per lineal foot ranging from $5.31 to $7.97. Realistically you are going to be closer to the high end. If you are charging about $20.00 per lineal foot then you will be generating about $37,000 per month.
Now what I don't know is what your overhead is, what your labor rates are, etc. You will need to sit down with your accountant to determine if it is worth the investment.
Also, keep in mind the setup cost, as well as the learning curve. Don't expect to be up and operating your CNC to full production for at least three months. This, of course, will depend on the type of machine, how good the training is and how good your operator is.
There are also numeous shortcuts to make your CNC run more productive. In future articles I will discuss some of these shortcuts that even some manufacturers are unaware of.