Penciling Out That CNC

With all the advancements in stone technology today, it’s easy to get confused or overwhelmed. What should I buy next? Do I really need a shiny new robot? What benefits will I get from a fully automated shop?
None of these questions is easy to answer; the problem is that it’s easy to give in to a snap judgment and:
• get something because you think you’re falling behind the times; or
• get nothing because you can always find an excuse to keep things they way they are.
Bringing automation into a shop is a tough process, but it’s not hard to at least get started in the right direction. And while it’s good to consider all the technical info you’ll get at any trade show, the real answers are at the end of a sharp pencil at the shop back home.
To begin with, you can’t really justify buying major equipment until you know the cost of producing stone counters. In other words, it’s your actual monthly overhead, divided by the average amount of square footage of finished stone produced in a month’s time. With all the math done, you can then estimate your production costs and compare them with automating the process.
Another aspect to consider is average demand (from your clients), and supply (your ability to produce in a timely manner). Are you backlogged? Are you having a hard time keeping up with demand? If you answer yes to these questions, it’s definitely time to consider automation.
The next part you need to consider – and it involves your sense of how the shop operates as well as pencil and paper – is manpower. How many skilled fabricators do you currently employ?
By skilled fabricators, by the way, I mean expensive fabricators. If you have several high-paid employees, and still can’t keep up with demand the way you’d like to, it may be time to consider automation to increase output and reduce your payroll burden. (I know no one likes the idea of saving money at the expense of an employee, but that is the direction the industry is headed.)
A CNC router, for example, should be able to produce the same amount of work as two average fabricators working by hand. Let’s say, for argument’s sake, the two employees cost you an average of $25 per hour each. At 40 hours weekly (well, if you’re behind schedule, it’s probably more like 50 hours a week, but we’ll stay with the usual 40), that comes out to $2,000 a week, not counting workers comp, SSI, and benefits.
Wow! $2,000 per week is, on average, $8,600 per month. (There are 4.3 weeks in a month, in case you thought my math was off.)
Now back to the CNC, and let’s put a price tag on it of $300,000 fully loaded, including tooling and site incidentals (such as water upgrades, air upgrades, and electric upgrades). If you amortize that amount into a five-year term, at 7.5-percent interest, the average payment will come out to $6,011.00.
Wait a minute, did I just say $6,000 a month? And how much was the cost of my employees, about $8,000? Hmmm…that’s a tough one, with a CNC saving $2,000 a month and having the ability to do more-precise work in a more-efficientl workflow.
By the hard numbers, it’s not much of a choice, and the machine’s not going to kill a few minutes here and there drinking coffee, either. Then again, there are some disadvantages.
Hey, hold on again … there are disadvantages to saving money? Yup. Remember that when you take two guys out of the shop, you’re also bringing in a new set of possible problems.
For one thing, we haven’t discussed the additional backlog created by such things as the training time away from your business, down time from the electricians shutting your power off to make the changes needed to power the CNC, and the initial learning curve. You’ll also need to retrain an employee to do the drafting and programming for the new CNC, or hire someone with CAD experience.
In addition, you’re going to make mistakes, you will crash some pieces, tear-up some polishing bits (even though I told you, in a previous article, that you shouldn’t waste your time trying to polish on the CNC), and cut some nice and expensive vacuum pods because you didn’t pay attention to proper placement. All the above becomes rather expensive when it happens two or three times.
Now, how about the cost of the programmer/operator? Let’s assume that you end up hiring someone on the low end of the pay scale at $15 per hour. That’s $600 per week, and $2,580 per month (at 4.3 weeks per month).
A few paragraphs ago, I’d saved you $2,000 a month by getting a CNC. Now, the money is going the other way, by close to $600 a month. You haven’t saved any monthly expense at all – in fact, you’re losing money.
OK, everybody calm down here. Just as CNC machines can do a lot of complex things, the factors going into cost- and labor-savings are more than a couple of additions and subtractions.
The obvious difference is that a CNC should speed up overall work through the shop, which means that more pieces are going out (and revenue coming in) the door every month. This is where the math in figuring production costs pays off; you can estimate increased production and what you’re going to clear.
You can also save some more labor expense by getting more from less-skilled finishers. With the CNC doing all the hard stuff now, for example, you don’t need a skilled employee to drop that undermount sink anymore.
How much you can save depends on you and how much you are paying your help; however, it’s also my opinion that you should keep one good fabricator in the shop for backup. From time to time, you won’t be able to run the sink cut outs on the CNC, as well as occasionally making the mistakes we mentioned above. It’s a good idea to have a skilled employee on hand to fix those mistakes and drop the odd undermount sink that couldn’t be done on the machine.
Don’t forget on-going expenses as well; tooling, for instance, will wear out and need replacement, and diamond tooling for a CNC is expensive. The average set of tools for one profile could cost you about $3,000, depending on the brand and shape. That adds up quickly if you offer a lot of different profiles. (You can save some money by having your tooling reshaped before it gets too worn.)
Regular maintenance is another issue to consider. You’ll need to maintain that shiny new robot or CNC router. These expenses vary greatly by machine, so I will only touch on a few items: water filters need to be changed, oils need to be changed, ways need to lubed, etc.
Remember we’re talking averages here. Not everybody will see the same savings or expenses that I listed above. But, you can also see why you need to have a handle on your costs before you sign that six-figure contract.
Ready? Now it’s time to go shopping, and I highly recommend you do a lot of research before buying any expensive machine. You can peruse Websites, ask for customer lists from the vendors, and find out about parts and service availability. All of these things can be a great tool in deciding where you’ll buy your CNC. Make an educated decision before you drop that deposit.
Good luck … and, until next month, Donny Taylor.
Donny Taylor is a fabricator in Florida and a member of the Stone Fabricators Alliance. To ask him a question, log on to www.stoneadvice.com, or send an email to donnystoned@hotmail.com.