I have a small one man shop and have recently been asked about the feasibility of manufacturing a run of engraved or embossed book covers for a cookbook he is getting ready to publish. His idea is for a simple 1/4" plywood front and back cover with a simple illustration and title on the front. Normally, I wouldn't really take this too seriously, until he mentioned that he would finance the required machinery and that the first printing would be in the 5,000 to 10,000 range. That definitely got my interest. I've been looking at smallish CNC routers as well as laser engravers and would be interested in what the experts out here think.
My initial impression is that the laser engraver seems pretty simple to operate, requiring only decent printing software as opposed to complex programming, doesn't create the mess that a CNC machine would, and takes up relatively little space. Also the price seems reasonable and I can definitely see a myriad of other uses for my woodworking business. I've worked with some small CNC routers, have a basic knowledge of CAD and am familiar with some of the drawbacks; they're messy, loud, require frequent maintenance, bit sharpening, etc. What do you think?
From contributor E:
If you are really going to consider this I would like you to know what you are getting into. To jump into this you will probably earn enough money to pay for the machine but you will earn every minute of every day. If you buy a less expensive machine you will be buying a lower power machine. Which means you will take longer to engrave the covers. If you buy a higher power machine you will spend twice as much to be able to do it faster. The laser works by burning into the surface, or burning away the material. It controls it's depth by the power and speed by which it is set.
I would be reluctant to do this because one customer wants to engrave 5,000 of anything. A standard book cover is 8x10. That's 80 square inches. If you’re lucky you will cover 8" wide x 1" tall in say two minutes. Each book cover could take 14-16 minutes to complete. That is about 70,000 minutes or just under 1,200 hours of engraving. That's 145 days of just loading the machine. Now there are companies that make superfast machines just for this process but you would be looking at 100k plus.
I know companies that have a say 100 machines running the same thing at the same time. They also have machines that are running multiple copy heads - more bang for the buck. I would look into taking this on but not doing the work, let someone else worry about the 145 eight hour days. Take your cut and make some money.
I've been there, if you are still really considering it, take a sample of the book cover art work and there material he wants to engrave it into and go to your local trophy shop and have them engrave the cover. He should tell you the run time because most of them get paid by the minute. Maybe I am wrong about the run time maybe I'm not. See what he charges for the service. Then multiply out the numbers. It's a very inexpensive lesson to have some else this first. The laser is easy to use, yes but it is not a plug and play device.
On a CNC router this could be done in nested format making loading and unloading one sheet result in 40 finished parts per 4 x 8 sheet if you respect grain, 46 finished parts to a 49 by 96 if grain is not respected. Work other projects while it is cutting. At ten minutes per part a 40 part sheet would run in 6.6 hours. 12 minutes equals eight hours. The thing is, this means many months of work for one machine in one shop. This may not be feasible for you, or maybe it is.
What is very feasible though: sub quantities of 500 to a thousand to shops already set up with this equipment, make the total turnaround a few weeks instead of months, and take your cut that way. There is a lot of excess capacity out there and it would be a win-win scenario to take advantage of it. You will avoid a lot of complexity a one man shop does not really need, lessen your risks since 20 machines will not ever be broken at one time, build relationships that you can leverage in the future, learn a lot about CNC on the way and maybe make a few bucks too. Reach far and wide geographically, since the shipping costs of these things would be relatively small via common carrier.
If you engrave, the router makes lettering like a headstone has utilizing a lot of small movements, many of which have a z component. Three axes have to me mixed and this means lifting the whole head against gravity constantly. The Z component of moves is often slower than the x/y component is, so to follow a path the slowest axis is the limiter. Lasers don't really have to do a lot of z moves since they really sort of "pocket". A router can also pocket, but with very small letters would have to use a very tiny bit and these tend to be very brittle and thus limiting in terms of resolution and speed. If you use a router you will want to engrave, I would say.
Contributor C has good points, and laser can give you very precise “pocketed” lettering, you can literally do a small typeface with perfect clarity and get and a whole set of effects from contrast in color. The edges can be made perfect, though I don’t think you can get around the charring completely. No eased edges. All in all I agree if I had both I would likely use the laser too.
Carving is when a similar bit goes back and forth over the design moving across it at about a 64th to 100th of an inch with each pass. This would not be an efficient way to do this project. However it is the way the laser would run the covers.
As such, the CNC would probably be faster but the laser would give you color contrast because of the burn. The CNC on the other hand would give you a deeper more hand carved sort of appearance. I think the final decision here is best determined by what your customer wants these to look like.