A Cut Above

A few months back I wrote a “Shop Talk” entitled “Heavy Metal”, about some of serious metal working tools of the commercial sign shop. This month we’ll take a look at several different cutting tools, for various materials and applications, from the front of our shop, to the back fabrication area. Some of these tools we acquired recently, others we’ve had for quite a while. But all are worth getting a look at because they help us work faster and more efficiently, which translates directly to our bottom line.

CUT LIGHT

Let’s start looking at tools for cutting the lightest substrates first. Since we are sign shop screen printers, and sometimes produce vinyl decals in quantities, (several on a page), we need tools beyond an X-acto or paper cutter to slit them into individual items for our customers. Nowadays, sign shops doing digital printing can have the same requirements since cutting groups of decals into single images can be the most time consuming and labor intensive part of the job.

One handy tool for this task is an electric slitter or sheet cutter like the one we keep in our screen department. The decal sheet is simply inserted under a clear guard, the bottom edge of which serves as a switch. An upward bump of the operator’s hand signals the super sharp wheel shaped blade to track left-to-right along the hardened steel back edge of the table, cutting the sheet very quickly. With the next cut, the wheel moves in a return stroke right-to-left. There is no wasted motion as each move is a cutting stroke.

Our unit, which we bought at a Sign Business Show several years ago, is an Italian made machine by Neolt, costing around $2,000. We added our own fluorescent light with a standard bulb, since we had trouble keeping the original bulb working, but we’ve never even sharpened the blade after about a million cuts, so we’re not complaining. (Note: We use this tool to cut in the weeded out spaces between multiple decals, not through the vinyl decals themselves, since it leaves a slightly serrated edge on one side of the cut.)

GANGBUSTER

Another machine we use for gang cuts of vinyl decals is a “guillotine shear”, with a capacity to cut sheets up to 18” x 18” in size, and up to 100 sheets thick. These types of cutters are standard equipment for printers (paper printing, that is), but are valuable for extremely fast cutting of stacks of printed vinyl decals.

Our model is German made, by a company called Dahle, which we shopped for on the Internet. It seems that 18” models are the jumping off point, costing around $2,500 for a good one, but 24” units of this type of heavy duty shear cost over $6,000, a bit much for our tool budget.

But, if several decals are printed, with no spaces in between, on sheets not wider than 18”, and trimmed true and square at one end, the rest of the cuts can be done a stack at a time, 50 or more sheets in a stack, which can allow us to cut up hundreds in just a few minutes. This beats a paper cutter many times over.

CUTTING CORNERS

In previous articles I’ve mentioned the essential role of at least a 48” sheet metal shear in any commercial sign shop, so we’ll leave that subject alone. But since so many signs are made of pre-finished metals, normally .040 or .063 aluminum, and after cutting many have to be punched for holes or have round corners, let’s take a look at those tools briefly.

Again, shopping at an SB trade show, last year I visited the guys at Accu Cutter, the makers of our original round corner punch which they manufactured. However, it was no job for them to convince me that we really needed the heavy duty model they are selling these days. Made from a standard arbor press mated to their precision punch-and-die units, the round corner punch we are using now is really hard to beat.

We have only the 1/2” and 1” radius die sets, but those two sizes seem to cover the bases nicely, and changing them out is instant, as they simply slide into a recessed fitting on the base, no tools required. There are other mostly larger dies available for this machine, and all drop into place, so the transition from one task to another is a breeze. One reason all sign shops should have a good round corner punch is simply liability exposure of the products we make. Even if your customer does not specify a round corner on their metal signs, any that are to be pole mounted in a location where a person or child might bump into them, should have corners that are rounded to decrease the risk of injury. This is no small consideration in the litigious world we live in.

PUNCHING HOLES

Another tool that goes hand-in-hand with our corner punch, is a simple Roper-Whitney hole punch for sheet metal. These tried and true tools are not expensive (the bench model we’ve had for years cost around $125), but are a must when punching holes in sheet metal signs. Drilled holes are not only slow, but leave burrs that will scratch and damage signs that are even temporarily stacked together.

We mounted ours to a square of 3/4” plywood, and I also made a plate aluminum guide which attached to the surface of the punch with small machine screws. This guide keeps the holes just the right distance from the edges of the signs, so we can do this job accurately and quickly. This tool truly is a must in sign shops producing sheet metal signs, and that includes just about all of us.

DRY CUTTING

Going from sheet metal to structural metal, let’s look at a tool that hasn’t been on the market all that long, ours being made by Milwaukee Tool Co., but there are probably others. It’s called a “dry saw”, but functions something like a “cold saw”, with some significant differences. A “cold saw” uses a circular blade to cut steel angle, pipe and square tubing without sparks or liquid cooling. The blade turns fairly slowly, but throws out small chips which carry away all the heat. But cold saws are expensive.

The circular “dry saw”, also cuts steel angle, pipe and tubing without liquid cooling and with very little sparks, unlike the typical abrasive wheel cutoff saw, but uses an expensive carbide-tipped blade turning fast. The cuts are quick and clean, faster even than a cutoff saw or cold saw. The operator, however, must make each cut with the correct technique. If he does, the $200 blade will outlast so many abrasive cutoff blades that it will actually save the shop money. But, let me save you the first $200 blade, by telling you what your tool dealer may forget to mention. That is, if you cut slowly with a dry saw, the blade will spark more and actually get hot, very quickly dulling the carbide tips. (They can be sharpened for about $40 if not badly damaged.)

I realized this before it was too late, and told my guys they had to make their cuts as rapidly as the motor will easily allow. As long as the motor doesn’t bog down, you cannot cut too fast. However, in unpracticed attempts to follow my instructions, they pushed the whirling blade into the steel too quickly and damaged our first blade beyond repair ($200 down the drain!) The correct technique, of course, is to spin the blade up to full rpm, ease it into the steel being cut, and then move through the metal as fast as the motor will allow, which is fairly fast indeed. After that expensive learning curve, the tool has proved itself to be a workhorse, faster than a band saw or a cutoff saw, especially cutting 90 degrees in lightweight steel.

Now, one other tip. We found that when making mitered (45-degree) cuts, the nice quick-release clamp that comes with the machine, would sometimes slip and the metal would pull toward the cut a bit. This distorts the cut, and might even be dangerous. To correct this, we simply made a small ledge of angle, and bolted it to the machine, to give us a lip for a backup clamp when making mitered cuts of any significant size.

METAL-CUTTING BANDSAW

One last tool we might mention, which is useful for cutting structural steel of larger size (ours cuts up to 6” square tubing and large angle), is of course a metal-cutting bandsaw. A lot of sign shops will have these, but the one we bought recently might be of interest. It is a modestly priced import, but seems to be of good quality, and comes well equipped with a liquid coolant system, and good materials clamp, three speeds and other features.

Made under the brand name Vectrax, and sold by MSC Industrial Supply nationally, this unit seems to do a very good job, and costs only around $1,000. And for that amount of money, the quality and features are an extremely good value. The nice thing about this type of saw is that you can clamp the material to be cut, even something thick walled and large in size, and merely walk off and leave it. It will make the cut and turn itself off the second it’s finished with the task. Also, even if the cut is just through small angle, the angle can be stacked sideways, clamped securely, and a dozen or more cuts can be made at one time. Ganged cuts can be made in flatbar and tubing as well, again without the need of an operator to baby-sit the machine.

THE WORKHORSE

One other tool I feel I have to mention perhaps one more time, is a panel saw, the standard workhorse of the commercial sign shop. Any sign shop trying to function without this time-saving and accurate saw for cutting wood, plastic, and composites, is wasting time and losing money. Our old Safety Speed Cut model has made thousands of cuts, and still gets a workout every week. A good place for shopping for this type of tool is also at the Sign Business trade shows.

As I mentioned early in this article, being efficient at all the various cutting tasks required of a commercial sign shop has a direct connection to the business’s bottom line. Having the right tools for each job is a challenge for most shops, since equipment budgets are often stretched in many directions. But, the tools we’ve looked at in this month’s “Shop Talk” have certainly been worth their purchase price, and we expect them to keep helping us work faster, safer and more efficiently for many years to come.