This month’s “Shop Talk” is a bit different, but as a project it was fun to do and very useful too. And hopefully other sign makers or sign shop owners, who find themselves wasting time punching or drilling holes in countless sign blanks and riders, may want to copy this idea or some version of it.

A TIME TO BUILD

The motivation for the project shared here was to minimize the time it takes to punch holes in the hundreds or even thousands of yard signs and sign riders we produce every year. The holes are always the same: 1/4" diameter; 14 1/2" center to center; and about 1/2˝ in from the edge of the metal. Whether 5" x 18" rider or 18"x 24" sign face, the holes are identical.

But, measuring and hand punching, or drilling (even less ideal), is cumulatively a serious waste of time. I have always wanted some way to punch either two or four holes at a time, perfectly spaced, and become efficient at this, one of our most repetitive jobs. A search in every sheet metal tool catalogue, around town, online and anywhere we could think of, turned up nothing like I envisioned. So, to heck with it, it was time to build something. Since I had not even found a reasonably priced bench punch, I even decided to convert a couple of inexpensive hand punches to bench models. This part was simple as I designed a base, and a handle end (with a hole to accommodate a push rod) to be welded to the punches, and had a local waterjet company to cut these small parts from 1/4" plate for us. This cost about $50, and the two punches cost only $20 each, so the total cost of the main parts was less than $100. A bargain!

ONE SATURDAY MORNING

Before starting the building project, I took time to sit down at my computer, and just working in SignLab, I sketched out the machine I needed, full scale and with correct dimensions. The drawing produced was quite helpful when I went out to the shop that Saturday morning. (I had to do this on a Saturday, as there is no way my clients or my employees would leave me alone to tinker like this during the week.)

The stand and top were made of 2x4s and Duraply, and stood about 32" high. The mechanical or linkage parts were simple, and consisted of two pairs of push rods, and one pair of pivot arms, plus a couple of metal tabs for the push rods to attach to the foot pedal.

Foot pedal? Of course, as it’s much less tiring to operate a punch or shear by foot than by hand. The foot pedal works a lot like my grandmother’s old Singer sewing machine, and was cut from another piece of 1/2" MDO. Since I knew the punches would be set exactly 14 1/2" apart (center to center), I made the legs of the stand to have an inside clearance about the same. That way the pivot arms could mount directly to the 2x4 legs, using 5/16˝ diameter lag screws to secure them and to serve as pins for them to rotate on.

As one can see from the photos and the drawing, as the front of the pedal is pressed downward, the back edge of the pedal rises and pushes two push rods upward with force. These pushrods connect to pivot arms, which reverses the force downward on the opposite end of the arms, which are connected by push rods to the handle ends of the punches. Pulling the handles downward punches the holes. Simple, simple, simple.

Two springs are used to snap the pedal back to the “up” position, which also must be done quickly and with force, since the punches have to be pulled up out of the metal being punched. It’s not just a matter of offsetting gravity, but of exerting a quick amount of force to pull the punches out of the stock. This being the case, the cross member that the springs attach to was elevated a couple of times until the spring tension was just right. I should mention that the punches were mounted recessed into a table top made of two sheets of 1/2" MDO, the top piece being notched to fit around the bases of each punch. Then a third and elevated top was made, somewhat smaller than the first, spaced just right to make a sign blank slide perfectly into the jaws of the bench mounted punches.

IT’S JUST PLAY

The only other thing that needed to be done was to secure registration guides (strips made of .040 yellow aluminum) to facilitate sliding the sign blanks in place and in perfect centered alignment with the punches. And other tabs made of two layers of .040 aluminum put together with double-sided VHB tape, serve as back stops on either side of the punches. The top layer of these tabs extends over the sign blank to hold it down when the punches snap up. The bottom layer of the tabs and d/s tape acts as a stop, controlling how deep the sign blanks go into the jaws of the punches, placing the holes the correct distance from the edge of the sign face or rider sign.

Marks on the table top show where to align the shorter rider signs, and the tab stops again control the hole distance from the edge of the metal. Either way, no measuring is required and all holes are accurately placed.

Now, when we need to punch holes in sign blanks or riders, which is every day around our shop, our new punch is kept in a handy place to be able to do this task accurately and quickly every time. It may sound like a small thing, but multiplied by thousands of signs needing this step each year (we sell 100 to 200 yard signs and riders a month, punched top and bottom), the time saving is significant, and the accuracy is a plus as well.

Was this project just a waste of a perfectly good Saturday? Certainly not. And besides, who doesn’t enjoy taking on a project like this from time to time, and building something other than signs? It’s ”Monster Garage”, or Tinker Toy time in the sign shop, and that’s just play time for me.