I’ve bought a thin sheet of foam rubber. Now I need to cut with an exacto blade small cross or X cuts across the whole sheet. Then 1/4" acrylic rods will be able to be pushed through the cuts. But I have to cut a lot of them. My first few cuts went fine but take a lot of time. I was hoping that someone made a punch with two thin perpendicular metal blades with the ends sharpened. Then I could push it in to the sheet over and over saving me time.
Went to Michael’s and they had nothing. I refuse to shop at Hobby Lobby because of their awful CEO. Amazon has everything but none of my search terms have worked.
If you really have lots of “X”'s to make maybe try purchasing 2 thin long bladed knives, sharpen the other side on each and then cut a slot down the top by the handle on one and then a slot from the tip back on the other. Slip them together and then using a couple of copper wires sharpened to points put a few spot welds( using a 12V car battery ) down the joint from the tip back.
Then it should be just jab jab jab jab…
To cut the slot, you might need to find a hacksaw blade without the undulations down the length to keep the slot thin.
No idea how deep your cuts would have to be but if you would by some break offcutter blades , and use a 0.5mm cutter to cut parallel grooves into a baseblock inserting the blades there would give you a comb with parallel knifes… and after cutting one direction you could turn your comb device to cut the perpendicular direction (so if I would have understood your problem…)