I got commissioned by my sons' science teacher to create some bed-of-nails balloon poppers for their class. It's a board with a bunch of holes you can put different patterns of nails into and then see what arrangements pop the balloon sooner or later, and how much force it takes. When the teacher showed me the one she had and asked if I could make 8 more, my first thought was, "That's a lot of holes!". I needed to come up with an accurate but quick setup. I started by printing a spreadsheet with gridlines at the spacing I needed. I just went to the formatting options and set the row height and column width to my hole spacing, and set inside and outside borders on the cells. I then set the print options to print empty cells and printed out one page. I taped this to the table and aligned it with the original kit the science teacher gave me and marked the spreadsheet where the corner of board would be to drill the first hole.

I used the fence to keep the first row of holes aligned.

By moving the board over to the next row of the spreadsheet, I got a line of holes, as precisely spaced as I needed them.

I used some spacers against the fence to move to the next row.

And so on for the grid.

Because the rows were offset, I decided to do them by setting up two overlapping grids. I just re-positioned the paper the same way to do the grid for the offset holes.

8 sets for 816 holes in all, including the larger ones.

POP! Goes the balloon
