Press Fit Boxes

Press fit boxes in illustrator the quick & easy way.

There's a number of different ways to make press-fit boxes in illustrator but I'll show you a technique that I discovered after doing things the hard way. We'll be making a cube in this instance because it's the easiest (6 equal pieces) but you can make rectangles with a few tweaks. 

First you'll need these awesome scripts for illustrator by Sato Hiroyuki 

http://park12.wakwak.com/~shp/lc/et/en_aics_script.html

The script that we'll be using is this: Adjust Dashes

http://park12.wakwak.com/~shp/lc/et/en_aics_script.html#dash

In this example we're working with 3mm thick plexiglass. 

Step 1: 

create a 50mm x 50mm square in illustrator, with a black fill and black outline

Step 2: 

In the stroke settings, change the stroke thickness to 3mm, 

make it a dashed line with 10mm dashes and 10mm gaps (it works best when the pegs are evenly divisible by the total length of each side),

also align the stroke to the outside, this will put the dashes on the outer edge of the box

the dashes are all weird so now we'll apply the script

Step 3:

now if you duplicate the box you can see how they now line up pretty well.

however if we were to cut these out now and tried to put them together, the pieces would not stick together. we need to adjust the pegs so that they are slightly larger than the gaps. the best way to figure this out is to do a test cut on the laser and measure you pieces with the digital callipers to determine how much material is removed when the piece is cut. From my tests I've found that it's usually about 0.22mm, so I adjust my pegs accordingly. 

Step 4: adjust the pegs. right now your pegs are still not editable so you'll need to do a few things get them to be editable:

4a: select your box, and from the menus choose: object/expand appearance. this will turn the dashes into editable objects. however they're still grouped together in a compound path

4b: select the dashes and then choose object/compound path/release/

4c: select the dashes and then choose object/ungroup/ , now you can edit the pegs

4d: adjust the size of the pegs, this is a little tricky but it's easy enough to get the hang of 

follow these rules: 

add +0.11mm to each of the end pegs, make sure they're anchored correctly to their respected edges, 

add +0.22mm to all the other pegs, change the anchor to the peg's centrepoint 

Step 5: almost ready to cut now, but if we change from fill to outline mode we can see that all the pegs will fall of if cut.

 You'll need to use the pathfinder to combine all the pieces with the unite option. This should be your final piece. 

Now duplicate it 6 times. AWESOME! You've got your press-fix box.