This is a design that allows you to create a customized Perler (aka Hama / melty beads) bead base in Fusion 360. I originally designed this in OpenSCAD but found that it took way too long to render. Fusion 360 allows you to have a cusomizable parameterized design. Just open up the parameters and choose how many rows and columns you want. You shouldn't need to touch the other values, but you are more than welcome to.

You can also download this from Autodesk using this link: https://a360.co/32yNcXQ

I've included a 25x25, 20x20, and 15x15 base. If you need a different size, I can upload other sizes on demand.