This is a parametric bracket generator for MakeBlock which can generate parts of various sizes. All MakeBlock structural parts use M4 screws with the holes separated by an 8mm pitch, so I created this generator to generate flat parts with a specified number of holes in the x and y directions (as well as the part thickness). Most printers close inner holes up a bit, so a 2mm radius will create a part where the M4 screws "bite", and 2.4mm radius will create one where they're loose and need a nut.

You can also create longer openings within the part (such as I did in the 3x9 part) by adding the "open" row or column to the appropriate "open_" array, starting at column/row zero. For example, to make a 3x3 part with a cross in it, put 1 in the open_xs and 1 in the open_ys with rows=3 and columns=3. For multiple rows or column, separate with commas, (eg. 0,1,2). Note that you can create islands with this feature, so be careful.

MakeBlock is a hobby robotics platform which spans from kids learning bots to advanced self-balancing bots, 3-d printers, robot arms, engravers, and more.

If you create a new Thing with Customizer, please name it descriptively.

v2: Version 2 increases thickness to 3mm as per the original parts. It also has less rounding on the exterior corners. Finally, it centers the part on the origin so it transfers easily to MakerWare.
v3: Modular code. Lets you set corner radius and pitch independently. STL files are identical.
v4: Make it easier to create right-angle corners (corner_radius=0).
v5: Expose additional parameters in Customizer.
v6: Add comment for Customizer to use 2.4mm radius for "loose" parts
v7: You can now specify long open rows or columns in Customizer with a comma-separated list.

For L-Shaped Parts, see my MakeBlock Parametric L Bracket.