I made it at TechShop http://www.techshop.ws
If you have a 1/3 sheet or 1/4 sheet finish sander, then you know that pre-cut sheets of sandpaper can be purchased, but how many times have you cut your own from a full sheet? You probably cut it crooked with a utility knife, dulled your scissors, or tore the sheet.
Well not any more. Now you can easily cut perfectly straight 1/4, 1/3 or 1/2 sheets every time.
Scrap 3/4" plywood, particle board or MDF
(1) 10" hacksaw blade (longer blades can be used, but you will need to adjust the design to fit.)
(2) #6 x 3/4" round head wood screws
Laser engraver/cutter (available at TechShop)
Step 1: Layout
Sketch a layout, such as the one shown in this step, to mark the proper sizes for the different size sheets, relative to the cutting edge of the saw blade.
To save yourself a step, you can also download our .DXF and CorelDRAW files at http://www.lime3D.net/instructables/sandpaper_cutter.zip
Using the 60 watt Epilog laser at TechShop, etch the lines and text using the vector cutting settings.
Tip: Vector cutting material with settings that do not cut all the way through your material will result in razor sharp text and images.
Step 3: Finish woodwork
Using the outline created with the laser, cut out the board with the band saw (as shown in the photo) or the table saw.
Sand the edges and round off the corners with a sander, the flat areas (to remove any soot marks) with a finish sander, and drill pilot holes for the screws as shown.
Step 4: Attach the blade
Fasten the hacksaw blade to the board with two #6 wood screws. To allow the sandpaper to slide under the blade, do not tighten the screws all the way down.