Just sharing with you all how I make my own. With the use of a Dremel Moto Shop anda bit of perspex sheet. Slot the sheet and drill holes in the table of the say and then you can adjust the distance between the sheet and blade for whatever size you need See Photos. Sheet balsa is a lot cheaper that square or triangle stock, I got the Dremel moto Shop back in the late 70's and have been using this to make all my stock. I also stocked up on blades as they were almost impossiable to get here a few years ago.

Cheers</p>