What is the Base Board on this string art making machine?

Please refer to the photo above.

1/ The base board on this string art machine is composed of two pieces of hard wood laminated board which is hard to get deformed. The below one is to lock the gearing mechanism, and the upper one is installed onto the below board, and provides the scale mark and locks the nail board.

2/ The size of the base board will vary along with the size of nail board. As our nail boards have three sizes (42CM, 50CM & 60CM), our base boards have three sizes as well.

3/ Our price for string art machine includes only one size of base board which buyers can decide. If you want to buy 2 or 3 sizes of Nail Boards, then you will have to buy additionally 1 or 2 sizes of Base Boards.