Full view of base using Modpod's great pdf file. I have rotated it to show all three arms on one BIG page.
I seem to have gotton some minor discrepanices when measuring things out and having to rotate the templates etc. So I made a full size version that I could print on lager A3 sheet that I could just stick down on the board lining up the dotted edge with the edges of the board and marking it all out in one go.
The middle of the dotted lines represents the edges of the board. I could line it up with two sides of the board in a corner and it only required two cuts plus trimming the corners.
Thanks for the plans Modpod, they really helped.