I designed this puck to mate with the puck that i have posted here: Clam Hub Accesories Mounting plates by Travis Foss | Download free STL model | Printables.com
The hole spacing to add your accesories is 2" center to center. One of these is designed to have a ¼" bolt added. The hex head should fit into the bracket to lock it in place. The second one is designed to have M5 heatset inserts added. On the one that i printed I used DigiKey part 2254-M50X375C-ND.
The author marked this model as their own original creation.