With two simple wooden crosspieces, a Workmate becomes a solid and stable sawbuck.
The jaws of the Workmate clamp and hold the sawbuck vee pieces securely.
These photos show in detail how the Workmate jaws hold the sawbuck pieces. They are gripped from above and below in a wedging manner and 'alternate' in such a way that great lateral stability is realized.
The vees shown here were made from 13" lengths of good 2x4. They are actually "X" shapes with two short legs, the latter being long enough for the Workmate jaws to grip from below as shown in the previous step. The short legs on the prototype shown here are about 1-1/2" long.
The angle between the legs is about 85° which is the largest angle our Workmate jaws would accommodate.
Four 3" deck screws hold each crosspiece together - two from one side and two from the other. A tight clearance hole was drilled through the 'top' piece to preclude splitting which would adversely affect rigidity. Also, waterproof glue was used to ensure absolute rigidity (but mostly because this tinkerer likes to use glue !).