Making the upper blade holder from a bit of flooring laminate.

Fitted here at the front of the main arm is the extension blade arm that is adjustable (slides front to back) so the blade can be set at 90 degrees to the table.

The actual blade holder (clamp) inside there and pivots on small bearings.

The slots in the main arm were routed out with a 6mm straight bit.

Side view of the blade holder with a blade mounted.

Front view of the blade holder with a blade mounted.

Here you can see the blade tension spring.