The design is based off the clamps from Dream Factory and Romanov Tools. Magnets for the needles and everything. Overall, very happy! However, if i were to make another, i would opt for the design Bilim Design Studios uses, with the spring at the bottom below the hinge https://www.etsy.com/listing/720182182/table-pony-b-pony-bi-lim?ref=shop_home_active_2 Their design is so simple, i would have had a beautiful clamp made in less than half the time.
Lessons learned:
1) Don't buy birch plywood from big box stores, it's full of voids and the layers are horribly fragile, which will end up causing you to spend so much time touching things up.
2) The proportion of the distance from the bottom hinge > screw clamp > jaws is very important, if the screw clamp is too close to the hinge and too far away from the jaws, you will have to put a ton of force on the screw clamp to get your item tight enough in the jaws, and your brass threaded insert will wear out much faster as a result.
As a modification, you may want to consider a flap cover over the knob to keep thread from tangling around it. Looks beautiful. Nice hand work.