You know how you have a list in your head of things you need for the shop? Some things shoot right to the top, get purchased and crossed off. Other things get removed from the bottom of the list because after a while you realize that you don't need them after all. But a third group of items seems to float in limbo right in the middle of the list - not so important that you make it happen, but not so unimportant that they get dropped. For me, that would be holdfasts.
I've been wanting to buy a pair of holdfasts for a long time - maybe Gramercy's or maybe some from Galena Village Blacksmith. But here's the problem; I made a pair some time ago, and while not perfect, they ARE functional, and thus the purchase stays in list limbo.
Here's my setup being used for planing a large rabbet:
Just some rived spruce, oversized holes to allow pivoting, washers, wing nuts and long carriage bolts. The bolts go down through my dog holes, with wing nuts and washers on the bottom.
The wing nuts are for adjusting the amount of play in the system. The real clamping pressure is from the wedging action of the small blocks of wood under the ends of the arms. Slide the blocks in towards the bolts (fulcrum) and the pressure increases - slide them out and things loosen up. Pretty simple really, just a little slow, especially when I need to remove and then replace them multiple times, and they take up a lot of real estate on the bench.