There are lots of tool choices in the SMT Rework field but many are expensive. Over the past few years there has been an increase in the amount of tools available particularly from low cost Chinese manufacturers (Hakko, Aoyue, Tenma, etc). Most of the equipment I use is from these low cost manufacturers since I simply cannot afford to spend $1000+ for a single specialized piece of hardware. The only expensive piece of equipment I have is my JBC Hot Air Pencil that was purchased from a former employer and I couldn’t pass up the deal. One area I see lacking is board holders. There are plenty of systems out there for holding boards but the cheap ones are … cheap. The expensive ones I’ve seen are complicated or just cost too much. The best holders I’ve used are made by Martin SMT. They’re simply a magnet base with a spring loaded clamp that holds the board. But they unfortunately cost $70 each. You really need 3 at a minimum and 4 is good for the bigger boards which will run you $280, ouch. So, I set out to make my own.
Update Aug 2, 2016: Finally, there is a well engineered, moderately priced magnetic board holder available called PCBite in a set of 4 with steel plate. Mine have been doing me well for more than a year, but it might be time for an upgrade.
Update: Check out my instructable on how to build your own
My first 2 prototypes worked, but didn’t look so good. The first set had a round wooden base cut from plywood with a hole saw. The second set had bases made of plexiglass. Both prototypes used hex bolts without a flange. Using a bolt without a flange had less of a grip on the board and would sometimes pop out if too much pressure was applied. Later, I glued a washer under the hex head that matched the outer diameter of the flange bearing. The prototypes showed me that I needed a flange bolt and a real base.
The heart of my latest design is the aluminum base. My father in law happened to have a scrap round aluminum bar that was 2” diameter. Four discs were cut 1/4” thick from the aluminum stock. Next he drilled/tapped a hole for the flange bolt and drilled a 1/8” deep hole for the magnet. I screwed the bolts into the bases, marked the bolt threads where they protruded out the bottom then cut off the excess. The rest is easy. Slide the flange bearing on, slide the washer on, slide the spring on, put some thread lock on the threads and tighten the bolt on the base. Finally, insert the magnet in the hole on the base. The magnet holes were drilled perfectly and the magnets stuck with a pressure fit. You could also use some epoxy if they were a bit loose.
My homemade board holders work great with my Tenma Pre-heater. The original board holders that came with the pre-heater broke the first time I went to use it (really, they did), so, I just removed the heat shield and use my new homemade holders. The pre-heater itself is a good machine and gets constant use, just the original board holders were junk.