Added Details and Links
In the past I successfully have used "Hands Free Soldering Jigs", but I wanted more functionality.
I found on ebay Machinist Magnetic Indicator Dial Gauge Holders, with a little 3D Printer Designed Adaptor they could be used as a Hands Free Soldering Jig.
A single Knob adjust and locks all three major joints.
In this case, the yellow alligator clip adapter was 3D Printed.
Also, another adapter (black) was printed, and a "Hat Pin" heated and inserted. This makes for a very nice PCB probe, an Oscilloscope probe can be attached to the top of the pin.
Once adjusted, these Dial Indicator Holders are "Rock Solid", once positioned they stay put, allowing for precise probing. I use tape to hold board under test to the bench (thanks, Jeff - KO7M).
If used, the Magnet Base needs a stable steel attachment point, in my case, my bench edge is metal and provides as necessary. The Magnet Base could be abandoned for something that could be attached to a wooden bench.
-- Home Page: https://WA0UWH.blogspot.com