Intending to build a couple of wheels, and despite having built at least a dozen wheels before, I thought I might get myself a cheap spoke tension meter.
When I say cheap, I mean cheap. This thing is pretty rubbish.
The idea is that the tensioned spoke slots in along the dotted line and the sprung central boss deflects the spoke and the resultant deviation is read off as the tension. It was clear it needed work though. The bosses themselves are only press fit into the rest of the tool, and indeed at least one of them was clearly not firmly attached. I drilled and tapped the reverse of the bosses so I could use screws so that they had a positive fixing. It was claimed that the tool was calibrated after it was manufactured, but what little confidence that I had in said calibration before I deconstructed and improved it was now essentially at zero. Therefore I needed a way of adjusting it against a known metric such that it was in the right ball park of being correct. Here’s the extremely crude solution I came up with.
Basically it’s a little platform on which I can use my own body weight to pull on a single spoke that is fixed in the vice. Using physics equations (waving hands vaguely), in theory I now know how much tension is in the spoke, so I was then able to set the tool up to the point where the values it reported were at least plausible. It’s definitely not the best tool ever, but it is at least now useful. What it might lack in absolute accuracy it makes up for in being relatively consistent, in the literal sense of relative.