[MENTION=195134]edthesped[/MENTION], great, I built one and have played with different springs etc. I also printed a second one out for my nephew, I don't think he has put it together yet. I have nothing to compare it to other than the Park tensiometer. It is very consistent in it's readings. Without a calibration chart I can only guess what the actual spoke tension is. I tested mine with a wheel I built that I knew was near perfect when it came to consistent spoke tension. Still it would be nice to see how it fair against some of the very high priced tensiometers this mimics. I think I built mine with mostly Chinese parts (slide, bearings and gauge) for under $30 plus about three hours of printing. I can't take any credit for the actual design, I found this on Thingiverse myself. I just had to remodel the parts to fit more readily available parts you could buy on Amazon.