Delta Turret Problem!

I made the delta turret shown in tricky’s video on youtube, i used gates as he did and i used and expression 2 that i made myself as well, with the same result: The turret aims a bit off, error increasing proportionally with the distance to the target. The elevation/headshot issue is ok i guess, but it’s not a perfect headshot at longer distances. But the real problem is the first, the turret misses by a metre or so (depending on the distance).

As the complexity of your wire contraption increases, the better the idea of going to becomes.