Toolhead centering guide for Ratrig V-Core 4 belt tuning

For tuning the belt tensions, it is possible to measure the self-resonance frequency of a belt with a known length. These guides help center the toolhead, so that the belts left and right of the toolhead, in front of the gantry, are the same length. Consequently, tuning for equal belt tension is simply tuning for the same frequency. 

You can print both if you want to make sure the head does not move during tuning. Otherwise, just one should be enough.
 

When tuning the frequency, note that small variations in the belt width can affect the weight of the belt, and thus the frequency. The frequencies could be slightly different even if the forces are the same.