[CORRECTION] Synchronizing Dual Z-axis Motors

[Homer-S]

Hi!

I had a question about the video linked below, specifically G34. Assuming you are on a printer without a fixed bed, doesn't G34 for calibrating a dual z-axis with dual drivers align the gantry to a moving bed that itself is trammed using the z-axis? I would expect for the bed tram to be accurate the x-axis gantry would have to be trammed to something fixed, either the upper frame or the lower frame of the printer. I was thinking something like one of these:

https://www.thingiverse.com/thing:4924870 https://www.thingiverse.com/thing:5198069

https://youtu.be/6UgT9YqY3UA

Homer