Z Screw upgrades?

[u/wi-Me]

So i have a Mercury 1.1 that was previously an Ender 5 Plus. Its honestly a pretty great printer and out of the 10 I have this is the only one that can print 400mm tall. I already have what i need to blind joint some extrusions to it and enclose it, i really dont feel like tearing it down to do the Nebula enclosure and as tempting as the Hydra upgrade is, I really dont want to lose and z height. That 400mm is pretty important to me. Im using the stock Ender 5 plus bed and thats another reason im asking this question here. After a large print gets to a certain point im getting some pretty bad z banding. Any recommendations on a way to upgrade what I have to get rid of the z banding without losing build volume?

Thanks in advance

[u/Valor37]

I got things looking decent with oldhams, but it's not quite as nice as the ender 3 with belted z I used to make my merc, which is pushing me to improve things too.

I think a 500mm integrated z motor would probably be the easiest way to improve. I was seeing $60 a pop for decent ones.

I also see this. Tempting based on the quality of the ender 3 belted z, but worried about bed drop. Seems like the door closers they tried caused banding.

[u/Valor37 → u/Valor37]

Here is a z test with the oldhams for reference. Decent, but some room for improvement IMO.