then change to ballscrews - it will reduce backlash but not eliiminate it unless you put some effort into an anti-backlash nut.. but it will maintain that backlash for a long time unlike a delrin nut which will wear and backlash changes as it warms up...

but you wont (easily) find 12mm ballscrews, they usually start at 16x5mm (although MD currently have 16x2.5)