Hi,
I added aluminium rails for my express following the recommendation here…
Having read others comments I didn’t even try directly on the wood.
I also had issues on z-axis which solved with Z-axis issues, Express: heavy fall, stuttering, stalls - #8 by ranguard
It took quite a bit of adjusting settings to get setup right but after initial struggles haven’t had a problem in 4-5 months of running…
I am really just using it for watering, found the seeding and weeding to be too hit and miss.
Hope that helps