Hello everyone,
This year i have purchased a 2nd hand CNC, a Suda 1325 (1300mm x 2500mm).
Its a rack and pinion machine with hiwin HG20 Rails.

The machine was almost never used, and when i bought it i just had to make some minor cosmetic upgrades.
I checked all the dents of the rack and pinion, cleaned both, and lubed the rack and pinion with lithium grease (the white stuff seen on the pictures) and because i didnīt have a grease gun, i lubed the Hiwin rail with Teflon Oil.
The machine worked perfectly for almost 20 Hours doing different jobs in perfection. Some of them very small and detailed, all in PVC plastic.
Yesterday i was in the middle of a job, and the machined suddenly made a loud sound and moved slightly in the Y axis (it started doing the job with 2mm distance offset from where it was machining before). I stopped the machine, and when i tried to send it to the X0Y0Z0 (Home) Position, the machine made the same sound again and stalled.
Minutes before i went around air spraying, cleaning the machined area, and both the rails and rack.

Reading on the web i concluded it could be due to the dust, and lack of lubrication. I also thought that the air spray wasn't a great idea...so i cleaned the rack and pinion, and the Hiwin Rails. I have used WURTH HSS CLEANER -http://www.wurth.co.uk/data/productdocuments/070035.pdf to clean the rack and pinion, and after everything looked clean i checked the rack dents for any defects. Nothing seen i have greased the rack and pinion with WURTH HHS LUBE -http://www.wurth.co.uk/data/productdocuments/070025.pdf - and tryed to lub the Hiwin HG20 Rails with a small gun and some wurth multi purpose grease. Unfortunately i felt i wasn't getting inside the snippets, so i lubed the rail by hand with the grease, Although i felt the rail of the Hiwin still was lubed.
I started the machine i moved it back and forth in the Y axis, and i was very happy to see it go back and forth, without stopping until in the 10th travel the machine stopped in the end of the Y axys. It is only stopping 1 in 10 times when it gets almost to the end of the Y axis.
I will try tomorrow to grease the hiwin snippets with a proper hand gun, is there anything else i can do?

How can i make sure that both the Y axis Stepper motors are rigorously aligned?
All help and suggestions are welcome, i don't want to ruin my machine, and i really need to end this work so i can put food on the table...
Best regards from Portugal