Ballscrew Lubrication Schedule

Howdy all,

Haven't been posting much lately but I've been having some issues lately that have cost me some serious cash and need a solution. I'm running an Xzero raptor (small one, 24x36) which has a 2510 ballscrew. Because I'm using this thing to try and make a living, I run it pretty hard and fast. I've found that the cleanliness of the ballscrew has a direct impact on how hard I can run it and as the ballscrew gets dirtier, the performance suffers and I start to get stalling.

As an example, with a freshly greased ball nut and clean ballscrew, I can run that axis with an acceleration of 80 and a top speed of 400. For reliability I dropped it down to 60 but after a few weeks (maybe 4 to 6) of work, I got stalls at 60 and even 55 (dropped the top speed down to 380 as well).

Part of the reason was that I have the machine on a homemade stand which had a plywood top which severely restricted access to the ballscrew for cleaning. Yesterday, I cut a large hole in the bottom of the table which gives me very good access to the whole length of the ballscrew for cleaning and lubrication.

So as not to burn cash like I have been, I'd like to find a lubrication schedule for my ballscrew/ballnut but I've heard a lot of contradictory advice and anecdotes out there. I've heard some people say that the less lubrication the better, that over greasing can cause more damage than do good to the opposite extreme that one pretty much needs continuous lubrication. I also heard one story (hi Ger!) about a machine where the ballscrew oiler broke and the machine ran for years that way with no lubrication what so ever (I think that was a servo machine though - I have standard steppers with no feedback).

Currently, I grease the ball nut maybe once or twice a year and wipe down the ballscrew more often. After wiping down, I'll put some motor oil on a rag and then wipe the whole ballscrew with the oily rag.

My initial thought for a new schedule is to stick to greasing the ballscrew maybe twice a year but to do the wipe down say every Monday morning or something like that. My concern is that the motor oil on the ballscrew (even though it's not much) will dilute the grease in the ball nut and I may have to grease it more often. I figure that wiping dust off the screw is obviously not a bad thing but that will of course also wipe off grease and eventually the ballscrews will go dry.

Anyone in the know on the proper maintenance of a ballscrew?