Ar last!!! Started my Gantry 3-Axis CNC Build

[Lee Roberts]

Thanks Lee, Routernc and Komatias

I've not been able to find any info on the web about lubricating these SBRXXUU linear slide bearings. So I might just have to grease / oil the rails (lightly) I guess. I found a useful source for the ballscrew grease (Mobilux EP2) ( here) and much cheaper than Ma*Di* who charge £12 for a 50ml syringe! The tech support guy at Simply Bearings is making enquiries for me , so if I get a reply I'll post it here.

I hope to start on the electronics soon - within the next 3 weeks, so more questions and photos to come. Thanks to Jazz for posting a solution for the safety circuit and the use of proximity switches for homing. Now I understand how to wire the emergency stop system!

Just get yourself some lithium 2 grease and that will be fine, it's cheap as well.

Just consider the bearings glorified skate bearings because that's all they are really, so don't require anything specialised unless you really want to make the effort, grease will last longer than oil but obviously it gets gummy once contaminated and so on, but again the wipers on these units do quite a good job at keeping the raceways clear of foreign bodies.

I could be wrong on the side grubscrew being there for greasing, they may have improved the design or something but all the open type bearing cages I've handled were closed on the casing, I'll have a look shortly on the TBR I've got here and take some pics but I'm confident on those being closed...

Edit: Just looked at the EP2 you linked, it says "is a premium quality multi-purpose, lithium-base NLGI No 2 grease".

The stuff I can get is a multipurpose NLGI lithium 2 grease but it's only £3.50 a tube and doesn't have a major brand name to inflate the price:

A Premium quality mineral oil, lithium thickened lubricating grease suitable for general purpose applications in plain and anti-friction bearings.

Conforms to leading bearing manufacturers specifications for general purpose industrial and automotive grease.

Can send you a tube if you want, I've been using it for everything and for years with np.

.Me

[MikeyC38]

Thanks Lee for the comment. From my research a lot of ball screw manufacturers recommend the Mobilux EP2 for their ball nuts @ 0.8-1.0ml per 10mm of ball screw diameter, so that's the only reason why I'm choosing it. However £3.50 is much cheaper so I'll have a look around for alternatives as you have suggested. For my 1605 screws this works out to around 1.5ml per ball nut per axis. The SBR16UU and SBR20UU have a side screw but I believe this is for adjustment / pre-loading as you have already said.