Our Shapeoko CNC routers and Nomad Desktop CNC machines are generally trouble-free, and we've got many users who have never performed even a little bit of maintenance on them over years of ownership.
While that's not our recommendation, we say that to ease the fears we see from some new users who are very worried about maintenance on their CNC machines. Following the simple outline below, you'll have a machine that runs for years.
The most important thing you can do to maintain your machine, particularly the linear rails and ballscrews, is to keep the machine clean. It's so important that we include a Sweepy dust boot with every machine. To get the maximum life out of your machine, be sure to use Sweepy and a shop vacuum to keep your machine as clean as possible.
Linear motion guides are available in a range of sizes and shapes, but we only use two types, the HG-15 and the MGN-15.
HG-style rails are sealed and use 4 rows of bearings, two on either side of the rail, for maximum rigidity.
The MGN-style rail uses two rows of ball bearings, one on either side of the rail. MGN-style bearings are not sealed, so dirt can get into the bearings.
MGN-15 is used in:
HG-15 is used in:
In either case, the Linear Motion Guide is made from two parts, the "linear rail", the ground steel bar, and the "linear bearing block", which is the moving part that rides on the linear rail.
For all of the maintenance tasks below, we recommend Mobil Vactra Way Oil if possible.
All of the linear rails themselves are made from precision ground steel. They are not stainless, so they will rust if not cared for.
How often do you need to wipe them down? That depends on the environment you live in and how clean you keep your machine. We have a shop about 3-5 miles from the Pacific Ocean in Southern California. We don't have a lot of humidity, but we have a little salt in the air sometimes. We rarely clean our rails, but we do keep them very clean. If you live in a more humid environment, you should wipe them down with oil every few weeks.
The important thing to note is that if rust forms, it usually forms on the top face of the rail since it has a more coarse grind on it. While unattractive, this will not affect performance because no bearings ride on this surface. If this happens, use a small pad of Scotch Brite to scrub it down and apply a little oil.
A ballscrew assembly is made of two components, the ballscrew itself, and the ballnut that travels along the screw. Ballnuts are not sealed, so it's important to keep the ballscrew as clean as possible so dust and debris do not get pushed into the ballnut.