Like a car, or any other mechanical machine, 3D printers do require periodic maintenance to ensure smooth and accurate operation. One of the required maintenance tasks is to regularly lubricate the moving axis.
There are many lubricant options on the market, and most options will work fine. However the best lubricant options are discussed below.
Before applying a lubricant, it is best to wipe the surfaces to remove dirt, debris and old grease.
Good for X & Y axis. Bad for Z axis
This is a thin oil that is good for lubricating bearings and rails. The low viscosity means that it will provide a nice thin layer of lubrication between metal surfaces without adding significant drag or friction. This is not a good choice for the Z axis, as the low viscosity means the oil will run off the surfaces too easily.
Ok for all X, Y, Z axis.
There are many lubricants out there that are silicone based. These are generally designed for water-resistant applications, and are not optimal for 3D printers. Depending on the formulation this may be a little more “thick” or “tacky” than is required in a 3D printer for x and y axis, but can be a good choice for a z axis as a thicker grease will avoid the lubricant simply dripping down vertical shafts. However, silicone greases can cause increased wear in metal bearings. Silicone grease is good for use on plastic gears.
Great for Z axis, good for X & Y axis.
These are generally good for higher load-bearing parts, such as gears, are good for sliding surfaces, and can be good for use on linear rails as well. The main disadvantage is again, dirt and dust sticking to rails.
Great for all X, Y & Z axis
PTFE based grease contains a polymer that creates a thin coating on moving parts. PTFE based lubricants are excellent for use in 3D printers, and are the best option for avoiding dust and debris being attracted to (and collecting on) the linear rails or rods. Dry lubricants are commonly used on bike chains in dry and dusty environments, so a bike store can be a good place to find a PTFE based lubricant.
The best recommended options are listed below:
For more detailed information on this topic, you can visit the RepRap wiki page on printer lubrication.