Linear rails are one of the best upgrades you can make to a 3D printer. The rigidity allows little to no flex, which translates to greater precision and accuracy in the motion system. However, to achieve the maximum performance, some preparation is required prior to use.
In this brief guide, we'll look at how to clean and lubricate linear rails, several of the most popular methods, and the best products to use when doing so. Please note, the instructions provided are but a few ways to approach this task.
While the pre-applied factory lubricant is viable, it's a temporary solution at best. This is a protective coating that prevents oxidation in storage and is not ideal for performance. As such, we advise cleaning and re-lubricating the linear rails with a low viscosity, high quality product. The question is, what should be used?
1) White Lithium Grease
2) Super Lube 21030
3) Mobilux EP1 / EP2
1. Remove MGN12H Carriage
To ensure that the factory grease is thoroughly cleaned out, we recommend removing the MGN12H carriage from the linear rail.
This does however run a risk of losing the ball bearings, where it's best to perform this step inside of a container, or over a magnetic tool tray if possible.
Turn the linear rail upside down and carefully slide it out of the carriage.
2. Degrease Components
Place the MGN12H carriage into a container, soaking it in 91% Isopropyl alcohol (IPA) or better for 10 minutes. Agitate the part by moving it around to help break up and dislodge any debris.
Once the carriage is sufficiently cleaned, remove it from the bath and set it aside to dry. The alcohol should completely evaporate within a few minutes.
Use this time to wipe down the linear rail with IPA, removing any residual grease which may have collected dirt and dust.
3. Install MGN12H Carriage
With the factory grease completely removed, proceed to install the MGN12H carriage back on the linear rail.
Place the carriage on a flat surface upside down and carefully reinsert the linear rail. Take care to align the side channels when doing so.
4a. Grease Lubrication (Recommended)
Fill a syringe with the preferred grease. Insert the tip into the grease port on the MGN12H carriage, squeezing until the lubricant starts to overflow from the ends.
Move the carriage back and forth several times along the length of the linear rail. This will help to distribute the lubricant.
4b. Grease Lubrication (Alternate)
If a syringe is not available, the grease can be applied directly to ball bearings inside of the MGN12H carriage.