Prusa Lubrication Set Adapter

TL;DR

• The models were designed to work with a 0.40mm nozzle width and 0.20 layer height, 0.15 layer height is better, 0.25mm nozzle w/ 0.12 layer is ideal.
• The lubricant should be primed in the syringe tip, and the air should be squeezed out of the tube as connecting it to the adapter, to prevent air bubbles in the syringe body. 
• The adapter can be left on the tube to serve as its cap, which can then be sealed with the plug.
• The 20g tube is only available from Prusa (and they frequently sell out), so a 40g tube adapter has been modeled as well (coming soon).

Introduction

Prusa offers a Lubrication set for the maintenance of the linear rails used on their XL and Core One printers.  Unfortunately, in the How to lubricate linear bearing rails (XL) guide, the “Attach the Cartridge” step provides no adapter, instead depicting the holding of the tube against the syringe.  This frequently results in lubricant squirting out and making a mess.  This model provides an adapter that uses the existing threads on both the tube and the syringe to create a seal.  When used as designed, the gloves provided in the kit are no longer necessary. 

Details

The first end of the adapter screws into the threads on the Klüber Lubrication MICROLUBE GL 261 20g squeeze tube.  Note that the 20g tube seems to be a private offering only available through Prusa, and they do not always have the kit in stock.  There are 40g squeeze tubes publicly available, which uses different threading, and has been modeled as well (coming soon).

The second end of the adapter screws into the threads on the 2.5 ml syringe, which uses a standard Luer Lock connection.  For those interested, there are syringes with Additional Capacities available. and there are even 45° Needles available, which make inserting the needle into the bearing holes easier.

There are two types of adapters modeled, “full” and “thin".  The full version simulates the original cap that comes installed on the squeeze tube.  The thin version is more minimalistic, reducing the double wall of the original cap to a single wall.

For those that want to avoid repeatedly unscrewing and screwing the original cap back onto the squeeze tube, there is a Closed Tip End Plug available at McMaster-Carr.  The plug seals the syringe end of the adapter, allowing the adapter to remain on the tube.  For convenience, an STL file was created from the SolidWorks file and uploaded here.

Print Settings

The walls of the model have been designed with a 0.45mm extrusion width (0.40mm nozzle) in mind.  However, the smaller threads, along with potential lubricant pressures, dictate that a 0.25 nozzle would be more appropriate.  If you print with a 0.40mm nozzle, a layer height of 0.15mm is recommended.

Recommended Usage

The following steps are the recommended order in which to install and use the adapter.  It is assumed you have already used the syringe (and made a mess) at least once, and that there is already some lubricant in the syringe and needle.

1. Pick up the syringe.  Unscrew the needle from the syringe.  Point the syringe upwards.  Push the piston into the body until the lubricant reaches the tip, then stop.  Wipe clean.  Screw the adapter into the syringe.  Put the syringe down.
2. Pick up the tube.  Unscrew the cap from the tube.  Wipe clean.  Point the tube upwards.  Squeeze the tube gently with increasing force until lubricant reaches the opening.
3. Maintain squeeze on the tube to keep lubricant at the opening.  Pick up the syringe.  Screw the adapter onto the tube.  Put the adapter down and rest your fingers.
4. Pick up the adapter.  Squeeze on the tube to create pressure.  Pull back on the piston to draw lubricant into the body.  Maintain pressure on the tube as the piston moves.
5. Stop pulling on the piston when the capacity of the body is reached, then stop squeezing on the tube.
6. Unscrew the syringe from the adapter.  Put down the syringe.
7. Unscrew the adapter from the tube.  Screw the cap onto the tube.  Put the tube away.
8. Pick up the syringe.  Screw the needle onto the syringe.  Point the syringe upwards.  Push the piston into the body until the lubricant reaches the tip, then stop.  Wipe clean.
9. The syringe is now ready for use!

Additional Notes

• If using a fresh syringe, it is recommended that the body be primed with lubricant to avoid trapping air at the front of the piston.
  • Remove the piston from the body, then squirt a small amount of lubricant into the body, then insert the piston back into the body.
  • Go to Step #1, and jump to “Point the syringe upwards.” …
• It is possible to leave the adapter screwed onto the tube, avoiding the need to repeatedly unscrew and screw the adapter onto the tube.
  • Replace Step #7 with “Screw the plug onto the adapter.  Put the tube away.” ...

Conclusion

The lubrication of the linear rails on the XL and Core One is important!  I hope this model encourages you to do this maintenance task more frequently.