Lubrication

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Revision as of 15:55, 20 April 2010 by Bogdan.kecman (talk | contribs) (after talking to Forrest)
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Lubrication is important aspect of every cnc machine and RepRap is no exception. Proper lubrication will make your machine run smoothly, will remove ugly noises and reduce wear and tear of your components..

Lubrication

The main parts of the RepRap machine that need to be lubricated are:

  • threaded rod + nut
  • bearings
  • sliders

Threaded rod + nut

All "current" RepRap models have at least Z drive constructed using threaded rod and a nut. Some Z drives use one, some to and some up to four threaded rods to achieve Z movement. There are reprap clones that have X and Y also made with threaded rod and a nut. Friction between nut and threaded rod, especially for Z drive and Darwin based models is huge and if not lubricated Z drive will produce ugly sqeeking sounds, ugly metal powder and soon your threaded rods will show signs of wear and tear (especially if you use advanced raft creation method netfabb engine uses). Properly lubricating the rods will reduce the wear and tear of the rod (not to mention it will remove the ugly sound). So far, high viscosity PTFE filled oil (super-lube for example) shown best results here.

Bearings

There are two major types of bearings found in RepRap machines

  • roll bearing
  • linear bearing

Roll bearings

are usually closed and have their own lubrication so no additional lubrication is needed.

Linear bearings

come in open and close package. The closed ones have their own lubrication and no additional lubrication is needed while open ones need additional lubrication. high viscosity PTFE filled oil (super-lube for example) shown best results here. Synthetic Gear Oil also shown very good results.

Sliders

Depending on the type of a slider (PLA on Chrome, PTFE on Chrome, ABS on Chrome ..) you will need to find appropriate lubricant. Note that some oils do not interact well with some plastics. In most cases when using PTFE on Chrome no lubrication is needed but some PTFE filled oil will help a bit especially if you use PTFE inserts for X or Y movement. Multipurpose grease also shown nice results.

Not so good experience

  • WD40 is the worst lubricant I tried on my Darwin based RepRap rapman. It "eat up" mine Z threaded rods and produced huge amounts of ugly black gue that was impossible to remove while not improving Z movement at all.
  • Light oil produced some gue, reduced the sqeeking sound but did not really help with friction and on the sliders it even increased friction (by attracting dust and creating sticky surface on the slider rod)
  • Silicone grease that is often used with RepRap is actually meant to be used with rubber gaskets, o-rings and similar equipment. It is not "bad" and some users report good results with it. There is also silicone grease with PTFE that is reported to work good.