The manual for my Roland PNC 2100 doesn't say anything about oiling the rails for any of the axis points (x, y or z).

Does this make any sense? Surely, I should be oiling the rails to prevent the bearings/etc. from premature wear?

I just doesn't make sense that one doesn't have to oil mechanically moving parts.

If it uses plastic sliding parts, usually delrin(sp?) for these, you must use a pure silicon oil or the plastic will swell. If it is metal to metal, the Super Lube grease would be the best.

Most manuals do not talk about lubrication for some reason.

Philadelphia, PA (Really Bensalem)

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