Skipping layers?

[EagleSeven]

Yes, I think putting a drop of oil on bars, often, really helps,
as long as you clean away the dust that collects at ends of bars, in the oil.

[EagleSeven]

You can also print them out, couple of prints out there

http://www.thingiverse.com/thing:231310
http://www.thingiverse.com/thing:42250
http://www.thingiverse.com/thing:53125

Yes, if you print them you still have to locate the correct springs, bearings, screws and bushings,
which seemed difficult when I tried to find them, mainly the proper type spring.

But if one ever gets damaged or broken I will certainly try printing a new one !