Rotring 600 Cap Wobble Solution

[steelblue]

I've had a Rotring 600 for ages but never used it as I like pens posted and hated the annoying cap wobble when writing. Finally occurred to me to use one of the small, extra O-rings included with my TWSBI Vac 700 to slide over the end post and this has all but eliminated the "problem". No play or rattle at all while writing now and the small ring is practically invisible on the end. There is still some minor movement of the cap if you really jostle the pen but for normal use it greatly dampens the movement. TWSBI doesn't list these O-rings on their site but I'm sure any similar ring would work just as well.

Possibly I am the last person to figure this obvious solution out but posting it anyway in case I'm not.