How to refurbish plotter pens?

[David Gesswein]

On Thu, Apr 20, 2017 at 07:37:43PM +0200, Philipp Hachtmann wrote:
> I know the following configs:
> 
> Outer shell (always same), narrow inlay, narrow top cap --> for the
> pen you pictured,
> 
> Outer shell, wide inlay, wide top cap --> For the Fisher pen
> 
> Outer shell, some other inlay, ink top cap, some plastic ink pen
> stuff --> The ink pen config
> 
> I should have all those. Don't know if more existed.
> Not yet tried the ink variant.
> 
Felt tip was also available.
picture here http://ferretronix.com/1627/