Perhaps I am missing something but my Rotring Core and Pelikan Furture pens use standard ink cartidges fine, but when I try to use a standard converter, it doesn't fit (it isn't the length of the converter, it doesn't clamp on). The standard converter fits other pens, e.g., MB just fine.

I am just bewildered how this could be. How could a pen possibly use standard international cartridges and not standard international converters? Please help.

I had the same problem with my Pelikano when I tried to fit my Rotring converter in it!
I bought a Pelikan converter and it's a very tight fit, but it works.

Same cartridges, but different converter, how strange!

Samovar

Hi,

There are slight variation in the size of the cartridge/converter connectors. When you push in a cartridge or converter for the first time, the connector impresses its size and shape on the connector of the converter.

Dillon