I have been struggling to fill my pens with larger nibs with most ink wells and have resorted to transporting ink into a separate 5mL container to fully submerge the nib. Getting a complete fill in my vacuum  / plunger type pens (Pilot 823 for example) was a whole other issue. I started looking at the design of the TWSBI Vac 700 ink well and the Visconti travelling unit for a solution. The make-up of the Visconti example is a simple rubber seal in a narrow ink container that you turn upside down when filling. At the $70 USD price point I couldn't justify such an investment for filling my pens. The TWSBI ink well is more affordable but specific to their Vac 700 pen. I figured that if I could form a tight enough seal around the section I could turn my 5 mL container into a 'travelling ink well'. A product available from Lee Valley Tools made it possible, I use this well religiously and haven't had any issues with clean-up or mess when filling. Here's how I did it.

     Roll out a nozzle cap and cut off the end. I insert the rubber cap about halfway into the container and stretch the remaining portion over the top rim. If you have a 5 mL container with threads for the cap it will be ideal for holding the rubber in place. There you are.

I fill the container with the syringe then push the pen into the ink well. Do not be concerned about clearing the entire rubber but focus on a tight seal. Tip upside down and operate the pens filling system. The setup can be easily broken down for cleaning plus you have a bunch of nozzle caps left to make another.

You need scissors, syringe, container, and cap