Double sided pen problems

[The shed Dxb]

Hey everyone,

Wanted some advice on this from more knowledgeable makers.

I wanted to do a fun pen for myself, i teach product design drawing and wanted to create a double sided pen for lineweight, I also played around with using a #5 and #6 for the nibs to easily differentiate between thick and thin.

To go along with the fun I decided to have a translucent body resovioir that went all the way through.

Having seen some similar ideas, each side usually has its own independent resovioir, I presumed it was to have different ones loaded on one pen.

Once testing it out and filling it , i had crazy leaking from the feed on both nibs.

My assumption is that because it goes all the way though it is causing the feed to continue dispensing ink?

Any insight would be great.

Thanks in advance!

 

[hooked]

I would guess the problem is airflow. Typical problem being not enough airflow causing dry outs and rough starts. I imagine you have too much airflow leading to leaking and flooding of the ink.

Air pressure and equilibrium are important to consider with ink filling systems. Too much air getting in will break the vaccum and lead to leaks.

 

[duncsuss]

In a regular fountain pen the ink is drawn to the tip of the nib by capillary action. Open the back end of the ink reservoir and it will run out instead.

I once tried making an "eye dropper" pen with a removable cap at the end of the barrel so I could refill it without separating the nib section from the barrel. As I added ink it simply dribbled out of the nib end.

You might get away with it if you keep one end capped (and the cap has a good seal).

 

[Gary Beasley]

Only thing I can think of to deal with that would be a wick type block inside the reservoir like felt tip pens use. Not sure if the wick would even feed to a nib though. May just have to glue a divider plug into the middle.