Question about wetboxes

I'm planning my next mod to be a wetbox based on a 10ml syringe and 2 off 703480P LiPo cells that will give 3400mAh at 3.7+ volts. I've cut most of the shaft from the plunger of the syringe and will put a hole in the remaining section so a hook can be used to pull the plunger out for refilling. Question I have is how far should the needle extend from the center contact of the battery connector into the atomizer?

View attachment 131

 

The needle pokes through about 10 mm, on my wetbox

 

I realize this an older post, but a few random observations.

The length will depend on how universal you want it to be. For cartos it can be longer, for atties shorter. But an SLB/DSE 510 needs a shorter tube than a Joye 510.

The diameter/.comge of the needle also comes into play. With cartos too big and it starts to stiffen the draw, basically cutting off the air flow. Cartos rely on the center hole much more than atties do, hence the slotted connectors they use.

You should use a drip well/catch cup. Folks have come to rely on watching for liquid seepage through the air inlets when pumping. The catch cup can provide a buffer and mini reservoir for liquid. Set the connector in deep and as you drag any accumulated liquid will be pulled up through the connector inlets.

You can even try having none of the needle sticking through/visible like the new REOs.

FWIW I'm a major proponent of the Tilt and Squeeze design (no down tube for bottle users). Just tilt and squeeze (don't pump), the liquid with the help of gravity is now taken away from the connector, right to the 'business end' of the atty/carto. Not pooled in the bottom of the connector waiting to be sucked up to where it should be.