Easy Splice Adapter for Sunlu Filament Connector

I have many nearly empty spools of filament that are needlessly taking up space.  If I'm starting a new project, I like to start with enough filament to complete it.  I've manually spliced filament in the past using a lighter, then sand the joint.  The process is cumbersome, so I decided to purchase the Sunlu FC01 filament connector.

I'll say I'm NOT especially pleased with the FC01 filament connector.  Releasing the clamp after a filament splice causes everything to go wonky, making the splice ugly and sometimes failing all together.  Turning the device off and letting it sit for 10 minutes after a splice helps with that, but still I wasn't happy with the results.  While I'm complaining about the FC01, I'll mention also that I'm not fond of the PTFE cutter setup that feels like I'm going to snap the acrylic lid without putting much of a dent into the PTFE.

I designed this adapter to sit completely inside the FC01 that holds each end of the filament to be spliced straight.

This add-on prints quickly and easily as modeled in the STL without any need of supports.

NOTE:  None of the images associated with this model are multi-color prints.  The point in purchasing the FC01 filament connector was to save filament.  Lacking an efficient means for multi-color/material printing, I print this in a light colored filament then run a black Sharpie over the raised text.  :)

UPDATE 03262026:  I added two more versions of this model, one with Sunlu's logo, and one with no logo at all.  While I favor the "Easy Splice" name for this model, I thought some may prefer to have Sunlu's name on the thing while others prefer models with no branding at all.  The unbranded version could also be easily customized with whatever text or logo the maker desires.