, due to the operation simplicity,
and attached to the cupboard with a piece of foam-cored double-sided tape.
There is a teamaker. The filter assembly needs to be removed for refilling the vessel with water, and the filter with tea leaves.
For that, the filter either needs to be placed on the cupboard, where it leaves a stain, or to somewhere else where there is a risk of cross-contamination, or requires to be held which blocks one hand.
The top of the filter assembly is a mushroom-shaped knob. This suggested the possible shape of the adapter. There is a cupboard conveniently positioned with its bottom side just where a holder adapter could be.
The adapter was made by 3D printing, due to the operation simplicity,
and attached to the cupboard with a piece of foam-cored double-sided tape.
The part was parametrically modeled in OpenSCAD. The inner width was dictated
by the width of the mushroom top, the gap width by the width of the stem, the inner
height by the height of the top. All plus some safety coefficient to not be too tight.
The depth was dictated to be 25mm by the width of the double-sided tape. The top was
made somewhat wider, to provide more area for the tape to stick and hold.
 Rendered holder |  Rendered holder |  Rendered holder, operating position |
The printing took about 20 minutes. There was some minor filament seizing that was manually assisted. The part was oriented to make the tensile load parallel to the layers, and to print without need for overhangs.
After printing, the top layer that was to mate the doublesided tape was heated with a torch and pressed against glass, yielding a smooth surface. It was then briefly licked with a dremel mill, to make it a little rough to provide more area for the adhesive. Probably an unnecessary overkill.
 Printout |  Printout |  Deployment |  Deployment |
The part functions as designed. The tea filter drips surprisingly little, grossly limiting countertop staining in comparison with the earlier handling.
After getting a request for more, the design was improved and modified.
The size was shrunk a little, few millimeters were taken from both width and height, the gap was made narrower, the walls were made thinner a notch which also solved the filament jamming within the infill layer.
The entry sides of the gap were chamfered for easier access.
 Rendered holder, new gen |  Rendered holder, new gen |  Operating position |
The old model was retired and replaced with the newer version.
 Holder, new generation |  Holder, new generation |  Holder, new generation |  Holder with adhesive tape attached |
 Two new and one old |