Designed this for desk at work. It is designed after an A-Type Heat Exchanger Channel.

The Filler Files slide into the pass partitions. You can scale them to allow longer or shorter items to fit into the pass partitions.

I Assembled parts with CA Glue.

The tubesheet I use as a coaster.

Update: Fixed Issue I just found with the Cylinder Recess for top flange being too deep.

Print instructions

Resolution: Any

Infill: 20%

Notes:
The only parts that require a support are the Top and Bottom Flanges, and the Nozzles.

Filler Small and Filler Big files should be printed with 0% infill and no Top layers. You can scale them in Z axis only to adjust size.

You need 2 Nozzles and 2 Couplings, and one of each other file.