Big, heavy, weighted tape dispensers are, so to speak, indispensable, and they last forever. But the spindle core, that the tape refill fits on, goes missing from time to time. You can buy them online, but I don't think I've ever seen one for sale in an office supply store. So here is one, modeled directly on the original from my probably 60-year-old concrete-filled bakelite dispenser.

This fits the North American standard 1" core tape refills, and is designed for ¾" wide tape. It should also hold ½" fine, or it can be adjusted in Z for ½" or 1" tape. The proper, smooth sliding fit will depend on the precise settings of your printer. This works great for mine. If you find it slightly too tight a fit, I would recommend filing or shaving down the splines very slightly. It is a very subtle fit. I found the final dimension across the splines needs to be between 26.0 and 26.1mm, but my Fusion model measures 26.3mm to achieve that in the actual model; small features like that can be tricky. If it needs more adjustment, you can use XY adjustment on your slicer.

This is built in three parts, and simply press-fits together. You have to print two copies of the Tape Core Main part, and one of the pin. If the press-fit is not quite good enough, you can use a little bit of CA glue, or use XY adjustment on the pin to fit perfectly. 

I printed in PLA, no supports, but used a brim around the pin, which may or may not be necessary.