After producing quite a mess while trying to grease my bearings, I quickly designed this injector for LM8xx bearings which fits on the original SKF grease tubes.
Just slide it in carfully, press and rotate the bearing - done (see attached video on https://www.youtube.com/watch?v=eEiKf8TaOOQ)
I added a cap so you can leave it on your tube
I also uploaded the step file in case you need different threads than M15x1,5
I printed it with 5 perimeters (0.4 nozzle) to avoid infill in the thinner parts