This adapter will allow you to use bulk filament for the CubeX. I have made it to where the shaft is parallel to the printer so it feeds in with little resistance. The holes are just to reduce the weight a tad and there is a crossbrace to reinforce it. The only problem I see is having the shaft coming out break along the stratus lines. It holds the original cartridge very easily and I am going to try with a bulk filament spool.