Oral B old brush adaptor

Here is a way to re-use old oral b Electric toothbrush:
1/ Print the adaptor
2/ insert a M10 nut in a plastic tube (0.63 inch OD in the photo, 0.51 inch inside on the photo, electric housing tube (16/13 mm)) using a heatgun. Make sure the nut is inserted enough so that the plastic retracts behind the nut and it does not come appart.
3/ insert the threaded part of the adaptor in the nut (may be difficult at the first time, you probably will have to cut some thin parts of the begining of the t