Screwdriver Handle - Hex Insert Bit

I recommend printing with a lot of walls and thick top and bottom in a strong plastic like PETG. I used CR-PETG from Creality to make this tool handle. The fit is very tight so to insert the hex bit or extension, heat it up to at least 100c and also warm up the handle with a torch past 75C to make the plastic more flexible. I used a rubber mallet to drive the bit in. It's permanent.