Adjustable jar opener

I was watching my elderly father try to open a jar recently and thought, I can help him with that.This design was inspired by tools that are used for taking oil filters off cars. To build you will need some GT2 belt. 9mm is best but it will work with 6mm too. First print the files (obviously). PLA is fine but PETG might be more hard wearing. Measure out two lengths of GT2 belt. One should be approximately 34cm give or take. The other 6cm. You can experiment with different lengths. 28cm is about the lowest the long one can be. Next, feed the belt in to the base handle piece. Make sure the teeth are facing towards the middle.Then push the other end through the other sideNext, thread the slide nut on to the threaded shaftGrip the belt in the slide nut and push it down so that it's snugNext, take the short piece of belt and capture it in one side of