Tighter collar for 8mm Lead Screw (For Fractal Vise by TeachingTech)

I made the excellent Fractal Vise by TeachingTech: https://www.printables.com/model/180109-fractal-vise

The only problem I had was that the leadscrew collars were slightly too loose for me, and they would fall off when using the vise. So, I have made a remix of that part with tighter tolerances. My remixed version self-threaded onto the leadscrew for me and is working much better with the leadscrews that I used.