Redesign of the TikTok Gravity Knife Fidget Toy

Update 9/1/23: Second “Inside" piece designed with a little more room for the blade and handle. Should help with printers that can't print tight tolerances.

I really enjoyed this toy, I just wanted to make a few changes. I started with a black slate taking design ideas from the original to get started. The biggest issue was the way the two pieces went together. You couldn't tighten them without inhibiting the movement. And they would get loose with lots of playing. So I made a device that lets you tighten a nut and bolt fully so it will not get loose with play. The other change was to make it so you don't have to open it too far to get the blade to release. And the last was giving the knife some grip. I was dropped it so many times. I have made two handle designs. Enjoy.

Need:

1. M3 nuts (2)
2. M3 bolts
   1. 16mm (from thread to bottom of head)
   2. 20mm (from thread to bottom of head)

Hints. 

1. If you find the dowel not long enough, in your slicer you could increase the z size a slight percent. You should be able to tighten down very snug without causing issues.
2. Print pieces standing up with large brims, you will have to burnish the brims off so the pieces slide freely.
3. Make sure the blade has a lot of perimeters and infill to make it heavy. The other pieces I would recommend 3-6 layers and 25% infill. 
4. PLA works great.
5. Add a little wax to the dowel and that same join will help. 

Differences

1. Larger
2. Adjusted screws to not get loose (dowel added)
3. Angle at which the knife has to open is less before the blade releases
4. Added knurling to not be so slippery