You may remember that I recently printed a press. While the press works quite well, the one thing I didn’t like about it was the fact that I needed a screwdriver to adjust the tension. That was a quick fix though. You see, I am not a newbie when it comes to knobs.
I had one other issue when assembling my press. While it calls for M5 bolts, I only had M3 and M6 on hand, so I did what any Imperialist would do, and used non-Metric hardware. A #6-32 bolt is smaller than a 5mm bolt, but it’ll do.
You can see above the quick model I made in OpenSCAD. The idea was to built a knob in two parts around the head of the bolt. A nut tight against it would keep it from spinning loose. (We just need to finger tighten it anyway, not torque it down hard.)
Here is out bolt, nut, and two printed parts ready for assembly.
We put the bolt through the hole in the bottom. It needs to be screwed in as it’s meant to fit tight to give it a little more “bite” into the plastic.
There! Screwed in all the way. (Not pictured: the power screwdriver I used to drive it in all the way.)
Now we put the nut on. You can spin this all the way to the end so it’s up against the plastic.
Once the nut is at the end I hold it with some pliers and gently tighten the screw by hand. (Not pictured: screwdriver I used to tighten the bolt.)
Now we snap the top part in place and that’s about it. I was pleased that both the Prusa i3 MK3 at work and my Monoprice Maker Select at home did a great job of printing these parts and they fit together perfectly.
That’s it! Tiny knob is assembled. That was pretty easy, and it works quite well. I am pleased.
In my mind, the beauty of a 3D printer (like any tool) is that it can help you solve problems. This may not be world changing, but the fact that I can solve a problem by making a computer drawing of an object and then telling a machine to “print out” that object is still some sort of magic. But as the saying goes “Any sufficiently advanced technology is indistinguishable from magic.” So, yeah…