One of the fondamental parts of our 3D printers is the hobbed bolt, that drives the filament into the HotEnd; there are a lot of good ones on sale, but you could need to custom it, like me.
Obviously you should use a lathe with gear-cutting and a good bit to do it precisely, but I did it without these tools.
Let’s see how.
I took as an example some procedures that I found in this wiki.
Things you need:
-a drill press
-a dremel with some cut-off wheels
-a cylindrical file
-a Dremel Holder
You can start putting together the bolt, the big gear and the washer with the extruder.
Insert the filament into the extruder and mark the bolt like this:
Attach the bolt to the drill press and mill it between the signs with cylindrical file:
Print the dremel holder that you can find here:
If you use the Dremel’s flex shaft attachment you can also download this one.
Cut along the bolt grip at the milling; I suggest to use the gear teeth to obtain equidistant cuts.
Then drill between two theeth with cone router bit to obtain more cutting edge:
This is the outcome: