Clogged bolts. Left, three bolts, some homemade,

Clogged bolts. Left, three bolts, some homemade, with sharp teeth that clog after a couple of hours and stop extruding. A world of pain. Right, a bolt (from learcnc on ebay) that extrudes all day every day. Utopia. The issue is microscopic so you just have to make 'em and buy 'em till one works.


Is this the difference between “authentic” precision manufactured components and 3d printing?

Just a guess without seeing them, but do the 3 on the left have straight material for the teeth or is it hooked one way or the other that causes them to peel away material as they turn. (either by the hobbing process loading them in one direction causing curl on the teeth, or possibly burs ) ?

A big part of the deal on the bolts to the left is the teensy pitch which was used to make them. The one on the far left looks like an M3!

Hmm, good point, I did all of mine in M5, but hear some people use M6

It’s all about lips teeth that grip.

M5 works well for me, too. The material seems to have a rather large influence on long-time performance, too - stainless steel is harder and therefore doesn’t have issues with bent teeth. The right one looks like stainless steel, are your DIY ones stainless as well?

The far left one looks like a hyena from arcol?

No one ever told me how important this one was… I fought “clogged extruder tips” over and over and over… …until I found out it was a slipping hob instead. I put a proper amount of time in fabricating one to the correct dimensions (radius, depth) and never had a problem again. --The importance of this little curved notch should be in big red letters on all instructions everywhere.

I went up to M10, but i mostly use M8, even with 1.75 filament.

@Bjorn_Marl what size bolt are you using?

M8 bolts. I printed a small holder with bearings and cut them on a simple mill. The larger the cutter the easier it is. At first i thought M8 threads would be to large, but it is more important to have a clean sharp edge than to have dense cuts.