In this video I show a fast way to make a custom thumbscrew on a minilathe.




Transcript:

Making a Thumb Screw

Cutting off a piece of aluminium hex bar

Clamping it in the three jaw chuck of the mini lathe

Facing it and making a step in the middle.

The step has no function but I think it looks nicer

Tom Lipton (oxtoolco) has shown this tool in one of his videos.

Chamfering to remove the sharp edges

A little more..

Now the other side

Facing

I am turning the small handwheel of the mini lathe with one hand only. Therefore the non continuous move. But it doesn't matter when roughing.

I could have prevented chattering by reversing the tool and running the lathe backwards (as shown in my video: The Ultimate Trick: Cutting off with the Mini Lathe)

Finishing (removing a small amount of material to get a good surface)

Tiny chamfer

Center drilling so that the normal drill will find it's way.

Drilling 3.3mm for a M4 thread

Making countersink

Tapping (quite brutal and with no oil, so that I get a rough but clean thread which is useful when using Loctite later)

Deburring

To polish it I hold it with a long threaded rod.

Coarse abrasive in wax.

And now mirror polishing with fine abrasive. It's very important to use a different wheel for every abrasive.

Now I cut off the threaded rod that I will loctite in.

I rotate the rod slightly against the motion of the saw blade so that the blade can't "catch" it. (similar to conventional milling vs. climb milling)

Facing with belt sander and portable drill.

Chamfering and deburring: It's important to hold the rotating rod downwards so that the burrs get out of the thread and not into the thread.

Not recommended

I polished the tip of the thread off camera.

Now glueing it in with strong threadlock

Unfortunately there are marks from the jaws of the chuck that my old eyes didn't see before. I should have polished them out or better I should have laid some copper sheet metal between jaws and workpiece.

Here it's in my double pendulum that I will show in a later video.

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