A Lathe Spindle Handle is a cranked handle which enables the lathe chuck to be turned by hand. It is slid into the hollow end of the spindle and clamped in place by turning a central knob.

It is particularly useful when cutting threads on a lathe using a tap or die held in a holder placed in the tailstock. It is used whenever a very slow, controlled, rotation is needed. It should never be used under power.

Alternative names are: Mandrel handle, Threading handle.

There is not much new in my design - there are many other examples available online. However, I was quite pleased with the use of a large coach bolt as the axle for the wooden handle - the domed-end looks very neat and the threaded fixing method is very rigid. Also, the large aluminium knob works very well (mainly by luck) because when using the device, it does not need any tools (like a spanner or allen key). Also, when releasing the device, the knob is big enough to hit with the heel of your hand to release the wedge - again, no tool is needed.

This Instructable shows the basic design idea which was governed by the materials I had to hand! The main elements are in mild steel. The Instructable steps are in the same order as I made it:

The main mandrel
The wedge
The knob
The crank
The axle for the handle
The wooden handle

It was pretty simple to make. I'm still a real novice on the lathe and there was little precision in the manufacture, but the end result is very useful.

Step 1: Main Mandrel

The photos show the process.

  • Cut the bar to rough length.
  • Turn the main outer diameter and check to see that it slides snugly into the lathe spindle
  • Drill out the central hole (6mm) from one end as deep as possible.
  • Enlarge the central hole by drilling out to 10mm diameter - for about 40mm depth
  • Flip the bar in the chuck and drill a 6mm hole to meet up with the one from the other end (hopefully).
  • Form a shoulder on the unworked end of the bar (this shoulder must fit through the hole in the changewheel guard).
  • Turn down the top end of the bar, ready to accept an M12 thread.
  • Cut the M12 thread (I used a die).
  • Cut four slots to permit the mandrel to expand (I simply used a hacksaw, having no other method).
I considered cross-drilling two through-holes at the tips of the slots (before cutting the slots). Other ones I saw on line had done this (so the slots ended with a hole). This looks good, and would be essential to stop cracks propagating from the slots in some applications. Here, I don't think it is necessary, and because I have had difficulty cross-drilling on my bench drill (the bit wanders and never seems to go across a diameter properly) I thought it best to give this a miss!
<p>Great idea!! Sure beats turning the chuck with your hand! </p>
<p>Perfect documentation and a really nice looking handle - great work! :D</p>
<p>Thanks for your kind comments!</p>

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