I did this as I find that it is easier to work with than a disk fitted to an angle grinder and does not produce the high speed vibrations that an angle grinder does. (high speed vibrations have a tenancy to cause the aches and pains to flare up)
Flap disks also give a much more pleasing finish on metal than a grinding disk. They are also very good for sharpening knives and blades.
This is quite a simple how to and requires only 2 nuts that match the thread on your wood lathes spindle.
I used a friends metal lathe to turn down the 2 nuts. A good engineering philosophy is to buy the tools that you use all the time and to know what specialized tools your friends have that you can get acess to for to occasional times you need to use them.
Thanks for looking and I hope you find the idea useful.
Step 1: Making the Collet and Keeper.
As it was not rocket surgery I more or less eyeballed it and checked it against a flap disk untill it fitted snugly.
The collet has a slight taper so the flap disks will self center against it.
The keeper is just a nut turned down to approx 1/2 - 2/3 of its original thickness.
Step 2: Fitting to the Lathe.
Center the flap disk on the collet.
Add the keeper to the spindle and tighten up until the disk is held firmly. Don't pull the nuts up to tight or you will risk destroying the thread on the spindle.
You now have a ultra useful attachment that can be used to remove burs and sharp edges on metal.
Flap disk don't have as harsh a bite as grinding disks and leave a super smooth finish and are also very useful sharpening knives and blades.
Thanks for looking, I hope you find the idea useful.
Remember to play safe when you have fun with powertools.