My name is Wilson Logan.
I was contacted a while ago by an Italian chap who asked me if I could make record cutting needles. I make tungsten carbide Drag Engraving cutters and that's how he found me.
I am working from a 80 year old patent drawing.
I have replicated the gross geometry but I am very keen to implement the patent description in full.
This means creating the "burnishing facet" which as you can see is umm.. 25 microns across.
I am experimenting with electrochemical machining as trying to create this facet mechanically seems like a fools errand.
My needles are 12mm long by 1.5mm diameter with a location face opposite the cutting face. 87 degree front face angle, 45 degree back angle.
Anyway, the Italian chap has left me somewhat in the lurch by deciding to dismantle his home made lathe for repair / modification.
I'll be honest, it took me a long time to get this far and I can't really complain.
But I would like to have someone test my needles.
My eventual aim would be to sell them but I did this for fun and really to see if I COULD do it.
Its precise work and not my usual thing so I just initially wanted to see if it was possible with my motley collection of 40 year old machine tools.
These are some early tests.
I don't have pics (yet) of my latest efforts. The finish has been improved since.
Clearly I could make any needle with roughly this geometry.
Locating faces can be cut as required. Holders fabricated as desired.