How to make a Tungsten stylus

[Blazin Studios]

Hi trolls,
Gabriel / fonogabor read my thread at https://www.lathetrolls.com/viewtopic.php?f=15&t=9892 and asked me to explain how I grind my tungsten embossing styluses.

Here is how:
I use 1,6mm tungsten rods, which are in fact TIG welding electrodes.
Clamp the rod in a vise at an angle of 15 degrees towards you.
Take a high speed Dremel like tool (>10.000 rpm) with a fine aluminiumoxide abrasive disk, a geotriangle and a magnifier glass.

Use the geotriangle to define a 45 degree angle (XY) and 90 degrees (YZ) to the vise, while the rod is clamped in a 15 degree angle. Grind the 1st side to at least half of the rod’s thickness. Check with magnifier (I use 15x) and geotriangle. Redo if not OK.

Grind the 2nd side on a 45 degree angle (XY) to the middle of the rod. Check if the angle is OK and if the tip is in the middle of the rod. Redo if not OK.

Grind the front side of the rod as to create a flat surface of about 1mm wide, 90 degrees to the rod (-15 degrees to the vise). Check with geotriangle and redo if necessary.

Polish all surfaces with polishing disk and polishing paste, clean the stylus.
Cut off the stylus to the required length.
Check stylus with a microscope and rework if necessary.

As seen from the front you now should have a perfect 90 (+/-2) degree tip (XY) which goes upwards in a 15 degree angle (YZ). The result is shown in attached pictures (unpolished).
My embossing is set at about 5 degrees backwards, 38 grams, unheated, lubricated WD40 on polycarbonate. Only the sharp tip with the flat front will emboss the record, due to the resulting 10 degree clearance. Please note that the shaft is still round so fixating it in the cutter head should be done with high precision.

I hope this helps. Should anyone have good advice as to improve on this manufacturing method please let me know.

Greetings,
Tom

[ascii83]

A note on safety, many tungsten electrodes are thoriated.
Commerical tungsten sharpeners (used for putting a fine point on the tungsten to weld) will collect the dust to stop you breathing it in.

SC

[Blazin Studios]

Thanks SC for this valuable warning. I shall add dust extraction.

Tom

[ascii83]

Try to avoid the thoriated kind altogether if possible.
Thoriated ones are favoured for welding due to capacity for higher currents, but plain tungsten ones do exist.