So, after seeing this on the shelf, the last time I went in to Harbor Freight for some cutoff wheels, I thought I'd bring in a piece of 3/32" tungsten to see if it would work, without doing anything to the tool. Sure enough, it does.
http://www.harborfreight.com/bench-g...l#.UxqU6T9dXbx
The chuck for the end of the cable drive has a plastic sleeve that just slips off with a hex head on the chuck.
The chuck needs some working by hand initially, the threads are a little burred, but once you've worked the threads a few times, you don't even need to use a wrench to get the tungsten to sit nice in it.
It goes larger than 3/32" and it looks like with a little bit of cutting in the 4 reliefs on the chuck sleeve inside, you could get it to work on smaller tungsten, too.
The grinder is only $35 on sale.
The grinder wheel does work, but I bought a 3" diamond cutting wheel that is for a 1/4" shank (comes with an adapter to a 1/8 dremel tool), centered it on a 1/4 bit on the drill press and drilled it for the 10mm shank of the grinder.
http://www.harborfreight.com/4-piece...l#.UxqUdD9dXbw
It says it's 1/8" in the ad, and it does come with an adapter to a 1/8" shank, but the hole is larger. The wheel comes with a few other pieces that can be used, but for $10, you can't go wrong.
The grinder starts out really slowly, but it has a speed dial that ramps it up quickly if you want it to, with plenty of power to run as a quick sharpener and it's small enough to put on a welding cart.
If you really wanted to, you could chuck up a finer grinding or sanding bit on the other end, to put a polish on the tip. Haven't tried that yet, but this thing saves a ton of time, space and money!