12-30-2019, 01:36 AM
(12-29-2019, 02:26 PM)blgentry Wrote: Speaking of belts, ... Any suggestions for belt brand/model and coarseness?
Nobody else is responding so I guess I’ll chime in. A belt grinder is just a handy machine to have around and useful for tasks other than just sharpening. I use the Kally for lots of different things like grinding the head off a bolt, polishing, surface conditioning, removing rust, thinning a washer, etc. Having a bunch of different belts will always come in handy sooner or later.
Belts are inexpensive so trying several types is easy to do. Folks seem to have favorites and the only way to really know is to check some out and see what you like the best. I have belts ranging from something like 10K to 30 grit and different abrasive types makes and models. At one time or another I have used them all.
Aluminum oxide: Super inexpensive but they don’t last that long.
Silicone Carbide: Cuts really well when new and cuts super hard material. Very friable with a short life.
Specialty belts like Norax, Cubitron and other ceramics: 3x the price of AO, but they do last longer. Personally I prefer ceramics like Cubitron.
Diamond: Really expensive, $150.00/belt. I’ve never played with one.
CBN: Sounds like a good idea but I’ve never been able to find one. There are other reasons why CBN is not appropriate for belts.
FWIW, except for the odd occasion when I want a polished edge, I use only 3 belts for sharpening and deburring; a 150 grit Cubitron for grinding, a blue (I think it’s called extra fine) surface conditioning belt like Scotch-Brite for deburring and a leather belt to clean things up as a final step. This seems to routinely produce clean 100-130 edges.
150 grit is a bit gnarly but there is a reason for that. Final cleanup using the leather belt tends to smooth and round the toothy edge that I enjoy. A 150 grit edge survives touch-up with the leather belt and leaves a wonderful clean toothy edge.
As I have mentioned before, I use very light pressure when grinding. Cubitron is designed to fracture under high pressure and this fracturing of the abrasive particles is claimed to keep it the abrasive particles sharp. That said; with extremely light pressure I’ve found they just stay sharp. When new they are pretty aggressive, but after a short break in they settle down and just last and last. Cubitron 150 grit is my hands down go-to belt for sharpening.
I would suggest paying a dollar or two more per belt and using higher quality belts because they maintain grit level longer. For example, AO belts are great when new but soon the abrasive brakes down and become smoother so it’s hard to know how what to expect as the belt gets used.
Trizact, Norax, Cubitron, etc., and ceramics are all very different in the way they feel when sharpening. They are all good belts and I think it ends up a matter of personal preference. I’d recommend spending $20-$25 bucks and play with different types in the 150 – 180 grit range. Try the major brand names and some general ceramic belts. Don’t just take my word for it or get swamped in all the opinions and Internet hype and blather. The only way to understand is to check them out and see what brings you sharpening joy.