Thread: light bulb test

Incandescent lamps are being phased out by our ignorant government,in favor of CFLs (compact fluorescent light) which contain heavy metals. Please do not try this with a cfl. Also please use gloves and safety glasses when you do this with an incandescent lamp.

i think the basic idea is very good, actually, and it's a matter of figuring out if there's an easy way to make it work.
basically what is important for us in a hone is how it removes hard steel. typically people like to look at it, but our ears are much more precise instrument than our eyes, so if we can hear it that would be quite nice.
the question is how to suppress the signal from the irregularities of the surface and use the one from the scratching of the metal.

Maybe light bulb + piezo (transducer) + oscilloscope could be a solution... I could give it a shot with both my digitizing agilent scope and analog tek.

Two things I see as a problems. One, this can tell you how aggressive a hone is, not its grit- I imagine louder being either more aggressive or rougher, and softer being either less aggressive or smoother. I think the aggression of the hone is probably going to be more consistently associated with loudness rather than the grit. Just a thought (sound loudness is dependent on amplitude, pitch is determined by frequency).

The other issue I foresee is resonance. Different "drums" like a lightbulb all have a resonant frequency and near this (practical resonance) your results won't be very accurate. Lets say for argument there is an inverse linear regression with r^2 of .9999 (ultra good) between loudness and grit (louder=coarser). One would expect a 100 grit hone to be the loudest and a 30k grit hone to be the softest. If the stone resonates at 19k grit, one might buy a mystery hone off the bay and hear it as VERY loud. One assumes it is a low grit and tosses it aside. What if it was actually an 18.5k grit Charnley?

Just some thoughts. This would be awesome if you figured it out Mackie.

I may never figure this out. Heck, maybe none of us ever will. Problem is when I get something like this in my head I can't get it out. There has to be a way to differintiate the grit of stones. I can look at it under magnification and I can tell the particle size but not what grit it is. That is why I tried the sound test. I thought maybe the scraping sound It made would give a clue. It would be very helpful to a lot of people if someone could sort it out. I'm not any good with electronics. That is my weak point and that is probably how this will eventually be done. The people who make stones know but we need a simpler method.

Accidents DO happen. Please wear saftey glasses so if the bulb breaks it will not get in your eyes. Can't shave if you get blinded.