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revchrisA few years ago, a couple of our grad students decided to start a small company making bells.
They gave one of the mostly-finished ones to our chair because they were doing it in our foundry.
He's leaving, and told me to throw it out. I kept it, and today took it down to the shop to clean up the rim, since that part was still in the as-cast finish.
One thing they don't tell you about bells when you're learning about machining is that when you're turning them on the lathe, they can be very loud.
Thinking about it, it makes sense - it's a tuned, resonating cavity. Excite it (in this case, with a cutting head from the lathe tool), and it will vibrate. Continue to excite it, it will continue to re-resonate. Very Loudly (it was loud even through my 35dB ear protectors).
The real problem with this is that it is vibrating. You can't make a clean cut on a vibrating object. It just doesn't work. I got it close, and then took it upstairs to the sample prep lab and ground it down the rest of the way.
They gave one of the mostly-finished ones to our chair because they were doing it in our foundry.
He's leaving, and told me to throw it out. I kept it, and today took it down to the shop to clean up the rim, since that part was still in the as-cast finish.
One thing they don't tell you about bells when you're learning about machining is that when you're turning them on the lathe, they can be very loud.
Thinking about it, it makes sense - it's a tuned, resonating cavity. Excite it (in this case, with a cutting head from the lathe tool), and it will vibrate. Continue to excite it, it will continue to re-resonate. Very Loudly (it was loud even through my 35dB ear protectors).
The real problem with this is that it is vibrating. You can't make a clean cut on a vibrating object. It just doesn't work. I got it close, and then took it upstairs to the sample prep lab and ground it down the rest of the way.
