Skip to main content
Topic: To harmonize, or resonate (Read 143 times) previous topic - next topic

To harmonize, or resonate

I used to tell folks that, if reincarnation really happens, I want to come back as my wife's dog, really though, I want to come back as a machinist, who's married to my wife of course, and the dog is still in play :)

Since none of the above is really going to happen, I'm on a quest for a more perfect, affordable drill press. After talking to a couple guys who have real jobs, working for real companies that make real things for the likes of the military, the net result distilled down to a 3-phase motor with a variable frequency drive, or VFD as it's generally known.

What in the heck does this have to do with guns? Hang in a bit, I'll connect my crazy dots in a bit.

What I'm learning is that just about everything has certain frequencies where they ring like a bell. It never occurred to me that a heavy machine like a drill press could vibrate to a degree that calls attention to itself or, more importantly, could trigger vibrations further down the food chain, as in X and Y axis instrumentation.

What I discovered once the VFD and 3-phase motor were in place is, I now could dial in motor speeds that avoid the resonant frequencies of the entire machine. I may be overstating the case but, all I really want is a silent, smooth, powerful drill chuck, not a vibratory disco dance floor  :o

Which made me think about barrel tuners, something I know little to nothing about.  One more thing to think about at 3:00 am :)





Chris

Re: To harmonize, or resonate

Reply #1
Benefits of a balanced race engine?

Re: To harmonize, or resonate

Reply #2
Yes, most things mechanical have a natural frequency where they will resonate, unless you have a way to dampen it (harmonic balancer for some of the engine crankshaft frequencies...doesn't help the valve train), a tuner for the barrel or staying out of the resonance frequency (VFD).  I have been looking at VFD's for a possible upgrade when lathe arrives....which brand did you go with?
Bob
If everything seems under control......you're just not going fast enough

Re: To harmonize, or resonate

Reply #3
Bob,

For the VFD I went with a Teco-Westinghouse L510, $185 for the 115V single-phase input model.

A 230V single-phase model is $15 less but the cost to run that service, just in copper alone, would be greater. Since the 115V model can drive up to a 1HP motor and the 3-phase motor I'm running is 3/4HP, I decided to avoid the sheer joy of crawling around the attic on my knees :(

https://www.wolfautomation.com/vfd-1hp-115v-single-phase-ip20-med-duty/

FWIW, I called Teco support with several programming questions, I was immediately transferred to an expert who got me squared away in minutes, that's good customer service.

Chris

Re: To harmonize, or resonate

Reply #4
Ya My truck exhaust resonates bad at 1700rpm under light load, I always wanted to make a Helmholtz resonator for it.  Now that my truck is getting old ish, 2011, I don't want to bother with it anymore lol.