Ironic, isn’t it. Well at least it’s a testimony to the quietness of the spindle !
75 decibels seems awfully loud for a cooling fan. Having said that, how loud is the cutting noise with say a standard 1/4” upcut bit in something like pine? I’m still a flat earther when it comes to spindles personally, my Dewalt with SuperPID is still quieter that most of the cutting noise and I only added the SuperPID for the lower speed range. I’ve always thought of quiet spindles like turn signal noise next to a Harley with straight pipes. When I’m running my XXL I’m usually cutting plywood with a single straight flute bit which is exceptionally loud though, maybe if I was cutting renshape I would care about a quiet spindle?
The effort to keep noise down stems from my specific situation: shapeoko in a small garage, neighbors on the other side of the wall, and wife watching TV on the other side of the door. So I try to deal with all sources of noise. I could almost never run my Makita at 24000 RPM before, it was just way too loud. I was living in 10-12K RPM territory at that time for that reason. Since I upgraded to a water-cooled spindle, and now that I think of it, pretty much all my toolpaths are now in the 18K-24K range.
Of course the cutting noise is still there, but it’s inside the soundproofed enclosure, while the VFD is outside the enclosure, and close to where I sit, so I just notice it more.
For me the spindle quietness was a game changer (high RPMs, here I come), but I agree it may not matter much in a more typical shop.
-3db is half the power so that’s significant
Just as an update form my side, after cutting AL for several hours, the VFD fan (with the resistor switch) never came on. The VFD is not hot (not even warm). Of note, my 800W spindle never pulls more than 1.5A (per the VFD reading), with a median of .9A.
The temp in my garage is around 68F.
Switching to a spindle (w/o the noisy fan) is orders of magnitude quieter than using the Carbide router. My noise readings, while cutting AL, is about 73dB with the air compressor and the S3 set-up running.
My S3 is in a wooden enclosure, with plexiglass sliding doors and side windows. The top, back, on of the side (which is windowless) and bottom have a 1" closed cell foam padding (a former camping sleeping mat) as sound insulation. The compressor sits on the cement floor with a fan blowing to keep it cool next to it (the compressor was not made to run 100% all the time).
Quick update: FINALLY received my switch today, installed it quick and dirty, we’ll see, but I enjoy the silence already
Honestly the fan doesn’t both me much.
With that said. What about going water
so I backed down. Seriously though, he also said
and that plus the “just use a paper clip” tip convinced me that for once I would take the easy route. I’m pretty sure that this small annoying fan is useless anyway considering the giant sink AND the fact that my jobs typically put very little load on the spindle/VFD.