Another aspect you might want to consideration is operational cost.
Compressing air is probably more costly than the few amps it takes to run
the Foredom.

You might also consider an electric die grinder, like the Makita I have. A
Foredom is not the tool of choice, IMO, when you are putting strong side
loads on it. You can snap the drive shaft if the wheel gets pinched. A die
grinder (air or electric) will either keep cutting or stop.

Noise from cutting will vary depending on the bit or cutter you are using
and the material you cut.

"GCN" wrote in message
oups.com...
Hi,

I live in a confined space where excessive noise will not be tollerated
by neigbours. I need a tool to grind mosaic tiles.

My current considerations a
OPTION 1
Foredom 1/3 flex shaft tool with all the diamond bits. Around $400

OPTION 2
Ingersoll Rand mini die grinder PLUS dentist/laboratory type "quiet"
compressor. I found a shop that sells a second hand "rotary vane" quite
compressor delivering 4CFM @ 10 bar with only 62 dBa noise ! Total
outlay around $1000 (new it would be around $2000). ouch.

I would prefer the Foredom as the outlay will be significantly less.
However will it drive my neigbours mad? Does the sound travel through
walls like my 1HP 4 1/2" Bosch angel grinder?

Thanks for your thoughts

Guido