Spindle thought

[Al_The_Man]

How quiet are treadmill motors? I been given one and pick it up tomorrow.

I know they're 180v not too sure if thats DC or AC? this ones 1.7hp which is decent for a spindle.

The vast majority are DC, although I have seen a Universal motor with rpm/tach control on one, one thing to watch out for is some have offset brushes making them uni-directional, usually the cheaper ones.
The KB/Baldor drives on ebay are a good candidate for a drive.
Be suspicious of HP claims, they often would not run at the rated hp in a sustained mode.
Al.

[SPEEDRE]

I have found that using a router for sustained usage will burn it out relatively quickly. Yes they are ungodly noisome. I have a treadmill motor and a variable controller from Supluscenter.com, but its weight has made some build/strength issues in the past. If you don't mind over building your machine it gets my vote for a quieter cooler machine.

[Wombilly]

Most noise from spindle motors is down to balancing, if the spindle and tool is perfectly balanced, including the collet nut, then noise should be to a minimum,