Quote Originally Posted by Davek0974 View Post
Anyone here running a BR2J head at 4000 rpm?

I've wound my inverter up to 133Hz which gives 4000 rpm but didn't want to risk damage.

Seems the spec sheets show 2300 or 4200 rpm - is there a difference in models here?
I'm not a Bridgeport specialist but the two speeds you mention sound remarkably like the result of different motor speed options. If you can find parts details for the two any difference may give a definitive answer.n