Re: [CAD_CAM_EDM_DRO] Re: Laser specs ?

Pete Brown (YahooGroups) wrote:

>>>175,000 rpm<<
>>>
>>>
>
>
>
>Are you sure they're that fast? Honestly, I didn't know they come in speeds
>like that.
>
>
>

Sure. The industry standard used to be (maybe still is) Excellon. I
have a bunch
of parts off an Excellon drill. It had two Westwind air bearing
spindles with AC
motor drive that run to at least 80,000 RPM. I think for higher speeds
they go to
air turbine spindles. The smaller the drill bit, the faster you need
to turn it to
keep the linear velocity (SFPM) of the cutting edge at the optimum for
the material.
As the smallest hole sizes used in PCB manufacture get smaller and
smaller, the
RPMs have to go up.

I adapted one of those spindles onto my Bridgeport, and drilled down to
.018"
holes at 24,000 RPM (the limit of the VFD I'm driving it with is 400 Hz).

Dental handpieces run at 300,000+ RPM now, with air turbine drive.

Jon