RE: [CAD_CAM_EDM_DRO] Machine mounted Tachometer with Surface Meter Per minuteThis

Nah, the speed controls are usually sealed units, but you already know that.
Even then you'd only get the no-load speed.

You're pretty much stuck with opening it up. On the plus side you could use
whatever sensor you like, if there's room.

Everyone who is suggesting optical (bouncing IR off the collet) has never
tried it, the dust screws it up. Otherwise it's ok.

Tony

> Yeah, I know, I will have to take the plunge: open up the router,
> install
> something (?) and make hole in the body for the sensor but I was hoping
> (secretly) someone would come up with a way to derive the actual speed
> from
> router's internal speed control electronic. ;-)
> Gaston
>
> On 2010-09-09 21:00, Tony Smith wrote:
> > Routers go up to 30,000 rpm. You can put a 10x divider in between
> the
> > sensor& tachometer, so for every 10 pulse the sensor receives, the
> tacho
> > gets one. Something like a 4017 decade counter chip would do. The
> tacho
> > would say 2,500 when the router is doing 25,000.
> >
> > Most of the handheld tachometers bounce IR off a foil sticker added
> to the
> > object, or they paint half the item black& half white and the sensor
> picks
> > that up. You could put that on the collet, but it's a bit
> impractical.
> >
> > You'd need to drill a hole in the housing, and add something to the
> armature
> > itself. Magnets& hall effect sensors are common for this type of
> thing,
> > optical is too unreliable due to dust. Optical may be ok inside the
> router
> > body.