Getting started with Mach3

[swbre]

Hello group-
I was recently introduced to Mach3 by a friend who has a small engraver that is run with Mach3.  He and I also have a CNC Masters Baron CNC tabletop mill.  He has had his for ~10 years, I bought mine this past March.  I know how to use it and I am a competent machinist.  I am considering replacing the Master XU software with Mach3.

I have read the Mach3 Controller Software & Configuration Manual.  I also bought and read David Benson's book, CNC Solutions for the Experimenter.  I want to go slowly and understand what I'm doing and how it works as I go.  So I want to start with something that I can attach to my existing machine to display actual spindle RPM.  I believe an encoder will do this.  I don't think I would have problems with mounting the encoder (or other suitable pickup) to the machine - that part is mechanical.  I understand the general concept is to count pulses as it rotates but I have no idea what device, software, breadboards, cabling, power supply ... I would need or want.  And can I make the actual RPM display on a Mach3 screen?

Can someone recommend hardware that I can buy to measure actual spindle RPM?

Thanks in advance
Stephen.

[Hood]

In Mach you just need a single pulse per rev and most use an optical switch and a disc with a single slot. If you are using the parallel port then the Index pulse of an encoder is too short, if you use an external controller such as the SmoothStepper then the Index pulse from an encoder is fine.
Hood

[swbre]

Thank you Hood.

I googled "optical switch" and found:  http://en.wikipedia.org/wiki/Slotted_optical_switch
On the bottom of the article was a link to a datasheet for OPB610 and OPB620 slotted optical switches.
I can figure out how to make a wheel with a slot and how to mount the optical switch.

I see the optical switch has 4 terminals (pins).  What do I connect to those pins?

-Stephen

[Hood]

I use OPB 916B or 917B
They have 5 wires, Red goes to a 220 Ohm resistor then 5v, White goes to 5v, Blue goes to an input , Black and Green go to 0v (Gnd on breakout)

Hood

[swbre]

I use OPB 916B or 917B
They have 5 wires, Red goes to a 220 Ohm resistor then 5v, White goes to 5v, Blue goes to an input , Black and Green go to 0v (Gnd on breakout)

Hood

OK.
I found the OPB 916B in the Allied Electronics catalog.  Also found an online pdf datasheet.  I'll order several. 

You said above, Blue goes to an input.  Does that mean pin 10-13 or pin 15 of the PC parallel port?

Thanks again
Stephen

[Hood]

Yes any of these input pins, you then set up the Index in Mach and set it to the port number and pin number you have used.
Hood

[angel tech]

There are complete units available that take the worry and possible heartache out of this.

http://www.cncdoctor.co.uk/index-pulse_62.html