[choelzen]

I looked and haven't found a spindle speed controller for Mach3 for a generic router. What is needed is a feedback to the computer that tells Mach3 the RPM and a circuit that powers the router from the PWM pulses generated by Mach3.

The index sensor can be a Hall sensor mounted to detect the rotation.. An optical system may be a problem with dust. For high speed routers a divider/counter to lower the pulse count to Mach3 will be needed.

I designed a PC board to drive the 120V universal wound motor in most routers. It can be populated to run 5, 10, 15 or 25 amp motors.

Comments please.

Chuck

[Al_The_Man]

Most ordinary routers are Universal motors and can reach high rpm, you need a prox that has a high freq characteristic, I have used the Honeywell Automotive gear tooth sensor GT1 series, they can also be obtained at auto scrap yards, they are used for Ignition timing on an engine.
Also you could supply the digital tach feedback to the spindle controller, for a while there were surplus Treadmill motor controllers that were intended for Universal motor control, They were based around the motorola TDA1085 IC and had digital tach feedback input and Triac control.
The IC was designed by Motorola for Washing machine Universal motor control and worked quite well, I still have one on my band saw I converted.
Al.

[gfc62]

Can you give more information on the speed ocntrol board you designed?

[Zero Cool]

Yes Please more info on your motor controller!

[Drools]

There is a unit available from CNC4PC that will do what you are doing however it is not a closed loop system. It just takes the output from Mach3 and sets the speed accordingly. It works fine for the people that do not need an exact rpm control. I have yet to try it at low speed as that will be the kicker, low speed usually means less torque on universal motors, correct?