Finally got my magnetic pulse sensor working and getting reliable readings within Mach3. Now I am trying to calibrate the spindle so I can do some threading on the lathe.
I have a Grizzly machine, and calculated my motor to spindle ratio to be 0.8, however it is a chinese machine so I'm not 100% sure that is accurate. My motor runs 3450rpm through a Hitachi VFD, and I'm running Mach3 through a Gecko G540 via USBCNC100.
In my Spindle Pulley setup I've chosen my theoretical top speed which is double the factory top speed where I have the belts, which is 1380x2=2760 rpm. I have set the ratio to be 0.8, so the spindle spins 80% as fast as the motor will spin. This also equals 2760rpm.
When I enter these values and plug a speed in like 700rpm, I see 680rpm. At 850 set in Mach3, I see 835. At 1000 set in Mach3, I see 990.
Can I actually calibrate this accurately without a tachometer to judge the actual speed at the motor vs actual speed at the spindle? Or is there enough data to do the math? It's late and I can't figure it out.
Thanks,
Carl