I am using the CNC4PC insex pulse board sensing a disk on the spindle with 4 slots, one larger than the other 3.
So the high figure displayed may be 4 times the speed.

Thanks for the rundown on  the spindle display vmax. I shall put that in my manual for when I get to threading, it sounds very useful.

thanks
tmsmith

You may need to do an auto calibrate on the spindle to let it correct the display. Also did it go to the index pin or Timing pin. With multislot you should use the timing pin setting. (;-) TP

Vmax,
Tried Timing as opposed to Index. It gave a steady reading of 4520rpm. However when I changed the speed the rpm stayed the same!!.
Tried auto-calibrating the spindle. It started at a fairly high speed and gradually reduced it to zero. I am sure when I did this some time ago it took the speed up from a low value to a high one.
In fact spindle speed control seem to be poor; I think its time to look inside the box.
When on Index setting I tried increasing the debounce to 5000 but it made no noticeable difference.

tmsmith

I think I would try taping over the 3 small slots and try the single large slot. set the pinout to the index signal and reset the debouce back to zero. that way it only gets the one signal for testing. See how that works. (;-) TP

I think for testing purposes I would tape over the 3 small slots, set the pinout to index, reset the debounce to zero. Doulbe check the spindle motor setup and make sure the pid functions are turned off for now. See how that works. I don't use the digispeed I run the Campbell board and a commercial photoptical switch. THe speed controls down to about 3-4 rpm tolerance. Let us know how it works (;-) TP

HI vmax,
sorry for delays in replying but bad computer crash put computer in dock.
To carry on from where we were.

Taped over 3 small slots set pinout to INDEX - active low.
not sure about PID; there are values in there but nothing selected.
Min PWM set at 10%

On MDI screen entered S1500, M3   indicated RPM 1100  good control.
                                 S1800                      RPM 1390    "        "
                                 S2000                      RPM 5000    "        "

As you see sudden increase in revs for small increase in S.
A question; could the spindle calibration be the cause.
I do not understand the calibration. It increases the requested speed in increments of 20 and draws a graph.
After  it finishes there are some buttons to press, not sure about the order but then what happens to the data.
My graph is more like a Z than a 45deg slope and this may be the cause of the above strange behavior.
I am sure it was not like that in an earlier period.
I will await your comments before recalibrating

tmsmith

OK so now we have good RPM control go ahead and recalibrate the spindle.
(;-) tp

I have tried the default button; control  remained as previous post.
Recalibrated spindle,  still no difference.

I don't class my control as good control though the RPM indicated varies very little for any particular value of S.
Setting of S upto about 2000 gives steady increase of revs but still low figures.
S2900 to S2990 steps the revs up to 5000RPM from around 2000RPM. S2960 gives around 3000RPM.
Not condusive to correct setting of Revs when cutting metal

Just a thought, is a reboot required to make Mach take notice of a new set of calibration data.

tmsmith 

HUM, Starting to sound like a speed calibration problem in MACH.

Does the graph remain like a z?

I did mine before the calibraton option..

Retry the calibration sequence and write down each rpm step in the test as you go.

Then go to mach and set each speed S********* and see if the values are correct, write those down also as a reference.

Art may need to see them if it is a Mach problem.

A reboot may be required ( it could not hurt:-) )

(;-) TP

Will do.

tmsmith