Have not been successful getting the right RPM from my spindle following the warp9td document “Setting up the SmoothStepper and Mach3”. Trying other docs I get the same results.

My Taig R16 headstock is driven by a Sherline 90VDC motor with KBIC VS controller which is plugged to 120VAC wall outlet. The KBIC has its own Pot and measuring the volts across P3 and P1 I get 11.5VDC. I disconnected the KB 3 wires and I tapped into the same terminals and fed the C11G BOB and now I have power on the analog side.

The spindle turns ON/OFF with Mach3 but I only get about 1800RPM (measured with my handheld tach). Playing with the Mach3 setting “Pulley Setup” I was able to get 8000RPM at one time but later I lost it and I’m back to 1800.

I understand that pulley #4 is the default but to me looks like pulley #1 is more responsive.

In the motor tuning I have set the spindle to max for Acceleration/Velocity.

Any idea how to fine tune the spindle?

As far as I can see from the C11G documentation it expects to see a PWM waveform at 1000 Hz which it smooths to generate an isolated 0 - 10v for the speed control (see p7 half way down).  However the Mach documentation also points out that the speed resolution depends on the kernel speed selected.  If you select a kernel speed of 25kHz and a PWM frequency of 1 kHz as the C11G seems to want than you will only get 25 speeds (25000/1000).  That's assuming that the PWM frequency of 1000 Hz is possible at all.  Usually the PWM frequency is set to 20Hz or so, but then the C11G may not smooth the signal very well (the documentation is poor on this point).  I assume that you have ticked the PWM Control box in the spindle tab of Ports&Pins?

Very good point John, thanks

ESS General Config doc has the spindle set at 32 KHz and in the spindle PWM section it is ticked and has Base Hz 300. Then in ESS Spindle THC & Laser Config it has in the PWM section a base Hz of 1000. In addition in the Mach3 Engine Config Ports and Pins the ESS doc under spindle has no selection for Step/Dir Pin# neither for Step/Dir port. And in the same ESS doc under the Motor Tuning and Setup has both the Velocity and Acceleration slides set to Max (which I think it’s wrong).

Since this is the first time I get hands on experience with the ESS I can see a problem setting the right frequency between ESS and Mach3 for the spindle. If you have any suggestion I’m open to give it a try.

Besides the above I don’t know which pin to use for Output#1. Most say to use pin#17 but this pin is used by the SCHP. So this is another confusing part.

Reading my notes I have from other projects I set the Velocity/Acceleration in the motors tuning half way up in the scale and on pulley #4 I set min speed 1, max speed 5000 and ratio 1. Now by using M3S5000 I get about 8000RPM on the spindle (its belt driven) and I can also see on the Mack3 screen the same spindle RPM (about 10% less). That’s pretty good and perhaps by trying I can get even higher.

I'm not familiar with the ESS and I think you can read the documentation as well as I can.  But it seems to me that Mach controls spindle speed either by (a) step and direction which is not applicable; (b) as a PWM mark/space ratio; (c) (I think) via modbus (which isn't applicable).  So PWM is the only option, and presumably the PWM frequencies need to be the same across Mach and ESS.  Unless you want to run your spindle in reverse you could ignore Output 1 I think, just tick Disable Spindle Relays.  Is there a support forum for ESS?

Just post my first post in the ESS forum. I will post back here soon as I have an answer

To conclude this subject the wrap9td forum was very helpful with my questions. I understand that Mach3 has a fixed frequency of 500Hz but in Mach4 this frequency is adjustable.

I had not adjust the 12VDC pot on the C11G and yesterday when I tried to do so I discover that I only had 3.5VDC instead of the required 10. The same terminals inside the KBIC controller have 11.5VDC. So my conclusion was (along with discussions from others) that the KBIC has a problem with the analog side of the C11G BOB. At least now I know what was the spindle speed problem.

Now I just ordered a 12VDC PSU from Amazon to feed power to the analog side of my BOB and when I get it I will re wired what is needed and hopefully all will be fine.

Nicolas

Be cautious!  The KBIC is not grounded and it floats at about half mains voltage.  That's why the C11G pwm circuit is opto isolated and gets its supply from the KBIC.  So is the 12v PSU fully isolated from the mains?

Good for you John to let me know and I’m aware of it.

I have a 12VDC adaptor (wal wart) and I bought it a few months back to feed the analog side of the C11G. This adaptor is plugged into a power bar I have at the bottom of my control panel among other adaptors and all have 2 prong plugs. When I checked continuity of the 2 slots where the adaptors are plugged to my star point ground I had continuity. I should have known that because the white wire on 120VAC circuity eventually end in the ground.

When I did the same check between the negative terminal of my 48VDC PSU and the star ground there was no continuity so I figure them PSU are designed to have the negative isolated from the AC circuit. Do you agree to this?

Really I have almost no knowledge of electrical stuff however I try to be very cautious when I work on them.

The attached schematic is what I plan to do when I get the new 12VDC PSU and I hope it will work. Before I had the KBIC terminals P3 and P1 connected straight to C11G and between them at KBIC I had 11.5VDC but on the C11G I only had 3.5VDC. Now the P3 is not connected, the P1 will be connected to the negative of the new PSU and the positive of the new PSU will be connected to the C11G 12V terminal. Part of this schematic comes from the vendors site. Perhaps you can tell me your 2 cents on this schematic?

Nicolas

Do you mean that you had 11.5v on the kbic before connecting and 3.5v when connected to the c11g? That would be consistent with the pwm circuit on the c11g requiring more current than the kbic can deliver.  Your circuit should work (though I haven't checked the pin assignments) provided the isolation on the 12v supply is OK, but since it has to allow for the negative output to be grounded it should be.  The key factor in isolating a psu is having a transformer inside, either a chunky mains one or a tiny high frequency one in a modern switched mode type.

The KBIC P3 and P1 always measured 11.5VDC and when I connected these terminals to C11G and measured between them they only had 3.5VDC (on the C11G side)

Yes my problem now is to assure the new 12 PSU (will be here tomorrow Sunday) is isolated and the only way to find out is to check its negative and case against my star point ground