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Author Topic: Mach4 real spindle encoder support - which board?  (Read 591 times)

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Offline Rimmel

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Mach4 real spindle encoder support - which board?
« on: August 05, 2020, 01:10:52 PM »
Hi I am upgrading a servo based CNC lathe to Mach4. I already have one running nicely on Mach3.

Looking for recommendations for a good motion controller that supports a real spindle encoder (a rotary encoder with 60  pulses per prev for example) also with A and B outputs.

I have an ESS on the Mach3 but at the time the ESS only supported one index for threading = has that changed?

Anyway - looking for recommendations for a board that will handle servo's and 2 pulses for threading index.

thanks
Re: Mach4 real spindle encoder support - which board?
« Reply #1 on: August 06, 2020, 08:39:57 PM »
Hi,

Quote
I have an ESS on the Mach3 but at the time the ESS only supported one index for threading = has that changed?

Yes, the ESS now supports multiple pulses per rev up to some modest maximum,say 1000 ppr. It lacks the resolution that you would expect
for a motion controller closing the loop on position capable servos, but much enhanced over single ppr.

Also the ESS Mach4 plugin supports encoder feedback to spindle PWM, there again much lower bandwidth than you'd expect of a servo controller
but it is a closed loop velocity control none-the-less.

Craig
My wife left with my best friend...
     and I miss him!

Offline Rimmel

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Re: Mach4 real spindle encoder support - which board?
« Reply #2 on: August 07, 2020, 03:50:25 AM »
Thank you for the reply Craig - I had narrowed it down to ESS (which I know) and Pokeys57CNC.

Do you know much about the Pokeys? generally the spec looks a little higher than the ESS and it the POkeys has the 0-10v spindle voltage control on board. The connecting to the polkets seems a little difficult if you don't buy the connection kit.

thanks again
Re: Mach4 real spindle encoder support - which board?
« Reply #3 on: August 07, 2020, 05:14:33 AM »
Hi,
I don't know enough about PoKeys to be definitive, they are generally well spoken of.

The ESS is much faster, it is capable of pulse rates of 4Mhz, whereas 100kHz or maybe 125kHz from the PoKeys.
PoKeys on the other hand has analogue inputs, very handy if you need them. The ESS has realtime THC support,
whereas the PoKeys does not....so there are pluses and minuses with each choice, but both are good and well
supported.

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach4 real spindle encoder support - which board?
« Reply #4 on: August 07, 2020, 08:14:16 AM »
Ess have limit of output?inputs?
the outputs are reley? or need add reley?
how about noise protect? is ESS is stayble ?(always supplier blame the "noise" ,but ....our machines are always very electric noise place)
how about the screw to connect wire ,are they very small(almost imposibole use normal wire) or can order bigger?
the input ,must be "0" or can be also "24v"?
all this i asked because i found this basic question never asked but for me its the basic and main root to decide which use
thks
yaakov

Re: Mach4 real spindle encoder support - which board?
« Reply #5 on: August 07, 2020, 04:51:54 PM »
Hi,
the ESS has 51 inputs and outputs, whereas the 57CNC has 57.

The ESS is TTL input/output, that is 5V. It is expected that the ESS be partnered with a breakout board and
the MB3 by CNCRoom is a nice example. It has a mix of differential, 24V single ended and opto-isolated inputs and
outputs with proper screw terminals. Using such a breakout board means you do not EVER direct connect to the ESS.
So whether inputs and/or outputs are TTL level, that is 5V, or 24V,  the industrial norm, depends on your choice of
breakout board not the ESS.

I've been using my ESS for six years and I've had one occasion, with several events over the course of an afternoon, where
I experienced electrical interference enough to stop the ESS. I was pushing my spindle to the very limits on that particular
job, but that is the only occasion that I've ever had a 'noise' problem.

I use a pair of MB2's from Homann Designs (not to be confused with the MB3 of CNCRoom, totally different animals) which
are single (parallel port equiv) port bi-directional TTL level breakout boards. You might argue that 5V signal levels are more noise
prone (than 24V), which is not in fact the case.....if....and ONLY IF....you choose the appropriate impedance level for your signaling circuit.
There is a rather complex (mathmatically)  reason why this is so, and I could refer you to various texts, F.G. Stremmler, 'Introduction to
Commuication Systems' (Addison-Wesley, 2nd ed.), the chapter (4) on power spectral density, and Ramo, Whinnery and VanDuzer, 'Fields and Waves
in Communication Electronics' (Wiley & Sons, 3rd ed.), the chapter (5) on circuit concepts and impedance in the presence of EM waves is fundamental
to the 'noise' question.

With appropriate impedance design a 5V system can have the same noise immunity as a 24V system (with the same signal power).

Craig
My wife left with my best friend...
     and I miss him!
Re: Mach4 real spindle encoder support - which board?
« Reply #6 on: August 10, 2020, 06:35:04 PM »
pokeys can connect up to 10 output relay cards ,each 8 reley ,so total 80 output
input you have 24 on the main card ,but can add another  small card with more then 24 input
pokeys input is "0" its not easy because you always must look for npn sensors(not always on market) and if you not have filter on card you must add to avoid 24v will flow into the card
i had several issue with noise ,some they fix they said its bug and they fix it ,but in 1 or 2 machine we still have from time to time
when we have that "noise" its 2 thing can happened ,1- machine loose position for 1 or 2 second,second one of the output activate by itself
one very important point with pokeys ,that they can do custom cards ,like we order that include extra filter ,and bigger wire connector
about inside clock i didnt know there such big difference between pokeys and ess
thanks
yaakov
Re: Mach4 real spindle encoder support - which board?
« Reply #7 on: August 11, 2020, 12:40:48 AM »
i forget add  about the npn disadvantage,we always use spindle with tool change and there 2 sensor inside ,and we cant replace them ,so we need add relay,and i always worried about the delay with this relay ,(we add some more releys because this"0" input,but this look more important not have deley)