[dresda]

Good stuff guys, now here is where I stand. I have been servicing and rebuilding CNC machines for over 35years mainly on the mechanical side, my buddy is a fanuc engineer so he takes care of the electronics although quite a bit has rubbed of on me over the years. All the CNC machines from the 80's would be analog +-10v then later digital, so I started looking for a control to retro-fit onto those old but good drives and motors. I was not to well up on the step/dir or PWM so went ahead with the mach3 anyway. I had a knee mill with a baffed out Fagor, Dc brushed servo motors and drives, kept the servos and motors but now I need a motion control and that was a $1000.00 DSPMC from Vital systems but found and still find there are some conflicts between mach and the motion board. I have spent a lot of time and effort putting it through it's paces and it works great but I just know if it's stable enough to put it out for general use in the industry. Now I'm looking at EMC2 but find it doesn't have +-10v analog for the drives either, but step/dir and PWM, do I still have to buy the motion board? don't want to use steppers and go backwards and don't want to load of money on state of the art drives and motors. I feel like a'm going around in circles.
ray.

[samco]

Now I'm looking at EMC2 but find it doesn't have +-10v analog for the drives either, but step/dir and PWM, do I still have to buy the motion board? .
ray.

there are at least 3 suppliers that have +/-10v hardware that work with emc2. Mesa, Pico systems, vital systems.. In that order of popularity IMHO. What sucks is I would guess the motion board you bought from vital systems isn't supported by emc. (emc doesn't want or need a 'motion' board.) but the hardware is quite a bit cheaper because of that.

http://wiki.linuxcnc.org/cgi-bin/emc...orted_Hardware

I am using mesa hardware with their analog daughter boards.

sam

[Al_The_Man]

Now I'm looking at EMC2 but find it doesn't have +-10v analog for the drives either, but step/dir and PWM, do I still have to buy the motion board? don't want to use steppers and go backwards and don't want to load of money on state of the art drives and motors. I feel like a'm going around in circles.
ray.

Did you look at Dynomotion? it uses USB from the PC, which it uses as just the front end, the whole controller is outboard, it has ±10vdc analogue and it's own front end or has a Mach plug in.
Al.

[dresda]

Here is where we all get confused, well I do. talked to pico systems and he only supports EMC2 and he said his drives are PWM and will not drive fanuc motos. Vital systems has a motion board for EMC2 for $500.00 so I guess that's PWM.
No Al, i haven't looked at them yet, what do you think Al?
This all started because when I got down to the short strokes testing Mach3 running the wizards, I found when I was running a wizard and then went to look at that wizard screen to check the parameters that I had set, the machine jumped about 1/2" and snapped my 1/2" end mill, when I posted it I got answers like well what do expect from $159.00 software....
Ray.

[dresda]

Sorry Al, I should have said what do think of Mach3 vs EMC.
Still trying to find out where the dynomotion puts out +- 10volts for my Fanuc motors.
Ray.

[dresda]

Do I read correct, Dynomotion puts out 80V, my Fanuc require 180v.

[jmelson]

Here is where we all get confused, well I do. talked to pico systems and he only supports EMC2 and he said his drives are PWM and will not drive fanuc motos. Vital systems has a motion board for EMC2 for $500.00 so I guess that's PWM.

Ray.

No, if you ask too specific a question, you may get too narrow an answer. Pico Systems DOES
have an analog-out servo interface. It is a bit expensive, $780 for the basic 4-axis
board set. It is designed for industrial retrofits, so everything is plug-in boards. There is a 4-axis
encoder counter, a 4-axis analog output board, and a 16-in 8-out digital I/O board. You plug in
what you need. Need another encoder? Plug in a board. Need more analog or digital I/O,
plug in a board.

Yes, our products are supported by EMC2 only, as all the smarts are in EMC. The boards just
count encoder pulses, output +/- 10V analog, and do digital I/O. This system is called our
"PPMC" for Parallel Port Motion Control.

We also have some products for using Fanuc Red Cap motors with our brushless drives, as
well as with other makes of servo drives.

Jon

[dresda]

Thanks for clarifying that Jon, it was as clear as mud to me. Anyway I might have to go over to the dark side like EMC after testing Mach3 and a few weird things happened that could be very dangerous.
So, back to square one, all I have are 3 small Fanuc motors (6amp) with Diff, encoders.
Ray.

[jmelson]

Thanks for clarifying that Jon, it was as clear as mud to me. Anyway I might have to go over to the dark side like EMC after testing Mach3 and a few weird things happened that could be very dangerous.
So, back to square one, all I have are 3 small Fanuc motors (6amp) with Diff, encoders.
Ray.

Sorry, this stuff IS complicated, not like plugging in a toaster.

So, Fanuc has had a number of different systems over the years, and it is getting a LOT
worse. The original brush motors were simple, and mostly industry-compatible. When they
went to brushless motors, the schemes got more complicated, and Fanuc made a number of
different paths available for different uses.

Commutation is for the motors, as the drive needs to know which motor terminals need plus and
which need minus, to match up with the magnets in the rotor.

The first Fanuc brushless system (the #S-series where the # represents a number like 5, 10, 15, etc.) were pretty simple, they had a traditional quadrature encoder plus index (ABZ), with added tracks for motor commutation. This was not a standard arrangement, but used 4 signals to
give rough absolute motor position for commutation. I have made a converter for this that
allows my servo amps as well as those made by others to be used with this first-generation
Fanuc rd cap motor series.

But, then Fanuc came out with their serial pulsecoder scheme, where there is NO quadrature signal at all. Everything is encoded into a 77-bit serial data stream that is sent by the
encoder on demand from the CNC control. There are variations of this where there is no absolute position info, and the encoder synchs to the index position only when it passes that position. On these encoders, the motor needs to be manually cranked one rev before a brushless drive can know the rotor alignment, so an encoder backup battery is necessary so the drive can control the motor at power on. A limitation on this is that while the CNC control is off, the encoder saves the last known position, but does not sense movement. If the machine were to be moved while powered off, the commutation would be all fouled up. So, they require a brake to prevent the motor from moving when the control is off. There is another type of serial encoder where a rough absolute position is derived from the encoder disc, this allows the motor to move under control of the drive even if battery power is lost or the motor was moved during power-down. These encoders are called the Alpha series, and there is the Alpha i where there is no absolute info. These are marked the (lower-case Greek alpha) (Capital I) and numbers such as 32, 64 and 128, for 32768, 65536 and 131072 counts/rev.
The absolute versions are the (alpha) A 32,64 and 128. There is also a million-count version
of this encoder.

So, that is what I have figured out about these Fanuc encoders, so far.

Jon

Jon

[andypugh]

Here is where we all get confused, well I do. talked to pico systems and he only supports EMC2 and he said his drives are PWM and will not drive fanuc motos.

Converting PWM to an analogue control voltage needs at minimum a capacitor and a resistor. (Though it gets more complicated if you want bipolar volatages, or want them isolated from the PC).

The Pico system could be plug-and-play, depending on _which_ Fanuc motors you have. (I think Jon has a converter card for the 4-bit red-cap motors).

Alternatively and if you don't mind doing rather more wiring and setup, the Mesa 5i25 and 7i77 combination is rather inexpensive. You could use that with the software Fanuc conversion in the bldc component (if you have the 4-bit Gray code and not one of the other feedback systems).
In honesty, this setup would be experimental, but parts of it are being used by jsheerin, who has got a fanuc motor running with EMC2.
http://www.cnczone.com/forums/1020710-post212.html
The Mesa 7i77 is near the bottom here:
AIO Daughter cards
It needs a $89 5i25 PCI card to hook it up to the PC, that isn't a Parallel port connector. It also doesn't technically exist yet, I don't think. (but EMC2 driver support is in place)

[chester88]

Dresda

If you end up trying EMC it would be nice if you revisited this thread and mention your opinions.

By the way what part of Canada are you in? I'm on Van Island BC

[dresda]

I know Emc would be better than Mach but Mach does have some nice bits like the wizards. I will try to run them side by side when I get some motors and drives for my donor machine.
I live in the Toonto area.
ray.