Reply with QuoteWill it be small enough to fit in the Red Cap?
Do you have a projected price yet?
Al.
drive for Fanuc "red cap" brushless motors
I have just developed a signal converter that allows Fanuc red cap brushless motors to be used with Pico Systems, as well as other brushless drives. The problem was that Fanuc had a proprietary scheme for encoding the commutation information. My converter reads the proprietary position information at startup and converts to standard Hall signals. Once the motor has passed the index position, the converter counts the quadrature pulses to determine the right commutation phase.
I will be demoing a prototype of this at the EMC Fest in Wichita May 21-27, and should have it out as finished product in about a month after that.
Jon
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Will it be small enough to fit in the Red Cap?
Do you have a projected price yet?
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
I hadn't thought of trying to fit it inside the cap, but that is definitely possible. I have been looking at red cap motors on eBay, and I see some of them have the external connector wired to the encoder with a flexible printed circuit. So, it would be a major hassle to make such an installation on those motors. The PC board with the electronic components would only be about 5 mm thick, so it seems like it should fit in there, at least in the larger motors. It will probably be less than 2" square. It would require some modification of the internal wiring. I would have to at least leave holes for the screw terminal blocks, as many people would not want to modify the inside of the motors. But, I could sure sell it without the connectors, and you could hand wire it as you desire.Originally Posted by Al_The_Man
As for price, I'm not too sure at the moment. There is not a lot to it - a crystal oscillator, an CPLD, and a differential receiver chip. I think maybe the no-connector version might be able to go for $50, and the one with connectors might run $65. The CPLD is $12, so that sets the price floor.
Jon
After looking at the cap and encoder on the ones I have it looks like it would be a squeeze.
I guess it could go in the enclosure, do you intercept all the differential signals?
Have you done any extensive testing?
I am definitely interested as I am ready to use a Fanuc motor for a spindle.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Another couple of questions come to mind. Is the interface set up for 8 pole motors, which most Fanuc are as far as I have found.
Also if you count the encoder pulses after the marker, how does different encoder counts/rev affect this?
Does the motor need to be rotated initially to set up the configuration?
Al..
Last edited by Al_The_Man; 05-15-2009 at 04:34 PM. Reason: Afterthought
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
The four commutation signals are not differential, but the encoder ABZ are. The prototype doesn't use the differential pair of ABZ, but the final version will do that.
EXTENSIVE testing? I NEVER do extensive testing, just enough to make sure it works! This is a hand-wired prototype, and I was astounded that it worked at all on the first try, and perfectly on the second. I just made the motor move for the first time less than 24 hours ago!Have you done any extensive testing?
I am definitely interested as I am ready to use a Fanuc motor for a spindle.
Al.
I will have to do some more testing when I get final boards made, and I'm sure we will do some testing of it at the EMC Fest when I show it off. But, really, if the motor moves smoothly over a range of speeds, there isn't a whole lot more to do.
The brushless DRIVE, itself, has had quite a bit more testing, I've been using them on my own machine as well as having sold a few of them. The big problem with brushless drives is motor/encoder compatibility, and the only way to know for SURE is to test at least a motor from the same series.
Jon
Yes, the motor I am testing with is 8 pole, and all the ones that are clearly described also seem to be 8 pole.
I think the red cap "pulse coder" is standard at 2500 pulses/rev, which equals 10,000 quadrature counts/rev. If there are any that are different, then the program will have to be changed to adapt.
The commutation is initially controlled by the B1 through B8 signals, and once the index pulse is seen, then position is counted from the quadrature encoder. The motor runs normally in both modes, I can't detect the changeover by feeling the shaft. So, that initial move to get to the index pulse would be during the axis home sequence, and would be under control of the CNC program.
Jon
The Encoders I have are 2000p/rev.
Fanuc also have 1000, 2500, 3000 and some at 10,000.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Well, that is no problem, I just need to know in advance what resolution you need. I may have enough space in the CPLD to make the resolution jumper selectable, but I can't guarantee it until I try it.
Jon
I have what your looking for
If you like I can get you some dimensions for this. I have a Fanuc Robot S5 I sent you a PM with a link. It has 5 servos on it and I think the top 2 are teh same size and the lower 2 are the same and the very bottom is different as well... I just got it Today givin to me from my Work!!!! I was so excited about it. I got the Controller the 2 hand held Wands or computers all the cables! The Robot its self works just fine! The controller is screwed up but the instructor said the drivers and encoder just might be able to be salvaged...
I went and took picture
First time uploading to this site hope i did it right
Here are a few
More of the Bot.
Theses Servos have
They have 19 wires coming from them... Can I use theses for my CNC machine? There AC servos, how can I make this work?
Fanuc has quite a few different configurations of encoder including a serial transmission type, so the actual encoder part number or type would need to be known.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Jon, A question I have is what is the nature of the commutation until the timing is sync'd by the marker?
The drives I use all require to see a correct sequence otherwise the drive will error out.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Where do I need to look,
Where is the encoder part # located? I'm pretty new to all of this if you could walk me through it, that would be great.
is it under the read cap? Or is it in the control box? There are some numbers located on the sticker on the motor.
The standard "red cap" motor/encoder set has a 17-pin connector (Amphenol 20-29 size).
There are 6 wires for differential ABZ, plus 4 wires for the commutation encoder, plus 2 for encoder power. There are two more wires for motor temperature sensing. So, that is 14 active signal wires. They use two pins each for +5V and ground, and also one shield pin. So, that uses all 17 pins.
These encoders look a bit different than the "red cap" motors used on machine tools. I also don't see the Amphenol connectors, so these may be different.
Jon
Traditionally, on Fanuc machine tool motors, at least, there is NO separate label for the encoder. The motor/encoder unit is treated as a whole. As for the encoder, it just generally says "pulse coder" to differentiate between resolver feedback and encoder.
Jon
There is a separate number for the encoders also, in the ones I have this is on the encoder, they even often break down to two separate part numbers for the same encoder!
Also the last two digits of the motor part number indicates the type and resolution of the feedback, e.g. -Byxx, y is the shaft type.
I have the Fanuc resolution reference for most of the -Byxx encoder types.
Did you spot the question in post #15?
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Here is one of the servos I pulled off
Yes I did read all theses post. I read #15 last night but I didn't understand it... I am very new to all of this so forgive me if I seem ignorant. I'm learning one step at a time. I pulled one of the smaller Servos off of the Robot arm and here are the Picture's.
I said in last nights post I had (5)Five AC Servos on the Fanuc Robot S-5. Turns Out I found One More inside one of the arms! Its like Christmas!
Now I have six so far but I think thats all Im going to find Im running out of hidding places.
Let me know if you can see the #'s If not Ill have to pull out the Real Digital Camera instead of my Phone.
Last edited by Musick7; 05-16-2009 at 03:25 PM. Reason: Pictures didnt Add to this post.
