[tc429]

standard fanuc timing, or modified by cinci?

just put together a replacement motor for a buddy, timing looks screwed up, but parts should not have altered...yrs ago had seimens, cinci swapped two wires to bastardize the motor, wondering if they somehow did on fanuc too...
motor is A06b-0501-B006/0073

I'd thought the 0073 was the goofy vee key only, but unsure...

afraid if i time it normally it might not run on a cinci? any ideas? trying not to take a hour drive if I can help it

[Al_The_Man]

Do you mean the Commutation?
The encoder normally has the double keyed shaft and on a 8 pole motor it normally orientation does not matter if you are 180deg out, but the three tabs for the housing have to be lined up and the is a mark on the case and one of the tabs for alignment.
I made up a little 4 led display that plugs into the encoder to read the C1 - C8 outputs, DC is connected to the 3 stator leads to align the rotor to read the LEDS as per the Servo service manual.
Al.

[tc429]

thanks Al- I already shipped it, timed normally...yeah Ive got the LED box, even a portable 120 volt 6050 drive with all the adapters for test running...

the timing was exactly 45 degrees off, moved the key, test runs OK. I had always *thought* Fanuc timed the key to the magnets/rotor- he had a flooded size 10, I just pulled a good stator from one of our thousands of spare robot motors, popped new bearings in, put back together- same rotor(vee key)/same encoder, but it wouldnt time...tried every possible dc combination to get the +A/-BC=124 (8 at toggle), float C hit again get ccw shaft movement and 2&4 only on, every combination was off.
the books dont mention floating C re-hitting, but as weve had some rewound with backwards rotation, never hurts to verify rotation in case somebodys been in there before

did a little reading, couldnt find anything on the 0073 being a cinci oddball commutation, so went ahead realigned the key, put back together- I did warn them the home WILL be off by either 1/4 or 3/4 of a rev as I moved the encoder key 45, and shoulda noted the arrow when I pulled it off...I know better, but was trying to hurry- didnt think the encoder was any good as the motor had a inch of water in it, but looked like it was just below the encoder, nice and clean inside it...

the reason I'd asked, we had a bunch of Acramatic 850 controls with Seimens motors, motors had a odd part number, identical looking standards wouldnt run- I tore one apart, here Cinci had swapped only two of the Hall sensor wires to make it a 'cinci only' special, they had a modified drive that required the swapped halls to work. we used the rest of our cheaper standard seimens motors by swapping the hall wires. I was just hoping they didnt do some other such silliness on a 'standard' fanuc...guess not, apparently Fanuc timed some of the keys to the stator, swapping stators= rekeying required...

theyre gonna throw it on tonight and see if its OK, if it jumps theyll send it back down tomorrow and I'll put it back where it was (wrote down the patterns just-in-case), but I'm 99.9% sure its a standard timing sequence and will be fine. I dont even know if its got 6050 or 6057 amps driving it- 57's *could* have cinci tweaked servo rom to 'fix' the commutation, doubt it would be done on a 6050 as theres no ROM for commutation...
thanks for the reply-
Tim

[Al_The_Man]

As you probably know, the Fanuc AC motors do not use the normal Hall commutation, the 4 bits are used to create a pseudo sine wave.
All these encoders I have seen you don't really have a choice of the key being off?
It can be out by virtue of the the 120deg mounting tabs though.
Al.

[tc429]

maybe by dumb luck I grabbed a miswired stator, but it looked original...yes it had the square red encoder, 90 degree bolt patttern, 'cant miss' timing- (well 180 on the shaft can happen)but the encoder key was 45 degrees out for whatever reason. rotated it on the armature shaft till it timed right, hooked it up and it ran...didnt get a callback, so assume no news is good news.

I really dont like cincinnati...the vee keyway on the 19mm shaft just looks wrong...first fanuc ive seen like that, sure looks like that shaft could be wrung off if crashed in rapid- the bottom of the vee key is near shaft centerline, so its only got 270 degrees of a 19mm diameter for support(all cut from the normal 35mm shaft... must be that 'new math'
Tim