Need Help!- Servo Wiring, Baldor / Indiana General

[Jet A]

Hello, First post here. I bought a series 1 bridgeport Hasbach NC machine. I am going to convert to a cnc with gecko 320's. The machine currently has (2) indiana general 90v servo. the baldor is the same style with the same connections. Currently, The motor/enconder has 11 connections (9) are connected. 2 for the motor (1 red, 1 black, heavy gauge (10 or 12 maybe)). Shown at top of diagram "0"

I have traced 2 more of them to a power supply(assuming 5v), they would be another set of red and black of a smaller gauge. they are next to eachother in the center of the connector (diagram below). T



...... OO
...*...... *
..*.. *..*..*
....*......*
........*


Here are the 5 i have left!!

Orange
Purple
Brown
Red
Green

I have tested continuity at the motor on all of the above pins, including the smaller power and common wires. None shown continuity with another.

I have no part numbers on the baldor, indiana general is 4050d-21.


How do I test these connections to find phase a and b for the gecko?

I am about 85% sure i have the power and ground right, that gives me 5 unknowns. Please any and all help is greatly appreciated.

I can try to get some pics up tomorrow if it will help.

DP

[jalessi]

DP,

Spin the motor while testing each wire with a oscilloscope.

Jeff...

[Al_The_Man]

As per Jeff's pic, you can use any two that are out of phase.
Al.

[Jet A]

I do not have an o scope. Is there any alternative? Is this with power to the encoder or free from all connections? O scopes are not cheap are they, worth picking up for this project?

[Al_The_Man]

With power to the encoder, it should not need any other connection, you can use a meter and turn the encoder a slow as you possibly can, any pulse that behaves EXACTLY oposite, (the complement) of the first one chosen cannot be used, any other one can.
You could also rig up a couple of resistors and low current LED's to monitor any two visually.
Also if you detect any two that are both low or both high at the same time, then these should be OK to use.
Al.

[Jet A]

excellent idea. Leds never thought about that. Ok so I am looking for the two of 5 wires that output high and low at the same time. One side of the meter goes to the wire. The other goes to ground? Should this be the same as the ground supplied to the encoder or motor chassis?

encoders are most commonly 5v correct? Therfore I will be looking for 5v on the meter?

[Al_The_Man]

The output goes from 0 to 5v, one wire may be a shield, the other four as Jeff noted.
If you pick any one of the outputs, there will be one other one that cannot be used with it, either of the other two will work.
I would use low current LED's with ~10k resistors to avoid loading up the outputs too much.
The meter goes to the output and the 5v common supplied by the P.S.
If you hook up LED's then take them High, IOW output-resistor-LED- +5v.
Al.

[Al_The_Man]

I would have thought that the original set up would have used an encoder with a marker for homing, are you sure the two ypu identified as 5v power are actually not a pair of motor tach wires?
Al.

[Jet A]

I have only made that assumptions based on the leads coming from the same location as the power leads for the motor itself. the (assumed) 5v power leads are slightly larger than the rest of the 5 wires, and they are carried in there own grey sheath. I will try to attach a drawing of what exactly i am looking at.

Thanks again for all of your help.

[Al_The_Man]

I suspect that L&K are the tach, if so it looks like you have a single ended encoder.
The A,J & C could be encoder supply and ground.
It looks like you may have to do a bit more reverse engineering to confirm.
A tach will output a DC voltage if the armature is spun by hand.
Al.

[Jet A]

I forgot to mention, this setup is fairly old. atleast 10 years. probably closer to 15. I want to say it is older than electricity after chasing some of these pcb traces......

Also, after a significant amount of reading on the internet, it seems that older dc motors have tachs and resolvers . What if this is the case, am i able to still run the gecko cards?

So i will check to see if this is indeed a tach, in the event this is a tach, what are the next steps in checking the encoders? Can i apply 5v voltage to any of the encoder wires and test....or is this a real bad idea?

I will probably pull at least one motor apart, what am i looking for inside. i have found an exploded view of the baldor, and know what each actual sensor looks like, but on the encoder, what am i looking for to know which one i am to apply power to?


Thanks,

DP

[jalessi]

DP,

Purchasing new encoders for $30.00 each will cure the problem asap.

http://www.amtencoder.com/

Jeff...