Mick

Thanks for the manuals. I see now what type of kit you have.

The motor speed is proportional to the (effective) armature voltage applied to it. As you have applied both 1.5v and 9.5V and these resulted in similar speeds, something is clearly wrong and I would start by checking the bus voltage, as this is the maximum that can possibly be provided by the bridge output circuit of the drive. I'm not sure which motor you have but the specs give the voltage factors per radian per second so this should enable you to estimate the required voltage for the maximum speed you need to operate at.

The drives appear to be designed for a voltage input, so we are OK in that respect. They either implement a simple (switched mode) amplifier or a velocity loop if you have the tacho installed. Either way, they convert input command voltage to motor speed, which is what we need.

Sorry if this seems tedious, but we need to proceed logically one step at a time to try to identify the issue. If the bus voltage seems OK then something within the drive must be limiting its performance.

As Craig says, advise us if you have the tacho installed.

Allan

Hi
Yes tacho is installed. The motors are mt30. The wires I am using for the speed command are command HI low.
I can check the bus voltage when I get home. Pretty sure it's 130v when I checked it before.

Mick

Hi,
looks like these drives can have a velocity characteristic which requires a tach, or a torque characteristic that doesn't require a tach.
The difference is determined by the 'personality' board installed in the drive.

Are the drives and servos matched? Are they complete with all their original bits?
Are the tachs hooked up? Is it possible to wire them backwards?

The Command input is differentially signaled, ie two inputs command hi and command lo. You can wire them single ended as well....how have you
wired them? Be accurate about this, sketch it, check it, check it again, and check it a third time.

How is the CSMIO output configured....differential or single ended? There again no guessing....either sketch it and check the sketch per above or direct
from the CSMIO manual.

Craig

Mick

There are a few variants of the motor, with a voltage coefficient ranging from approximately 20V to 50V per 1000rpm. So your bus voltage sounds crudely OK but it might be worth a quick check under load.

You said you connected CSMIO pins 1 and 14 to the command + and command -. That is correct. The input circuit can certainly withstand +/-10V


Do you have a spare card that you could quickly swap in as a quick and easy check on the drive? You may need to keep to the existing personality module.

I'm off to work on a sick bandsaw now so will sign out for a while.

Craig

CSMIO has signal and ground outputs for each channel, so it sounds to me as if they are single ended but can conveniently be wired to the differential opamp using STP.


Allan

Hi,
well if the CSMIO is natively single ended then OP should wire the input of the drive the same way.

According to the manual take Command Lo to 0V, Command Hi to the output of the CSMIO and common both 0V.
You need to set a command of 10V so that the servo goes to max speed, ie will have to disconnect from the leadscrew.
The Command Gain pot should then set the max output voltage which is proportional to speed.

Craig

Hi,
got to say these servos and drives are OLD SCHOOL!. To OP: if they even look like crapping out don't waste your time and money fixing them,
get yourself some decent AC servos....modern ones......no bull********* having a controller to close the loop either....proper matching closed loop drives.

I have an Allen Bradley servo for a spindle motor....just brill! I bought second hand reasonably cheaply, they are way too expensive for me new
but Delta and DMM do some very very good stuff which will eat these servos...

Craig

Hi Both

Sorry for the delay. Heres what we have.

Sem MT30H4-33 Motors
Norwin 2110 drive

Encoders:
 A+ Brown pin 1 ON CSMIO
A- Yellow Pin 14 ON CSMIO
B+ Red Pin 2 ON CSMIO
B- Green Pin 15 ON CSMIO
Z+ orange Pin 3 ON CSMIO
Z- Blue Pin 16 ON CSMIO
5VDC White Pin 4 ON CSMIO
GND Black Pin17 ON CSMIO

Tacho Connected to pins 1 and 2 on the Servo Drive card going directly into the motor. This has not been touched, it is the original wiring.

Command Hi and Low going to pins 1 and 14 on the I/O of the CSMIO. The wiring for this has not been touched either on the servo side.

I have 108vdc at the bus on the drives.

The Only wires that have been disconnected are the Command Hi-Low and the encoder.

Am I right in assuming that the 5vdc on pin 4 of encoder channel 0 supplies the 5 volts to the encoder?

There are only two wires coming from the command Hi-Low. This is the original wiring. I am not sure what you mean by single end wiring and configuration for this?

Could this be anything to do with Peak Current Limit pot on the personality module? Haven't tried adjusting it as they were fine before.

Thanks for your time on this.

Mick



 

 

Hi,

There are only two wires coming from the command Hi-Low. This is the original wiring. I am not sure what you mean by single end wiring and configuration for this?

The two wires are differential inputs whereas the CSMIO is single ended. Command Lo needs to connect to 0V on the CSMIO.

Hi,
sorry hit <post> prematurely.....

Command Lo connects to CSMIO 0V
Command Hi connects to CSMIO analogue output
0V (pin4 TB3) connects to CSMIO 0V

Confirm the wiring.

Craig

Hi Craig

Thanks for your input on this. Can you simplify it a little more, please? I have attached the CSMIO page for I/O connector. I presume red will be high and blue low? At present, I have connected the red and blue wire to pins 1 and 14.
Is TB3 pin 4 on the servo drive? There has never been a wire attached to this pin.  

Cheers Mick