Need more help

[scrambled]

Hi everyone--

I am in the process of trying to get my motors working.

I am using 1125 OZ-in servo motors from Keling. I am also using 1200 CPR encoders from US Digital.

When I have the motor not connected to the gear box, I can get the motor to spin forward, and then reverse. It will also spin slowly and also speed up. It does not take much force to stop the motor. I can easly stop it with two fingers when it is spinning at a medium speed.

When I connect the servo motor to the gear box (a Tompson Duratru 5 to 1) input shaft, the motor will not even start to spin before it gets an OVER CURRENT fault. The input shaft of the gearbox spins really easy.


According to the motor specs---
the PEAK CURRENT is 40 A.
the CONTINUOUS CURRENT is 7.8 A.
the TERMINAL VOLTAGE is 90 VDC


I am using 80 VDC , 1000 watts power supply

I have the VSD-E set at---

motor type---BRUSH DC
Max. peak current---39990 MA
Max. continuous current 7930 MA
Current fault limit 42000 MA
Encoder resolution 4800 PPR


I have tried both position mode and Torque mode, same results


am I missing a setting? or just plain doing something wrong? I would thing the 1125 oz should not have any problems with the gearbox.



Thanks for the information



Steve

[radiantheat]

I had same or Similar Problem with my DC motor , after reviewing the manual I decided to wire up motor outputs in DC parallel mode ( A to D and B to C ) , that fixed problem.

[scrambled]

radiantheat


I will try that tomorrow. Do you know if it matters if I do not have a regerative breaking resistor installed? I did not think about the parallel setup.


Thanks


Steve

[scrambled]

radiantheat

sellecting Parallel mode did not help. It appears that the VSD-e faults out quicker now, but that is just a hunch.

I am also getting some sort of interference from the output of the VSD-e and the USB adapter. When ever the drive has a fault or the 25 pin DB connector is unplugged I can't communicate with the VSD-e.

I made sure that I am using a shielded cable, and that the shield is connected only at the DB25 connector end. I then connected the drain wire from the shield to the FG on the DB25 circuit board.

I also wrapped the outside of the DB25 connector with a metal foil tape to try to keep the noise down. This did not help either.

I double checked my wiring, and it is correct.

I have all of my GND s and all of my COMMON s from the powersupplies connected to a copper grounding block.


Any ideas??

Thanks for the input



Steve

[radiantheat]

I will see if anything like that happens on my setup.

[scrambled]

radiantheat--

I tried for 2 hours today, and still no luck. I even tried a second laptop, just to rule that out.

so far the only thing I can get the VSD-e to do is get a communication fault, and a over current fault.

Any additional ideas?

I am about to give up.


Steve

[radiantheat]

Re: Overcurrent Faults. I can get my 'step' response test to run and capture the test data ' in torgue mode only. I still get overloads in velocity and position mode.

I think there was some binding on my setup last week , so I lossened the 'gibbs' for this last test.

I did get great motion when trying homing ! the saddle traveled at a good speed , moved the 600 lb saddle very smoothly about 2 feet ! . Note , I should have hooked up a limit switch first , I had to do a emergency power off to prevent crash.

Re: Communication errors ; I have not had any comm error of any kind.





I have been wondering how to send simple motion commands ( like move CCW Nsteps ) , from GDtool. It would be very useful during this phase of setup , but I don't know how to send any motion commands from GDtool except response tests and homing tests. ? for example the saddle is now all the way to the right from the homing test , how do I move it back to the center ?

[scrambled]

radiantheat

I figured out what was causing the communication faults. If I removed the power from the VSD-E's that Iwas not communicating to, then it worked. Took awhile to figure that one out. I have checked and double checked my wiring, my FG and my GNDs. I am about sick of checking wires .

I will let you know if I figure anything out tomorrow.


Did you get my P.M.?


Steve

[TOTALLYRC]

Originally Posted by scrambled Hi everyone-- I am in the process of trying to get my motors working. I am using 1125 OZ-in servo motors from Keling. I am also using 1200 CPR encoders from US Digital. When I have the motor not connected to the gear box, I can get the motor to spin forward, and then reverse. It will also spin slowly and also speed up. It does not take much force to stop the motor. I can easly stop it with two fingers when it is spinning at a medium speed. When I connect the servo motor to the gear box (a Tompson Duratru 5 to 1) input shaft, the motor will not even start to spin before it gets an OVER CURRENT fault. The input shaft of the gearbox spins really easy. According to the motor specs--- the PEAK CURRENT is 40 A. the CONTINUOUS CURRENT is 7.8 A. the TERMINAL VOLTAGE is 90 VDC I am using 80 VDC , 1000 watts power supply I have the VSD-E set at--- motor type---BRUSH DC Max. peak current---39990 MA Max. continuous current 7930 MA Current fault limit 42000 MA Encoder resolution 4800 PPR I have tried both position mode and Torque mode, same results am I missing a setting? or just plain doing something wrong? I would thing the 1125 oz should not have any problems with the gearbox. Thanks for the information Steve

A 40 amp peak motor should not even notice that you have grabbed it with 2 finger and would probably rip you hand of if you could get a real grip on it at full speed.

The settings look good, but I would try an amp meter to see at what amp draw you are getting an overcurrent fault.

Stalling out with the gearbox attached goes hand and hand with the low torque you described. A motor will have more torque but less rpm in series and more rpm and less torque in parallel at the same voltage.

If my math is right, your power supply is capable of only 12 amps max, so you will never get max full load torque but it should be more than enough to spin the gear box no load unless there is a gearbox problem.

Remeber that the 1125 is an absolute max rating, for 1 second I believe.

Based on the continuos current, you should get around 225 continous torque.

Mike

[scrambled]

Mike-

I am planning on using 1500 watt power supplies for the larger drives. I am using the 1000 watt for the smaller drives. I am waiting on the other power supplies because they are on backorder.

Any idea on what I should do or try? I am open to any suggestions.



Thanks for your help


Steve

[TOTALLYRC]

Originally Posted by scrambled Mike- I am planning on using 1500 watt power supplies for the larger drives. I am using the 1000 watt for the smaller drives. I am waiting on the other power supplies because they are on backorder. Any idea on what I should do or try? I am open to any suggestions. Thanks for your help Steve

From my prior post, get an amp meter and see at what amperage the servos are tripping the overcurent settings at. It could be that you have the curent limiting incorrectly set or the drive has a problem.

If you don't have acces to an amp meter, temporarily increase the current limits to there max and then see if the motor has any more power.

Just be careful and don't forget to set them properly before using the drives for real.

Mike

[scrambled]

New development--

Somehow I have developed enough noise to prevent me from being able to communicate with the VSD-E servo drives.


here is what I know so far-

1. I have all of my neutrals and grounds connected to 1 2 x 6 copper grounding block that is connected to the ground pin on the electrical plug that is powering everything.

2. I have metal DB connector shields for both the encoder and the motor shielded cable. The metal shields are connected to the FG.

3. I can use a multi meter and test the continuity between the two DB metal shells and there is continuity between these two. I am assuming this means that the FG is working correctly. When I check continunity between the DB connector and the grounding block, there is no continunity.

4. None of my power wires are twisted. Does DC need to have twisted wires, or is this just for AC?

5. I have ordered 330 UF capacitors to use on the HV power. This is according to the manual.

6. My power supplies are all outside the enclosure box, and only the connector wires run to the enclosure with the VSD-E servo drives.

7. All of the neg and FG for the powersupplies are connected to the grounding block.




Stuff I am working on:

1. Installing 2 seperate grounding rods. 1 at each end of the table. I will then bond these together, bond to the grounding block, and also to the table. I am not sure if the plasma cutter ground needs to be connected to the point, but it looks like I have plenty of time to figure that one out

2. Install the capacitors once they arrive. Any place else I need to install capacitors, or any thing else?


I will try to get a picture posted of the way the enclosure looks. Hopefully someone will spot something that I am overlooking.




any ideas????




thanks


steve