Spindle acceleration and deceleration issues on VQC 250/50B

[sophtayl]

I will get a video of what it does as the problem and what it does with the good card for both low speed and from moderate speed ( 1-2 rpm and 500-1000 rpm)

Sent from my SM-G930F using Tapatalk

 

[noname777]

Bingo, you connected the dots!

I have seen the motors run, albietly lightly loaded, with 3 of the 6 sections not working properly. The service call was regarding breaking pockets on a VQC-15/40 magazine, The spindle was not locked during orient, but I could rock it around easily by hand. I developed this test to do a quick check when the machine seemed to have a brain fart and do something unexpected, before cycling power.

Lathes with a large chuck the accel time increase seems quite noticeable, on a mill not so much.

Bill


If one could post a video of one of these tests on a machine that is working properly, and one that is not, for future reference.

Bill

well I connected them long time ago, I was wondering if using FLUKE scope, with completely isolated inputs, it would be possible to see what is CE saturated voltage when transistors are fully open, as CE sat. voltage is what dictates (or can give some ideas about them) internal losses. But again, if AC motor was working fine with another IO board, I would say, some drivers are bad. Output voltage (drivers) is one thing, but output current is another. There is a way to see voltage, but charge/discharge current can only be quickly evaluated by rising and falling time. And that is exactly what never been done, according to above uploaded pictures.

P.S did you actually replaced all capacitors around drivers on IO board? They should be replaced every 5 years, as they work really hard and ripple current keeps them overheated all the time, that is exactly what shortens their life.

 

[sophtayl]

I have not changed the Capacitors on the IO board at all. I was hoping to get confirmation of the problem before changing them, but this is eluding me. Using Sudsys board has confirmed which board is the problem.

Nothing to lose now in changing them... I will post the videos tomorrow to see if it helps confirm the theory of the problem.


Kind regards


Mick

 

[noname777]

I have not changed the Capacitors on the IO board at all. I was hoping to get confirmation of the problem before changing them, but this is eluding me. Using Sudsys board has confirmed which board is the problem.

Nothing to lose now in changing them... I will post the videos tomorrow to see if it helps confirm the theory of the problem.


Kind regards


Mick

I told you before, 70 AUD from Jaycar to replace all capacitors on IO and CPU and POWER SUPPLY, except 2 big 350 VDC for main rectifier.

 

[sophtayl]

I replaced the ones in the Power supply, including the big ones, which I ordered through RS components.

I have also replaced the power supply, as I still had issues after replacing the caps in the power supply and it was not powering the drive. The tech that came pointed to the faulty power supply and advised it was the cause.

I will get some for the IO board and replace them also. I am mindful of touching too much till the specific issue is resolved ( heaven forbid I create a bigger problem).

Stay tuned...

 

[noname777]

I replaced the ones in the Power supply, including the big ones, which I ordered through RS components.

I have also replaced the power supply, as I still had issues after replacing the caps in the power supply and it was not powering the drive. The tech that came pointed to the faulty power supply and advised it was the cause.

I will get some for the IO board and replace them also. I am mindful of touching too much till the specific issue is resolved ( heaven forbid I create a bigger problem).

Stay tuned...

speaking of capacitors that are around those driver modules. Here is taken from QM150DY-H transistor module datasheet:

collector current -150A
Vce saturated =2Volts
Switching time = (on and of) , around 2.5uSec ( measured VCC=300V, IC=150A, IB1=–IB2=3A)

this Ib , (BASE current) is what should go into transistor base input, and it comes exactly from these capacitors. Better capacitors, faster it will open transistor, less looses. In reality this 100 years old transistor can draw much higher Ibase current.

 

[sophtayl]

Here is a video of the various states with Sudsys then my board.

The tests show
- speed set to 1 rpm (Sudsy's board spins much faster - I did not adjust any voltages for calibration)
- start and stop to 500rpm/ 1000rpm (you will see the key problem here)
- orient ( you will notice a bit of hunting in my board
- LEDs 18/19 and 20 when slow down and spindle stop are pressed.

Hopefully this helps

cheers

Mick

 

[sophtayl]

Hopefully this is the penultimate update on this topic.

With the direction and assistance of a guy well versed and experienced in these controls, we checked over the SEIO1 board again, and found everything as it should be, but the board still had issues. We could not identify the cause of the problem (as all the checks tested fine), but it was definitely something related to the board.


Without a schematic to follow to chase the board problem, we managed to get hold of an old SEIO1 board that had been sacrificed to the Gods of Spare Parts, and had also been through several repairs itself. A few drivers and transistors were missing, but the essence of the board was hoped to be intact.

My learned friend then set about replacing the missing drivers/ transistors from the original board and change out the remaining problem items (replaced 11/12 drivers, )and reworked some of the repairs to the board.


We reinstalled it this afternoon and all appears to be functioning as it should.


I have now picked up enough caps to replace all the remaining caps (cylindrical can type only) on the replacement SEIO1 and original CPU2 boards to minimise the risk of a future problem.


As we were testing the machine, we were conducting a facing cut on some material and I was relating the incident (crash) that caused the failure. It was a relatively minor incident that had the stock pull out of the 3 jaw on the table and break a tool. A key insight that my colleague pointed out was that it was more than likely the failure in the board that occurred that caused the crash, i.e. the spindle speed dropping and the xyz continuing, biting and pulling the stock out and breaking the tool.


So the plan is to replace the Capacitors tomorrow and box it all back up again.



Needless to say, this has made my Christmas and allows me to get cracking with the backlog.


Hip hip hooray

 

[sophtayl]

I changed the Caps today and ran through the tests again. All things look as they should and the machine is operating well.
will finish cleaning up and setting up vices tomorrow and get started on catching up with the backlog.

Thanks to everyone who has contributed to getting the machine up and running over the past few months. It is very much appreciated and the machine would not be up and running without it.


Merry Christmas everyone

 

[cnctoolcat]

Great job on getting the FR-SE spindle drive going. The pesky SE-IO1 card is often the culprit.

Now, to get maximum life out of your drive, slow down the accel/decel!! On the FR-SE, this is done by setting the little dip switches --- the mitsubishi manual should show the combination of settings and the resulting accel/decel rates.

ToolCat Greg

 

[sophtayl]

Great job on getting the FR-SE spindle drive going. The pesky SE-IO1 card is often the culprit.

Now, to get maximum life out of your drive, slow down the accel/decel!! On the FR-SE, this is done by setting the little dip switches --- the mitsubishi manual should show the combination of settings and the resulting accel/decel rates.

ToolCat Greg

Thanks Greg. I know the ones you mean. I'll look to see what is set at.

Cheers

Mick

 

[hitandmiss]

Another thing to check on the bad SE-IO1 card is the spring pressure on the contacts that fit over the square pins on the P.S.
And the solder holding the contacts for fine cracks.

Bill

 

[sophtayl]

Another thing to check on the bad SE-IO1 card is the spring pressure on the contacts that fit over the square pins on the P.S.
And the solder holding the contacts for fine cracks.

Bill

I had a couple that were suspect so I added a small piece of toothpick to it to test if it made a difference. The card passed all the tests as per the procedures, but still had the problem. We reused 11 out of 12 of the drivers (DK434) from the troublesome board into the replacement board. We did find some legs corroded so my thinking is that it tested ok with no load, but would breakdown when asked to carry a load..


I will look at the connections again tomorrow.

cheers


Mick