Orac not responding on manual mode

[seaman77]

Hi everybody!

Just before yesterday I bench tested my Orac and it was running fine.
So I moved to the next step which was to put everything back in place and start cutting.

But the machine did not like this idea and what I am getting now is...Drives glowing nice green led each and the distinctive oscillator sound that says we are ready to run your motors. Then I select manual mode and pressing arrow keys to move the selected axis, the screen shows actual coordinate position changing but none of the motors is willing to spin.
One of them I tried turning by hand but could not. This one generates strange and varying oscillator sounds even tough is immobilized. And the second can be turned by hand almost effortlessly.

I am sure many of you guys here can view things to which it looks I am totally blind. As considering all current machine symptoms I can not even come close to what may have caused this problem.

Any advise and help is highly appreciated.

regards

[Martin]

Has it tripped on a overtravel?

Press & hold the larger button which is below the control panel mounted on the tin work towards the middle. If it is then jog it to the middle & release the switch.

[seaman77]

Has it tripped on a overtravel?

Press & hold the larger button which is below the control panel mounted on the tin work towards the middle. If it is then jog it to the middle & release the switch.

Hi Martin and thanks for the Response.
There are 2 switches underneath mounted on the bottom sheet metal frame. The one at far right is a reset I think. But I should press the one in the middle. I got it.
Well, I am pressing it now. Situation is the same.
I am reading the Parker manual and it says ...\for Fast rotation requires pin 20 of 32 Pin input socket of SD2 drive to be connected to 0volts.
So I am now measuring the keyboard lines which leave the arrow button for manual jog, as the drive connecting socket not accessible, and is reading 4.8vdc.
When pressing the arrow button the test point voltage comes down to 0.650V
And when I keep this button pressed the screen shows the axis coordinates changing.
I must be totally blind I can't see what is going on. I must be real close solving this. Please note that I used a jumper wire to bridge the limit switch computer input to save some time testing limit switches. IF I do not do this the motors de-energize. Should i have done this or not?

[Denford Admin]

Have you rewired the motors since bench testing it ?
It sounds like one motor is not being energised at all (if you can move the shaft by hand)
The other may be wired up incorrectly somehow. It sounds to be energised but won't turn when jogged.
Linking out the limit switches until you get it working is fine, just be careful not to run the axes too far.
It might be worth taking the motors off the screws to see what's going on and if they are turning at all.

[seaman77]

Hi and thanks for the help.
I need to tell you that all the operating electronics and hardware are not tightened/screwed on the lathe. It is all on the bench where I will instantly notice when the change comes. I believe might be a wire left unconnected. For example I have omitted signal wires coming from the perforated speedometer disc, those coming from turret indexing sensor, as well as those directed to power chuck electropneumatic solenoid, those directed to Parajust VFD pot and stop/restart inputs.
When the machine's X-axis was losing direction 2 weeks ago, searching for faulty wire connections I found that the X-stepper was not wired correctly. When I restored this, both axes worked perfectly responding to sudden commands and this was just hours away. It is 5 days now. Both motors today retain good holding torque.
Last night I replaced the 30 year old stepper with the one seen in the attached image...With the StepSyn steppers this Orac worked non stop for 5 years 4 to 6 hours a day...

AAS.jpg (152.74 KiB) Viewed 6757 times

AA.jpg (144.99 KiB) Viewed 6757 times

[Denford Admin]

It could be an earthing issue if everything is wired up on the bench ?
Make sure earth studs and 0v/earth connections are made on the drives, supplies and control from a central earth point.

[seaman77]

I will do that. As I remember, there is one single earth stud mounted on the transformer frame where all ring ended earth wires are attached/tightened.

Thanks

[triac]

The effect you mention where the digital read-out is changing when you press the keys but no stepper movement takes place
is the same as the Stop button being depressed, that's the only way I have found to reset the read-out to X&Z zero without
any movement of the steppers.
If you find a simpler way to zero the digital readout please let me know, the question has been posted for several months
without reply.

Rgds, Emgee

[seaman77]

Hi and thanks for the reply.
You mean it may be a wire connected at the wrong place causing a similar situation as if the stop button was permanently depressed?
And you mean the emergency stop with the key right?