Denford Software & Machines

Hi,
Does anybody have any electrical drawings for a 1983 orac.
I am trying to get my spindle working properly.
It is running at a constant speed and I am unable to change manually
or in program.
I have tried both reset buttons.
I can run programs, but spindle speed does not change.
The bleeper works when -ve and +ve buttuns pressed.
The x axis did over travel last week and I managed to bring back
using reset button. The spindle has been like this since.
I have both green lights at front, all red lights at rear and all fuses ok.
I am sure it is something simple, opto switches or something.
Would really appreciate if somebody could point me in the right direction.


Kind Regards
John

I have measured the voltage at pins 17 and 18 on the PC1690 board and it is 5.2V. When the
-ve button is pressed to reduce the speed the voltage drops to approx 1.2V.
So am I right in thinking the 10V Zener is ok. If so, what do I need to check on the VFD.

Regards

John

Hi John

There are some drawings and Faultfinding info in the files section, as it seems more than 1 type/make of controller was used the faultfinding may not be for your model.
Did the spindle "stall" when the tool overan ? if so there is an electronic function that stops the motor, maybe this hasn't re-set for some reason and is causing you problems.

Rgds, Emgee

Hi,
I have tried reset buttons, but to no avail. I have had the PC1690 board checked out and the Ferranti ZN435J 8216 chip is failing, getting hot. I will try and source one of these or hopefully find a spare PC1690 board.

Regards
John