Anyone got any ideas, my Orac drops out of the program at the start of a threading cycle.
I have checked the spindle speed and position sensors, they seemed ok but have replaced them anyway, they both switch ok and the signal is getting to the control board.
Help please
Chris
Orac Threading
Moderators: Martin, Steve, Mr Magoo
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Steam-Chris
- Posts: 22
- Joined: Mon 03 Nov , 2008 10:07 am
- Location: Copthorne Sussex
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Steam-Chris
- Posts: 22
- Joined: Mon 03 Nov , 2008 10:07 am
- Location: Copthorne Sussex
Orac Screw cutting
Hi Martin.
The machine gets to the screw cutting page and then sets the spindle speed, moves the x axis to the start position and then the program ceases and gives you the manual X,Y axis position screen, the only way to recover is to press the program stop or reset and then reload the program.
What do you mean "Do both of the LED`s on the control card work correctly", which control card ?
Thanks, Chris
The machine gets to the screw cutting page and then sets the spindle speed, moves the x axis to the start position and then the program ceases and gives you the manual X,Y axis position screen, the only way to recover is to press the program stop or reset and then reload the program.
What do you mean "Do both of the LED`s on the control card work correctly", which control card ?
Thanks, Chris
If you open the back door to the electrics the card the bottom card on the left hand side has 2 red led`s that stand just behind the terminal block towards the centre. If you power the machine up & manually turn the spindle they should turn on/off. If you rotate the spindle to where it picks up it`s once per revolution pulse you should be able to test both lines.
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Steam-Chris
- Posts: 22
- Joined: Mon 03 Nov , 2008 10:07 am
- Location: Copthorne Sussex
Martin
Been a while, xmas hols and all that, not had time on my own in the shed but back on it now, my Orac is 1982, early version with no LED's on the PC board, have checked the signals at the terminals into and out of the board and they are Ok, next step is to trace them throuch the ribbon cable to the processor board.
does any one know what speed you can screw cut at or do i have to work it out from pitch.
Chris
Been a while, xmas hols and all that, not had time on my own in the shed but back on it now, my Orac is 1982, early version with no LED's on the PC board, have checked the signals at the terminals into and out of the board and they are Ok, next step is to trace them throuch the ribbon cable to the processor board.
does any one know what speed you can screw cut at or do i have to work it out from pitch.
Chris
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Steam-Chris
- Posts: 22
- Joined: Mon 03 Nov , 2008 10:07 am
- Location: Copthorne Sussex
Orac Threading
If anyboby is interested i have solved the problem with the screw cutting cycle dropping out.
i checked the speed and position sensors on the rear of the spindle, these were ok along with the signals getting through to the control boards, they where switching ok, 0v off 12v on then down to the 0v off 5v on when through the PC1602 board so i was stumped, until i had the idea to put a scope on the signal lines, this showed even though the signals were switching ok the mark space ratio of the speed sensor was drifting all over the place, this was rectified by adjusting the position of the sensor, i had set the sensors as specified in the manual at 3mm from the reflective disc and parralell, slightly turning the sensor gave and equal mark space ratio, that solved the speed side of things but the program still dropped out so i then checked the position sensor, the output looked fine, one on/off per rev, and the trace looked ok, looking further i could see the trace rise at switch on was thicker than the rest of the trace, so i altered the time base to strech the trace out and found the reason, the sensor was switching twice, a very short on and off then on for 1/2 rev off for 1/2 rev, adjusting the sensos cleared this and hey presto the screw cutting now works. i checked all was ok by cutting a 6mm thread and then rnning the same program another 7 times on the same thread, this proved all is ok as after cutting the thread each time the program was run, the tool did not remove any more material.
One other observation is that the programmed speed and spindle speed were not the same, i must check with tacho as i found the screw cutting pitch to speed graph and found my programmed spindle speed has to be cut by about 60% compared with that stated on the graph.
hope this info helps others with screw cutting on an ORAC.
What a wonderful machine, best £350 i have spent on my hobby.
i checked the speed and position sensors on the rear of the spindle, these were ok along with the signals getting through to the control boards, they where switching ok, 0v off 12v on then down to the 0v off 5v on when through the PC1602 board so i was stumped, until i had the idea to put a scope on the signal lines, this showed even though the signals were switching ok the mark space ratio of the speed sensor was drifting all over the place, this was rectified by adjusting the position of the sensor, i had set the sensors as specified in the manual at 3mm from the reflective disc and parralell, slightly turning the sensor gave and equal mark space ratio, that solved the speed side of things but the program still dropped out so i then checked the position sensor, the output looked fine, one on/off per rev, and the trace looked ok, looking further i could see the trace rise at switch on was thicker than the rest of the trace, so i altered the time base to strech the trace out and found the reason, the sensor was switching twice, a very short on and off then on for 1/2 rev off for 1/2 rev, adjusting the sensos cleared this and hey presto the screw cutting now works. i checked all was ok by cutting a 6mm thread and then rnning the same program another 7 times on the same thread, this proved all is ok as after cutting the thread each time the program was run, the tool did not remove any more material.
One other observation is that the programmed speed and spindle speed were not the same, i must check with tacho as i found the screw cutting pitch to speed graph and found my programmed spindle speed has to be cut by about 60% compared with that stated on the graph.
hope this info helps others with screw cutting on an ORAC.
What a wonderful machine, best £350 i have spent on my hobby.