Re: Help with Amada 103 hidraulic brake press. Servo drivers - DC motor with encoder - Feedback LOOP - hctl-1100 - mc1408 - rc4136
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Dankahn88 : Thanks for your answer !
?I forgot to mention that swapping boards was our first idea but the ( only one available in our country ) technician who tried to repair it said that the Y-axe motor ( 75v 110w 3000rpm ) is smaller than the X1 and X2 axes motors ( 80v 200w 3000rpm ) so the board can burn the motor ... I thought that it was the motor what determine the current but he is the expert... So we didn't attemp swapping them. I didn't find any information of the driver or the axes boards. Apparently this DC servo motors and servo drivers are obsolete. He offered installing a new CNC, motors, drivers, system, etc ...
So we dive into the boards with pencil, paper, multimeter, oscilloscope and patience... We found the described behaiviour and associated with the offset measured, but we are not sure...
And suddenly, it started working fine... So I'm making a circuit with an OpAmp as buffer and 2x 3v3 batteries to move the offset hoping to confirm the diagnostic
Why not start by swapping boards to see which portion of the drive signal is causing the offset. Hopefully the this drive is distributed on multiple boards.
Dan
On Monday, October 28, 2024 at 09:35:32 PM EDT, Diego J. Richmond < diegojrichmond@...> wrote:
[Edited Message Follows] Good night everyone ! ? I have a problem with the Y-axe DC motor on an hidraulic press. Sometimes it tend to slowly move clockwise when its suposed to stay still. I have measured 0.4 v on the motor conector while the others motor ( x1, x2 ) connectors have 0.1v . When it works properly the input driver signal varies from 0 to +10v or -10v It seems to me that the servo motor driver input has noise or a little offset coming from the axes board. This offset its enough to be amplified and slowly move the dc-motor. The encoder signals seems ok. They go to the driver and then to the hctl-1100 wich Is connected to the DAC wich output goes to the OpAmp. Is there a safe way to injetc a DC offset to compensate the signal ? Just trying to detect where the problem begins. I dont have spare driver modules, axes board, motor, encoder, etc... to change. The faillure is err¨¢tic. I'm also thinking in make it happen when its not failling. ? I'm thinking of using 2 x 3v batteries in series where the middle point Is grounded. Then a potentiometer between +3v and -3v AND the cursor to the signal. But my fear Is if the OpAmp could take the battery current without burning.? Also, do I need to perfectly balance the potentiometer before conecting it to the OpAmp output to avoid the driver speed up the motor AND crash it to the l¨ªmit switch ? ? Perhaps I should use another OpAmp to add the signals
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