Just an FYI. Steve's scope is vintage '07. I don't know if it has the redundancy spring I added to the design of the PGB system. Nor has it ever been 'cleaned' (over time it's good to take the ground board off and clean the pivot post, the inside of the bushing as well as the contacts and the contact plate). So my suspicion is indeed that there is an issue with resistance buildup over time. In diagnosing the problem Steve told me he was not using a battery (first thing to check if so as batteries DO lose their ability to store energy, even if they show a "full charge") ... but he was using a 12V PS. I mentioned that I always sold a 15V supply (either 4.5A or 6A). The reason for this is to increase the overall efficiency of the system and to give some headroom. By efficiency it needs to be noted that the ServoCAT uses SMPS's ... these will convert the incoming voltage to the 30V the motors run at (standard system). Also, there is a SMPS on the main logic supply. In all three cases if you increase the voltage you decrease the current needed (power stays the same). This then translates to less IIR losses in the wires and PGB system making it even more efficient. I had Steve try the system using the JOG speed (slightly less power required) - this worked with both axes in use. With that he decided to get a 15V supply to see if that allows him to go forward. I have not as yet (just remembered this) sent him the list of things to check re maintenance on the PGB. It is suggested that that be done as well in either case. (and in doing so we can determine if he does have the '+' circuit redundancy spring installed and installed properly).?
Gary Myers
StellarCAT?
