Our streak of problems with the Singer RoToR continued today. While Ayelet was copying a library, it tried to copy a plate with a pin-pad. This meant that the head squashed into the plate, got dirty with cells, and contaminated everything there.
Unlike last time, we managed to disengage the head for cleaning without damaging any wires. Cleaned it and let it dry. Upon trying to using the RoToR again, it kept pretending to have lifted the pads while actually working without ones.
Since I was to start three hours of meetings with undergradutes, I managed to email Ian at Singer Instruments about the problem and told him I will try to catch him later.
After my meeting, I contacted Ian through the Singer remote help interface and in parallel through Skype. We tried to figure out why the head does not pick up pads and yet believes that the pad is there.
Turns out that the vacuum tube that "sucks" the pad to head runs through a pressure sensor that can monitor whether air is moving through the tube or not --- if it stops moving than its a sign that the pad is held by the pressure. You can see the sensor as the little white box with the red light in the middle of the picture.
Ian asked me to tune the sensor sensitivity. This meant turning the small orange dial above the red light. The light indicates whether there is pressure or not, and I had to turn the dial just to the point where the light turns off.
The dial was very sensitive and often it sufficed that I touched it with the (mini-)screwdriver to change its decision. Each time we tested whether the head lifts the pad, and then whether it recognize when it had a pad to lift and when not. It was very frustrating as it either recognized that a pad is there regardless, or it didn't. We didn't manage to get it to setting (that is me tweaking and Ian directing the operations remotely) where it made the right calls.
In the middle of all this, a pirate stormed into the lab
and attacked the fridge
(and who said laboratory work was dull :-) This was Matan, my ex-student and dive-buddy, who came in to collect something. Apparently, he was on his way back from costume party.
In the end, Ian decided we should try the version of the software with the older user-interface. Since this is the version we are using day to day, it was fine with me. Surprisingly, in this version the tuning worked the first time. We performed several trial runs and the machine worked flawlessly. I am not sure if this is the end of the problems, but lets be optimistic.