I would think that defining the problem as specifically as possible would help determine if we need a closer look at the primary drive or the gear box and what part of the gear box.
Yes, testing each of the A,B,C and X, Y, Z settings in the gear box for inch threads would be a helpful at this point.
The numbered settings 1,4 and 5 seem to work so for now we can expect that the problem is not at that level.
Regardless, there is also a lot to be said for opening up the gear box just to see if all is clean and tight. I opened up the spindle drive gear box just out of curiosity and was glad I did. There was a screw holding a key in place that had worked loose. It was just a thread or two from falling out. The idea of a screw falling into spinning gears does not please me. A catastrophe was avoided but it was also good to learn how sloppy the gear shifting mechanism is and to see how gear alignment was more or less complete depending on how I worked the lever.
Yes, testing each of the A,B,C and X, Y, Z settings in the gear box for inch threads would be a helpful at this point.
The numbered settings 1,4 and 5 seem to work so for now we can expect that the problem is not at that level.
Regardless, there is also a lot to be said for opening up the gear box just to see if all is clean and tight. I opened up the spindle drive gear box just out of curiosity and was glad I did. There was a screw holding a key in place that had worked loose. It was just a thread or two from falling out. The idea of a screw falling into spinning gears does not please me. A catastrophe was avoided but it was also good to learn how sloppy the gear shifting mechanism is and to see how gear alignment was more or less complete depending on how I worked the lever.