So I have a Tree 325J. It has been a solid machine but a bearing in the Z axis servo died a very miserable death. Like an idiot I jumped right in before googling stuff and tore the thing apart (very carefully I might add), cleaned it up a bit and replaced the offending bearing. Now it can actually turn with out squeaking. Anyway, I reassembled it and now I do not believe that it is getting proper feed back from the optical encoder, the resolver/tach thing, or both. When I fire up the control and get started on the start up procedure, once I clear the Shut Down E-stop faults, the servo just starts spinning then throws the code Z Axis runaway or something to that effect. Trying to figure out what the deal is here. I am thinking that maybe stuff is just somehow out of adjustment. There seems to be rather little on the interwebs that I have been able to find that has been of any usefulness to this situation. The Servo is an MSI corp MTE 404-500-MA that I do believe is a brushed DC servo. Upon taking it apart I noticed that there are several pieces to the body. Pop off the non-shaft side cap and there is an optical encoder with 500CPR incremental disc. That sits attached to a secondary cap. The screw holes for the mounting screws for this second half are slotted for what I am thinking is some sort of adjustment to align the optical encoder with the tach/resolver thing that is hidden under this second cap. The Tach/Resolver thing has 4 small brushes in a plastic housing. 2 of the brushes have wires going to them. These are 90° apart. then there are wires connecting those 2 brushes to the other 2 brushes ( am assuming to the brush 180° am too tired to check right now, but I think that makes the most sense). These contact something that looks similar to the copper part on this (photo pulled from google):
Attachment 311898
This Tach thing looks like it would be rather hard to screw up unless one of the wires isn't making contact (which one was loose and I took care of that). So the thing that I am left with, is that is the alignment of the optical encoder dependent on an adjustment relative to the tach? Like does it have to be in phase with it some how to make all this work together for the control to do its thing properly? I am assuming that this might be the case due to the slotted screw holes. Anyone have any insight into this? I would really hate to have to buy a new servo as it looks like it might be a bit of a pain. Would rather try to get this thing going again with what I have. Otherwise its time to start looking at either dropping some $$$ on a conversion or selling it off and getting something else. Thoughts?