I recently had a nasty 'jam' on my Colchester Master 2500 resulting in loss of automatic feeds - now cured and covered in another thread on the forum, however left behind from this incident was an undesirable artefact ! Trying to engage cross feed ( ie X Axis) was stiff and crunchy and when engaged the gears felt pretty horrid with excess stiffness.
Now what happens is you pull a knob that slides a gear from mesh with the Long Feed (Z axis) pinion into mesh with the cross feed pinion this is fixed to the cross feed screw. Their meshing is entirely set by the machining of the Apron Casting (that holds the sliding gear) and the Saddle Casting (that holds the Cross feed screw with the cross feed pinion. They CANNOT move closer together but that is what seems to have happened.
The Cross Feed Screw and handle are mounted in a trunion fixed to the saddle by two cap headed screws, and by slackening them and moving the trunion upwards to the limit of play in the screw holes mesh was now perfect and the gear change shaft slid smoothly. There is not supposed to be an adjustment here - it's just tolerance in the machining, and only a few thou anyway.
OK now we can smoothly engage cross feed, but the slight upward displacement of the trunion has created a small step that the cross slide fouls on limiting its forwards travel by the length of the trunion.
So this mornings job was to dismantle it all and mill a few thou off the trunion. Goodness only knows why this should be necessary but it was, I've done it and now all seems well !
Now what happens is you pull a knob that slides a gear from mesh with the Long Feed (Z axis) pinion into mesh with the cross feed pinion this is fixed to the cross feed screw. Their meshing is entirely set by the machining of the Apron Casting (that holds the sliding gear) and the Saddle Casting (that holds the Cross feed screw with the cross feed pinion. They CANNOT move closer together but that is what seems to have happened.
The Cross Feed Screw and handle are mounted in a trunion fixed to the saddle by two cap headed screws, and by slackening them and moving the trunion upwards to the limit of play in the screw holes mesh was now perfect and the gear change shaft slid smoothly. There is not supposed to be an adjustment here - it's just tolerance in the machining, and only a few thou anyway.
OK now we can smoothly engage cross feed, but the slight upward displacement of the trunion has created a small step that the cross slide fouls on limiting its forwards travel by the length of the trunion.
So this mornings job was to dismantle it all and mill a few thou off the trunion. Goodness only knows why this should be necessary but it was, I've done it and now all seems well !