|Myford ML7 - Cross Slide Bearing upgrade|
↓ Before I dismantled the cross slide bracket assembly, I made a spigot. The spigot will be used later on, to align the cross slide bracket on the face plate.
↓ I made a block to fit on the faceplate.
↓ I fixed the block to the faceplate, using two M8 bolts, and nuts and washers. I left things loose for now.
↓ The cross slide bracket was tightly secured to the block with two M5x0.8 hex head screws.
↓ The cross slide bracket has to be centred on the face plate.
↓ I brought the tailstock up to the faceplate and inserted the spigot into the cross slide bracket.
↓ The spigot is a good snug fit in the 0.25inch diameter bearing hole in the cross slide bracket.
↓ After centering the bracket and rotating the faceplate, I noticed that the bore was not central in the boss. I could see a definite wobble. The bore was rotating on centre nicely, but the outside of the boss was not, which was a bit of a worry at first.
↓ These are the bearings I bought from Arc Euro Trade.
↓ The single bearing at the bottom is a small roller bearing.
↓ The 0.25inch bore in the cross slide bracket has to be opened out to 0.375inch or 3/8inch or 9.525mm, to accomodate the new feedscrew roller bearing.
↓ I drilled the bore out to 9mm, and then used the 3/8inch reamer. Sorry, I have lost the pictures of that operation.
↓ Houston we have a problem.
↓ I fitted four loose fitting spacers, and a bsf nut.
↓ This picture is of an earlier attempt, with only two spacers, and not the four I ended up using (but you get the idea).
↓ Now the cross slide was functioning again.
↓ I took a small cut, and then offered the dial and outer thrust bearing and washers assembly up to the boss, to test the fit. I repeated this procedure again and again, creeping up on the final dimension. It's the only way.
↓ If you compare this picture with one of the above pictures, you can see how much I took off the boss.
↓ I turned the boss down, a little at a time, until eventually the dial and outer thrust bearing assembly were a good fit against the cross slide bracket.
↓ Some views of the fit of the dial against the cross slide bracket.
↓ That was the end of the face plate work.
↓ The small bearing was put in place.
↓ The bracket was put on the feedscrew and the small bearing went into the bore in the boss.
↓ The outer thrust bearing assembly was put in place.
↓ The dial was screwed onto the feedscrew.
↓ With the cross slide bracket disconnected, I tightened up the dial.
↓ The handle and dial were then tightened together, by gripping the handle by hand, and applying a spanner on the flats of the dial (much like a double nut affair).
↓ The cross slide was back up and running again, and the action was smooth.
↓ After testing the operation, I took it all apart, applied lots of molybdenum grease, and reassembled.