Sorry if I'm asking too many J&S questions, but I have got a bit of a bee in my bonnet over my predicament.
Finally got the "nut" off today, bit of a mission it was too. Thinking I might have a bash at making a bronze insert and retaining original lead screw, as it doesn't look at all bad. I haven't any way of accurately assessing the thread type, and not sure if it will be ACME or trapezoidal. I know there isn't much difference, but would be nice to try and hit it as accurate as I can when grinding up the cutting tool for the nut.
Only other thing is, I do fear premature wear on the nut due to the slightly worn screw... not sure if I can make this or not, but might give it a go. Seems the combo is around 600 quid +VAT +shipping to NZ then import duty etc etc..... be best part of a grand, which is what I paid for the machine!
One thing I did find is that there is slop not only in the screw/nut mating, but also at the bearing housing (hand wheel end). This is what was causing lock up of the darn small adjustment dial it seems. The whole picture didnt reveal itself until i took off the cover, which has two dowel pins that had it seems been deliberately tapped back into the cover, so that they were not in use. The cover had then been put on a little skewed, so that when the wheel came forward (about 2.5mm slop) it didnt bind up the small adjustment worm gear. It was enough however, to prevent the cam from doing its job and advancing the Y feed each time. I thought that it was a case of "greased-up" (should be oiled), so I washed it all out, but no, it still didnt work correctly.
Now I see, its all stemmed from slop in the bearing housing. I think shim washers will be a good fix for that.
However, now I have it all in pieces, putting it back together without addressing the backlash..... ohhhh I just can't do it, my OCD wont let me.
Finally got the "nut" off today, bit of a mission it was too. Thinking I might have a bash at making a bronze insert and retaining original lead screw, as it doesn't look at all bad. I haven't any way of accurately assessing the thread type, and not sure if it will be ACME or trapezoidal. I know there isn't much difference, but would be nice to try and hit it as accurate as I can when grinding up the cutting tool for the nut.
Only other thing is, I do fear premature wear on the nut due to the slightly worn screw... not sure if I can make this or not, but might give it a go. Seems the combo is around 600 quid +VAT +shipping to NZ then import duty etc etc..... be best part of a grand, which is what I paid for the machine!
One thing I did find is that there is slop not only in the screw/nut mating, but also at the bearing housing (hand wheel end). This is what was causing lock up of the darn small adjustment dial it seems. The whole picture didnt reveal itself until i took off the cover, which has two dowel pins that had it seems been deliberately tapped back into the cover, so that they were not in use. The cover had then been put on a little skewed, so that when the wheel came forward (about 2.5mm slop) it didnt bind up the small adjustment worm gear. It was enough however, to prevent the cam from doing its job and advancing the Y feed each time. I thought that it was a case of "greased-up" (should be oiled), so I washed it all out, but no, it still didnt work correctly.
Now I see, its all stemmed from slop in the bearing housing. I think shim washers will be a good fix for that.
However, now I have it all in pieces, putting it back together without addressing the backlash..... ohhhh I just can't do it, my OCD wont let me.
