22-03-2022, 11:37 AM
(This post was last modified: 22-03-2022, 11:47 AM by Dennis Nicholas.)
BM 42 is fixed on to the bottom of the worm. You can see it is castellated on its inner diameter and it fits onto bottom which has similar castellations on outer diameter. It is held in place tight (Peened over?). Due to wear in the thrust washer part the steel castellations become exposed on the end face and become effective end cutters!!!! They cut into the internal end of the box (can't remember if there is a second thrust in the end face of the box).
Much has been discussed on this set including fixes and roller or ball thrust bearings to take place of original plain thrust washers. A search should reveal all the info. Or perhaps someone who has done it would advise what they have done.
BM134- felt support washer is a washer with outer diameter that makes it a push interference fit inside the outer column. It's internal diameter allows the inner column (with the worm on the end) to fit through easily so you will find it is quite thin from inner diameter to outer diameter, but big enough for the top felt bush to be supported on. As you say it fits down in the top smoother part of column down to where there is a very small shoulder....where you say it gets rougher.
You may find a previous owner has been over enthusiastic with a long rod poking up from bottom of column to clean out has dislodged and lost this part. Also if there has been much wear and felt bush gone dried out and thin then I/D of B134 could be very worn......I had one very bad worn and one missing. Nobody seems to sell a new replacement so I made a couple from a tube of scrap I had. (As it was not too precision dimensions wise I managed it as a novice lathe turner on my rather worn lathe...ruined parting tool as tube seemed very grainy and kept catching). One of the 7 workshops may be able to knock a reasonable one out for you from a totally scrap column?
The top felt bush is a flat diamond shape so that when rolled into a tube as shown the vertical edges that come together run spirally down round the column.
If found too long so poking out top it can be easily trimmed off in situ.
I suggest those getting oil drips on their trousers may want to fit a new felt?
Much has been discussed on this set including fixes and roller or ball thrust bearings to take place of original plain thrust washers. A search should reveal all the info. Or perhaps someone who has done it would advise what they have done.
BM134- felt support washer is a washer with outer diameter that makes it a push interference fit inside the outer column. It's internal diameter allows the inner column (with the worm on the end) to fit through easily so you will find it is quite thin from inner diameter to outer diameter, but big enough for the top felt bush to be supported on. As you say it fits down in the top smoother part of column down to where there is a very small shoulder....where you say it gets rougher.
You may find a previous owner has been over enthusiastic with a long rod poking up from bottom of column to clean out has dislodged and lost this part. Also if there has been much wear and felt bush gone dried out and thin then I/D of B134 could be very worn......I had one very bad worn and one missing. Nobody seems to sell a new replacement so I made a couple from a tube of scrap I had. (As it was not too precision dimensions wise I managed it as a novice lathe turner on my rather worn lathe...ruined parting tool as tube seemed very grainy and kept catching). One of the 7 workshops may be able to knock a reasonable one out for you from a totally scrap column?
The top felt bush is a flat diamond shape so that when rolled into a tube as shown the vertical edges that come together run spirally down round the column.
If found too long so poking out top it can be easily trimmed off in situ.
I suggest those getting oil drips on their trousers may want to fit a new felt?