Member postings for old mart

Tell me about it, several times, something completely wrong has come in the post from ebay, and when I checked the listing, it was my misreading of the advert in the first place.

I beg to differ, that's rubbish, hogwash, I feel better now, I shall go and make a cup of tea. Tea, that's awful, you should drink coffee.

Funny you should mention the other type of top jaws, Dave, these serrated with 1/16" X 90 degree pointed jaws for a 6 1/2" Pratt chuck came through the post this morning. I was lucky and put in the only bid on ebay, and got them for £8.75 including postage. I looked up the Thame code, AJ06 before bidding.

There's more than one way to skin a cat, goes the old saying. Some people stick rigidly to a generally accepted theory and it's obvious that they have not actually tried any alternative, rather like a religious dogma.

I suppose that some people would rather throw an antique in the bin than repair one bit, after all, the repair would not be original.

Casting new weights using the old ones for the lead would be the best of all solutions if you have the means to do it. If using plaster of paris for this size of mould, the plaster should be in a wooden or metal box to avoid the danger of the mould splitting open as the lead is poured. The new hanger bolt is held in position and the lead poured around it. It is important for the mould to be dried thoroughly in a warm place for a week or so before casting, as any dampness will cause steam explosions and lead will be ejected like a small volcano with unpleasant results. It is likely that the mould will only last for one casting.

Edited By old mart on 26/01/2020 14:43:40

Try a little paint stripper on a small part. When it has had time to work, try scraping with a bit of aluminium plate, the paint should come off easily. It needs to be removed from the front and back of the tee slot, and also from the underside of the slots to give metal to metal contact for the tee nuts.

Avoid trying to get every trace of paint off, it may compromise the important milled dimensions.

Edited By old mart on 26/01/2020 14:29:26

Steamdave has the best solution, check out his post.

It would have been normal practice to cast the steel part into the lead during manufacture. I always did that when casting my own fishing weights in plaster of paris.

I believe they are called slot & tenon and if you have a mill, it would be easy to make tops in mild steel or aluminium to bolt on to the master base jaws. Because of the bolt together design, they project further from the face of the chuck than one piece jaws.

26 tpi is a very common pitch, used for many BSC (British Standard Cycle) threads of varying diameters. 1/4 BSF is also 26tpi.

Motalia have printable charts which you can download to check. There is also the possibility that it is a Villiers carburettor proprietary size.

**LINK**

Edited By old mart on 25/01/2020 21:58:20

Looking at the photograph, I have my doubts about the thread being 1/4 20 UNC, it looks too fine to me. I would remove some of the other screws and measure them to get an idea of what threads B & S were using. It is common practice to use coarse threads in cast iron, but not universal, Smart & Brown lathes use BSF rather than BSW in their castings.

I think it might be 1/4 28 UNF.

If the weight is a plain cylinder without one end rounded off, you might fit the new eyebolt to the other end and cut the nail off flush.

I bought a combi microwave oven from them last year and opted for the extended warrantee, and it was printed out there and then.

Lathes have a high centre of gravity, so the makers put the bolt holes in them so you cannot claim it was their fault if it fell over.

You need to get an idea of the thread pitch. I would stick something like a match stick down the hole, and then the right diameter small screwdriver down the hole alongside it to squeeze it against the thread. Remove the screwdriver and then the match stick, and with luck, there will be an impression of the thread for you to measure the pitch.

I have just googled "locking mechanism for telescopic tube" and got some hits, try it.

Finished at last. The new end and its screws and shim have been put away safely, it probably will only be needed once in a blue moon. The other matching vise will only have the end cut off, there is practically zero need, or room for both to be set up lengthwise together. I am pleased to be able to use that extra inch of Y travel.

I never thought about which way up the drawing was when I posted it.

There are a lot of different grades available from Loctite, I suggest checking the website for the exact strengths and recommended applications. Asking for blue Loctite is not adequate.