Member postings for old mart

I bought some Lumiweld back in the late sixties, followed the instructions and it worked very well. I believe it is zinc based.

There's a Tesa digital caliper brand new on ebay at the moment, with a starting price of £100. I keep telling myself not to be tempted by it, I have plenty of the things. Tesa is Swiss made and as it is not as well known as Mitutoyo, very much less likely to be a far eastern copy in disguise.

Thanks Dominic, there was a nice cad drawing that showed exactly how it worked.

You will be able to worry it out as it already has some movement. It takes time and patience, the axial tapping and attempts at turning it will work.

Am I wrong in thinking that the weedy little screw is under compression when the bottle jack is clamping the jaws?

I have two pairs of Mitutoyo VERNIER CALIPERS, both parallex free, two Mitutoyo DIGITAL CALIPERS, 6" and 12" and two pairs of Lidl DIGITAL CALIPERS. The cheapies get used most of the time, but for tighter tolerances, I always use the Mitutoyo's. They are even good enough to measure bores to 0.001". Digital is much less likely to be missread and can be used to calculate things. For instance, set a digital to zero, open the jaws to the required size, re zero and measure the workpiece. You now know how much more metal there is to remove.

Dial calipers are nice to use, but must be kept clean, I had a 150mm Tesa, but it was so worn in the jaws that it was replaced by my first Mitutoyo digital, which has 0.0001" wear in the thin part of the jaws after 30 years.

I think it would be a good starter machine rather than jumping straight to an ML8 or the like.

I would take the vise to bits, clean, lubricate and adjust any gibs first. After making your new jaws, mild steel is fine for home use, line up the vise before fitting them. The fixed jaw is ready to be skimmed on the face and top. Then leaving the smallest gap between the jaws to allow the milling cutter in, skim the face of the moving jaw. Then do up the vise so the jaws are clamped together and mill the tops so they match.

This method will work with the type of vise that has the moving jaw running in ways that reduce missalignment.

Weedy little screw, that would fold up without much force. I would have used at least a 3" ACME.

Edited By old mart on 30/11/2020 20:42:02

Sealey sell parts washers and they are good for spare parts for their products.

We have a floor standing 50L SM19 parts washer at the museum. It has had parafin based solvent in it for years and the pump works fine. They also list a benchtop washer. Just google SEALEY, find the closest product and using the part number, you can get their spare parts.

Edited By old mart on 30/11/2020 20:34:52

If you look at my picture of the attachment on a S&B Model A, you will see that any taper turning close to the chuck, or in a collet would not be within reach of the toolpost. That is why some latitude in positioning is necessary.

A point to factor in when thinking of designing a taper turning attachment, is the need to move the whole attachment axially along the lathe. This is easy with a lathe such as the Smart & Brown model A and the 1024 models. They have a tee slot running the whole length of the rear of the bed which the taper turning attachment can be set at the optimum distance from the end of the spindle. Not being able to move would severly limit the versatility of the attachment.

Check out my recent post on Colin Martin 2's thread "mini lathe upgrade", it is easy to modify the four jaw independent type of chuck. The mini lathes have holes for three jaw and four jaw chucks in the spindle flange, one hole being shared. It would not be hard to drill some extra holes in your spindle.

Edited By old mart on 29/11/2020 21:37:20

My "camera" icon on the website is not working in my previous post as it is overlaid by the word "railways. This is why I have had to add a new post for the picture.

You could make the slide without the dovetails and just have square sides, I would think a milling parallel could be made to work if it was near enough the right size. Smart & Brown use a square sided slide rail with square sides, the sliding part can have square gibs to match. This poor photo shows the basic workings of the S&B model A taper turning attachment, possibly making an R8 arbor. Notice that the rail pivots at its centre.

Edited By old mart on 29/11/2020 21:16:21

I bought a couple of new chucks for my Warco 7 X 12 mini lathe, an 80mm three jaw scroll which was a direct replacement, and a 100mm four jaw indipendent, which was rear mount and required modification to fit directly on the spindle. They are Sanou, Chinese and better made than the original pair. It was not difficult to turn a suitable register and drill front mount holes in the 100mm body.

I would start with the edge of the vise jaw and move to the centre line, easier said than done unless you know the exact ammount of backlash in that axis. Then I would know that the probe was exactly tangential to the second axis. I use a Vertex electronic probe with a 10mm ball at the end. The second axis would be achieved by the same method, knowing the backlash in the other axis. Of course, the backlash will vary slightly as there will be uneven wear in the leadscrews. With a DRO, life would be so much simpler and accurate. I also have one of the co-axial centre finders, it would probably be more accurate and save time.

Edited By old mart on 29/11/2020 19:23:34

Being serious, though, as I take Lisinopril for blood pressure and am overweight and 71, any slight help is welcome

Not just Santa positive, but Rudolf's red nose is running, I hope it's not foot and mouth.

Smart & Brown stress in their instructions that the tool height must be exactly on the centre line when taper turning. Their model A taperturning attachment design was kept when the 1024 superseeded it as the simple design was deemed acceptable for toolroom lathes.