Member postings for mick

You've chosen the most difficult thread to cut, but a few suggestions. use a square tool the width of the bottom flat. Take the cut 0.020'' below the minor diameter. Then with a ACME form tool cut the flanks, thereby avoiding cutting the full form. Hope that helps.

I remember a few years back there was a series about a Myford rebuild which were accompanied by photos of his attractive daughter standing beside the finished lathe. Is that the sort of thing your after? Seem to remember she was wearing a cowboy hat!!

I presume your boring in the lathe, in which case use a 6mm or similar slot drill with the flat face very slightly angled to give you side clearance to bore the hole, that way you'll achieve the flat bottomed bore. Take the bore as close as you can to finished size before reaming as the leading edges of the reamer will not produce a size diameter at the bottom of the bore.

No workshop is too small for a shaper, mine is almost a hundred years old and still machines dead flat and parallel and builds up the right arm muscles as well!

Not wishing to be pedantic but, 2/16th, would that be 1/8th?

The thread should of course be as true to the register as possible, but all it does is secure the face plate to the spindle, the register is what dictates the true running, so if the face plate bore is a good fit to the register and the thread is free right up to its finial position then the plate will clamp in exactly the same position on the register every time and so once machined will always run true to it.

I'm an old G code man, I don't have CAD/CAM as I don't know how to use them, all my programs are hand written, I do now use the computer to work out the trig these days, so is CNC cheating? not if you use G code it isn't!

It looks like a floating reamer holder for a capstan lathe but with dowel pins it obviously can't be, the key way stops whatever twisting, so at a guess perhaps it held a broach to produce a square or hexagon shape in a stationary component.

They can be used for cutting multi start threads when mounted in the tool post, or for cresting screw cut threads when mounted in on a suitable handle. Or just use the HSS as tool bits First law of model engineering, throw nothing away as it will useful one day!!

Thanks all, good advice as usual.

Mick

I'll just hijack this thread as someone may know what to do. I had to up grade to Windows 10 some eight months ago as no one would repair my old unit which ran Vista, so I had to buy a new unit. I've had loads of glitches with emails, copying files and photos etc, but the main cause for concern is I now cannot connect any devices to the computer. It started with my Touch iPod which won't synct to the music library. Apple support said I would have to switch off my AVG security software. When I told them I wasn't too happy about doing that they couldn't help me with the problem. Now I can't connect my Cannon Sure shot to the computer. Windows support, via a chat line, told me to input my six digit PIN so they could access the unit, but as I don't have a six digit PIN that's another blind alley. All external devices worked okay until about five weeks ago. Does this call for a £50.0 ph house call from an IT engineer?

Thanks. Mick.

I don't know if this is relevant to the problem under discussion but many moons ago I bought a Colchester Student from my old college lecturer who had bought it from the college with a view to using it with a phase converter. The problem he encountered was that the Student doesn't have a clutch and so all the power was drawn off in one go when the starting handle was engaged, which tripped the converter.

As usual I'm sure someone will know the answer. Yesterday a joiner friend of mine asked me how to close the crocodile clips when shortening a flat belt in order to keep the adjustment, as he's just acquired a large wood turning lathe which has a flat belt from the motor to drive the spindle, which is a bit on the sloppy side. He seemed surprised that I didn't know, I explained that by the time I entered engineering totally enclosed V belts were pretty much the accepted thing. I suggested off the top of my head that they might have to be hammered shut, but I suspected the best option would be closing them under a press, as I said, I expect someone will come up with the definitive answer.

If the faces are reasonably flat and parallel mark out the centre position, then centre drill the blank. If you haven't got a face plate remove the jaws from the chuck, place the opposite face against the now flat face of the chuck, then use the revolving centre as a pressure pad locating in the centre drilled cone and with light cuts turn to your desired size.

Put an unimportant bit against a white grinding wheel, if it glows red but doesn't grind away then its carbide.

I've never come across a dividing head that isn't 40:1 What make is a 60:1 Certainly smaller rotary tables can differ, while the larger commercial ones, in my experience, are 40:1

I've said it once but I'll say it again, first stop every time is Metal4U if they don't have what you require then try the other outlets.

I had an interesting dividing head indexing problem the other day, I had to initially index 12 degrees from zero, then 16 degrees ,then 24 and repeat it nine times. I made a nine hole plate, which means every hole is one degree. I've used it several times since, its extremely useful for indexing any multiple number of whole degrees, can't imagine why I didn't make one years ago.

It fills the flutes and stops the web wandering when it starts to bite, use worn out emery tape folded double with the grit faces inwards, the resulting hole will be round but slightly oversize.

If its bar stock in different lengths 30cm to 3mtrs. them Metal4U takes some beating