Member postings for Bill Davies 2

Unfortunately, br, the copy in your photo album is too small to show dimensions.

Bill

MikeK - until you find a paper copy...

The Amateur Scientist

I use two IKEA Jansjo LED spotlight lamps, with spring clamp.I have attached a long bar each side of the column to mount the lamps onto. I don't know if they still sell these, the current pattern appears to be Navlinge.

The only deficiency is that these lamps tend to flicker slightly after some time (I also use them in bedrooms), I think due to low voltage and electrical contacts. I find that if I press firmly on the switch it is less of a problem.

Bill

I find telescope/microscope eyepieces, used in reverse, very good for detailed closed-up work.

Bill

Well, Mike, these shallow tapers are effectively wedges, so rely on friction to hold them together and also transmit force. It doesn't take much, as you'll know if you have used morse tapers. So I think you may struggle in the future in getting them apart. Are you likely to want to do that?

Bill

Black and white film, poorly digitally colourised? Early instances used relatively few colours, and did not know the actual colours of the original objects. I'm thinking of those reworked WW2 films, rendered with brown or green army uniforms, bright blue skies, etc. It is said that younger folk can't/won't watch B&W recordings.

Bill

I have read that some (all?) surface and cylindrical grinding machines have steel tape to take the surface load. I can't think of an engineering application that has hardened steel rollers in contact with hardened rollers, but I would suggest a larger diameter might reduce the effects that Michael has highlighted.

Bill

And if you use CIF it will adequately clean the tea stain, but produce fine scratches on the cup and spoon that then increase the rate of brown stain depositied. Contains limstone dust as a 'mild' abrasive.

Bill

Personally, Dell, I would keep them soft. If they have to deform slightly, say, due to a speck of swarf caught between the tee nut and slot, better that than a stress concentration that may break the top of the slot.

Bill

It seems a common brand, James, I have one, too.

The polypockets with a fine 'bobbly' surface work with laser printed/photocopied sheets. The smooth ones, in my experience, are the problem.

Bill

Hi, John.

Many years since I used one, however, engage the middle 'three position' lever in either of the outer positions? Then carefull tighten the star-shaped knob to engage the friction clutch. You should then get movement.

You can only operate one axis at a time.

Bill

And I've been somewhat dubious about those diecast zinc chucks (google zinc lathe chuck). But they are cheap - is that their only virtue?

Bill

I make no claim for my ability to achieve such accuracy, but my instructor taught us to mark out perpendicular lines, pick up intersections and lightly mark with a sharp prick punch (60° centre punch), then using an eyeglass, 'nudging' the position until properly located, then apply a heavier tap. We used a small centre drill and opened up and reamed in the usual way. He claimed, with care, 0.005".

I think Chapman's first volume of Workshop Technology also claims five thou. I've put my copies somewhere safe, and can't find them. There is a set of all three on Ebay for £27.99.

Machine Tool Operation ( [US textbooks] Burghardt, etc., 1953, vol 1) claims it is possible to set external calipers 'easily' to within 0.002-3" against an engineer's rules. In those days, they were accurately ruled and deeply etched.

By my time, vernier height gauges were universally used, and we had mills and jig boring machines for accurate work.

Bill

Michael, I have also been thinking about a press; I bought a 2 ton jack just before lockdown.

The option you linked has surprisingly small 1/4 inch screws, in shear and in plywood, but clearly it works for the example shown. I wonder what force was necessary for the bends shown.

I have seen examples that use large diameter studding in tension, which avoids welding, and I will probably use that method. I want to try pressing small sheet metal parts - not planning on coining, which requires much higher pressures!

Bill

This guy has an M2 (same type or compatible brand?) and code 4 indicates overload, sugessting some lube required/corrosion or whatever, ditto pgk's comments.

Garage door controller

Compatible brands

Bill

Fail to plan, plan to fail ...

Is it a core drill? More rigid than a two fluted drill, used instead on removing material from a cast hole. But I haven't seen one with cutting edges to the centre. But no, the size is far too small.

Bill

Edited By Bill Davies 2 on 31/07/2021 23:04:43

Hopefully not a nice thick pound coin, Michael!

Bill

And having worked in a school in recent years, the Physics is not taught completely using SI units, centimetre units are used for calculations until A-level, when sizes are converted into metres. Other units of measurement comply.

Bill