Member postings for Sam Stones

Can U/S reversing sensors fitted to one vehicle respond to the emitted (U/S) signal from another?

Just curious,

Sam

For what it's worth Jeremy ...

... Back in’t toolroom in the 50s and adopted frequently during the building of my skeleton clock (and other projects), I used this technique for fine finishing. The result is not unlike JasonB produces. Oh! and for brass in particular, no top rake.

The (HSS) tool tip is modified in line with a technique called diamond turning*. The flat, stoned parallel with the saddle traverse, spans a little more than the pitch of the feed.

Cheers,

Sam

*I haven’t been able to find any reference to 'diamond turning' as applied in this context, but it has nothing to do with diamond as a material, but the faceting.

Revisiting an old thread of mine from ten years ago, **LINK** the result of the kindly interest of John Haine in this thread **LINK**, I thought I would share my Eureka moment.

Back then, this was all I could extract from my final attempt to produce an acceptable spring.

I wasn't too impressed, but had run out of patience and 0.008" (0.02mm) guitar strings. 

Here’s an updated photograph of my method. I've added 'sharpening' via Photoshop to emphasize the bumps.  

On the borrowed lathe I was using (a HobbyMat) I had no ready means of adjusting the pitch, so was obliged to close-coil the wire.

It can be seen that in passing the wire over the toothbrush handle (the red bit), I had allowed the wire do (some of) the controlling itself.

Once there were a sufficient number of turns to grip the mandrel, I fed the wire at a slight angle over the toothbrush handle. Feeding the wire slightly from the left, 'steered' the wire onto the mandrel to form a tight helix.

(The toothbrush handle just happened to be a handy and relatively soft piece of material to hold the coils (gently) against the mandrel.)

What I hadn’t considered, and which can be seen clearly in close up, was the uneven surface of the toothbrush handle, a result of having been injection moulded from an EDM’d mould surface.

As the wire passed over the uneven surface, its direction (angle) could (and probably did) change depending upon which set of bumps it ran over. In other words, the ‘steering’ was imprecise, and the most likely cause of pitch variation.

How it looks on the clock …

I’m sure with a bit more effort in shaping the spring ends and adjusting their position, it could be improved.

But that’s how it will stay.

Keep safe,

Sam

Edited By Sam Stones on 19/06/2021 22:21:58

Having drifted further from the essence of this ‘Macro-photography’ thread, the mention of (left/right) image polarising for gaining a 3D effect raised a very distant memory along with a more recent observation.

In the early 50’s I recall visiting a local (Bolton, UK) cinema with my maternal grandmother. Each person received a pair of metal-framed spectacles, with instructions to hand them back at the end of the show. It was already clear to me that the ‘lenses’ were alternately polarised, one vertically, the other horizontal. I’m not sure how I knew this but, borrowing her pair of spectacles, I recall attempting to show her how, when one ‘lens’ was placed at right angles over the other, light would be blocked. What isn’t clear is how effective my explanation was in conveying to my GM, the very purpose of such a spectacle, pun intended.

Almost seventy years later, I was unable to resist responding to the current thread’s 3D occasional digression. This group of images demonstrates an effect that puzzled me. [If you’re in a hurry, the answer is in the link below.]

For no particular reason, I chose to display on my (aging) AOC 2436 desktop monitor a photograph of Waterman’s Dock in Hobart, Tasmania, (top left).

In each of the three remaining images, I’m holding in front of the PC monitor screen, a pair of polarising filters crossed at 90°. Where they overlap (as I explained to my GM long ago), most of the light is blocked.

What I found strange was if I repeated the test but rotated the pair at 45° as in the lower left image.

There was still a similar blocking where they crossed, but one filter almost completely blocked the covered part of the image. This suggests that the monitor is displaying a polarised image at 45°.

Taking the same pair of crossed filters and rotating them at about 60°/30° produced a similar result, although now allowing more light through (see lower right).

Testing our TV screen (a Bravia Oled) using a single filter, reveals that the display is horizontally polarised.

As often happens, I decided it was time to stop guessing and check the Internet.

Here I found an answer …

http://www.nelson-miller.com/why-are-lcds-polarized/#:~:text=Aside%20from%20the%20use%20of,feature%20a%20polarized%20filter%20layer

[A novel use of a pair of crossed polarising filters is to sandwich between them, a transparent object such as a PMM (acrylic) or GPPS moulding. As here from a CD case lid moulded in acrylic, the stress levels appear in multiple bands of the colour spectrum. The position of the gate into the mould appears in the upper left corner halfway up the part.]

Sam

The LINK 'mechanism' proved smarter than I realised, and had already inserted the URL.

Editing was unnecessary.

Edited By Sam Stones on 25/04/2021 00:38:01

Congratulations Nick!

I see what you mean about ‘ghosting’. I would guess as you suggest that the camera positions are a bit too wide apart.

However, with cross-eyed viewing, both sets of pairs worked instantly for me, and there’s a great sense of depth with your low level approach. A good DOF makes all the difference too.

As I see them, the primrose pairs (again easily viewed) appear with the ‘cross-eyed’ pair below the ‘straight’ (stereo?) pair.

Sam

A twist in the tail.

During a subsequent part of the postmortem, it suddenly dawned on me that the base and top of the fluid cartridge had been hot-plate welded and not as I suggested, ultrasonically or vibration welded.

It is a method used for joining and sealing the lid and container of automotive batteries ... (and many other things)

If that method of welding is not familiar and you'd like clarification, try **LINK**

Sam

Having convinced myself the ball had something to do with proximity detection, it didn’t enter my head that it could be a simple seal. Thanks for the idea Jason and others.

As for that hole being part of the filling process, I need to point out that …

1. The 2mm ball blocks a through-hole of about 1.5mm diameter,
2. The pump is lowered into the fluid cartridge down a hole about 29mm diameter,
3. The drain (or return) hole in the cartridge is about 13mm diameter,
4. The two holes are initially closed by a separate lid moulding heat staked in three places,
5. The stakes are deliberately friable allowing removal and disposal of the lid,
6. U/S or vibration welding was likely used for joining/sealing the base and top,
7. The shaver is not involved when installing the cleaner cartridge.

Assuming the steel ball is not for detection, the hole it blocks is rather small for filling. With larger holes 2, and 3, available for filling, the 1.5mm hole (into which the ball has been pressed), may be an air vent rather than a filling point.

Given that heat staking and welding were a part of assembly, I would assume the 1.5mm (vent?) hole could be closed by heat swaging.

The cleaning device has the ability to determine the presence or otherwise of (sufficient) fluid. Having now destroyed the cartridge and a new one lasting for at least three months, further investigation will have to wait.

Thank for your interest and comments,

Sam

PS - A cursory scan of the Internet failed to disclose the method of manufacture.

Edited By Sam Stones on 16/04/2021 03:27:43

Now in possession of a well-known brand of (wet/dry) battery-driven shaver, I was surprised to discover that embedded (pressed) into a recess of each cartridge of cleaner fluid is a single 2mm diameter steel ball.

The cartridges are injection moulded PP. Two mouldings, (a base and a top) are welded to form a closed tank. Moulded parts of the cleaner’s mechanism are POM.

I’m guessing that in production, the presence of the steel ball could signal that the cartridge is complete and ready for shipping; OR – that the razor cleaner mechanism has a means (electromagnetic?) of sensing that a cartridge has been inserted.

If the latter is the case, what puzzles me is that there are at least three ‘layers’ of moulded plastics between any sensor and the ball, a distance amounting to more than 8mm.

The ball has no detectable magnetism, but sticks to a magnet. In use, the cartridge, and therefore the ball remain perfectly still.

While this is just curiosity on my part, perhaps the upshot would interest model makers.

Any offers?

Sam

Edited to get rid of unexpected smiley face.

Edited By Sam Stones on 15/04/2021 04:59:41

I have no idea what it is William.

However, in the background of a couple of your pictures there’s a Taylor Hobson (or similar) pantograph engraver.

Let us know soon.

Sam

Edited By Sam Stones on 11/04/2021 20:48:46

Re your latest flower shot Raphael, I find it intriguing that so many flower petals, marine creatures, and other natural phenomena, e.g. Michael's micro-fossil, display in groups/segments of five.

By the way, besides being an excellent photograph, your daughter's pet is eye-catching

Sam

More of your pleasing images Raphael.

This has little to do with macro-photography as such (more about the colour of rust), but as a tip …

In the distant past, perhaps in my Ilford ‘Manual of Photography’

**LINK**, (when you could buy it for 30/-) I left mine behind in the UK; I read that orange and grey go well together. As some of your photographs indicate, it seems to work well with rust.

Sam

Hi Nick,

That’s a very pleasing result.

Going (viewing) cross-eyed, your efforts put a big smile on my face.

Then, just as I was about to send a congratulatory note, your follow-up post with technique description appeared and my smile turned into a grin.

As can be expected, out-of-register reflections from the glazing seem to cause the brain to switch between eyes producing a twinkling effect. This was discussed earlier, see Page 11 - 23th May 2020.

Sam

Jack, the moment I saw those front legs I had little doubt it was a mole cricket.

Back in Nicosia ’57-8, another chap in our camp had found one and was holding it gingerly between his finger and thumb inside a piece of rag. He claimed that its digging strength was so strong he could hardly stop it from moving.

The same chap had previously demonstrated his ‘ability’ to hand-feed flies to a praying mantis he kept as a pet. It chomped away as if eating a piece of watermelon, making no effort to escape.

Sam

Nick, I’d like to suggest that your fridge magnet would make a good subject for a stereo pair. Would you care to have a go?

Sitting on say BluTack, tilting it left to right a few degrees might be all that’s required.

Sam

Many thanks for the link Michael.

All became clear when the penny dropped. [Mixed metaphor?]

I could relax except to ask -

“Neil, Why is your picture just a blank?”

Sam

On second thoughts, are we talking about removing haze shimmer?

Any positive comment would be appreciated

Sam

Can someone provide images of before and after photo-stacking of the moon (or any other astronomical subject)?

I'm struggling with DOF and its relationship to the distance ratio of subject to distance of 215:1 (i.e. the moon's distance of 373,586 km divided by half the moon's diameter of 1735 km).

Or am I barking up the wrong ratio tree ?

Should I presume we are not talking about focus stacking?

Sam

What a brilliant camera/lens combination Steve.

Looking forward to seeing more of your impressive photography.

Sam

Michael, In not grasping the implications of 'Cookie Settings', I wasn't game enough to include the second part of the sentence.

Jim, I must take this opportunity to acknowledge the many stories in your website **LINK**

swarfology.com.

Most entertaining and very much to the point.

Cheers,

Sam

Thanks for the link Michael. What bothers my simple mind is ...

The modules occupy an area of 17,657 cubic feet,

Sam