Member postings for Kiwi Bloke

Well that's indeed creepy! It's also vastly more 'intelligent' than the nonsense I have got, repeatedly, from the (assumed) 'phone help (misnomer) line at a major UK high-street bank. Those jokers' jobs are surely under threat...

It's scary because, like politicians, the answers are glib and plausible, but almost impossible to check for correctness - unless you already know the answer. If you don't trust politicians, you shouldn't trust this sort of software! It will flood the internet with AI-generated content, but what will it do for the signal-to-noise ratio?

Although it's said to be based on the probability of words following other words, it must have been elaborated to extend the analysis of the text beyond single words, to phrases and beyond, if only to 'understand' the context. It is doubtless be a small computational step to parse text to extract ever more complex concepts, and then link them together (probabilistically?). The example given suggests it's well on the way to that. And that's worrying.

Philosophical question: if something works indistinguishably as if it's conscious, intelligent, whatever, isn't that effectively the same? How do you know I'm not an unconscious zombie, just acting my simulation of conscious thought pretty effectively?

Clive - fascinating! Please tell us more!

I assume your 'puddling' technique is stick welding - correct? What kind of rod is suitable? Is there any use for TIG welding in this application? I'm thinking that its smaller heat-affected zone could be either a blessing or a curse...

Clive, apologies, I overlooked the fact that your question is about an Appall device. Even though that company wants to trap you in Planet Appall, Libre Office has a Mac version - as others have said. Have a go - it's free!

I have no idea why anyone should consider buying MS Office - at any price. Libre Office is open-source software, that can be downloaded for free. It comprises an entire office suite, which does all that Microsuck's expensive product does, and has an attractive and intuitive interface that can be customised to suit preferences. It reads and writes MS-compatible files (even the ghastly .docx ones, that MS introduced to try to keep folk using their products), so reading and editing all your existing files is no problem - with the possible exception of a couple of proprietary fonts. However, substitute fonts can be downloaded, again at no cost, and full compatibility is assured.

'Fraid I can't tell you how to install it into Windoze, because I haven't used MS software for >20 years, but I'm sure others will be along to reassure you that it all goes as painlessly as a Windoze install can/can't be...

The use of a grease solvent is widely advocated, but it's not the best method. Think about it: the solvent produces a dilute grease solution, which spreads all over the substrate - then evaporates, leaving grease residue on the surface. If using solvents, you need to use enough to wash the substrate - repeatedly - so the grease is carried away. It gets expensives, and time-consuming. However, since it's so widely used, it is presumably good enough... Probably.

It's better to scrub the alloy with household scouring powder, and rinse with 'distilled' water (from de-icing the freezer, perhaps). Test for success by dropping water on the cleaned surface. It should completely wet the surface, with the drops forming a microscopically thin film. Any signs of the water not wanting to form a film, or frank beading, means it's not de-greased. Oh, and, of course, rinse and repeat...

Oh, sorry, I'm guilty of a sin that's all too common: not making an effort to help myself before seeking help. Now I know what 'hard rubber' is, thanks to Wikipedia...

I am restoring a couple of accordions, dating from the 1950-60s. They contain some components that appear to be moulded material of some sort. I'd like to be able to identify the material. I'm aware that 'hard rubber' (whatever that is - it's hard and black...) was/is used for saxophone mouthpieces, but don't know much about what plastics were around in my childhood. Accordions have traditionally been covered in moulded sheet celluloid, but the things I'm interested in are thicker-section items like feet and moulded key facings, which I doubt are lumps of celluloid (although the key facings might be...).

OK, I know there were thermosetting materials like Bakelite, and some thermoplastics, like acrylic, polystyrene, polyethylene, nylon and possibly ABS, but what else? Are there practicable ways of identifying plastics from this era? From plastic kit-making days, I could tell polystyrene by its smell, but my sense of smell is poor now, and, although a childhood pyromaniac, I've forgotten the burning characteristics of those plastics the identity of which I knew. Also what is 'hard rubber'?

Edited By Kiwi Bloke on 04/09/2023 11:28:52

Actually, I think that the 'real-world' background to my question is probably a distraction. I suppose I'm really asking whether a significant electrolytic cell is likely to be set up along the line of the interface on the exposed surface where bronze meets steel. This is a rather different situation from two dissimilar plates with an electrolyte between them, isn't it? I assume that provides enough area for enough current to cause significant corrosion.

Mark - unfortunately, it's the underside of the deck, so it gets sand-blasted (dusty conditions in summer), and caked with pulped wet grass. Paint doesn't stand a chance...

Brazing preferred because of fillet welds, with different thickness sheet/plate, so - at least at my skill level - undercutting, when welding, is an ever-present risk. Also, the speed of brazing was welcome in the difficult and uncomfortable positions my old body was required to adopt. Torch access always seemed obstructed by another bit of the deck. Using the pedal when standing, kneeling or crouching is always difficult... But using fixed current to braze was OK, whereas it would have caused holes, if welding, as I had to stop and start a lot.

With hindsight, I should probably have used chains of short weld runs, say 1" long, like the original MIG welds.

I'm a bit surprised that TIG brazing isn't more popular - it's a lovely technique, and poses little risk to the base metal, since the arc is always confined to the braze bead.

I've been TIG brazing pieces of 3mm sheet steel into a complex professsional ride-on mower deck, to replace rusted panels. I thought I was well-enough aware of the risks of dissimilar metal corrosion, but completely forgot about it as I merrily ran beads of braze over the deck. Fools rush in...

What happens at the exposed junction of steel and silicon bronze (braze), when water and oxygen do their best to cause corrosion? Have I just made an accelerated-corrosion mistake - should I have welded, rather than brazed?

Mike, sorry to hear of your difficulties. Are you 'missing something glaringly obvious?' Well, I can't tell, but you've left the door open for folk to risk insulting you with the basics...

it's nothing like as easy to set a boring bar's position with respect to the work as it is to set a lathe tool for external cutting. For a start, it's difficult to see what you're doing. A major risk is that there's interference between the bore and the bottom of the tool tip - obviously worse as the bore diameter decreases. We always try to stuff our thickest bar into the workpiece, so that's increasing the risk. It's often necessary to gain clearance by setting the tool at what looks like a horrible negative rake. Raising the point of contact so that it's a tad above centre height is also a good idea. I find it much harder to set a tool correctly in a boring head, but the geometry is the same.

I recently bored several bits of an unfriendly stainless steel (dunno what exactly) using an Emco Compact 5 and Arc Euro's no-name **MT and **GT inserts. Bore dimensions similar to your job. To be honest, I didn't expect much from such low-priced inserts, of unknown provenance, and used them as an experiment, reasoning that there wasn't much to be lost. They did the job splendidly! The Compact 5 is not the world's most rigid lathe, but the resulting bird's nests of stringy swarf were witness to the fairly serious cuts and feeds used (sorry, I can't quote any figures...). I can only think that success was due to the lathe being in good condition, and the careful setting of the tools.

I don't think a lesson in bad manners is an appropriate use of this forum.

Quite by chance, I came across what I think is this design. 'A Filing Rest' by L C Mason, Model Engineer 5 March 1971 (Vol 137, No 3412, pp 251-253).

When there are major breaches like this, do the outfits that you believe are keeping your private information secure get beaten up by the law? It seems to me that they just shrug their shoulders, and are allowed to carry on. There's a small rebellion against being pushed to do everything online, (probably mainly old geezers without smart 'phones, and being difficult by refusing to use online 'services', but it's so small at present, and not arganised, that we must accept that our privacy and security are no longer respected, or considered important. And we're considered difficult...

I'm naturally lazy, and my scrap bin has a nasty self-filling habit. so simplicity is attractive.

The spindle and spacer tube are the easy (easier) bits, particularly if simplified further, as I've suggested. I would do as much as possible on the spindle between centres, then rough out the collet taper, and follow Duncan Webster's advice to finish bore it, supporting the shaft end either in its bearing, or directly, by a steady. Don't rely on collets (especially cheapo ones!) for concentricity, even if there's an apparently long-enough surface to grip. And remember that, whilst you can 'dial in' something in a 4-jaw chuck, to run true where the indicator's probe bears, things might be different at some distance from the chuck. You can't rely on the jaws to hold exactly parallel to the lathe's axis (they should, of course, but don't make assumptions...).

It's the housing that's to my mind the most challenging. If it's to be a quill, you presumably need the bearing seats to be concentric with its OD. You might consider making a mandrel, so that the housing OD can be finish-turned on the mandrel, between centres. I'd try to avoid doing anything tricky down at the bottom of a bore, so my previous comments stand.

Andy_G - Yes, I agree with everything you've said, except I'm less confident about the last para. It might turn out like a camel - designed by committee. Let's hope not: it should be good. it might, perhaps, become a sort-of ME standard spindle, in a similar way to Prof. Chaddock's Quorn spindle.

Regarding machining the housing in one set-up: I suppose it depends on how confident one can be, working at the bottom of a deep hole. Boring and gauging the 'far end' of the housing, and how stiff the boring bar would be, given that it would neeed to be longer than the housing, have their own problems. Boring each end, supported on a good fixed steady, is the alternative, for both of our tail-end suggestions. Then, the three same-sized bearings job is easier. Even the single set-up idea would probably need a steady at the tailstock end.

I would hope that temperature variations don't affect pre-load significantly, with an alloy housing, given the bearing pair spacing is so short, but agree steel is better. More reliable, running in a steady, too.

Keep the ideas flowing - it staves off Alzheimer!

Addendum. Last suggestion means the tail bearing has to be fitted after the spindle has been fitted to the housing. This isn't a problem. The outer track should be a light push fit in the housing, and you have the screwed end of the shaft to take a nut and tube bearing pusher. It'll go together easily. The tail bearing bore in the housing must extend deeper along the bore, so the outer track of the bearing can float axially.

Yes. More simplification required!

Back in the '80s, when I was messing around with cars, I had a Ford Escort gearbox (2000) in pieces, next to an exploded diagram of a Triumph (Spitfire, IIRC) 'box. I was impressed how Ford had managed to simplify the whole thing, with far fewer components. It must have been easier, quicker and cheaper to manufacture, and far easier to strip and re-build than the Triumph, which was done the old-fashioned way. In addition, the Ford 'boxes were strong, reliable, and had a renowned, slick shift action. They were very popular (pretty well universal) among amateur motor racers, and constructors, such as the UK "Clubmans' Formula', which was getting close to Formula 3 lap times. I'm a long-time fan of simplicity!

OK, what can be done, to satisfy Ian? Well, the machining of the housing, to get the bearing housings aligned, is not a trivial job. If you're going to machine a smaller ID at the tail end, you might as well machine an ID the same as at t'other end - it isn't more difficult. Then you can simplify bearing purchasing too...

This allows the bulk of the shaft to be the same diameter, and the spacer to be plain-ended. Tail-end details will, of course, need to be adjusted also.

I'm finding this journey towards simplicity interesting. Thanks for allowing (encouraging?) me to continue disrupting...

Hmmm. I think that the two spanners should be as close together as possible, so that you can squeeze them together, like pliers handles, and also to avoid inadvertently applying a couple to the spindle's mounting, and possibly shifting it. By squeezing the spanners together, you can more-or-less avoid applying any force to the spindle assembly, other than the required torque. An open-ended spanner, made from say 3mm sheet, could bear on a couple of flats on the 9.5 mm Dia section, just behind the nut. Make the slots a clearance fit on the thickness of the spanner, and it'll behave itself better. Or a hook spanner, locating into radial holes. Might have to fiddle with dimensions to make sure there's room.

Just another suggestion...

(Should I just shut up now, and let you make the thing?)

I think you may be over-emphasising the ease of assembly. The tail bearing will look after itself as the assembly is pushed together. You're right, and others have pointed out, that a threaded-on pulley will self-tighten, and so doesn't really need a locknut. It's analagous to a screwed-on lathe chuck. But, should you wish to run the spindle in reverse, a locknut becomes necessary.

So, to simplify further, delete the green pulley hub, and thread the pulley directly onto the shaft. As I suggested before (or meant to, it was getting late), the pulley should, in addition to a threaded bore section, also have a plain bore, for best location, and I think this should be adjacent to the bearing. Thus, on your latest drawing, the 7 mm dia becomes plain, and the 6 mm diameter is threaded. The pulley itself is positioned as far to the right as possible, (over the plain bore section) to reduce the effects of belt tension. It will be easy enough to swap pulleys, and it won't disturb the shaft.

I think the spacer tube could be simplified, with plain, not stepped ends. Its right hand end can remain 7.1 mm ID, if the spindle's 7.1 mm OD extends just a tad under the inner bearing's inner track. I'd think that its left end could also remain 9.5 mm OD. It doesn't matter if it's a larger diameter than the bearing's inner track's OD.

One complication you might consider is a lightly pressed-on flange, on the 9.5 mm Diameter of the shaft, acting as a flinger or muck shield.

It's looking pretty well done - time to cut metal soon!