Member postings for SillyOldDuffer

Hi nodeng2000

I read the text just before you deleted it. And I had just the perfect riposte too! You're quite right though : this isn't the place to cause trouble. In a way it's a shame - what other people think is important and interesting to me, and I sometimes change my mind.

Cheers,

Dave

Not guaranteed that I translated the BASIC correctly but this is what the program looks like in Python3 which is a modern "batteries included" language available free for Windows, MAC and Linux.

#! /usr/bin/python3

ratio = int( input( "Ratio = " ) )
divn = int( input( "Divisions = "  ) )

holes = 0

while True :
holes += 1
maxi = ratio * holes
lot = maxi / divn
if lot == int( lot ):
    break

turns = ratio // divn
plus = int( lot - turns * holes )

print( ratio, " : 1", divn, " DIV" );
print( turns, "+", plus, "/", holes );

Edited By SillyOldDuffer on 26/05/2016 16:52:23

Edited By SillyOldDuffer on 26/05/2016 16:53:48

Don't forget that this cuts both ways. British manufacturers are disadvantaged whenever Europeans fail to pay duty on imports from outside the union.

Note also that British manufacturing will not be protected by the Union if we leave it. Instead European industry will be competing head-on with ours.

The risk is that British industry unfettered by European rules will get duffed up by German, French and Italian industry as soon as they also are unfettered by European rules.

I expect Neil will ban us now!

I think it means that you are liable to pay Customs Duty on the goods. As duty is usually collected on delivery you're probably in the clear. Fingers crossed!

Hiatus maxime deflendus!

Bit blurred but there's a scale in the lower right hand corner of the drawing. I think it says 1 1/2 inches to the foot which makes 7.5" mean the engine has a 5 foot flywheel.

Many thanks for the analysis Howard. Your numbers and description of consequences convinces me. I hope no-one thinks that my suggestion that "the potential violence of model boiler explosions is overrated" is any reason to believe that small boilers are safe!

My comment was partly due to something overheard at the Bristol exhibition. A chap was telling a friend that a small traction engine happily steaming away was nothing but a bomb on wheels. That I doubt, at least compared with a actual bomb of the same size.

Consider what Wikipedia has to say about Nitroglycerin: "Detonation of nitroglycerin generates gases that would occupy more than 1,200 times the original volume at ordinary room temperature and pressure. The heat liberated raises the temperature to about 5,000 °C" And the same source gives the detonation velocity as 7700 m/s. That's a lot of energy released almost instantly.

So there you have it: conclusive proof that filling a steam boiler with Nitroglycerin is far more dangerous than filling it with water! I claim today's prize for stating the bleeding obvious...

Neil's link about full size boiler explosions is interesting as is this one too.

I've never heard of a serious accident involving a model steam boiler. That inspires confidence in their build quality, maintenance and responsible operation.

Cheers,

Dave

Cheers,

Dave

Ubuntu 16.04 & Firefox 46.0.1 just uploaded a jpg with no problems here.

The message you get after refresh is OK, it stops you accidentally resubmitting a completed form. ( Resending a form would be embarrassing if you happened to be paying a bill. )

The white screen bit is wrong though. As your screenshots uploaded I can only think there's something odd about your other jpegs. The website doesn't just copy pictures so it might be their fault - uploads get resized and the forum's software could be gagging on something.

You could try using 'convert' on the pictures to force regeneration of the file, for example from jpg to png and back again. From a terminal:

$ convert your.jpg new.png && convert new.png new.jpg

5 minutes later, bird successfully rescued from my daughter's vile cat.

PS : convert can resize photos as well.  Minimising before sending has solved 'big picture' problems for me in the past.

Edited By SillyOldDuffer on 24/05/2016 17:31:17

Ah ha! That makes sense, no problem driving a governor with a belt.

Even though I can't see any valve gear I think it reciprocates too.

I'm a sucker for buying old technical books and trying to work out exactly what some of the drawings mean. Sometimes it's like doing a cryptic crossword!

I'm having a bit of fun in this thread decoding Andrew Johnston's Vertical Steam Engine. It looks as if a pin driven by the piston runs without lubrication in a circular groove: surely that would have caused trouble! It also seems that the valve gear is meant to be driven by a belt, which is peculiar too. (Not that I know anything about the subject!)

I guess the drawing is intended to give a general idea of the Engine's layout and some of the detail is missing.

Another mystery is what the designer thought the advantage of such a configuration would be? I wonder if it was ever built and what it was used for? If the brickwork is to scale it would be about 6 foot high. (The plan says it's scaled 1 1/2" to the foot but we don't know how big the paper is.)

The quality of the drawing and colouring is excellent: it must of taken a lot of practice to get that proficient. No TV or Internet back then.

Dave

This drawing reminded me of something I read somewhere, and the strange workings of my memory finally retrieved it this morning as being from Norman Friedman's "Naval Weapons of World War One".

It's a Hydrostatic Switch from a mine, not a horn. It's main purpose is to activate the mine after it's been laid.

This type of mine is anchored to the seabed by a kind of winch and cable arrangement that sets the operating depth. This could be as deep as 100m to catch submarines, but more usually would be just too deep to be set off by passing fishing boats. Mines do not float on the surface.

In storage the top of the switch is sealed with a soluble pad. The mine is safe until this pad has been slowly dissolved by seawater, by which time the mine layer should be well away. The outer top cap is pulled off just before the mine is dropped into the sea.

Once the pad has dissolved seawater can enter the innards of the switch to press on the diaphragm. At operating depth the piston is pushed sufficient against the spring to make an electrical connection between the two lower bolts. This brings a battery into the firing circuit and activates the mine. After that bumping a horn will set it off.

A secondary purpose of the switch is to make the mine less dangerous should it accidentally come adrift. Randomly drifting mines are dangerous to everyone. If the cable breaks the mine floats to the surface. With luck removing pressure from the piston will disconnect the battery, making the mine "safe". I say "with luck" because after several months in the water corrosion or sea-life might have jambed the mechanism.

Friedman reproduces a drawing on Page 361 of a complete British EC II mine that includes one of these devices. On the drawing it's labelled "Hyd Switch Mark III" .

The drawing in the book isn't as good as that traced by Georgineer's mum. Well done her!

Cheers

Dave

Sounds like we went to the same school!

One of my teachers, who had good cause to be concerned about the foolishness of clever inexperienced boys, often gave carefully designed demonstrations that deliberately broke the rules. Adding a test tube of water to a beaker of concentrated sulphuric acid; pouring water on to a large lump of Potassium; the travelling properties of petrol vapour upwind of a candle; Hydrogen and Oxygen; NI3. About a quarter teaspoonful of the latter was tipped on top of a tin of beans. He then spent about 30 minutes telling us stories of boys who had maimed themselves with home-made explosives before tapping the tin with a stick. The purple mushroom cloud was fun, but the hole blown clean through the top of the tin can was a lesson learned.

On the downside, having seen what a chemical explosion can do, I now suspect that the potential violence of model boiler explosions is overrated. Don't get me wrong, I'm not saying they would be harmless! But the amount of energy and the burst pressure must be relatively low. Has anyone in the Model Engineering community ever calculated the energy involved, or - even better - deliberately steamed a small boiler to destruction and documented the results?

Purple mushroom clouds!

Now you're pulling our legs! And Chrome bumpers were once as common as muck over here.

You might like to spend a penny before we unleash the dreaded Britishisms...

Edited By SillyOldDuffer on 18/05/2016 19:26:23

Hi Duncan,

In the good old days Microsoft earned a very good living by selling software licenses. Not just for operating systems but also a wide range of development tools, Word Processors, Browsers, Spreadsheets, Databases, Games, and Web Servers etc. They also sell an excellent range of services in support of their software and how best it can be used by a business.

Microsoft's traditional income from licenses is drying up due to market changes. They lost the battle for Supercomputers and - much more seriously - that for the absolutely massive mobile market. Android is based on a Linux kernel.

Another way of making money from the web is to accurately target potential sources of income with advertising and other offers. Microsoft are interested in this market.

Accurate targeting is best achieved by tracking the activity of internet users. Their purchase history, contacts, and interests can all be recorded and analysed. There are many ways in which this information can be mined, for example to create and sell lists of potential customers to interested suppliers, or to identify market trends.

There are several examples of Microsoft moving into data collection and analysis. The Bing search engine collects usage data much as does Google. Windows 10 is free to customers but, unlike Windows 7, it "phones home" by default so that Microsoft can collect data about what you do with your computer. Most, but not all, of the "phone home" features can be turned off but the user has to realise first that this needs to be done and then has to wade through various settings to plug the leaks. These features are off by default in Windows 10 Professional but you pay a license fee for that.

Microsoft don't profit from people who stay on Windows 7 and there is new money to be made from Windows 10 and future upgrades.

I'm not bashing Microsoft. I benefit from two machines running Windows 10. I don't suggest that Microsoft are in any way wicked in all this, it is simply that my and Microsoft's best interests are not necessarily the same!

Not everyone is worried by privacy issues. I'm pleased, for example, that this forum carries advertising targeted at me even though I am thereby outed as a Model Engineer! But, after a career in big IT I am very aware of just how much can be deduced from a large data set and also that the deductions can be used for good or bad. The Inland Revenue detecting tax-dodging is good. Criminals selecting vulnerable old people to scam is not.

Cheers,

Dave

English is a minefield for pedants. For decades even well educated Brits firmly believed in the correctness of "Standard English" and "Received Pronunciation". Today's view is that "Standard English" is just another dialect, no more or less valid than English as practised in Yorkshire, Scotland, Wales, Zummerset or Birmingum.

British readers looking for another example of ill-considered authority might enjoy Strunk and White. "The Elements of Style" is mandatory in many US educational establishments and students are marked down if they don't follow its directives. Although the book does contain much good advice, native speakers will easily detect "rules" that are surely only the prejudice and personal preference of the authors.

A friend went to school in the US. Aged 12 it was agreed that it was OK for her to stand facing the wall whilst the rest of the class swore allegiance to the flag, but her refusal to spell words like colour, theatre, and aluminium correctly was always punished.

On the subject of Aluminum, the spelling is consistent with Platinum and Tantalum. Does anyone know the origin of these variations?

Edit Fixed deliberate error.

Edited By SillyOldDuffer on 17/05/2016 10:45:13

Hi Bazlye,

I guess it should be "the reference below"? Or are you referring to the difference between "Above/Below" and "Over/Under".

I wonder what 'The Times' 's opinion would be?

I like to be pragmatical about these things. I used to drive a peppery colleague bonkers by using "practically" for "almost". He never twigged I was doing it on purpose! (He was spot on about my misuse of semicolons though; a habit I've never broken.)

Cheers,

Dave

Sam, if your Warco set happens to be the same as mine this listing may save you some time.

Cheers,

Dave

Hi Brian,

Yes my die holder already had a hole drilled through it. Mine looks just like yours from the side but it must be a different make. It isn't "made of pretty tough material" either: I didn't have any trouble tidying up the bore, possibly because the thing was cheap and cheerful!

I wouldn't go to the trouble of drilling out a solid shank especially when using a tube as suggested by Neil is such an easy alternative.

I've had mixed results when threading. I suspect my issues were due to a mix of cheap and/or blunt dies, awkward metals and inexperience. Although practice has made me much better at recognising when to back off, I still mess up more often than I like to admit. One good tip I learned on this forum is that slightly reducing the diameter of the rod being threaded helps considerably in awkward cases, as does using lots of cutting fluid.

It's worth double-checking the diameter of your rod too: I have various examples of "4mm" rod in my scrap-box that actually range in size from 3.85 to 4.1mm Chaos ensues whenever I try to cut an M4 thread on to the 4.1mm rod.

Cheers Dave

Further to Brian's original question I created a similar disappointment on a mild steel rod by cutting under power with a cheap die this morning.

The problem was due to swarf blocking the cutter. I was able to cut a reasonable thread using the same set-up by turning the lathe chuck by hand with frequent reversals to remove chips and add more lubrication.

I wonder if Brian's problem might be due to a blunt die tearing rather than cutting compounded by scrapings choking the cutter?