What did you do today? (2013)

[Sub MandrelParticipant @submandrel]

At work we've been advised by the IT support that Microsoft security essentials (free) is as good as anything for AV these days. Slow computers work better with it than they did with Mcafee.

I swear by Spybot for other problems.

Neil

[WindyParticipant @windy30762]

Just tried housecall no threats have tried others for malware etc. and still no threats.

PC seems to work OK but the friend with Norton 360 version made me suspicious of a naughty on it?

Paul

Edited By Windy on 01/09/2013 22:04:23

[John Stevenson 1Participant @johnstevenson1]

The new Blidgeport [ Chinese clone ] has the same handles on the bed as a Bridgy, as in Quorn on steroids.

Horrible bloody things, I was brought up on full hand wheels where you had to pass from hand to hard and whoa betide anyone who left tram lines in their work.

Add to this they are dangerous as they introduce a trapping area where the power feeds are concerned.

Look at where the large ball passes by the power feed body.

So located a couple of 8" chromed cast iron handwheels, bored out and keywayed to fit and now got X and Y axis a lot smoother and safer.

John S.

[GaryMParticipant @garym]

I spent an enjoyable few hours at Wortley Top Forge **LINK** in the River Don valley north of Sheffield where they were having a model engineer's special event day. First time I've visited and I was surprised how much interesting old metalworking machinery they have in the workshops.

Had a lengthy chat with a fellow in the workshop who told me the history of an old Hendey lathe they had discovered in one of the sheds. It was apparently used on a regular basis by the previous Countess of Wharncliffe.

Quite a few model locos taking people on trips round the miniature railway. An impressive collection of stationary engines including the largest one 'Elizabeth', a true vertical compound with grasshopper beam.

Worth a trip if you're within a hours drive.

Gary

[Speedy Builder5Participant @speedybuilder5]

Something a little different. I have a 6/12volt battery charger which has never performed well. When charging, the O/p voltage is 5.8 / 11.75 although the charge rate seems OK. At the end of the day, the batteries (Lead acid) are never fully charged. Now I thinks to myself – alternators charge at 14.5v.

Inside the charger, there wern't any tappings to change the input voltage, the bridge rectifier seemed OK. What to do? I had a roll of 1.5mm dia copper wire (retrieved from some old bit of kit), so added a further 20 turns onto the secondary of the transfoemer. BINGO, the output voltages climbed to 7.2 and 13.4 – Just the job.

Now, what was I really going to do today?

BobH

[NJHParticipant @njh]

Today saw the final coat of paint applied to the bloomin' garden gate which was threatening to disintegrate. It has been extensively "re-engineered" with attractive inserts of marine plywood, generous amounts of wood filler, repair plates and screws! The only (other) metalwork involved was making some thick washers to raise the gate on the hinges to allow ground clearance where it had "dropped". This washer construction filled my workshop with swarf as the only bit of steel that I had to hand was much too big and needed lots taken off. Thing is though that when you have a workshop pretty much ANYTHING is possible!

Here then is this weeks most boring picture – well I've been looking at it for days – so share the pain guys!

Norman

PS Just in time – it's started to rain.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, well not strictly M.E. but this evening I've downloaded all my photos from one of my Canon cameras onto an external drive. Some of which I took in Paris on my four day visit eariier this week.

The Eiffle Tower still amazes me from an engineering point of view, but something else that fasinated me was padlocks attached to some of the bridges over the Seine. Apparently this is done by loving couples, whereby they both go and attatch the padlock together and then throw the keys into the Seine in the hope thier love will be locked forever. There was a piece in one of the Frence papers early this week about the authorities having concerns about security and safety issues, the safty issues being the amount of wieght added to the structure and causing some kind of failer aqnd feel they need to address the stuation without being spoil sports.

If you and your lover are going to Paris sometime soon, then maybe you might want to machine yourself a heart shape and then engrave or pierce your names on it.

Some of those with just writing on are starting to rub off or getting weathered away.

Apparently the trend has started in London on the Millenium bridge and I did notice some at the top of the Eiffle Tower.

Regards Nick

[Sub MandrelParticipant @submandrel]

I stripped lots of layers of wallpaper and paint, with a steamer. the top 6" of wall had a layer of plain paper with yellow paint on atht had never been stripped, and must be lining paper for 1937 when the house was built. Some lazy git had stripped it off but couldn't reach all the way! It was really hard to get off as the yellow paint on it was oil based and nearly steam-proof.

I'm sure these would make great (and safe) boilers for running stationary engines slowly, off load. Lots of steam at low pressure.

Also discovered my chinese 12" rule isn't very straight compared to my English one and the slab of kitchen worktop I use as a surface plate isn't warped after all. But now I have an even larger replacement, blagged when I thoght the old one was dodgy!

Neil

[GaryMParticipant @garym]

Posted by Stub Mandrel on 06/09/2013 21:35:18:

………

I'm sure these would make great (and safe) boilers for running stationary engines slowly, off load. Lots of steam at low pressure.

………

Neil

Does anyone think this would work? I'd love to see the little wobbler I made last year running on steam and haven't got round to making a boiler yet so might give it a try.

Gary

[Danny M2ZParticipant @dannym2z]

G'day. I returned a set of T-handled hex keys to the local hardware store. I wondered why this one spun around in the socket. Hmmm, somebody is going to the 're-education camp'. I wonder how many of these slipped past the QC.

Regards from the land of the kangaroo

* Danny M *

[Sub MandrelParticipant @submandrel]

Looks like I have finally got my 'Intellicharger' to work properly with SLA batteries!

What a mess of bug-ridden spaghetti code? Whoever wrote it must have been mutilated by BASIC at an early age

I even got my endian-ness muddled up!

Neil

<At least Andrew might know what I'm on about!>

[jason udallParticipant @jasonudall57142]

Endian….either bitwise or gulivers travels?
..I was once accused of trying to make forth look like UCSD …..even err ed that way with pic’s…structured programming is an affliction…still find myself swimming against the tide in c#

[jason udallParticipant @jasonudall57142]

Grr

Edited By jason udall on 11/09/2013 23:02:56

[Anonymous]

Indeed I do, as alluded to by Jason, the original reference comes from the satire "Gulliver's Travels". In the first chapter Gulliver ends up in Lilliput, and participates in their long running war with Blefuscu about whether you should crack a boiled egg at the big end or little end.

The modern software reference is to do with competing processors from Intel and Motorola. If we consider a processor that uses a 32-bit double word internally, but needs to communicate with an external peripheral that only uses 8 bits, then the processor needs to send four 8-bit bytes. But should it send them most significant byte first, or least significant byte first? It's been a long time since I've designed anything using a Motorola or Intel processor, and I cannot remember who was big endian and who little endian. I preferred the Motorola processors, a much cleaner architecture than Intel with their page swapping.

Most of the designs I do now involve processors with ARM cores, so the issue doesn't arise. Most chips have the peripherals you need on-board, the only exception being SDRAM. And that's a whole different ballgame. In the last design I did using external SDRAM we ended up in a heated argument in the PCB layout review about differential timings of a few picoseconds. Build it and be damned was my considered view!

Regards,

Andrew

Addendum: SDRAM = static dynamic random access memory – what used to be dynamic memory, where the information is stored on a capacitor, which needs to be refreshed on a regular basis. This used to be done externally by the circuit designer, now it's all looked after internally. But the memory is fast, we were using DDR (double data rate) memory at 166MHz. The DDR means 32 bits are transferred every clock edge, positive and negative, so every 3ns. Light travels about 3 feet in that time in a vacuum.

[Bob LambParticipant @boblamb44747]

Andrew, i didn't understand a lot of your post but I do like the idea of light just travelling just 3 feet in a vacuum in a given time. Does this mean there is a "front" to the wave / pulse or whatever of light and, if so, what does it look like and does it change "shape" when it travels through air? Enlightenment on the back of an envelope please – you can tell this has been worrying me as I woke early this morning! Has this set me up for the day?

Bob

[jason udallParticipant @jasonudall57142]

Bob.light has dual nature wave and photon
.the photon is a “quantum” or at least covered by quantum mechanics..nothing in the quantum world has a hard edge.its all really probabilities but yes a photon is typically considered to be 1 nS envelope and travel 300 mm in that time. But really how long is a photon?….

[Gordon WassParticipant @gordonwass]

Jason – now you have started something.

[Anonymous]

Bob: The classical view treats light as a wave, so therefore it has a front, which travels at, well, the speed of light. The wave is seen as having amplitude, frequency and possibly phase. Light is of course an electromagnetic wave, therefore the wave consists of two parts, a magnetic field (A/m) and an electric field (V/m), which are at right angles to each other. Unlike other waves an electromagnetic wave does not need a medium to travel in, it can exist in a vacuum. Note the units of A/m and V/m, the ratio is in units of resistance; this is the impedance of free space, about 377 ohms, which also dictates the relative strength of the magnetic and electric fields. All this applies in the far field, ie, greater than half a wavelength from the source of the wave. In the near field, much less than half a wavelength, the wave is pretty much magnetic only, no electric field. In between the electric field gets it act together and we end up with the classical electromagnetic wave. The definitions of near and far field are a bit imprecise, as you might expect, since there are no sharp transitions. For light the wavelength is pretty short, less than a micron, so the distinction between near and far field is largely academic in everyday life. At lower frequencies this is not the case. A few years ago I designed a radio system running at 30Hz. Why so low? Because it had to work through 1" of cast iron, and over a range of a few metres. The wavelength at 30Hz is about 10000km, so clearly the radio was operating in the near field, essentially magnetic induction as there would be no electric field to speak of.

However, as Jason describes, light has wave/particle duality. Sometimes the behaviour of light can only be explained by treating it as particles, ie, photons, rather than a wave. Due to the Heisenberg uncertainty principle we can never exactly know both the momentum and position of a photon, so if we know it's momentum we don't know exactly where it is, and vice versa.

For the SDRAM issues mentioned the tracks and copper planes on the PCB are designed such that the signals actually travel as an electromagnetic wave in the material of the board. The speed of travel is slower than in free space, due to the relative permittivity of the board material. This value isn't known particularly accurately, 10% may be, so the argument about picoseconds mentioned was largely theoretical.

Regards,

Andrew

[John Stevenson 1Participant @johnstevenson1]

Decided to drill some holes in my new mill as I know it upsets the purists

Dead easy to fit stops the the X axis on a mill but the makers never give a thought to the Y axis.

Soooooooooo,

Belted a hole in the saddle and tapped it M12, length of stainless studding because i had it and a big block to clamp on the ways.

This WM40 has box ways and not dovetails so it makes it an easy job, nice solid thing and dead repeatable.

John S.

[Sub MandrelParticipant @submandrel]

Jason,

With that excellent syntax I am sure all you programs run first time

Andrew,

It's self-imposed little-endianness in an AVR. This suits the architecture but when you have aroutine doing some maths to calculate a target current level and put one of the inputs in the wrong way round you can get a very peculiar result…

John,

You can't put English holes in a Chinese mill!

Neil

[jason udallParticipant @jasonudall57142]

Run first time?
Only in ADA…
Most others were an iterative process

[jason udallParticipant @jasonudall57142]

Regardless of micro, os, language. I find NicolasWirth has it about right. Data structures plus algorithms equalls programmea

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, maybe John had some cheap Chinese twist drills, if so they would be Chinese holes, wouldn't they?

Regards Nick.

[WindyParticipant @windy30762]

Any body got some spare midnight oil I need a few gallons.

After the aerobatics on Saturday and Sunday at the Midland Area Hydroplane Championships major repairs are required.

The midnight oil is being burnt to resurrect my two-piece flash steam hydroplane for my last speed attempts of 2013 at Kingsbury.

It did manage a timed run of 123mph before take off on Saturday.

After some minor repairs it was ready for Sundays attempts.

The speed was building up when it took off again there was a clock reading of 130mph but that was in the air so could be a false reading.

The hull takes time as my epoxy adhesive takes 32hrs to cure but withstands heat better than many fast cures.

Generator and burners was mangled but repairable.

Engine has a steam leak to sort out then to play with cam timing.

Back to the workshop now.

Paul

[OH CHUFF!Participant @ohchuff]

Got my new (to me) lathe today. didn't want to drop it by being a muppet so got that landylift bloke Steve Cox to shift it up my uneven drive, very nice chap and glad i didn't attempt it myself. It's not yet in its final position as i still have some painting to do, but this is it.

[Author]

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