What did you do today (2015)

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jim Greenhill on 02/04/2015 23:06:18:

Niel , I am sure you did not buy concrete in Wickes

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Jim,

Are you really, really, sure ?

**LINK**

MichaelG.

[Nick_GParticipant @nick_g]

Posted by Jim Greenhill on 02/04/2015 23:06:18:

I once asked for a black and white printer catridge, which had same effect on the shop assistant.

.

There are actually such things, although they are not called such. Usually just a string of letters and numbers.

They are designed for printing mono images and come in various tones increasing in density until black (which also has various density's and tone types)

They are designed however for specific printers with the software and profiles able to support them.

On an amusing note not getting what you mean in a shop is illustrated in this classic. **LINK**

Nick

[Danny M2ZParticipant @dannym2z]

Not quite model engineering, but today I heard the local fire engine blipping it's siren as it inched up the road with lights flashing.

A great Aussie tradition here in Victoria on Good Friday, the fire engine is followed by volunteers with collection tins. Kids and parents, dogs on leashes. Unlike some charities, one is not asked for an email address, phone number or any details – just a big smile and a thanks is the reward.

This is happening in every small town and hamlet here in Victoria – The local CFA fieries are also volunteers, only the large cities have the luxury of a fully paid service.

**LINK**

* Danny M *

[Oompa LumpaParticipant @oompalumpa34302]

Well, yesterday actually, I swapped my venerable Quad 303 power amplifier out for my Quad 405's that I monoblocked about ten years ago. The Quad 303 was needing a a rebuild before I started using it in the Office/Workshop. It definitely needs it now! Why monoblock a pair of perfectly good Stereo amplifiers? Because I could:

However, for reasons I could never fathom (out of my depth) one of them would always give trouble and go dead. I struggled and fixed it the first time. The last time I knew I needed someone who actually knew what he was doing because I couldn't find the original schematic I had used to monoblock them I found it yesterday as it happens – looking for something completely unrelated!

Enter Les to the rescue and I can tell you right now, the effort has been well worth it. I rearranged everything yesterday afternoon and they have made a massive improvement. All I need now is my new USB interface cable to arrive (too much background from the laptop power supply) and I can start playing my archive at ten zillion watts!

This is the rear of the amplifiers and I get the hint Les (He has made little tin covers so I can't fiddle with the balance pots on the back – made me smile anyway)

graham.

[robjon44Participant @robjon44]

hi all, I have long believed that many 'old chestnuts' especially in engineering are so often repeated that eventually they are regarded as true, I recently was looking for some citric acid to clean up some copper & brass items, I understood it was used for sterilising babies bottles, wine making equipment, descaling kettles & irons & as an ingredient in fizzy drinks & baking, manufactured in huge quantities yet I could not find any. eventually an assistant in a shop told me that they were not allowed to sell it because it was used in bomb making! I searched the net relentlessly & found a website belonging to a lady giving advice on making hand made beauty products & lo & behold a recipe for making "bath BOMBES" to soften & invigorate ones bath water, you couldn't make it up, 2 days later Mr. Aldi had tons of the stuff, Kilrock descaler.

[DullnoteParticipant @dullnote]

Michael G , I may have got the concrete wrong, but the link made me laugh this morning, one of the best ever. I biuld my own house a few years ago and that is what it felt like in the builders merchant.

Thanks for the link and making me smile good way to start holiday

[Nigel McBurney 1Participant @nigelmcburney1]

Core plane memories,that takes me back to 1967,I was involved maintaining the equipment to feed the X,Y wires through the cores and weld them to the frames,the ferrite cores broke very easily and the pieces got every where in the machines mainly shorting out relays ,we had a suggestion scheme and I got enough suggestions approved for improving the machines that I was able to purchase a new Fobco drill which is still going strong.I was then a procurement engineer on winchester drives and large systems. Only a few MB from large disks ,thousands of punched cards, large systems that required water cooling,that was interesting,especially the traveling around the country working on the problems at foundries and machine shops and sheet metal workshops.When I took early retirement small hard drives had got up to 800 meg around the end of the 1980s ,nowadays its in terra bytes.incredable progress .

[Danny M2ZParticipant @dannym2z]

Citric acid is readily available in the foodstuff aisle at my local supermarket here in Oz.

Very useful to clean cartridge cases in an ultrasonic cleaner prior to reloading. Compared to my vibratory tumbler which takes hours to brighten the brass, three minutes in a cheap (Aldi) ultrasonic cleaner with a tablespoon of citric acid in a cup of water results in shiny cases and one doesn't have the problem of picking the media (crushed walnut shells) from the primer flash-holes. Unlike vinegar which leaves dark stains (from leaching zinc?) it gives a great result.

Bombmaking????? It's only lemon juice!

* Danny M *

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jim Greenhill on 03/04/2015 10:19:02:

… the link made me laugh this morning, one of the best ever. I biuld my own house a few years ago and that is what it felt like in the builders merchant.

Thanks for the link and making me smile good way to start holiday

.

Jim,

I think it's Nick that you should thank for the Fork 'andles link.

MichaelG.

[KWILParticipant @kwil]

Graham,

Quads, thats the ticket!!, I must get around to refurbishing my ESLs sometime, old age affecting us both

[Oompa LumpaParticipant @oompalumpa34302]

Posted by KWIL on 03/04/2015 11:00:16:

Graham,

Quads, thats the ticket!!, I must get around to refurbishing my ESLs sometime, old age affecting us both

Mine are in bits at the moment. Bought the full refurbishment kit from the chap in Australia about twelve months ago. Really must make the effort this summer. The thing that has slowed me down is you need quite a large room to work around the panels but – inspired by another thread on a forum far away, I am on the lookout for a Gazeebo thing with all four walls to make a pop up spray booth in the garden.

Wonder what she will say to that. I'll let you all know when it happens

graham.

[Neil WyattModerator @neilwyatt]

> No Ian, I learnt about Eccles-Jordan flip-flops as an RAF apprentice at No 1 Radio School, Cranwell

When were you there? My Grandfather, John Wyatt, taught radar at Cranwell in the post-war years.

Neil

[Les Jones 1Participant @lesjones1]

This is just to clarify the term "monoblocking" in Graham's post on his Quad amplifiers. When Graham asked me to have a look at the faulty unit I did not know what monoblocking meant, It means the stereo amplifier is used as a mono amplifier to give twice the power. There is two ways of doing this. The first one is to drive the amplifiers in antiphase with a phase splitter. the load (Loudspeaker) is then connected between the outputs of the amplifiers so the available voltage twice the original. If the amplifiers are rated for 8 ohm output impedance then using them this way requires the use of a 16 ohm speaker. No balancing is required in this configuration. The second way is basically paralleling the amplifiers. The problem with this is that if the gain of the amplifiers is slightly different the outputs will be different so there would be a difference of voltage between the two outputs. If they were to be connected directly together a large current would flow between them. To get around this problem a balance potentiometer is connected to the inputs of the pair of amplifiers. To adjust this potentiometer the input signal is adjusted so the amplifiers are giving near their maximum output with the outputs NOT connected together. The balance potentiometer is then adjusted so the voltage measured between the outputs is as near to zero as possible. This can be done with differential inputs on an oscilloscope or a loudspeaker connected between the outputs. Once this is done then each amplifier is connected to the common output terminal via a very low value resistor. (0.3 ohms in this case) These resistors reduce any tendency for the amplifers to fight each other due to any slight remaining inbalance in output of the amplifiers. In this configuration if the amplifiers are rated at 8 ohm output impedance then the load needs to be 4 ohms to get the full output of the pair of amplifiers. This is why I wanted to be sure the balance potentiometer was not moved accidentally which could cause the amplifiers to destroy each other.

Les.

[IanTParticipant @iant]

RobJon – re Citric Acid availability

I used to get mine at our local wine making shop (now long gone). I managed to buy 50gm (£2.65) at Tesco's pharmacy just before Christmas (enough for several jam jars for smaller items) but it obviously didn't last that long.

When I tried to get new supplies recently (at Boots) I was treated like an elderly version of the guy from "Breaking Bad". Apparently it is also used to 'cut' drugs these days.

Fortunately, it seems that culinary grade Citric acid is also used extensively in Indian cooking – and I managed to purchase a 1Kg bag for just over £5 on eBay – which included postage. So (at least for now) my solder & brazing 'pickling' activities are secure….

IanT

[Dennis DParticipant @dennisd]

Re Citric acid I usually get mine from Wilkinsons . Find it where they do the home brew equipment. Pity I retired from the sweet factory we had it in 1 tonne bags there.

[Neil WyattModerator @neilwyatt]

> Niel , I am sure you did not buy concrete in Wickes, did you not buy cement to make concrete.

Hi Jim, you can tell the concrete, it has 'concrete' written on the bags.

Neil

[BazyleParticipant @bazyle]

If I buy tinned custard in Asda I have bought custard (plus free tin). If I buy instant custard powder 'just add boiling water' have I bought custard or custard ingredients?

bother, now I'm thinking about apple pie and I've just finished lunch.

Edited By Bazyle on 03/04/2015 14:10:53

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bazyle on 03/04/2015 14:09:59:

If I buy tinned custard in Asda I have bought custard (plus free tin). If I buy instant custard powder 'just add boiling water' have I bought custard or custard ingredients?

.

Don't worry, Bazyle

Wickes use paper sacks, so it absorbs 'free' water from the atmosphere.

MichaelG.

[mick70Participant @mick70]

i know probably basic to vast majority here.

but made my first tapered shaft today, watched someone down model steam club i joined last month do so thought i would have a go.

well happy with it.

[Nick_GParticipant @nick_g]

Posted by naughtyboy on 03/04/2015 15:15:43:

well happy with it.

That's the important bit.

Nick

[Bob RodgersonParticipant @bobrodgerson97362]

Ian,

There might be one or two mud chemical suppliers to the oil industry that could supply it in 25 KG bags. It is commonly used as a cement inhibitor or used to alter the PH of drilling mud.

[IanTParticipant @iant]

Thanks Bob – that source would never have occurred to me for sure!

I needed enough citric acid to fill a bucket for some larger assemblies that needed cleaning up – but once finished, I just let the 'crud' settle to the bottom and then poured off the clearer liquid into plastic milk bottles. I'm sure there's plenty of work left in the solution still – but I didn't use all of the 1Kg bag anyway. So I've plenty of "made up" and "still in the bag" to see me now for a while thank you.

Regards,

IanT

[Robert Turner 1Participant @robertturner1]

A bit late for the thread about The Two Ronnies, but this (very rude) sketch from Stephen Fry and Hugh Laurie was an excellent update to the 'Four Candles' sketch

http://www.youtube.com/watch?v=noSOFIJdfwM

**LINK**

One of those links might work.

[SillyOldDufferModerator @sillyoldduffer]

I stripped the headstock gears in my mini-lathe. This is not a good way to start the bank holiday.

Lesson learned: use a steady when the work needs one. And don't assume that a border-line case will be OK just because the steady is awkwardly stored behind an inconvenient heap of plywood.

The 38mm diameter rod I was turning wasn't securely held in the chuck. It twisted out during a cut and jammed itself neatly between the jaws and the toolpost. The lathe stopped dead with a horrid crunch from inside the headstock. Dismantling revealed ten loose teeth and two mangled gear wheels. Also the drive belt has a small tear in it.

The good news is that:

• replacements are cheap and available.
• this is the first serious problem I've had with the lathe in 6 years.
• there was no sand or other nastiness inside the headstock casting, just grease.
• I now know how to get inside the headstock.

Taking the headstock apart was fairly brutal. I hope I can reassemble it without damaging anything!

[Brian O’ConnorParticipant @brianoconnor49474]

Posted by Neil Wyatt on 03/04/2015 11:21:25:

> No Ian, I learnt about Eccles-Jordan flip-flops as an RAF apprentice at No 1 Radio School, Cranwell

When were you there? My Grandfather, John Wyatt, taught radar at Cranwell in the post-war years.

Neil

Neil,

I was at Cranwell from August 1950 until November 1952, when the school moved to RAF Locking. I don't recall an instructor named Wyatt but then I'm not sure I can recall any of their names, it was such a long time ago.

B

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