What Did You Do Today (2017)

[BazyleParticipant @bazyle]

Over 40 years since I did any metallography but I don't recall using any chemicals more exotic than nitric acid (I think) Do students still have to draw pictures of the specimens or is it all digital colour photos now?

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by Andrew Johnston on 04/11/2017 22:10:12:

Ah ha, overhead crane for lifting bits of equipment? Now that's a real workshop!

Andrew

Hi, guess I must have a real workshop then.

Regards Nick.

[Michael GilliganParticipant @michaelgilligan61133]

Rod,

You may find this of interest … I certainly did.

**LINK**

http://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/metallography.pdf

Chapter 16 [see page 92 of the PDF] covers Etching and Etching Solutions.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Sunday Morning

We've just enjoyed watching this: **LINK**

"Woodturning the Eye"

lt's woodwork, but he has some interesting tools [*] & techniques, and presents much better than many.

MichaelG.

.

[*] Surprisingly, he does not appear to have a radius-turning device

[Anonymous]

Posted by Nicholas Farr on 04/11/2017 23:46:06:

Hi, guess I must have a real workshop then.

Neat.

Andrew

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Michael Gilligan on 04/11/2017 23:55:40:

Rod,

You may find this of interest … I certainly did.

**LINK**

http://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/metallography.pdf

Fascinating -thank you

Rod

[Ian S CParticipant @iansc]

The piece on making an eye was most interesting, I read up on making bowls that way when I was wood turning, but never got round to doing it, might have a go.

Ian S C

[MuzzerParticipant @muzzer]

This guy has a real workshop!

Murray

[Anonymous]

Went better than I thought; the jelly went translucent after vigorous boiling and adding loads of sugar:

Andrew

[Clive HartlandParticipant @clivehartland94829]

I often read about Medlars being used for jam, many say to leave them until they are all squashy ? I do make Plum jam as I have a Victoria tree in the garden, also I make Quince jelly which is a bit hard like the Quince themselves.

In fact i will make jam from any source like damson and I have tried Pineapple but a bit runny. Marmalade with the right bitter Oranges is nice too.

Clive

[Anonymous]

Posted by Clive Hartland on 05/11/2017 15:06:43:

I often read about Medlars being used for jam, many say to leave them until they are all squashy ?

Correct; when picked the centre of the medlar is white, hard and quite bitter. You let them"blet" in a cool dark place. It's a posh name to disguise the fact that the fruit is actually rotting. The centre changes to a light brown goo.

Surprisingly it tastes very nice and is quite sweet. The recipe for the jelly is two thirds bletted, one third not plus two lemons and two apples and water.

I've also had several jam making sessions this year with gages and plums; not least because I've run out of freezer space.

Andrew

[OldironParticipant @oldiron]

Posted by Muzzer on 05/11/2017 12:19:17:

This guy has a real workshop!

Murray

Read that this morning, fascinating. Got to admire his dedication and deride the authorities for their attitude.

[Anonymous]

Posted by Oldiron on 05/11/2017 15:54:37:

Read that this morning, fascinating. Got to admire his dedication and deride the authorities for their attitude.

Pretty impressive build, but I have a certain sympathy with the authorities. The aeroplane looks quite professional, but was it just built or was it designed properly in the first place and built with the correct materials? If he flies it and the wings fall off it's the authorities that will get the blame.

Andrew

[Speedy Builder5Participant @speedybuilder5]

Square windows – Remember the Comet !!
BobH

[Anonymous]

Posted by Speedy Builder5 on 05/11/2017 16:33:29:

Square windows – Remember the Comet !!

Yep, the water test tank was still at Farnborough when I started my training course in 1975.

Andrew

[Cornish JackParticipant @cornishjack]

Posted by Speedy Builder5 on 05/11/2017 16:33:29:

Square windows – Remember the Comet !!
BobH

With a max altitude of 13k, he's not going to pressurise, so window shape doesn't matter.

rgds

Bill

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Andrew Johnston on 05/11/2017 17:06:59:

Yep, the water test tank was still at Farnborough when I started my training course in 1975.

Andrew

I was there in Engineering Physics, July to December '75 on a thin sandwich course . We did some cool stuff on fire suppression systems – involved firing canon shells at wing sections. I never did anything half as much fun in the ensuing 40 years .

Rod

[MuzzerParticipant @muzzer]

Posted by Cornish Jack on 05/11/2017 18:36:53:

Posted by Speedy Builder5 on 05/11/2017 16:33:29:

Square windows – Remember the Comet !!
BobH

With a max altitude of 13k, he's not going to pressurise, so window shape doesn't matter.

rgds

Bill

I thought the Comet failures were due to cyclic stress concentrations and fatigue at the corners of the square windows. But I assumed the stresses were predominantly due to the aerodynamic / gravitational loads rather than pressurisation. I guess both would apply. Which was considered to be the primary root cause?

Murray

[Anonymous]

Posted by Roderick Jenkins on 05/11/2017 18:41:18

I was there in Engineering Physics, July to December '75 on a thin sandwich course

Oeeeer, we overlapped for a couple of months. I started in September 1975, on a thick sandwich course. I was based in the Student Engineer Training Centre by Queen's Gate and next to the IAM. Same corner as the RAE Hostel where we lived; built some time around WW1 and not updated since! Still had 3A and 5A round pin plugs in the rooms.

Andrew

[Anonymous]

Posted by Muzzer on 05/11/2017 19:50:03:

I thought the Comet failures were due to cyclic stress concentrations and fatigue at the corners of the square windows. But I assumed the stresses were predominantly due to the aerodynamic / gravitational loads rather than pressurisation. I guess both would apply. Which was considered to be the primary root cause?

Correct, up to a point. The stress concentrations at the corners of the windows were rather higher than expected. But the basic problem was metal fatigue, not well understood at the time. The root cause was cyclic loading due to pressurisation cycles.

Some fatigue tests were done prior to entry into service. But after the unexplained fatal accidents much more comprehensive tests were done. The large water tank at Farnborough took a complete fuselage, minus the empennage, with the wings sticking out via seals. The fuselage structure could be cycled with water pressure to represent a flight The first fuselage eventually fractured after about 3000 cycles. The prediction was between 1000 and 9000 cycles.

It didn't help that the rivet holes were punched rather than drilled, leading to a rougher internal surface more prone to crack initiation.

Andrew

[Anonymous]

Despite Halloween having been and gone it's been a spoky weekend, but I've made wheelie good progress.

I've been riveting the tyres on two of the front wheels for my traction engines. Here's the riveting set up (staged of course):

This weekend I've got to grips with fitting the spokes. Here is the build jig with the spokes for one side fitted:

And two completed wheels:

Of course there's still a long way to go. A third wheel is nearly done and one more after that. All the spokes need riveting and one pair of wheels need rubber tyres fitted. I've also got to do the rear wheels. Most parts for the rear wheels are made but there is still some welding and fettling on the hubs to do.

It's quite exciting seeing a wheel appear out of the assortment of bits that have been kicking around in the kitchen for months/years. I can even foresee a time when the engines are sitting on their own wheels.

At which point it will be –

Andrew

[Mike PooleParticipant @mikepoole82104]

That would give me a hangover these days.

Mike

[Sam Longley 1Participant @samlongley1]

Posted by Andrew Johnston on 05/11/2017 19:51:57:

Posted by Roderick Jenkins on 05/11/2017 18:41:18

I was there in Engineering Physics, July to December '75 on a thin sandwich course

Oeeeer, we overlapped for a couple of months. I started in September 1975, on a thick sandwich course. I was based in the Student Engineer Training Centre by Queen's Gate and next to the IAM. Same corner as the RAE Hostel where we lived; built some time around WW1 and not updated since! Still had 3A and 5A round pin plugs in the rooms.

Andrew

What is the betting that in a minute these 2 are going to find that they had a long lost daughter together that they never knew about

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Sam Longley 1 on 06/11/2017 07:33:02:

What is the betting that in a minute these 2 are going to find that they had a long lost daughter together that they never knew about

Unlikely. There was no room for me in the hostel so I was billeted in the "officers mess", which was populated by unsociable long term inmates – I went home at weekends.

Rod

[Sam Longley 1Participant @samlongley1]

Posted by Roderick Jenkins on 06/11/2017 09:50:19:

Posted by Sam Longley 1 on 06/11/2017 07:33:02:

What is the betting that in a minute these 2 are going to find that they had a long lost daughter together that they never knew about

Unlikely. There was no room for me in the hostel so I was billeted in the "officers mess", which was populated by unsociable long term inmates – I went home at weekends.

Rod

Yes I suppose so- one would be careful about a bloke who goes around looking at the pin holes in UK plug sockets . I wonder how many do that sort of thing!!!.

Dare not Google it,— in case I get a visit from the "authorities"

( he says as he ducks below parapet)

[Author]

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