Here is a list of all the postings JA has made in our forums. Click on a thread name to jump to the thread.
|Thread: Who invented the elastic band?|
Edison, or Marconi.
They claim to have invented, sorry, patentented everthing.
|Thread: evening course|
Many years ago I used workshop evening classes. Everyone happily used the machines and the instructor put his feet up, had a fag and read the paper.
Somehow I felt that we were taking the Micky. Evening classes were about learning and self improvement.
|Thread: Is this usual?|
I have more than one project on the go at any time and swap between them. Like XD351 I box every thing when I stop on a project. I also like to loosely assemble as much as possible.
I feel that keeping a diary of the work done and taking photographs is invaluable. In the olden days this meant having a note book and a few pictures. Now, with computers, one uses a spread sheet and can take thousands of photographs for nothing. My simple spread sheet has a few columns; Date, Part, Part number, Action, Comment and Photograph file name. This is a daily record of work and tries to record everything particularly minor disasters, required tools etc.
|Thread: Buying a Propane Torch|
I use Propane with a Sievert torch (range of sizes) for silver soldering and hardening including case hardening.
I bought every thing other than the gas from CuP Alloys. The gas comes from the local hardware store.
|Thread: Mills with tilting heads..?|
I have a Wabeco with a tilting head. The head is dowelled to keep it vertical in normal use. It is infrequently used tiled, about once or twice a year. However I think it is a useful feature.
One comment, the head moves in the vertical plane but the tool will move at the angle of the head. This, sort of, doubles the thinking required before machining with the head tilted.
Edited By JA on 26/10/2019 12:52:13
|Thread: Slideways oil|
Engine oil should be avoided. New oil contains a lot of additives about which you know nothing. Old oil will contain even more rubbish.
Use the correct stuff which is meant to stick to ways etc. It is cheap and can be bought on the internet. I usually buy my oil direct from Morris. Since they did not sell a slideway oil I ask them where I could get some and was pointed at Premier Oils & Lubricants at Stoke. At this moment they can supply you with 5 Litres of Sideway 68 for £19.20 (incl. VAT) plus the delivery charge.
|Thread: MIDLANDS MODEL ENGINEERING EXHIBITION|
I went yesterday and thought that the show had not really changed other than there were fewer major firms. However I came away with what I wanted - some metal, small bits and pieces and silver soldering stuff.
The models were good but quite a few had been seen before. This does not worry me since models take time to make and there are not too many people who are prepared to display their work.
My major gripe is that the site is small and the major hall is quite cramped. Having said that I liked the chairs along the inside wall. I did not use the catering, we had a late lunch at a local pub.
As for the lack of traders, it was nice to see that the likes of Home & Workshop Machinery, Polly Engineering and Myford were still there. I think Myford may have got their stand about right - you bring things to the show that punters will buy there and then. OK they displayed a couple of lathes. I fully understand the commercial logic for dealers to stay away but I think they should be present is to meet, in person, their customers. In an earlier life I was involved in a large motorcycle club this was always the question; "why should we have a stand at shows?" - the only real answer was "because our members expect us to be there".
Vickers Pyramid Number?
|Thread: A cord of Ash|
While I agree I seem to remember from my boy scout days (60 years ago) that Ash is the ideal wood for fires, kindling, starting and providing heat.
|Thread: Metrication of models|
I re-opened the very old Small Metric Screws because I am about to design and hopefully make a metric model steam engine. My definition of a metric model is that, in addition to metric screws and nuts etc, all the dimensions would be based on millimetres, not inches either decimal or fractions. In other words the bore of the cylinder would 25,00mm not 25,40mm and so on.
Tooling for such a model is very easy. You can buy any cutter, drill, tap or die in metric sizes. I am told you can even buy metric lathes (a Myford owner here). However it soon became obvious to me that small un-plated mild steel screws and nuts were not readily available. Hence I re-open the old thread.
Happy with the replies I was not going to go any further with the thread however DBM decided to run with the subject.
I now realise there is at least one further hindrance to the concept of a metric model - An awful lot of material is still only sold in imperial sizes.
I had not intended for this to become a rant for S.I. units or inches (fractions or decimal). They all have their good and bad points and I am happy using any of them. All I want to do is to try a build a metric engine of my own design.
We were going metric before we joined the Common Market. I remember the hassle at tech, which I left in 1969, with the change to Newtons from the sensible lbf.
Just to keep us oldies happy the metric system does have a M6.35 x 1.27 x 55degrees thread.
Edited By JA on 04/10/2019 17:41:06
|Thread: Metal expansion|
|Thread: Small Metric Screws|
I just sent her the Reeves equivalent of the Zeus booklet.
I know your views about castings but I am not sure if their use will die. This could lead to a debate about castings, barstock and additive technologies such as 3D printing - really another thread.
Many thanks for the replies - nothing has changed.
I re-opened the tread because I have started designing a model steam engine. I decided it should be metric including fixtures. Tubal Cain, in his Model Engineer's Handbook, reports that this was discussed in 1981 and the BSI published a document Guidance on Metric Screw Threads and Fasteners for Use by Model Engineers, PD6507-1982. I have not seen this and I doubt if anyone else has (a copy costs over £100). Soon I have to make up my mind whether to stick to BA or take the plunge and go to metric.
I think, as JasonB suggests, this has serious implications for our hobby.
Obviously there is little point in converting most models to metric since they are only made by the experienced. However the opposite is true for entry kits such as some Stuart models. To be presented with the drawing for a Stuart 7A can be quite a shock for someone who has only known metric units etc. I know from experience since my niece decided to make a Stuart 7A while in six form (the school had, probably still has, a well equipped workshop) fifteen years ago. With the help of her teacher all the dimensions were converted to mm but problems arose when it came to drill sizes. Neither of them had any idea about number drills and the usual shops (local, Axminster Tools) could not help. So uncle was phoned.
Perhaps someone should buy a popular Stuart model and try building it, with a blog, as a complete metric model with dimensions based on mm and not converted from fractions of an inch and with metric fixtures. Just a thought for the future of our hobby.
I do not apologise for resurrecting this very old thread.
Has any progress been made in the model engineering fraternity, users and suppliers, about metric fixings? We seem to be the last to use odd BA sizes and I am sure all BA sizes will go.
|Thread: Aero Fuel|
It is difficult to think of what else an aircraft piston engine would run on. In addition to the above reasons, petrol was a relative safe fuel that people were familiar with.
The only alternative I can think of is a lighter, more volatile, "petrol" that would make starting easier in cold climates. The Russians could have used such a fuel. Their general jet engine fuel is more volatile than aviation kerosene for this reason. In the very early days of the petrol engine more volatile fuel was used with surface carburettors.
One must add that diesel aircraft engines were also used during the War.
|Thread: Water in fuel|
I think the latest postings are slowly drifting off subject again but I have been dying to write something.
AVGAS went up to an octane rating of 130. All the piston aircraft engines used by the British and Americans in the War were designed and initially developed before the War. These engines were either naturally aspirated or had a very low boost pressures. The compression ratio was usually about 7:1 and the octane rating of the fuel was 100 or lower. As the War progressed fuels with higher octane ratings allowed the boost pressure to be increased resulting in very large increases in power with no change in compression ratio.
One little question: How do you dispose of waste fuel responsibly?
Edited By JA on 27/09/2019 20:22:57
Thank you. I have been trying to prevent myself from posting something on water injection.
Major problem with fuels is that the refiners and distributors do not have to tell you what is in the fuel. This includes additives. All the fuel has to do is to meet the specification.
About 12 years ago there were a spate of cases where a fuel additive was destroying an engine sensor and thus engines. I think the fuel suppliers legally hid behind the fact that their fuel met the specifications.
There are firms out there, such as Carless, who will blend a fuel to your specification. We used them at work. Obviously they will not put in banned additives such as tetra-ethyl lead and they will only deliver in bulk. You will have to be able to store it legally and pay tax (VAT and vehicle fuel duty).
Addition - I am sorry to say Vic is probably right. They know who you are - You don't pay road tax and your vehicle does not need an MOT.
Edited By JA on 26/09/2019 14:00:06
|Thread: citric acid|
If it just citric acid I guess you pour it down the sink.
My pickling acid, made from powder bought from CuP Alloys, is now a nice green colour since used acid is returned to bottle. I guess the green is copper citrate. I would think the powder I bought contained a biocide since I never had anything grow in the liquid.
I would guess it is a fungus or some form of lower life. These can turn up in unexpected places such as in petrol and aviation fuel.
Why don't you just try using your citric acid. It will either work or not work. What ever it is will not eat your copper.
Fungi are more likely to be killed by copper than citric acid.
Edited By JA on 23/09/2019 19:05:47
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