Here is a list of all the postings Weary has made in our forums. Click on a thread name to jump to the thread.
Thread: Model Engineer 4366 |
08/12/2009 18:57:34 |
My subscription copy of Issue 4366 arrived today, Tuesday 8th December. |
Thread: How many Boiler makers? |
07/12/2009 11:22:41 |
Tracy tools have that size tap... link |
Thread: Model Engineer 4366 |
04/12/2009 20:32:03 |
Receiving my subscription copy after the issue is on sale in W H Smiths has been the norm for me since about two months ago, I assumed that this was a new policy as a result of some management decision.
Previously, over many years, my subscription copy was always received well before the issue was on public sale.
As now seems to be the normal arrangement I have not yet received the latest issue (4366, 4th December ->
![]() I live in Fulham, SW Central London. |
Thread: How many boiler tubes? |
01/12/2009 22:46:13 |
Evans gives some worked examples, to take one as an illustration:
Formula (as above) d= square root (L/65)
d= internal diameter tube, L = distance between tubeplate. All dimensions in inches
(Suppose)..... 'the distance between tubeplates is 11inches. Then
d= square root (11/65)
= 0.41inches
The nearest standard size tube in this example would be 1/2" outside diameter x 20 swg.'
(thickness of tube walls is dealt with elsewhere in the book).
later in the book he refers to spacing of tubes, referring to drawing the firebox backplate to fit the tubes
' ........ draw in the required number and size of superheater flues as decided beforehand along a horizontal line placed high on the tubeplate. The ordinary tubes are then drawn in, and if the more usual horizontal diamond arrangement is adopted, the top row can be marked out on a horizontal line immediately below the flues and with a pitch spacing of Diameter x 4/3, the center-lines of each subsequent row of tubes being Diameter x 9/8 below one another.
A closer spacing of tubes than this is not recommended, or the circulation of water - never good in locomotive boilers - will be impaired.'
Note: Superheater element and tube requirements are dealt with elsewhere in the text.
I'm afraid that I cannot illustrate the horizontal diamond tube arrangement, but if you experiment with the ratios given above,drawing the tubes as close as possible to each other, then I think you will see that they 'nest', each group of four tubes describing a diamond shape.
This is a 'vertical diamond tube arrangement'
O O O O O
O O O O O O
O O O O O O O
The 'horizontal diamond tube arangement would have the horizontal rows dropped down as close to as possible to each other. In an illustration M Evans places a line drawn horizontaly through the lowest point of each tube in a row below a line drawn through the upper edge of each of the tubes in the row below it.
You are probably best having a look at one of his boiler designs to get the layout he favours.
In the 'original' shay, K Hiraoka seems to have his tubes in a 'vertical diamond tube arrangement' as above. Three tubes in top row, four in second row, three in third row, two in bottom row. |
01/12/2009 21:05:59 |
Maybe of some help as a starting point:
Boiler Design:
(Excerpts from Model Engineer, Vol. 182, No. 4096 Page 748 18 June-1 July1999
![]() ..... 'Conventional wisdom says that the combined tube area should be 1/5th to 1/6th of the grate area and that the tubes themselves should be based up on a ratio of their length divided by the square of their internal diameter. The ratio is suggested to be around 80 and is denoted by the letter 'k'.
Referring to coals high in ash and extra grate area thus being required:
....... 'Experience also teaches that the 'k' ratio might be better reduced by some 25-30% for this situation.
.........Some of the indifferent steaming stems from cramming too many small bore tubes into the barrel which raises the internal resistanc eof the boiler to gas flow.'
Martin Evans in 'Model Locomotive Boilers, their construction and design' writes:
...An examination of the most successful full-sized locomotive boilers shows that the length of the tubes divided by the square of the internal diameter works out at between 50 and 70. For model boilers of all scales therefore, the following formula is recommended:
d= square root(L/65)
where d is the internal diameter of the tube, and L is the distance between tubeplates, both being measured in inches.
As a footnote the 'original' 3.5" Kozo Shay boiler seems to have 12 tubes, each 10mm outside diameter.
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Thread: Maisie GNR |
25/11/2009 09:21:38 |
Sorry about causing chaos with long URLs.
*hangs head in shame*
Thanks for fixing it on my behalf, have checked David Clark's posting 11/06/09 at 09:42, so in future will try and do it right! |
25/11/2009 09:21:34 |
Sorry about causing chaos with long URLs.
*hangs head in shame*
Thanks for fixing it on my behalf, have checked David Clark's posting 11/06/09 at 09:42, so in future will try and do it right! |
24/11/2009 11:36:52 |
Suggest you search using
Henry Oakley atlantic
GNR atlantic
etc. as search term and setting search to images
Also in addition try searching
Maisie
GNR Atlantic
etc. on you tube as there are a number of videos there. Edited By David Clark 1 on 24/11/2009 18:55:10 |
Thread: Boiler making hearth |
06/11/2009 23:28:18 |
This thread elsewhere may assist:
Check ebay for vermiculite fire bricks
I got my fire bricks here: http://www.stove-glass.com/
They gave me good, cheap, quick service. |
Thread: Professor Chaddock |
05/11/2009 11:06:29 |
A couple of searches here http://www.itech.net.au/modelengineer/ should turn up dates, issues, etc., of something of interest.
Most of Prof. Chaddock's turbine writings seem to date from 1950/1 |
Thread: 3d printing!! |
03/11/2009 19:29:58 |
It would be great if you could keep us posted on the machine, how you find using it, how long it takes to learn to use, and any limitations. It seems an excellent piece of kit and I could see lots of uses for it, however I would like more information about real life experiences with the machine from a user like yourself.
Phil. |
Thread: Quartering loco wheels |
23/09/2009 10:08:40 |
Certainly doesn't sound like a quartering problem as your chassis seems nice and free-running.
Fortunately it is often the way with model engineering that further consideration of a perceived problem shows that it is not as disasterous as first thought.
By your step-by step approach you should be able to isolate the point of resistance.
In my limited experience a firm grip is needed to turn a new engine over until it is run in on air.
It sounds as if you have the problem under control - (do you have clearance between the cylinder ends and pistons at full stroke?).
(It seems that only you and I have issues of this type!)
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22/09/2009 19:49:15 |
Yes!
If a balls-up is possible, and even on occassion when it is seemingly impossible I still manage cock things up. Hopefully you can get the faulty wheel-set apart with minimal damage and re-set it, maybe using glue to allow a bit of faffing to get it absolutely exact.
Oh, by the way, even with four-coupled wheels the quartering can be out (how do I know this?), maybe best stick to 'singles'? |
Thread: Novice beginner |
16/09/2009 19:43:58 |
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Thread: Subscription number going AWOL? |
29/08/2009 21:14:08 |
And I thought that I was the only one with this problem of the website seeming to not know that I was a subscriber despite my number being entered, seems as if there is a host of us. |
Thread: old mags |
24/08/2009 19:10:41 |
It can also be worthwhile looking on abebooks.com |
Thread: Moorcock ME 1960 |
30/05/2009 18:30:41 |
Have just spotted that 'myhobbystore.com' also list plans at two different scales for a tug called Moorcock! Link to plans catalogue on this page at right hand side. |
30/05/2009 11:40:41 |
As for plans, this site: http://www.scalehobbies.net/id3.html is listing a fibreglass hull and plans at 1/32nd scale for Moorcock (£55). Don't know if it is the same boat, but might be a good place to start. |
30/05/2009 11:19:59 |
There is a response to a reader's enquiry in ME Vol. 131 (1965) page 191 as follows:
You do not say whether you prefer a petrol or a steam plant or at what scale you propose to build Moorcock. A 5-10cc petrol engine will drive a 1/4in scale model and a suitable steam plant is The Trojan M6 in the Plans Catalogue or the Stuart 10V.
For the larger scale model you could use a 15-30cc petrol engine, the Warrior steam engine (M7) or the Stuart Double 10V.
Index for ME: http://www.itech.net.au/modelengineer/response.asp
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Thread: brazing/siversoldering |
20/05/2009 19:56:25 |
I find that Bullfinch nozzle 4104 running off 6kg Propane bottle is fine for Tich boiler and general brazing. 4105 nozzle is next size up, and whilst I have a 4103 (next size down) it is no real use for copper work, but OK for brazing small steel items.
I also have an Oxy-acetylene set but find it difficult to use for boiler work and so would be interested to hear what size nozzles others are using for this equipment.
Phil
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