Here is a list of all the postings julian atkins has made in our forums. Click on a thread name to jump to the thread.
|Thread: 5" Maid of Kent Build Log|
The late Percy Wood won IMLEC with a Joy valve gear inside cylinder MOK.
If the Don Young Stephensons valve gear version is improved it ought to be equal if not superior to the Joy valve gear version.
I had drives many times of the outside cylinder version and personally I disliked it. Tricky to drive and fire with the sloping grate and leaning over a long tender. But others with different examples had different experiences.
MOK. Where to start!
For the SR L1 (inside cylinders version) you have a choice of Joy valve gear or Stephensons valve gear.
The Joy valve gear version is regarded as very good, but not prototypical.
The Stephensons gear as designed by LBSC in the late 1940s is awful.
Hence, K N Harris, and later Don Young redid it. The K N Harris version is more of a complete rebuild, and has a peculiarity from memory.
The Don Young version is less radical and I would suggest be considered. See ME 7th and 21st November 1969.
The Don Young version could do with amending in some minor details as there is no suspension offset, and the lifting arm length may be wrong on the weighshaft, and I am far from convinced that the rocker arm bearing is in the optimum position.
As for Joy gear being not to prototype, there are lots of things about MOK that are not accurate, and to start with it doesn't have piston valves, so personally I wouldn't be too bothered about this.
The driving wheels are BIG!
|Thread: LBSC 3.5" "Maisie" - steam regulator valve assembly|
Yes, the regulator rod should slide out of the green bit on it's square.
You don't have to undo the red screws at this stage.The valve and linkage will drop down and be retrieved by the wire I specified you must add to stop these bits falling down into the boiler.
Don't remove your '1' and '2'. Don't disturb this assembly please!
If you only need to deal with slack in the linkage of the regulator valve to the square on the regulator rod, then I would leave the regulator body and the steam pipe and tubeplate flange well alone.
You can remove the regulator rod and valve and linkage by removing the regulator handle and the gland for the packing. The regulator rod cannot be withdrawn at this stage because of the collar fixed to it as shown in John's drawing. Therefore you need to remove the flange that screws into the backhead bush.
Be very careful here if the backhead bush is screwed into the backhead as per the drawing (and not additionally silver soldered. Even if this is caulked with 'soft solder' the soft solder can shear.
You can then withdraw the regulator rod but before you do so put some wire around the linkage to stop the regulator valve and linkage falling into the boiler.
The wire can then be used to drop the valve down and be lifted out with the linkage and arm attached.
|Thread: Hydrostatic Lubricator|
Yes, the detail is missing from Don Young's 'Newport', as it is from all his designs except one...
You need to get the copies of LLAS where 'George' is described and the drawings provided.
Another useful source is Roy Amesbury's 'President' design in ME.
Ignore the Cottam/Evans design as per 'Torquay Manor' as this is pointlessly complicated and also has a jet in the sight glass that is far too big IMHO.
If you PM me I might be able to help out.
|Thread: taper pins or roll pins|
Sorry for the delay in replying.
I personally would never use roll pins on the motion, and especially the crosshead to piston rod. Why? Because I've had to remove them for an overhaul, and with great difficulty - with the battering ram effect of piston rod betwixt crosshead distorting them.
A solid fixing is preferable, via a taper pin IMHO.
|Thread: Don Ashton|
Thank you Nick for that information about the 'wayback machine' and Don Ashton's website.
For those who would like to know how much Don Ashton helped us all please see
(I hope the above link works)
Edited By julian atkins on 17/04/2020 01:32:47
Thank you Dave, and Hopper.
To be quite frank, I am surprised that more have not commented on Don Ashton's death. He did so much for our hobby, and was a beacon of light in the darkness of the understanding of miniature locomotive valve gears for the past 45 plus years, and was such a great friend to many of us.
It is with much personal sadness that I have to report the death of Don Ashton of miniature loco valve gear fame, and much else besides.
|Thread: Somerset and Dorset Railway Trust, Washford|
Edited By julian atkins on 11/03/2020 22:32:58
Edited By julian atkins on 11/03/2020 22:51:56
I was deliberately trying to be objective on all this, but you have brought up Mark Smith's press statement, as a WSR PLC board member, that is inflammatory and subjective towards the Somerset and Dorset Railway Trust describing it as a 'cuckoo in the nest' etc.
Probably best to discuss this with me via a PM, rather than detract from the situation the SDRT currently finds itself over Washford and the WSR PLC board serving a 'Notice to Quit' with no warning whatsoever, and less than 2 years after it agreed to a new 50 year lease.
Lots of you must have visited Washford, and lots of you might have an affliation with the old S&D, and anything you might individually be able to do to assist the SDRT would be very much appreciated.
|Thread: Recovering from disaster|
As I stated the other day, I am very pleased that Neil wasn't affected.
I have been very badly affected by 'Storm Dennis' here in South Wales, and have been unable to get buildings insurance for flood or river damage for the past 3 years. I have had to use a specialist company who will insure homes close to a river, but with exemptions for flood or river damage on the policy.
3 years ago my insurance company refused to provide further buildings insurance at all, simply due to a postcode check of the proximity of my home to the River Sirhowy, and my stating the house was within 30 metres of the river, despite no history of flooding whatsoever and the river, apart from last weekend, being 12 feet below the level of the back garden normally.
I used to live on the Isle of Wight where large parts of the Isle of Wight are not covered for subsidence in buildings insurance, if you can get it at all.
|Thread: Allchin 1.5" Injector Options|
Suggest you contact Paviersteam, usual disclaimer, though currently the website omits the previous extensive list of Len Steel injectors to the Gordon Chiverton designs, so I don't quite know what has happened recently.
What is wrong with your father's original injector fitted?
I recall Bill Hughes stating he was going to describe the injector for 'Royal Chester', but I don't think he ever did. I thought I had a complete set of MEs for 'Royal Chester', but I might have missed an issue, as I am not that interested in miniature traction engines generally.
|Thread: 3 1/2" gauge Caledonian Dunalastair III.|
I did have access to a full set of ME's, but don't any longer, but your example is no doubt based on the E L Pearce loco described in ME in 1901 in what was the first 'sort of' construction series of a miniature loco.
Phelps of Treherbert doesn't ring any bells with me, despite having a long association with South Wales.
You should take very careful note of Phil's (Weary) advice.
If you have been told that the LBSC designed valve gear is not worth improving, then those who gave you that advice don't know what they are talking about. KN Harris had a 'go' at redesigning the valve gear, as did Don Young for Reeves; neither solved the problems. Only Don Ashton's redesign gets it right. You can run all 4 on a computer valve gear simulator which will prove what I state.
On the fullsize loco the short combination lever has for the top two 'pins' a 'pin within a pin' to get the required proportions correct with no drop link. The 2 top pins are contained within the valve gear crosshead and guide.
LBSC used a pin below a pin for the 2 top pins, and therefore the combination lever proportions are incorrect.
He also dispensed with the valve crosshead and guide, which causes undue wear on the piston valves. LBSC 'Speedys' are notorious for piston valves that 'blow' after a bit of use, resulting in steam going straight up the exhaust with a 'woof 'woof' rather than a smart 'chuff' 'chuff'.
Roger Froud's example on the modeleng.proboards.com forum site as linked by Phil also has super duper piston valves for bronze cylinders, a redesigned smokebox draughting, and an improved boiler design, and much else besides, plus of course the Don Ashton designed valve gear.
It has the correct curves to the rear of the bunker, and the correct type of rear buffer beam - all defects with the LBSC drawings when compared to fullsize.
|Thread: PGK's 1" Minnie|
The front foundation ring section is milled and filled to be a jolly good fit between throatplate and inner firebox tubeplate, also as you note fitting the side curves of the inner firebox tubeplate, having determined where the inner firebox wrapper will be, to which it will end up abutting. The step on the ends is milled. It isn't a big step, but enough to intersect with a step on the foundation ring sides and avoid that problematic butt joint plus avoid the foundation ring sides moving latter on.
I make the flange depth quite generous.
Quite the contrary.
The front (and latter rear foundation) ring bits are milled and filed to fit the inner plates namely the inner firebox tubeplate, and inner firebox doorplate up to where the inner firebox wrapper starts and later ends. You dont have to have the inner firebox made up to do this for the front piece of the foundation ring, but you would have to hand the already flanged plates for the inner firebox to hand.
Obviously, to do this you need wider section copper first than the simple width of the water space.
Many boiler makers have problems doing the foundation ring sections, and to my mind anything that makes this easier and less fraught ought to be adopted.
I hope this makes sense. A simple sketch would probably make this a lot clearer.
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