LNER Y4 Build

[jma1009]

hi peter,
you would be far better looking at the gordon smith safety valve designs marketed by Polly engineering.
you will have (i think) to make them yourself as ive done, but they are far superior to the normal valves sold commercially by the trade, and will easily pass the dreaded 'accumulation' test.
cheers,
julian

[peter99]

Julian your advice is appreciated. I will check out with Polly Engineering. Thanks!

[Deleted]

Hi JULIAN---------- why do you say "Dreaded" regarding the safety valve/s accumulation test ??...........If your boiler is rated at 100psi for operating pressure (OP) and the test requires (for instance) no more than a 10% extra (110psi) and your safety Valve system cannot stay below that, then you either have to re-think the valves OR---- down-rate the OP to say 80psi.. This will give a much more attainable 88psi to be held over whatever the period of time the test requires........An added bonus might be a more flexible loco to drive..........I might well have to do just that very thing in the near future with the Bear........I have used Peter Rich's 5" STAR and CASTLE tube sizes allied to a short combustion chamber, fired by a full-width grate...This grate is on a par with a Brit. or a Duchess so I'm anticipating the Evap. rates to be similar........ My boiler has been designed and calculated with 100psi as the OP and will have its' initial Official Hydraulic test done at that pressure.......If the first Accumulation test shows the safety to be struggling then I'm quite happy to down-rate the OP to 80psi.......If that does happen then I might re-configure the superheater design to compensate for that loss of energy.............Well have to "Suck-it-and-See" when the time comes....Maybe those first Hydraulic tests will give an early indication ??............. But that won't be for at least another 18 months ie}--- When John Ellis has actually finished building it...which helps I suppose ?? LoL !!

[jma1009]

hi alan,
i dont quite follow your logic. any safety valve ought to discharge all the steam on the accumulation test. like you ive been at this lark long enough to remember things before the accumulation test in miniature.
there are very few safety valve designs in miniature that will comply with the accumulation test. i spent some considerable time studying gordon smith's articles as i couldnt quite get my head round his reasoning and how his design worked. ive made plenty of 'pop' valves that work perfectly ok. simply enlarging the size of the valve doesnt often have the desired effect. far too detailed to type up why now, but i can send you the EIM articles if you want.
if a safety valve doesnt satisfy the accumulation test then dropping the working pressure is unlikely to help. the gordon smith designed valves have very light springs. i thought to myself 'no way is this going to work'! but you would be surprised!
ive a whole drawer full of the old type stainless safety valve springs that i now consider to be obsolete in the light of gordon smith's design. gordon's design must rank as one of the most important and useful contributions to model engineering in the last 30 years!
cheers,
julian

[peter99]

Has anyone mounted the Y4 brake cylinder?
Am at the point of trying to re-position the Brake Cylinder from the original Y4 drgs to Doug's latest drgs.
Doug's Drg. No.4 shows the centerline of the brake arm/brake cylinder 1" from the centerline presumably of the rear buffer beam,
this agrees when you scale the main GA drg. No.1.
However, the drg of the rear buffer beam, drg No. 2 appears to show the centerline of the brake cyl as 3/4" from the center line of the rear brake beam.
But unfortunately the dimensions locate the brake cyl centerline from the hole for the brake column and they give a dim of 1/16" from the beam c/line!
Am tempted to use the 1" dim as correct, but I thought it best to check with the forum first.
Someone else must have had the same prob?

[peter99]

Further to my above post have now decided to keep the Brake Cylinder in it's original position. i.e. outside of the frames.
Just too many probs what with all the other things to do! Will have to fit the 2nd injector where ever!

[peter99]

Still progressing with the side tanks, cab and the little fittings like lamp holders and lifting eyes etc but think I have solved the balance pipe.
I tried various bought out pipe fittings and made some of my own but none seemed to work very well.
Then whilst browsing the Wickes shelves I cam across a pipe fitting:-

'End feed 15mm full cross over' Pt no. W194602W

It seems to bridge across the two tanks very nicely with no mods so far! Have yet to slot in the boiler but it seems OK!
Worth a try!

[peter99]

Still progressing with the Y4 (slowly!).
I connected up to the airbrush compressor and surprise, surprise, the wheels went round!
Albeit, for about 4/5 seconds before it ran out of puff!
So I have got something right!
Have moved down to the ash pan area, not my most favorite place to be.
Looking around for suitable non-rusting material to hand to make from, all I have is a couple of square feet
of strange 16 gauge stainless steel with an embossed pattern on both sides, which I will have to m/c out and
two sheets of copper, 16 & 18 gauge.
My question is, is there anything wrong in making an ash pan out of copper?

[joanlluch]

Aug 18, 2015 10:40:27 GMT peter99 said:

My question is, is there anything wrong in making an ash pan out of copper?

Copper will oxidate at a fast rate over 300 C. Stainless steel will stand temperatures as high as 900 C with little effect on it. In the core of a burning piece of coal you may have temperatures above 1000 C. Whether these figures are relevant for a mini loco ash pan, I don't know, but I suppose they could tell something. I'm interested as well on whether a copper ash pan has been tried.

[peter99]

Many thanks for your comments 'joanlluch'.
Am sure temperature could be a prob for copper eventually.
Have made a cardboard ash pan to drg but is dosnt fit as it foals the hornblocks etc.
According to drg the ashpan should be a snug fit over the skirt of the boiler. No way!
So as the ash pan is not going to be straightforward, but what is!
Have decided to make out of copper to make easy to hack about and modify.
Then at a later date, out of stainless, like my super heaters. Out of copper now
but later no doubt s.s!

[jma1009]

hi peter,

save the valuable copper and use it for something else! cardboard is much cheaper to try out with!

1/16" steel plate is perfectly ok. stainless is better but not so easy to work with particularly if you have an awkward shape to deal with in the home workshop.

copper is also far too soft. when you drop the ashpan after steaming up the ashpan gets all sorts of abuse. copper will also stay hot if you need to catch the ashpan on raised track steaming bays.

cheers,
julian

[peter99]

hi Julian,
I do take your point. Have been having some doubts about copper.
Just dos'nt seem right for the job.
Will look out some 1/16" steel plate which I have and see what I can do.
Will post a pic of the Y4 shortly.
Currently its on its side as I need to poke about sorting the ash pan!
Cheers,
Peter

[peter99]

Am back on to the Y4 0-4-0 GER/LNER loco. It’s been some years for various reasons. A not small one being the realisation that the boiler does not fit. Although made professionally recognised as being good by the parts supplier, to the drawings andI I have checked this, it is too long.
The frames, cab and tanks were supplied laser cut. The CAD drawings supplied look impressive and I have three sets, what does strike me being an ex-Draughtsman of the old school, is that none of the drawings are dated also on updated copies no mention is made to what the revisions are. All rather in my old school, how shall we say, somewhat unprofessional.
The problems are the two tanks foul the boiler feed valves and the cab fouls the safety valve cover. Also problems with the ash pan fouling. The ash pan looking nothing like the drawing in order to fit.
Anyway, having to sort out my garage/workshop/hobby room for the fitting of a new central heating boiler after 42 years!, I decided to bite the bullet and try to sort the Y4.
The loci runs very nicely even on an air brush compressor albeit not for too long!
The ‘to do’ list is a fair amount, the copper tubing from the header and to all the varies valves etc the mechanical lubricator, the cab and problems which will ensure for sure.
I will endeavour to attach a pic of the loco so far.

[peter99]

Jan 12, 2020 20:57:52 GMT peter99 said:

Am back on to the Y4 0-4-0 GER/LNER loco. It’s been some years for various reasons. A not small one being the realisation that the boiler does not fit. Although made professionally recognised as being good by the parts supplier, to the drawings andI I have checked this, it is too long.
The frames, cab and tanks were supplied laser cut. The CAD drawings supplied look impressive and I have three sets, what does strike me being an ex-Draughtsman of the old school, is that none of the drawings are dated also on updated copies no mention is made to what the revisions are. All rather in my old school, how shall we say, somewhat unprofessional.
The problems are the two tanks foul the boiler feed valves and the cab fouls the safety valve cover. Also problems with the ash pan fouling. The ash pan looking nothing like the drawing in order to fit.
Anyway, having to sort out my garage/workshop/hobby room for the fitting of a new central heating boiler after 42 years!, I decided to bite the bullet and try to sort the Y4.
The loci runs very nicely even on an air brush compressor albeit not for too long!
The ‘to do’ list is a fair amount, the copper tubing from the header and to all the varies valves etc the mechanical lubricator, the cab and problems which will ensure for sure.
I will endeavour to attach a pic of the loco so far.

[martian]

I have just bought some castings and the latest Doug Hewson drawings for a Y4.

What thickness did you use for the main frames? The drawings call for 1/8 inch plate but I'm having difficulty finding a suplier of imperial sizes.

Are the original Blackwall plans available? I'm interested in the installation of the axle driven pump.