BOXHILL by Martin Evans

[Nigel Bennett]

we havent discussed the Stroudley livery yet....!
What we really need is for Phoenix Paints or somebody to bring out some spray-on Aerosol cans of Stroudley's fully-lined out colour scheme - with perhaps a SE&CR one as well....

[Jim Scott]

Julian
Thanks for including the photo of the 10 ton truck - it will look good as a tender.

Slidebars. I too wanted to fit the channel type but the relief required to clear the links etc precludes this. Alignment of the slidebars during assembly depends on some very careful machining beforehand, both on the rear cylinder cover and the motion plate. In fact Martin Evans suggested making dummy slidebars in mild steel first to check for correct fit before replicating same with silver steel. I eventually made some provision for slight adjustment at both supporting points.

A quick note re the valve spindle bushes on the steam chest. Redesign these to be removable, ie with flange and securing studs, then you will be able to install the buckle and valve spindle in one piece, easier than joining them in situ. And of course they could be made to look more to prototype...

Stroudley livery? Painting is at least a year away but I'm already halfway through Chris Vine's book....

Don
Bill's animated diagram shows a horizontal engine, crankshaft on left, cylinder on right. As I understand it, he is measuring link rotation clockwise/anti-clockwise from the link true vertical position. I will look at the Wallace and other sims again though, as previously I wasn't sure about the terminology used.

Glad I'm not starting from Julian's position, although he will undoubtedly be very pleased to have a 'designer' valvegear arrangement. Could put his selling price up!

Jim S

[jma1009]

thank you jim, that is very helpfil advice and i will modify the steam chest glands as you suggest. i have to do a modification in this area anyway because as a result of Don's excellent work the valve travel and lap is now greater and at the rear end of the steamchest the valve buckle boss hits the end of the steamchest if left as designed. i was going to silver solder the valve glands in position onto the steamchest after hearing horror stories of the press fit as designed working loose...luckily i havent done this yet so your advice is very timely.

the big problem with the valve gear as designed appears to be the excessive eccentric throw, apart from all the usual niggles such as no suspension offset, uncorrected eccentric rods, and fine tuning of the lifting arm and lifting link lengths and weighshaft position. Don has increased the lap by a small amount and arrived at excellent valve events in full and back gear without me having to make a new crank axle which has fitted to it the eccentrics of the original design throw of 0.375". Don has redesigned the expansion link to give greater pin centres to compensate for the excessive throw of the eccentrics. this limits the expansion link swing now to 25 degrees, which is a great improvement, and there is a bit more meat on the expansion links for increased clearance, die block movement, and bigger pins. there is also now a suspension offset, and a figure for corrected eccentric rod lengths, and the all important angle of advance and calculations/dimensions for setting the eccentrics. and all squeezed into a very compact space particularly the bottom of the boiler!

so as you can imagine i am incredibly grateful to Don for his hard work.

whilst i'm waiting for the boiler material to arrive i will crack on with the revised valve gear bits!

[donashton]

Jim S,

Re the Hall rotation of the link, I'm sure you are correct and I came to the same conclusion. I must try to be less facetious in future postings! Having said that, I think my invoice to Julian for £4000 will wipe the smile off his face. (can't be bothered seeking the appropriate smiley)

The salient point is that very small dimensional changes have transformed the equality of valve events. Looking at these side-by-side with the Boxhill results makes one wonder that it could run at all in original form, but they do and they satisfy until more people experience the difference.

Don

[jma1009]

as an aside on the Stroudley livery, if i go to Brighton i pay a visit to the Brighton Museum and Art Gallery and say 'hello' to COMO,
Dr J. Bradbury Winter's superb model of this Stroudley loco in Stroudley livery. it was painted by the foreman painter at Brighton Works at the time that the Stroudley livery was still in use, and is therefore regarded as the most accurate example of Stroudley's famous 'improved engine green' livery.

if you are in the area do go and see COMO. it is rightly regarded as one of the masterpieces of miniature locomotive building. exactly 1" scale and correct in every detail, and although never steamed it was run on air after completion.

[isc]

jma1009, I have a bound vol 1, COMO was one of ME's very early articles, interesting reading, sorry I,m too far aay to visit it. Bet they don,t use the same method of keeping rust at bay as Dr j. Bradbury Winter did (He used little trays of pure sulphuric acid, and changed it when the volume increased by 8 times with water). e started it on the 24th Dec 1884, and finished in March 1897. In 1889 he ran it on steam from a small vertical boiler. When intererveued in1898 he had started thebuild of the tender and, expected it to be finished it about 5 years. isc

[jma1009]

thanks isc!
i do have access to a complete set of ME's, and remember the articles on COMO and the rather frightening way Dr J. Bradbury Winter kept rust at bay in his workshop! he also built the congreve clock, and the silver model of ROCKET that is housed in the Institution of Mechanical Engineers, 1 Birdcage Walk, Temple, London, where incidentally a collection of Cherry Hinds' models can also be found.

according to J.N. Maskelyne the Science Museum also had a contemporary Stroudley livery panel which the late Dr Arthur C. Hovenden arranged to be painted at Brighton with a Stroudley brass numberplate in the centre of the panel. Dr A.C. Hovenden was a founder member of the SMEE and owned a number of LBSCR miniature locomotives, and his photographs of the Brighton Line locos at the turn of the last century can be found in a number of books on the LBSCR. (i havent been able to trace the current whereabouts of this panel).

i mention all this because when GLADSTONE and BOXHILL were painted in 'Stroudley livery' at Brighton in 1927 and 1948 respectively, the shade of 'improved engine green' and details of the livery were heavily criticised at the time as being 'wrong'! and even J.N. Maskelyne himself made a number of errors when painting a model he made of a Brighton loco in Stroudley livery!

anyone building a Terrier has an enormous range of liveries and colours to choose from depending on which loco and which period...including Stroudley yellow, Marsh umber, GWR green, LSWR green, IWC red oxide or black, K&ESR blue, SR Maunsell green, and BR black!

[jma1009]

a bit of an update here folks!

ive done the frames and nearly finished machining the horncheecks (hardly any machining allowance on the castings i had!), and have roughed out the axleboxes. martin evans' drawings for the axlebox/horn assembly is atrocious! ive machined up the wheels as close to the fullsize wheels as i can get them (balance weights NOT proud of the wheels unlike martin evans' drawings, and hub and rims a bit thicker, and chamfer to the edge of the hubs). the wheels are finished and ready to go on the axles.

ive also made the chassis and wheels etc for the LBSCR 10 ton wagon.

will try and take a few pics. the cylinders and crankaxle i made years ago so they are all finished.

cheers,
julian

[smallbrother]

I bet you are not making the basic errors I am Julian.

Discovered I have made a right hash of the offset holes in the eccentric sheaves of Scamp.

Lots of swear words in Aberdare today.

Start again tomorrow......

Pete.

[jma1009]

a pic of the LBSCR wagon chassis to go behind STEPNEY...
having never built a wagon before i didnt realise how much work was involved!

Attachments:

[jma1009]

my own version of BOXHILL in the form of A1X STEPNEY is coming along in leaps and bounds. apologies for the poor photos.
photo 1 is a sort of side view of the frames and shows part of my not very tidy workshop,
photo 2 shows an end view wherein can be seen the prototype frame stretchers of 'tray' design that i have incorporated, and the stay over the rear axle for the drawbar and reverser trunnion, again as per prototype.
and photo 3 shows the steam brake cylinder coupled up to air, the cylinder needing to be fitted at an early stage to drill for and clear other bits and bobs. the motion plate is a sif bronze fabrication so i can add the prototype webbing latter on when fitting the slidebars etc. the wheels and axles and crankaxles are ready for fitting too.
i tend to do things in a bit of a daft order to make sure ive drilled all the holes in the frames early on before dismantling for painting, so next job is the sandboxes and hydrostatic lubricator tank hidden in the left hand rear cab box, and right hand rear cab box which all require solid fixings and linking together.

Attachments:

[jma1009]

sorry having a bit of problems with photos.. the above is the 3rd photo..hopefully this is the 1st photo

Attachments:

[jma1009]

this is the 2nd photo

Attachments:

[alanstepney]

Its good to see that you picked the best prototype!

[jma1009]

i took some hopefully better pics yesterday on my mobile of STEPNEY's frames

Attachments:

[jma1009]

another one from the end

Attachments:

[Shawki Shlemon]

Nice job , good progress , all the models have a lot of work on them to do , that is why this is a good hobby , the purpose of the hobby is to kill spare time ;D ;D that is if you have time .

[jma1009]

that is very kind of you, shawki.... i appreciate your comments!

cheers,
julian

[jma1009]

some pics of further progress... buffers fitted. self contained thanks to greenglade's help, and i had to wind the springs myself. there is packing underneath the supports same thickness as the running plate material. STEPNEY had the buffers raised and these supports fitted 1907 and still has them.

Attachments:

[jma1009]

buffer bolts are odd at this stage as need to turn up some new ones which i havent got round to yet!
cheers,
julian

Attachments: