BOXHILL by Martin Evans

[jma1009]

I should perhaps add to the above that my own exhaust arrangement differs from Jim's and I have a much freer exhaust. My own example, when run on air, had a very decided GWR type 'chonk' to the exhaust, so far as could be ascertained on air, but that has nothing to do with the valve gear on mine.

I have a large ex-WD compressor of ancient vintage that causes the domestic lights to flicker when running. My workshop is run off the domestic electric circuit off the kitchen and the compressor has quite a large motor.

However, there is a large reservoir tank attached, and so when up to say 60 psi will run a chassis on test for quite awhile with the compressor turned off, and no background noise so one can concentrate on the chassis and playing around with it.

I think the house electrics date back to 1978 so 40 years old... so probably about time to have the house re-wired - but an old 1826 cottage with 20" thick stone walls is not an easy or cheap proposition to get re-wired!

Cheers,

Julian

[Jim Scott]

Sept 5, 2018 23:40:38 GMT runner42 said:

................Did you modify any of the original valve gear arrangements and or the method of sealing the pistons. Notwithstanding any changes the design is probably one of Martin Evans' finest examples of Stephenson's valve gear....................

Hi Brian

Many thanks for your kind words.

Regarding the 'Boxhill' valve gear I am generally in agreement with Julian's comments. Well designed Stephenson Gear should give almost symmetrical results in forward and reverse but the small adjustment Julian mentions - the suspension pin offset - is critical if the cut-off is to be altered during running. The absence of this dimension, which is only about 0.060", and the fact that the eccentrics have too much throw, means that as drawn Martin Evan's Boxhill design doesn't really produce good results. His description in Model Engineer of setting Boxhill's valve is effectively trial and error, which tends to reinforce this. However, although many models have been built and operated as designed (?) I suspect the reverser is left strictly alone when running.

Just a note on simulations - you can get them pretty damn good on the computer but it requires great care to get the dimensions exactly the same on the model. Accumulative small errors will make a difference, eg you can't round up dimensions etc, but generally speaking an accurate simulation is well worth the effort.

Getting 'Earlswood' to run at all using my tiny compressor with a very small volumetric output was quite a surprise to me. Although still a bit 'tight', I can only put it down to the fact that the pistons are sealed with Viton o-rings operating in micro-finished bores, ie no blow-by at the pistons. Even at 9 psi the exhaust beats can be heard quite distinctly but you do have to put the pipework to your ear. I don't fancy running from an Oxygen cylinder as Ed suggests but I did consider hooking up my Argon bottle, - but then its all getting a bit silly.

Onward and upwards now. I hope that this little flurry of posts on Julian's Boxhill thread will perhaps have an effect and stimulate a little more work on 'Stepney'?

Jim S

[jma1009]

Hi Jim,

Your encouragement has not gone unnoticed, and I am very grateful. I am very busy at work currently and working silly hours as you know, but it is I agree silly to have Stepney nearly completed, and within sight as I type this.

Cheers,

Julian

[Jim]

Hi Julian,

Just to add my voice to Jim's in that I hope you soon regain your interest and passion for completing 'Boxhill'.

You have a masterpiece in model engineering nearing completion in thread that has many followers. To stop now would be a tragedy.

Hope to see some progress soon.

Jim (the other one)

[Deleted]

+1 to Jim's comment...hope you find time for Stepney soon Julian.

atb

Pete

[jma1009]

Thank you Jim and Pete!

Your posts were most apt, as I had told Don Ashton the other day as soon as I have finished work on my water damaged porch, having effected repairs to the roof 3 weeks ago, and having cemented and replastered and repainted the interior this week, I promised to get on again with Stepney.

I opened my lounge door into the porch this morning to find a torrent of water cascading down the inside of the porch, and clearly my repairs were of no effect and Storm Callum did it's worst this morning. All my hard work was to no avail, so I will have to get the professionals in.

What a day! And then my end of Ynysddu had a power cut from 3pm till 15 minutes ago. Very pretty and quiet except for the noise of the River Sirhowey at the end of the garden, swollen by Storm Callum, the prettiness being due to candlelight and my collection of old oil railway lamps lighting up my old cottage. Still the drip drip into buckets where the porch meets the lounge door, but no longer a torrent of water as it has stopped raining for the time being.

So my promise to Don has had a bit of a set back. I can't quite understand where the water is coming from, though the rain here today was quite exceptional and severe.

Anyway, Stepney is quite dry and secure, being in the kitchen/dining room.

Cheers,

Julian

[terrier060]

Very sorry to hear about our Welsh weather defeating your cottage, which sound delightful by-the-way, with the stream at the end of the garden! Yes you must get Stepney finished, or after 28 years at it I shall beat you to the line. Your comments are always regarded as valuable and I can blame you if Fenchurch doesn't steam well with your drafting arrangements!! Dare I say maybe you should go CNC (OOOOOOOOOH!!) it has done wonders for my enthusiasm, though I still keep my hand in and do things the old way where I think it is more practical.

I know you have been very busy with work - lets hope you get more free time soon.
Ed

[danlank]

Sorry about your porch, that sounds very frustrating... But I am excited to hear that we may have more instalments on Stepney soon!

[dscott]

Terriers or Roo ers came up in conversations twice over our Weekend and Friday at the Bluebell?
Friends started a quiz and within did various footplate poses as one of them Chris Eden-Green
had a model made by Rapid Prototyping. So kneeling down on the floor, cramped up with left hand
on a lever and other on a shovel. Got a universal Terrier from all.
Sunday on the S15 for an invited few minutes Got "They are Roo ers wi out the TEA!!" When I described
my build collection. As of course The S15 has a levered Firehole door!!

David still floating from the experience.
And Lily who enjoyed the countryside and meeting pets on the stations.

[jma1009]

A bit of an update...

Stepney is now on the kitchen table having the valve gear and motion being dismantled to remove the driving crank axle wheelset.

The other 2 wheelsets will also be removed for painting with Jim Scott's paint.

All thanks to Roger and Ed's visit last Wednesday, and encouragement in forthright terms.

The last thing I think I did on Stepney was March 2018 to make the very long (in my case) specially turned up stainless steel bolts for the wet header.

Since September 2017 I have been researching the involvement of the SS Californian in the Titanic disaster ('The Californian Incident'); this has been most absorbing and enjoyable, and has now sort of come to a conclusion with the publication of a new book by Sam Halpern a few months ago, plus I followed all the hearings day by day of the Grenfell Tower Inquiry in Phase 1.

So Stepney now has my attention again.

I might have to send to Roger pics to post on here - I have a Flickr free account - but cannot fathom out how to post from Flickr on here these days - or from the official ME Forum that I have used a lot on here for much of the later pics.

A major problem is that the boiler has not been officially tested yet. All the construction stages were approved and inspected by the Merthyr Club boiler inspector and the club secretary, but when it came to arrange a proper club boiler test, the club secretary would not release to the boiler inspector the club paperwork to allow the test to be arranged; that led to a big fall out with the Merthyr Club, as you can probably imagine. On here is step by step record of the construction of the boiler plus my own hydraulic tests of the finished boiler to 180 psi with lots of pics (you have to go back to page 25 on here and before for this for my own tests of the boiler and it's completion).

It all got very silly; at the April 2015 AGM of the Merthyr Club it was suddenly and spectacularly claimed by the Chair that I hadn't paid my subs in front of the meeting, and had not been received by the Treasurer, but Dai Roberts got up to say he had received my subs and passed them on to the Treasurer, and my membership card was signed accordingly! I showed the Chair my signed membership card of subs received. Stepney's boiler was completed in June 2014, and in the period between June 2014, and the April 2015 AGM, no date whatsoever could be arranged for a club boiler test!

Very very silly.

Cheers,

Julian

[Deleted]

Hi Julian

Great to see your build active again, I very much look forward to future updates...ahh...clubs and their politics, gets a bit silly at times...I'm sure that when you can do the official test that Stepney will pass with flying colours...

Kind regards

Pete

[dscott]

Some Clubs do have problems and it is usually down to bitter individuals who have found a place to have power that they once had prior to Retirement. 13 years ago I had a big bust up with the Cardiff Club. Basically a younger mob that loved to get drunk, Heavily criticised anyone from England! And turning up with someone brown and Chinese and Pregnant for the weekend event, was the last straw.
Again there was no input from our side of the story, we were not asked. And the fact that the drunken mob had been asked to behave themselves at least twice after midnight speaks volumes. I quietly heard that some events the Police had turned up!!!!

I just walked out of the Newton Abbot Club and rejoined the Plymouth Club after many pages of track rules came out and some did not practice them. They had the use of a JCB early on and did not put the earth in the right places? Yes it was possible to get stranded at one point and need a 7 or 8 pallet stack to get off under the track. At the other end you have to have the shortest footrests to get through a cutting not dug deep enough!!!!! HONESTLY. So a perfect tease when we all turned up at the Garden and Woodland Railway in Thame together.

The Big Railways have their Internal Wraglings as well and The Midhants Thankfully have left that behind but now rely on a mostly PAID staff.

David and Lily.

[dhamblin]

Good to read that you're back on the build Julian, highly appropriate in the Bluebell's 60th anniversary year given the prominence of a certain Terrier

Best of luck getting the boiler officially approved.

Regards,

Dan

[mbrown]

Very much looking forward to seeing progress resumed on Boxhill.

Flickr is easy enough - I don't post pictures very often so I keep having to look up the instructions on the relevant thread this forum. But it comes back to me soon enough.

Malcolm

[jo479]

Who was it that said. "power corrupts and absolute power corrupts absoutely", and I'm speaking as a boiler inspector, it's usually the person who's bought a loco, professes to be an expert and reaches the dizzy heights of Boiler inspector, has never been in charge of anything in their lives, talks through their backside and idiots on the Committee believe them , a recipe for disaster.

[coniston]

I feel for you Julian, this sort of behaviour is just not acceptable in a hobby. I am only pleased that both clubs I belong to have very experienced knowledgeable and pragmatic boiler inspectors. Glad you're back on with Stepney and look forward to hearing about progress.

Chris D

[jma1009]

I think my own experience recounted above was indeed rather extreme, especially as I had been an active member heavily involved in the construction of the new Merthyr Club track at Cyfarthfa Castle.

Never ever had a problem with arranging a boiler test in the IWMES or the Cardiff Club; indeed on the IWMES after I moved from the Isle of Wight in November 1999, boiler tests would be undertaken on their busiest day on annual visits to the April Rally, and on one occasion when Albert North wrote down the wrong date for expiry for the test (IWMES boiler test), Roger Sully of the Cardiff Club did a boiler test with no notice at all so I could run on a busy public operating day (I had joint membership of both clubs for quite a few years).

Anyway, enough of that!

Thanks to all those who have posted and sent PMs and emails.

Cheers,

Julian

[David]

Great news you're back to working on Stepney! Looking forward to future updates and hope you figure out how to get pictures posted.

[Doug]

Fantastic news it’s such a lovely model it really needs to be in steam.

[jma1009]

I suddenly and unexpectedly have this week off as holiday at work as we have to use all our holiday up at work before 1st March!

So I gave up trying to get the crank axle out of the chassis after Roger and Ed's visit in 2020.

However, this afternoon, in just under an hour, I got all the wheel sets out of the chassis. The wheels can now be painted with the IEG arranged by Jim Scott nearly 4 years ago, and a number of other outstanding jobs attempted. One of those is rather tricky.

Years ago I roughly set the valves and valve gear and ran it on air. One of the jobs is also finally to set the valves and valve gear to the sort of precision I aspire to and that Don Ashton, now looking down from above, would be content with.

Cheers,
Julian