Member postings for julian atkins

the Myford Super 7 was primarily designed to give a much higher top speed than the old ML7.

if you run your old ML7 at much higher than the stated top speed (which will require some steppng up on the drive anyway or a faster motor) then please be very careful!

what a lovely gift!

leadscrew handwheels are easy to obtain... i saw quite a few on sale at very reasonable prices at last year's midlands exhibition. you will definitely need the oilers for your top speeds! they arent difficult to make but can easily be bought too. i would stick to the myford oil specification carefully, and before you run your ML7 at top speed make sure the bearings have been cleaned etc, and not too tight and keep a regular check on the temperature with the palm of your hand as loco drivers do on loco bearings! if you are drilling with very small drills eg for injectors then an added sliding drilling spindle to the tailstock can be recommended to increase the speed.

cheers,

julian

hi speedy,

i am very sorry to be pessimistic but if i was presented with a completed boiler with porosity in any joints i would refuse to pass the boiler at all on the basis that any hidden joint could have the same defect eg crown stays. i would have little confidence in full penetration of any joints without seeing both sides of the joint. on a speedy boiler i would especially want to see full penetration of the throatplate to barrel and also that the tapered barrel joint (potentially the most dangerous) was sound too.

i cut up a suspect boiler last year i had been given...good job i did because although the inner firebox looked ok the silver solder hadnt penetrated properly and the (hidden) water space side of the tubeplate joint was defective. it had passed a hydraulic test but wouldnt have lasted long in service and was lethal.

a porous joint has no strength.

suggest you put it down to experience (albeit costly) and have another go. there are many of us on this forum who will be glad to help to ensure your next boiler is sound and a success.

cheers,

julian

not necessarily the 'greatest mechanical invention',

but hidden away and often overlooked and still in regular use are quite a large number of church bells cast as long ago as the 13th century in the UK.

the process used in their manufacture in the medieval times was an incredible art, and by far the largest manufacturing process at the time and for many centuries until the industrial revolution.

that so many ancient church bells remain in regular use is to my mind truly remarkable.

later the same process was used to make bronze cannons.

there was quite a debate in the later part of the 19th century and early 20th century as to whether 'modern' bells' had the same tonal characteristics as their medieval counterparts. and a lot of modern rings of bells incorporate medieval bell metal.

imagine witnessing a half ton bell being cast in 1280! what magic that must have seemed!

have a look at the medieval stained glass windows on the north side of the chancel in York Minster which show how these early bells were cast!

cheers,

julian

speedy,

i dont really understand what could have gone wrong here, in the sense that a porous joint should have been noticed by your club boiler inspector as you submitted the part built boiler at each stage for inspection. a porous joint is pretty obvious and easily seen on inspection after pickling after the relevant braze up. a porous tube joint would be easy to spot. there is quite a well established proceedure for how to braze up an inner firebox and the tubes, depending on the method of fixing boiler stays, and each of the 2 methods avoids direct heat where the silver solder is applied, virtually eliminating the risk of incorrect penetration and overheating of the silver solder.

i agree with keith 100%. ive been using non-cadmium silver solder used by RN as a replacement for easyflo for years. i only use easyflo No.2 for very fine boiler fittings and the like these days.

cheers,

julian

hi phil

i knew don young and he used to supply all the relevant calculations with his boiler drawings for ME. these were checked (he presumed!). the only comment i recall is don being told his safety factor was too great and his plate thicknesses over generous and his stay pitch could be more. he refused to alter his designs which although entailing more work would have reduced the safety factor. i only recall martin evans providing his own calculations for his own boilers and putting them in print when he was heavily criticised over a design. generally the 'calculations' arent published by ME.

what may be a perfectly adequate joint for a professional experienced boiler maker can be a can of worms for a beginner, hence what is often a belt and braces approach with regard to flanges etc.

there are some classic 'bad designs' some old (eg LBSC's BRITTANIA throatplate) and unfortunately some new. a bit of thought and common sense and advice from your boiler inspector will avoid the pitfalls of design AND construction. (a well designed boiler badly made with porous joints or inadequate penetration of the silver solder is as dangerous as a bad design). some of martin evan's 'novel' ideas at simplyfying boiler construction in the 1960's are regarded as pretty 'iffy' these days.

catastrophic failure causing injury (according to the late Jim Ewins) is most likely to occur with a barrel seam coming apart or a dome blowing off when fixed with steel as opposed to stainless or hard PB bolts. unfortunately i still see lots of ordinary steel bolts fixing domes.

i cant imagine you will have a problem reducing your barrel diameter and altering the location of some bushes. however i personally wouldnt reduce the boiler diameter for the sake of saving £35-45 in buying a new piece of tube. it will muck up the tube spacing and water circulation of the boiler and could mean the difference between an excellent steaming boiler and something quite mediocre. although the barrel doesnt contribute much to heat transfer via the tubes to the water, the effect on water circulation would possibly be detrimental, and any alteration required by the smaller barrel in the number of tubes will have an effect on the free gas flow through the boiler which IS very important IMHO. so unless you know what you are doing and can predict the effect of any changes on boiler efficiency too i would stick with the boiler as designed. after all, you will be using considerably more silver solder in value than the cost of a new bit of barrel tube.

i am not familiar with the NORTHUMBIAN boiler design.

cheers,

julian

i have used silverflo 55 quite a bit on boiler work and dont have any problems, in fact i prefer it on boiler work to easyflo. sounds to me like you are overheating the silver solder in the oxy acetylene flame. you must let the copper heat and melt the silver solder.

cheers,

julian

the alan stepney website contains invaluble info, and martin evan's model locomotive construction book contains the info/formulae applied to ME designs. KN Harris's book does likewise. an ability to quite same is essential for any 'new' design or variation of a proven design for a silver soldered copper miniature loco boiler. ive got 4 locos 3.5"g and 5"g which have boilers that arent to any published design. and quite a few of the published designs are very 'iffy' IMHO!

cheers,

julian

Edited By julian atkins on 12/10/2012 00:21:06

hi martin,

i can send you copies of the LLAS article aand drawings for the LSWR S14. the very similar C14 class lasted well into BR days.

i suggest you try and buy a set of ME's for 1968 and 1969. if you have difficulties ive got a full set.

cheers,

julian

RAILMOTOR in 5"g designed by don young...

there are actually 3 variations. No.1 is a model of the Rhymney Railway Hudswell Clarke 0-4-0(T) locos to which don added a tender rather than the carriage originally fixed to the back of the loco. the No.2 version has a smaller boiler and cylinders and a different arrangement of walshaerts valvegear. i built mine as a No.2 chassis (extended and 'narrow gauge-ified', with the bigger No.1 boiler). a very detailed construction series appeared in ME in 1968/9, and don himself built a No.1 RAILMOTOR with a boiler built for him by alec farmer.

the 3rd version is an LSWR S14 0-4-0T loco. 1 sheet of modified drawings by don and a construction article by steve titley and harry lumb appeared in don's magazine LLAS

as don acknowledged, the basic design can be easily altered to suit the builder's own taste. the basic design is unusual in that the rear axle is behind the boiler, so many builders extend the rear of the frames to give a more balanced looking loco, unless you are building a copy of the Rhymney Railway loco. the loco you have pictured has the rear of the frames lengthened.

the RAILMOTOR No.1 boiler is an excellent steam producer and very efficient.

i dont consider walshaerts valvegear unsuitable for a beginner. however having re-built a SUPER SIMPLEX, both the SIMPLEX and SUPER SIMPLEX valvegear parts require a great deal of work. the RAILMOTOR No.2 walshaerts valvegear is very easy to make and you can profile all the parts too if you want (and which i did).

cheers,

julian

i think the main consideration is that it should be a loco you really want to build. it takes a hell of a lot of time, and to maintain that enthusiasm is important in my book.

personally i would stay clear of SIMPLEX and SUPER SIMPLEX. i know many will disagree, but they arent called 'COMPLEX' for nothing. the super simplex is grossely over cylindered with too large a bore. the axlepump you refer to wouldnt work as originally designed. personally i dont like locos with sloping grates which both the above have.

my first loco was a don young RAILMOTOR with No.2 chassis and No.1 boiler as advised personally by don to me. that was 29 years ago! as a beginner's loco i cannot recommend it enough, and don's construction series in ME 1968/9 is excellent. martin evans never drove locos like don did, and don's locos have that something extra compared to martin evans'. so please have look at don's designs... there are lots of excellent designs to choose from. don's designs also dont suffer from some awful valvegear errors and atrocious backheads that perpetuated in martin evans' designs. i am currently building a 5"g terrier STEPNEY, though i have hardly used the martin evans' drawings so far as they are so awful!

anyway, choose a loco you really like the look of that will maintain your enthusiasm, and avoid some of the well known dreadful designs! LBSC's MAISEE is an excellent loco as previously suggested, though the original boiler design is superior to the combustion chambered design in the book. my own favourite to recommend is LBSC's joy valve gear MINX (LBSCR C2X 0-6-0 loco ME 1949/51). unfortunately it isnt listed today..... but is an excellent 5"g loco IMHO

cheers,

julian

Edited By julian atkins on 06/10/2012 00:24:01

Edited By julian atkins on 06/10/2012 00:26:00

hi robert,

i dont know if your drawings have been 'modernised', but your concerns also apply to all the other stuff screwed into the boiler plates on the original PANSY boiler drawings such as the wet header for the steam pipe on the smokebox tubeplate and the regulator bush on the backhead. all should have proper phos bronze (unleaded) bushes silver soldered.

aart from the belpaire firebox stays which are caulked with comsol or silver soldered in position, everything else fitted to the boiler should have proper bushes these days.

cheers,

julian

hi bill,

please put the rings on the ends of the tubes but on the inside (water space) where they fit into the tubeplate. make the clearances about 2 thou, with a few nicks in each hole with a swiss triangular file. flux up generously each side. heat from the opposite side from the rings ie the inside of the 'firebox', and you will see the silver solder flash around each tube once up to heat. this also avoids the risk of burning the tubes. i would silver solder up the inner firebox assembly first before silver soldering the tubes, or do all at the same time if you are a bit more experienced. for the 'smokebox' tubeplate you have to feed silver solder round the end of each tube where it protrudes slightly through the plate with the same clearances and nicks, silver soldering the 'smokebox' tubeplate into the boiler at the same time, making sure there is plenty of heat directed at the top and outside around the top of the boiler as you work around. do not make the tubes a 'press fit' and no need to turn the ends. just make sure absolute cleanliness by way of pickling and rinsing before each stage. when feeding the siver solder into the ends of the tubes at the smokebox end from the outside make sure the job has heated up to the right temperature and try and avoid the silver solder melting in the het of the flame. it should melt by way of the heat of the copper.

good luck,

cheers,

julian

hi robert,

you can make the fitting out of solid then silver solder to the boiler. i would be inclined to fit a phos bronze bush into the boiler and screw the fitting into that. or you can have a look at keith wilson's DUKEDOG and BULLDOG design.

the main problem with the PANSY top feed is the check valves being covered up by the pannier tanks...a huge job to remove if the clacks play up. on mine i followed other examples of the prototype and fitted the clacks into bushes in the backhead with pipes going forward to the front of the barrel.

the top feed isnt the only problem with the boiler fittings... the backhead fittings and blowdown valves were all an after thought partly caused by LBSC's use of the SPEEDY boiler backhead and his row with ME at the time. the blowdown valve arrangement is atrocious as is the lack of a proper manifold/turret. on mine i fitted a proper manifold/turret of GWR type into a bush silver soldered onto the end of the firebox outer wrapper. due to the drawings showing too short a barrel, most builders cant do this, but you can always move the cab forward a bit or better still lengthen the barrel to the correct length. i fitted a 'vertical' blowdown valve on the backhead just above the foundation ring. LBSC's afterthought arrangement weakens the frames at their weakest point already.

cheers,

julian

gosh 0.8mm is small! i would be inclined to use a smaller drill first, and deburr on the inside after, then drill through 0.8mm. i use WD-40 or similar (paraffin alternatively) for drilling copper. there is an ideal drill angle for copper, but you wont be able to do that for a drill of that size by way of re-grinding. not too fast.. not as fast as say drilling brass that size.

good luck!

cheers,

julian

i found graham meek's replies fascinating and very informative. thank you, graham!

i have wanted to make some bulls eye perspex lenses for 5"g loco lamps, but have put this off due to lack of info how to turn and polish the lenses from clear perspex bar.

any cheap sources of small dia clear perspex rod please?!

cheers,

julian

michael, i guess im with you on this one, and whilst i admire 'fizzy's' unconventional approach, i reckon a 6mm inner firebox of steel on a medium sized 5"g loco boiler (where most of the heat is transferred to the water) is unfortunately going to be more than a shy steamer and therefore a complete waste of effort. i built a similar sized conventional all silver soldered copper boiler last year in 6 weeks for £220 in materials (copper and bronze) and say another £100-£200 in silver solder (cant say exactly the amount or value of the silver solder as i already had most of it in stock from many years ago). so not that different in cost to 'fizzy's' boiler.

cheers,

julian

some years ago there was an excellent tool emporium in nottingham permanent market. there used to be a large bin of small BA spanners (chrome vanadium, and ex WD) for sale for pennies each! i bought up quite a few including a selection of metric spanners in the same bin. i have found the metric spanners to be invaluable for BA bolts that turn out to have metric hex heads and are a permanent part of my running kit for my locos. i also often turn up steel BA bolts that are supposed to be BA hex but often arent, so again these spanners are invaluable. also the small hex socket sets (see the market stalls again) are often metric and cost very little. so from my point of view i dont see a problem. the spanners and sockets you need are available! 8, 9, 10 and 11BA seem to be the problem with the trade selling 'BA hex' that is usually metric. for some odd reason i seem to have tons of 12BA hex that i will probably never use up completely!

cheers,

julian

i use old eclipse hacksaw blades ground to the appropriate width for miniature loco springs. not sure i would want the 'bounce' with carbon fibre type blade material!

cheers,

julian

soz meant to type 61962 instead of boldminer. martin evans falways followed the Greenly formlae as set out by 61962. you should be ok with design as drawn, though check with the 1:3 and 1:6 templates.

whilst i dont disagree with Boldminer, who follows the 'Greenly' formula, it would be useful to know what loco you have and cylinder and boiler sizes. also what type of loco, as smokebox volume and dia and height of chimney have a significant effect, as often the 'Greenly' formula wont work with 'squat' chimneys in big express locos with large dia boilers and smokeboxes.

cheers,

julian