Member postings for julian atkins

hi duncan,

if you have any gaps in the construction series let me know and i'll photocopy and send you any missing. the later references are simply comments by don on building his own RAILMOTOR, and dont add anything to the excellent construction series. the only other comment i would add is that on the original designs the water gauge top fitting is on the manifold... i drove a RAILMOTOR before starting my boiler and was rather surprised at the alteration in water gauge level caused by any of the other manifild valves being opened, so fitted a separate elbow to the top of my boiler. i also opened up the exhaust ways from the cylinders and fitted larger connections to the cylinders, and re-designed the exhaust pipes and blast pipe connections. i ended up with a 1/4" dia exhaust nozzle (not bad for a small loco i thought!)

cheers,

julian

Edited By julian atkins on 21/05/2012 23:34:58

hi nigel,

with the greatest respect i think you are about to make a complete cock up of a boiler. ive built a few in 5"g and done IMLEC. i think you are way off the mark. try it as an experimental design by all means, but be prepared to throw it in the scrap bin! i would recommend a copper boiler with 3 x 1" dia superheater flues as the top row, and 12 x 1/2" OD flue tubes underneath. this will give ample free gas flow (though i think your grate area is excessive... beware the 'Greenly' lazy grates problem.... in which case what size are the cylinders?) i would have thought a total of 15 square inches grate to be sufficient for a 5" dia boiler. the keiller formula (as amended by jim ewins ie slightly larger bore tubes) hasnt been bettered in 5"g as a formula. i would depart from it at your peril!

dont forget that the last 1/3rd of the tube length contributes nothing to heat transfer as discovered by jim ewins in a standard type boiler. 22" long tubes for a 5" dia barrel seems rather long to me...makes me wonder what type of loco it could possibly look like! i would be inclined to recess the front tubeplate quite a bit. if you have a wide firebox it is possible you could go up to 9/16" dia flue tubes but you wouldnt get so many in or have the even spacing as described above (from someone who has built a few boilers with 5" dia barrels). in your proposed design you are basically having a huge firebox with a very long barrel with enormous sized flues contributing nothing to heat transfer... the main heat transfer will take place only in the firebox... so what is the point of the long barrel? it does nothing at all for steam production. btw, if you consider heat transfer in the flues, the slower the gasses flow some say the greater the transfer...but if you take this to the extreme and reduce the flow to zero there is no heat transfer!

good luck!

(sorry for the edits... my spelling or keyboard playing up!)

julian

Edited By julian atkins on 21/05/2012 23:03:05

Edited By julian atkins on 21/05/2012 23:18:34

Edited By julian atkins on 21/05/2012 23:22:32

hi duncan,

everything you need is in the 1968 and 1969 volumes of ME, though i think some of the drawings for the No.1 version are missing from ME. i started mine when i was 16, cycling to adgestone to see don himself and inspect his own loco before departing with a set of drawings and a saddlebag full of castings! don confided not to open the cylinder bores more than the No.2 size and to fit the No. 1 boiler, which advice i followed (mine had a No. 2 chassis). steamed on a candle and such a boring loco to drive as it did everything and more required of it without any hassle and plenty of steam! it's still running regualrly now, though a friend now has it. excellent begineer's loco. ive driven a few, and ended up having don's own loco for awhile, which is still on the isle of wight.

if you need ny further info i'd be very pleased to help.

cheers,

julian

hi clive,

i would split a length of 12mm copper tube inserted over a wooden dowel and use that as a lap, or else use a wooden dowel with very fine wet and dry paper (1200 grade) wrapped around till reasonably tight in the bore. wash out afterwards with paraffin. it is very important that the lapping compound cant be squeezed into a recess and cut deeper than required.. hence a split lap or the use of fine wet and dry paper (in it's dry state), plus the use with (very fine) compound of a lap that must be softer than the cylinder material. avoid valve grinding paste like the plague... it's far too course for our requirements. if you use 'brasso' make sure it doesnt dry out during the lapping process. personally i prefer 1200 grade wet and dry paper.

good luck!

cheers,

julian

hi bob,

before you put the driving wheels on, make sure there isnt excessive clearance between the inside of the axleboxes and the outside of the crank webs. martin evans' dimensions have excessive sideplay allowing the crankaxle to move sideways by quite a large amount. about 10 thou each side is all that's required, otherwise you will get excessive wear on the eccentric straps and conn rod big ends.

good luck!

cheers,

julian

hi bob,

the Terriers have Stroudley's pet arrangement of balancing... the crankpins on the wheels are in line with the cranks, and not opposite. the balance weights are opposite the cranks which is why the balanceweights are quite big. by the way i wouldnt personally press on the crankaxle to the wheels and always loctite mine, to avoid damage to the crankaxle. dont forget to put the axleboxes on first if they arent split! (mine are split as per fullsize).

cheers,

julian

my method after pickling is then to scrub the boiler in hot soapy water in the domestic sink. the hot soapy water also helps get rid of heated flux deposits. it issurprising what extra muck comes off after such a wash in hot soapy water. the black stains included.

cheers,

julian

Edited By julian atkins on 16/05/2012 11:56:12

i must wrote in defence of joe and Macc models as i think Deltic007's comments are very unfair. ive been in this game long enough to know of long delays in ordering stuff with Reeves at Marston Green etc for items they have listed in their catalogue but which werent in stock. i have used Macc models a number of times and have always had a reply to my emails and joe has been very helpful in cutting stuff up for me and the postage and packing has always been superb. it takes along time to build a loco, and its not difficult to order well in advance, which is what i always do. i would happily use Macc models again and again. the quality of his materials is excellent and very competitive prices.

i remember visiting the trade counters of some of the more well known suppliers with lists of my requirements and often i would end up with only half the items on my list! expecting same day type service is in my opinion unrealistic unless you are prepared to pay a hefty premium for such a service.

cheers,

julian

hi ian

i have built a few boilers. i dont think you will have any problems using propane for your MANOR boiler.

plenty of thermolite blocks or vermiculite. main problem isnt how you get enough heat but how you produce your tapered barrel. check with your club boiler inspector what type of joint is acceptable on the barrel. the dovetailed castlelated joint requires a high degree of precision even if this type of joint is acceptable these days. a plain castlelated joint may not be acceptable either. how you plan to silver solder the stays is also a concern.... if silver soldering the stays (which i would recommend) you will need to leave the inner firebox door plate off IMHO.

a 4942 burner will be adequate. things get pretty hot and take about 10-15mins to get to temp. then a few seconds of silver solder disappearing very quickly! i havent had any problems with silverflo 55 either, in fact i prefer it for boiler work. main problem with lots of proper firebricks as a furnace is the very intense heat throwback when trying to do the silver soldering. the extra services of another club member with their own propane torch and bottle for the final bits of the foundation ring and the backhead can be recommended.

i do all my siver soldering in doors where i can judge and see the temperature better, and the gas bottle keeps warm! (yes, i leave the door open!)

cheers, and good luck!

julian

hi bob,

i have sent you a PM

cheers,

julian

hi bob,

they are 13/16" x 1 7/8" each, 5/16" thick. thats 13/16", not 1  3/16"!

hope that helps!

cheers,

julian

Edited By julian atkins on 08/04/2012 13:10:54

Answer.... an old one! an old warding file should do. it will remove a skin, and if there isnt a skin it wont suddenly remove a large amount of cast iron, as cast iron is surprisingly easy to file. i file all the spokes on loco wheel castings, so am aware of the problem

hi glenn,

tuning of bells is as complicated as you have established, as there are lots of important factors to determine the correct 'sound' such as the shape and material of the bell, its diameter, and what harmonics you want. the striking mechanism can also make a difference to tone.

a secondhand set of small handbells might be a possibility (try an advert in the 'Ringing World' magazine). however good sets are expensive and probably wont fit in a normal sized clock case anyway. i have repaired/restored sets of handbells, as well as helping out on restoration projects to restore rings of church bells, but casting and tuning a set (of whatever size) is something for the few experts who do this professionally. you can have a go, but you might be very disappointed at the result and have wasted a lot of time and effort. you might get the right strike notes, but getting the right harmonics is quite another matter. i wouldnt want a longcase clock chiming that annoyed me every time it chimed because of some disonance or clashing harmonics!

as you will note from Claude Reeves, he used dome shaped bells to get them to fit into the clock case, and even someone as skilled and knowledgeable as him bought them from Whitechapel Bellfoundry rather than make them himself!

i commend you for making a quarter chime longcase clock. if you contact your local church bellringing guild or local library there are lots of detailed books on the subject though all out of print. trevor jennings' book can be recommended and will lead you on a fascinating path of discovery!

have a look at the following site for a brief analysis of bell tuning

http://www.hibberts.co.uk/tuning.htm

good luck!

cheers,

julian

hi neil,

good luck!

looks like you have quite a bit of careful silversoldering to do to the tensioning ring and tailpiece. the brass probably isnt good stuff so go easy! good quality banjos have bellmetal/gunmetal tensioning rings etc. i would then get all the parts of your banjo properly replated. any cracks in the wooden hoop?

cheers,

julian

hi neil,

i have repaired ukulele banjos. i dont think John Grey and Co made very valuable banjos...pretty bog standard really. the tensioning ring is vitally important both to solidity of construction and tightning of the vellum and tone, and if cracked can otherwise cause an annoying buzz sound. anything other than silver solder as a repair wont be strong enough. easy to silver solder, you just need to get it replated afterwards.

can you take a pic of the tensioning ring where the crack is please? happy to help if i can.

cheers,

julian

hi bob,

you are quite correct about the boiler drawing, and it is a pity that martin evans' drawings show no detail of the firebox stays which can lead to confusion, though if you can obtain copies of the MEs for the contruction series all may become clearer (martin is a bit vague about staying BOXHILL and the methods to be employed). 2 methods of staying are described in the construction series, and there are various methods of making and fitting stays. they connect between the inner and outer plates and on the drawings are shown as 4BA but no detail provided as to material or how to fix them on the drawings. my stays are 1/8" snaphead copper rivets with the snaphead on the inside of the firebox, silver soldered in place with a slightly smaller stay spacing than martin evans at 5/8" pitch on mine, so more stays. i added a few 5BA threaded stays near the backhead on the sides of the wrapper and foundation ring, these stays being made out of 1/8" hard drawn phosphur bronze rod which is easily obtainable. the threaded stays stop the risk of anything shifting when silversoldering it all up! i left my inner firebox doorplate off when silver soldering up the inner firebox. this can be a bit complicated when fitting the inner firehole door and backhead to everything else, and i made up some 3/16" x 40 tpi special stays to go in the inner firebox doorplate when silver soldering the firehole ring to it. the special stays then had a plain 5/32" dia portion to fit in holes very carefully positioned and drilled in the backhead. all fun and games!

the alternative is to use copper or phosphor bronze threaded rod and fit nuts on the inside of the firebox and 'caulk' the stays with a high melting point soft solder such as 'comsol'. with this method the boiler plates are drilled, threaded, and stayed after all silver soldering has been carried out and the boiler is otherwise complete. martin evans sometimes specified gunmetal rod for stays but 3/16 x 40 tpi threaded phosphor bronze rod is IMHO much better and easier to obtain and make. the threaded stays have a plain unthreaded length on the outside of the wrapper.

there are quite a few good books on the subject (one by martin evans and the other by alec farmer) but if you can obtain the MEs for 1968 Don Young provides what i think is one of the best descriptions of boilermaking for beginners in his RAILMOTOR construction series. far better than martin evan's description for BOXHILL IMHO!

the other point about BOXHILL's boiler is the side extension pieces on the outer firebox wrapper. if you think about it there is no need for one each side if you cut and bend the wrapper accordingly...only one side needs an extension piece which simplifies things, and make it the right hand side of the boiler coz the reverser is on the left hand side. this also avoids the extension piece getting in the way of the foundation ring if you are otherwise making the boiler to martin evans' drawings. the extension piece should IMHO be done with quite a high melting point silver solder such as silverflo 24 and you need the appropriate flux for it too. the rest of the boiler can be done with silverflo 55.

i flanged all my own plates, and Don Young had a better method for the dome bush recommended by alec farmer using only a small register compared to the dome bush outer diameter.

hope this is some help!

cheers,

julian

Edited By julian atkins on 03/03/2012 11:54:30

hi bob,

the BOXHILL boiler is unorthodox. there are no longitudinal stays or crown stay girders that connect with the outer wrapper or crown rod stays. the longitudinal stays are replaced with 'palm' stays - the strip of material on the backhead and smokebox tubeplate to strengthen it. (incidentally the new boiler for DOLGOCH built recently by the SVR for the TR has these type of stays). the lack of proper girder stays between crown of the inner firebox and the outer firebox wrapper was a new departure by martin evans in 1963 using instead a curved inner firebox wrapper crown with girder stays that only fit to the inner wrapper. he reckoned that this design avoided the need for proper girder stays and the 'difficulty' of fitting them to the inner and outer wrapper.

i have never had a problem silver soldering proper girder stays to the inner and outer wrapper, so i dont know why martin evans did this. bearing in mind that the BOXHILL boiler has quite a high working pressure because of the small cylinders, and the inner wrapper is shown to be only 1/16" thick, i think his boiler design can be improved upon. (i dont like the BOXHILL boiler design AT ALL!)

see my post of 21/02/2012

http://www.model-engineer.co.uk/forums/postings.asp?th=56115

it is quite a small boiler so poses no problems being a small round topped boiler.

however as you will note from the above link, i have made my TERRIER boiler to be what i think is both an improvement on martin evans' design, and far more like the prototype boiler.

there is no reason whatsoever why you shouldnt fit proper girder stays and longitudinal stays to martin evans' boiler as designed.

cheers,

julian

Peter,

that's a great pic of what appears to be a very well made loco. you could always put the front axle between centres when dismantled for painting and turn the section between the axle boxes down to 1/2" dia.

cheers,

julian

if you make the tanks as a self contained unit anyone starting from new can make the running boards out of steel plate anyway which saves on brass!

peter,

did you find there is much clearance between the top of the front axle and the bottom of the crosshead on your TERRIER? the axle dia is supposed to be 5/8" all along and i would be interested to know if yours is relieved locally to clear the crossheads.

cheers,

julian

hi peter,

it wasnt my intention to put anyone off building BOXHILL, merely to list some of the design faults for the unwary.

i have never liked martin evans' habit of using the running plate as the bottom of the water tanks as this makes assembly and painting difficult, and the saving in brass is minimal and not worth the extra hassle... so i would recommend anyone to make the tanks as self contained units.

also be very careful with the castings as there is hardly any machining allowance on them.

good luck with completing your own TERRIER and the radial tank!

cheers,

julian

Edited By julian atkins on 22/02/2012 10:35:39