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This issue waspublished on: 18 June 2025
The next issue will be on sale: 18 July 2025
Thinking About the Unthinkable
It’sa sad fact that, at some point, we will allhavetoleave behind our hobbies. In many cases our lovedones will face aconfusing collection of items with litle knowledgeof their function or value. This wasbrought home to me recently,inthe case of an engineer whopassed away suddenly.Whatmight have been afew thousand pounds’worth of lathe and millweredisposed of at aknock down price; perhaps moredistressing is that ahouse clearance companywerepaid to remove the rest of the workshop contents. Inthis case,the relatives really had no option as the home needed to be cleared forsale and they had no information on the
contentsortheir value. It makes sense to have at leastarough inventory of the main items in your workshop and their values, perhaps with photos. Youmay well enjoythe exercise, satinyour workshop foranhour or so,going through your favouritetools andmachinery with acuppa or two. Such alistwould also prove invaluable in the eventofa thef,fire or flood. Formorethoughts on this subject, including advice forrelatives, there’san excellentarticle by RogerBackhouse on the www.model-engineer.co.uk Forum at tinyurl. com/229dhy3s, or followthe QR code.
AClub Record?
Some greatnewscametomyatention this week, from theWorthing &District SME. Possibly arecordfor any club, three powerful new5”gaugelocomotives took to the track in four weeks! Firstly, Vice-chairman GeofBashall ranhis superb Southern Region Pacific, Merchant Navy Elder-DempsterLines,followedbyClive Patenwith an Eastern Region Pacific, PeppercornA1 Silurian (who’s build Clive has been serialisinginthe Worthingnewsleter) and mostrecently Chairman,Kevan Ayling unveiled his second scratch-built
BR ‘proposed 2-8-2, Vortigern (see photo). TheClub is justifiably very proud of these membersand their achievements and wonderswhether anyother club mightbe able to matchthis remarkable spectacle.
Club News
One of the stories in last month’s Club News regarded acautionary tale aboutpastevents at another club,mentioned in the Worthing & District Society of Model Engineersnewsletter. I’dliketoassure readersthatDaveCox’s conversations allhappened with the train stationary.InDave’swords "Omissions and mistakes have put acompletely diferent 'spin' on the incidentand made us all involved in the hobbylook rather careless. Particularlythose who go out of their waytotalk to interested membersofthe publicand atempttoatract newmemberstolocal societies, the grass roots of the hobby!" Ourapologies to the Worthing Club and Dave forthe distress caused Therewerealso severalinaccuracies in the report on the Pickering Experimental Engineering and Model Society newsleter, notleast mis-spelling PEEMSand the fact thatJonathan is Chairman, notPresident(MikeSayer).Our
apologies to MikeSayersand PEEMS. It is the nature of Club News thatany material included has to be summarised to fit the space and generally presentedina light-hearted context. Notwithstanding this, it is importantthatwedoour besttopresentthe facts behind the stories accurately Neil
Your magazine is growing and changing into Model Engineer &Workshop.Find out more and letusknowwhatyou wouldliketosee in the new, larger magazine at: www.model-engineer.co.uk/forums
Download drawingsfor Gavin Blakeman’s Rotating Tailstock Chuck Adaptors in largerand smaller sizes usingthis quick link or QR code: htps://tinyurl.com/ybfuk5ah
Hottopics on the forum include:
Aparallel action hand vice started by Fulmen
One interesting solution raises other examples of parallel clamps
Keratin Glue started by Michael Gilligan Memories of various unusual and ofen smelly adhesives.
Farm Boy started by Dalboy Making awellknown hit and miss engine model.
Come and have achat!
On theCover Next Issue
Our coverfeatures one of the StafordModel Engineering Society’syounger members driving a7 1⁄4” gaugeBRClass 2under the supervisionofDaveBurrage.See page 56 for morenewsfromStaford.
As well as plenty of engineering and hobbyrelateddiscussion, we arehappy for forum memberstouse it to shareadviceand support. Come and join us –it’sfreetoall readers!
In our next issue,
Stuart Gunn makes astart on one of Stuart Models'moreunusual designs.
ARotating Tailstock Chuck Adaptors
Gavin Blakeman recently decided to build an adaptor to allow arotating chuck to be mounted on thetailstockofhis lathe; he lookedata variety of sizes and drawings of larger and smaller versionscan be downloaded from www.model-engineer.co.uk.
tailstock chuckadaptor, photo 1,allows mounting arotating lathe chuck in the tailstock of the lathe. This can be useful for holding work thatcannotbesupported on acentre, photo 2,orbyusing the fixed steady.Examples of usagewould be pipe that needs to be machined on the outside diameter(OD). This canbeheld by the chuckinnerjaws and then the OD machined. If a4-jaw chuck is mountedonthe tailstock, irregular work pieces can also be held formachining.Ifyou area followerof the ‘Cuting Edge Engineering’ channel on YouTube, youmay already be familiar with the use of atailstock mountedchuck
As astarting point, Ilooked at the various smaller 3-jawand 4-jaw chuck sizes. This indicatedthatthere arethree practical sizes to consider, 80mm, 100mm and 125mm. These sizesare available in both 3-jaw and 4-jawback-plate mountchucks. Further,the same size3-jawand 4-jaw chuck also shareregister sizeand have the same mounting hole pitch-circle-diameter(PCD). This impliesthatboth a3-jawand 4-jawcan be mountedon the same back-plate to provide additional flexibility.Thereare diferences in the boresizes between the 3- and 4-jawchucks; this can be overcome, however, by providing diferentsized
preload flanges forthe 3- and 4-jaw chucks. As the preload flangeiseasyto machine, this should notbeaproblem in practice. Additionally,3-jawchucks have three mounting bolts, and 4-jaw chuckshavefour mounting bolts,but it is possible to drill the adaptorfor both 3-and 4-hole bolt paterns. This write-up will provide details fora MT3 arbor with a 100mm diameter chuck. Design packsfor the remaining combinations maybedownloaded from www.model-engineer.co.uk using the link: htps://tinyurl.com/ ybfuk5ah.
Table 1 summarises the various chuck diameters,bores andregisters Ifound. Thechuck diameteristhe OD of the chuck. Youmay need to vary
Table 1
these forother brands of chuck.
Theadaptorconsists of three main components and severalsmaller components. Thereare three components to machine and four components to purchase. Themachined components arethe arbor, fig 1,that inserts into the tailstock and carries the bearingsand the backplate, fig 2, that carries the chuck and the preloadflange. Theadaptorissealed front and backtoprotect the bearings. The seal at the back is astandardlip-type oil seal, while the seal at thefront is provided by aplug with an O-ring thatfits in the boreofthe chuck. The lastcomponents arethe bearings. These arestandardmetric taper roller bearings.
Thelathe Iuse has an MT3 tailstock taper and aswing over the saddle of 230mm. Themain chuck is a160mm diametercamlock mount. Thelargest diameterthatIconsidered would be required forthe tailstock chuck would
Photo 1: Rotary adaptors with chucks fited.
be coveredbythe 125mm chucksizes. Considering thatIalso use this sized chuck on rotary tables and dividing heads, it made sense to plan forthis sized chuck.
Anumber of designs, covering prac-
tical chucksizes and common Morse taper tailstockswereconsidered. These aresummarised in Table2
BEARINGSELECTION
Taper roller bearings areused. In this application theyhaveanumber of advantages. Opposing pairsoftaperroller bearingsare able to support axial (along the axis)and radial (90° to the axis) loadsaswell as moment loads (bending). In this theyare similar to angular contact ball bearings. Taper roller bearings can also carry significantloads, largerthan ball bearingsofthe sameboresize. Taper roller bearingsare separable, allowing the inner race to be mountedseparately from the outer race, simplifying assembly. Another advantageofusing taper-roller bearingsisthattheydonot have to be widely separated to provide adequate support. Moreinformation in taper roller bearingscan be found on the SKF website(www.skf.com).
Thedesign uses backtoback metric taper roller bearingsofthe same size. The bearingsare mounted with the inner race stationary and the outer race rotating Thepreload of the bearingsisdoneby pushing the inner races towardseach other using acap-screw.The cap-screwis non-rotating.Itshould be possible to use angularcontact ball bearingsinstead of taper-roller bearingsastheyare available in thesame ID/OD configurations but have slightly smaller thicknesses (the B dimension in the SKF catalogue). Angular contact bearingswouldalso have a smaller load carrying capacity
Due to the designoftaper roller bearings, theycannothaveseals likedeepgroove ball bearings. Thesealing of the bearingsthereforeneeds to be designed into the application. Greaselubrication is fine forthe slowerspeeds typically encounteredonlathes. This also makes the sealing of the bearingseasier,asno arrangements areneeded to retain the lubricant.
Forthe choice of bearing, the morse-taper major diameterwas used as a guide to the limiting borediameterof the bearing.AnMT3 taper has amajor diameterof24.1mm,thus appropriate
bearingboresizes would be in the range of 20mm-25mm. Using alargershaf diameterdoes notprovideany additional strength as the maximum bending momentisatthe major diameterofthe arborwhereitleavesthe tailstock. This is also the point of least stifness as it tends to be unsupported at this point in practice.
As aresult, foranMT3, abearing bore of 20mm wasselected.
TheODofthe bearing is less constrained. 20mm taper-roller bearingshaveanODrangeof47mmor 52mm. This is significantly less than the diameterofthe back plate.For the 100mm chuck, a47mmODbearing waschosen.
Standardsizeoil seals areused to seal the back of the unit, while O-rings areusedtoform aseal in the boreofthe chuck. This should be suficienttokeep dirt and cutingfluid from the bearings. Thesebearingsare standardised and available from anumber of sources. Iused cheaper bearingsfrom
alocal supplier.Ialso purchasedthe oil seal and O-ring from the same supplier Features areincluded to alloweasier dismantling of the bearingsshould it ever be necessary.However,ifthe bearingsare adequately greased, they should easily lastmanyyears and are unlikely to requirereplacement.
Fig 2A
Fig 2B
Table 2
Fig 1
2: Asmall diameterpart supported by a tailstock chuck.
Component list
NOTES ON 4140 STEEL
4140 is ahightensilealloysteel. This makes it tougher (mechanically)to machine. Iuse carbidetools andtherefore cannotcommentonhow it would machine using HSS tooling.WhatIdo find is thatittakes alot more lathe power to machine than the free cuting steels. Also,when machining thereisalot of heatgenerated and the heatdoes not leave withthe chip.This means thework piece gets exceptionally hotifcoolant is notused, and it is easily possible to
burn oneselfonthe work piece if careis nottaken.
That said, it does give agood,machined surface. Youmay wish to machine using coolanttoremovethe heat.When you aremachining the areas thatrequirea tighttolerance,keep the work piece cool, or cool the work piece before measuring.Ihavefound deviations from hot to cold of 10-20µm (0.01to0.02mm)at times. These sizechanges from hotto cold areclose to thetolerances allowed and careneeds to be taken.
Theapplication is notsoarduous
Photo 3: Aligning the backplate.
thathigh-tensile steel is required and afree-cutingsteel should perform adequately
CONSTRUCTION
Iended up building both a100mm MT3 and a125mm MT3 adaptor. The discussion thatfollowswill featurethe construction of the 100mm MT3 tailstock chuck. Thephotosshowboththe 100mm and 125mm version. Thesame principles apply to both the smaller and largerversions.
Photo
Preload flange
BACKPLATE
Theback-plate,figs. 2A and 2B does notperform an onerous duty and is machined from 1020 or 1214 steel. Icould notobtain asuitably sized piece of 1214 and used 1020.This does requirealot of material to be removed, so an alternativeistomakeupabackplate assembly by welding twosuitable pieces of material together and then machining as aunit
Regardless of the source of the backplate,start by gripping the frontinthe 3-jaw. Face the backsurfaceand then machine the back surface features, starting with the spigot.I lefthe spigot parallel as it provides the gripping surface formachining the opposite side of the back-plate.You willalso need to machine areferencesurface
on the OD of the back plate.The referencesurfaceonly needs to be around 5mm long and should be slightly over the final diameter. This,together with the back surface of the back-plate,will beusedtoclock the back-plate once it is placed in the 4-jawchuck to machine the frontsurface features.
Drill through and boreto40mm (+1.5mm/-0.0mm). The40mm is nota critical dimension but cannotbetoo oversizeasitdoes provide the seatfor the bearing.Using alarge (stif)boring bar,borethe housing forthe oil seal andthe bearing outer race. This bearing outer race mustbeaninterference fit to the housing.The bearing housing should be:
Due to the interference fit, the bearing seatcannotbetestedby ofering the bearing up to the housing. If youmakeamistakeand oversize the bearing housing,donot despair, refertothe notesatthe end thatwill provide ameans to recover(or make Jacques Maurel’sinternal knurling tool as described in this issue! –Ed.).
Youcan machine the first 8-10mm of the bearing housing to 47mm to make it easier to fit the seal. Do notfit the bearing at this time.
Before removing the back place from the chuck, chamferall the edges. Iput alarge (2mm)chamferonthe outside edges and asmaller one in the oil seal area.
Once all the backside features are complete,remove the back plate,swap to the 4-jawchuck and chuck the back plate by the spigot/bearing housing Then carefully centreand align the back plate
Usetwo clock gauges and clock the back plate to as close to zero as possible in both the rotary direction and the axial direction. Anymisalignmentat this stagewill show up as ataper when turning pieces held in the tailstock chuck. Trytoget the run-out at both the periphery of the back-face and the 100mm OD to less than 10µm of TIR. This process took me the beterpart of half an hour to complete,alternately tapping with ahammer and adjusting chuck jaws, photo3
Once the back plate is clocked, clean up and true the frontsurface by taking afacing cut and bring it to final thickness. Machine the OD to final diameter and then machine the registerfor the chuck. This should be 2-3mm deep (depending on your chuck) and slightly
Fig 3
Fig 4
oversize, say0.05mm.
Once this is done, machine the front bearing housing.The diameterand tolerances arethe same as the back side bearing housing.The depth of the bearing housingsneed to be close, but arenot critical, as some deviation can be taken up using thepre-load plug. That said, the closer to specification the beter.
Once complete chamferthe front edges. This time, both chamfers should be fairly small.
It is nowtime to drill the holes forthe mounting bolts.
Iusedthe mill to drill the chuck mounting holes. The125mm adaptor wascounter-bored, while the 100mm wasnot.Inhindsight, Iwouldnot counter-boreand leave the mounting bolts flush with the surface, see100mm adaptorinphoto 1. A3-jawuses 3M8 holes and a4-jawuses 4M8holes. Youcan either drill fora single chuck, i.e. three or four holes, or drill forboth threeand four holes. Idrilledfor both. My approach is to use the zero-degree hole forboth3and 4-jawchucks, and then drill the rest of the holes, three at 120°for the three-jawand 4at 90°for the 4-jaw.
Additionally,toprovidejacking bolts to jack the chuck of the register, Ithreaded the 3-jawchuck holes (spaced at 120°) forM10.AnM8 clearance hole is 8.8mm while the tapping sizefor an M10 bolt is 8.6mm This does giveanM10 thread thatis notfully engaging,but forthe purpose of jacking the chuck of,this will be morethan adequate.Ifyou do use the jackingbolts, protect the threads on the chuck by either using aspecially machined bolt, or drop alength of suitable sized bar in the bolt hole for the jacking bolt to press against, rather than pressing againstthe threads.
Thereare also three groovestobe milledordrilled into the bore of the housing.These aredesigned to facilitate the removalofthe bearingsshould it ever become necessary
ARBOR
Thearbor is amorse-taperwith an extended shaf. This will be machined from asolid piece of round bar.Iused high-tensile 4140,but this is notnecessary, and anybar of known provenance will do
Face the bar to length and centre drill both ends. Drill and tap forthe drawbar (M10 x25mm)and the preload bolt (M8 x15mm). We will be machining thearbor between centres.
Once the holes have beendrilled and tapped, mountthe arborblank back in the 3-jaw. Setthe cross slide over
Photo 4: Seting up forMorse taper turning.
to 30° and using asmall boring bar, machine a60° included angle on both ends. This is required to allowthe holes to properly mate with the centres.
Leavethe cross slide at 30° and place afixed centreinthe chuck and machine afresh surface on the centre. Mountthe arbor between centres with asuitable drivemechanismand machine the bearing mounting surface. This is astraightforwardturning job, but the aim should be to getthe bearing to be aclosesliding fit:
Machinethe surface forthe oil seal to run on and then chamferthe available edges.
Thereare twoapproaches to machining the Morse taper; one is to ofset the tailstock. This has the advantage thatthe taper can then be cut using the automatic feed. Also, if your compound slide hasinsuficienttravel to cut the taper in one pass, this may be the beterapproach.
Theother alternativeistouse the compound and setittothe correct angle forthe taper,and then machine using the compound travel.
Iused the compound method. To get the angle correct, ImountedaMT3 arbor between centres and, using a dial gauge, setthe compound to the correctangle.A similar method can be used if youdecide to ofsetthe tailstock, photo 4
Before starting machining the taper,I used asharpietocover the surface to allowgauging of howfar along the progress was. As my lathe does nothavesuficienttravelonthe compound feed screw,Imachined the taper intwo sections, blending the jointasbestIcould. This turned
out well, and the blend line cannot be seen.
Machine thetaper and test fit to aMorse taper socket.Thereshould be no play. However, awordof caution, Ialmostgot thenew arbor stuck severaltimes as it would not withdraw from the socket and did not yethavesuficientdepth to engagethe ejection mechanism on the tailstock. Once the taper has beenmachined and fits correctly,machine chamfers on anyremaining edges.
Idid notneed to add atang However, your needs mayvary. If you do need atang forthe arbor,machine it from aseparatepiece of stock and thread M12. It can then be screwed in or removedasrequired.
PRELOADFLANGE
Thepreload flange, fig. 3 performs twofunctions. First to provide the preload to thetwo bearingsand second to providesealing forthe bearings. To simplify thedesign, the sealing is provided in the boreofthe chuck using an O-ring.Depending on the boresizes of the chucksthatyou wish to use, this mayrequirea flange forthe 3-jawand adiferentflangefor the 4-jaw.
Thepreload flangeisa simple turning exercise. Anysuitable piece of steel can be used. The sequence Ifollowedwas to grip the backend in the 3-jaw and then to machine all the frontfeatures,including theO-ring groove.Aferan1 1mm hole wasdrilled through, the part wasthen parted of,flipped and the reverseside wasmachined.
Thepreload flangemustbeasliding fit within the frontbearing housing of the back plate
ASSEMBLY
Clean all the partsofswarf and other dirt. If youwanttopaint, or otherwise preparethe surfaces, it should be done before assembling the adaptor, fig. 4
Start by mounting the bearingsinthe back plate.This requires some force, as the outer race is an interference fit in the housing
Initially Itried to usediferential expansion, heatingthe housing in the oven, while cooling the bearing in the freezer but this wasunsuccessful and Iended up pressing the bearings into position.
Iused an hydraulic press with suitable press tooling to press the outer races into position. Ifyou have asuitably sized hydraulic press, thiswill be the best option, ensuring thatthe bearing is properly seatedand goes in parallel to the housing
If youdon’t have access to an hydraulic press, it will be besttomakeupa plug with athrough hole and pull the outer race into position by jacking with ascrew through the centreofthe plug
Once the outer races aremounted, install the oil seal. This can also be pressed in as it can takesome force. Before pressing the oil seal in, remember to grease and install the inner race of the bearing
Thegrease used is notcritical, Ijust used anormal general purpose lithium grease. Be suretoget the grease on the inner race and work it into the space between the rollers, cageand inner race.
Slide the arbour through and then
grease andinstall thefront bearing inner race over thearbour.Followup with the preload flangeand preload cap-screw.Theninstall the O-ring on the preload flange
Thepreload cap-screw can be accessed with the chuck installed, so justdoitup lightly at this time.
Install the chuck and then place the completedunit in the tailstock Test rotation,while tightening the cap-screw.The unit shouldturnwith some resistance.
Tightening thecap-screw is removing anytolerance in the bearings.This provides the runningaccuracy and ensures no playinthe bearings. Once the cap-screw is tightened, there should be no axial or radial playonthe chuck. As the arbor, preload-flange and cap-screw areall non-rotating,the cap-screw should notwork loose and should notneed to have retainer applied.
MAINTENANCE
Theadaptorshould notrequiremuch maintenance butifyou wish to change the grease or bearings, disassembly is simply doneinreverse order
FINAL REFLECTIONS
Both the units Imade up came out well, photo 5.The 125mmhaving 25µm TI Ronthe frontflangeand 5µm TI Ronthe rotation axis. It maybe possible to improvethe frontflange runout by locking the adaptorwith the pre-load screw and then mounting in
the head stockusing asuitable adaptorsleeve and machining the front face. Ihavenot tried this so cannot commentonthe outcome.
The125mm unit is quiteheavy and, in hindsight, Iwould have limited myself to the 100mm unit, which is whythe 100mm drawingsare featured here.
BEARI NG HOUSI NG TOOLARGE?
If youmakeamistakeand oversize the bearing housing,thereare several ways to recover. One way(that Iwould notrecommend) would be to weld up the housing and re-machine it. The reason thatI would notrecommend this approachisthatitwill probably distort the entireback plate andit would be dificult to true up again.
Thebeter approachwould be to continue machining and aim to end up around 5mm largerthan the bearing OD.(Fora 42mm OD bearing, go to 47mm). Nowmachine up aplug thatis the same OD,orslightly under if you plan to Loctitethe plug.
With asize-for-sizeplug,the installation method would be to heatupthe housing,and then press the plug in place, using the thermal expansion to create the diameterdiference. Once the housing has cooled, the plug will notcome out.
Whether youuse an interference fit forthe plug,orLoctiteitinplace,once the plug is in place, it canbedrilled and machined forthe bearing
Photo 5: Completed rotary adaptor.
Photo1:Air-cooled hot air locomotivebyErnst Plank of Nuremburg.
Credit: GerdMaier 2020.
LBSC’s Toy Locomotive Identified?
RogerBackhouse hasunearthed more details about atoy hotair locomotive.
Following my article, HotAir Toy Locomotives in Model Engineer Vol. 226, No.4654,moreinformation has come to lightabout another type of hotair locomotive made by ErnstPlank of Nuremburg.
From his boyhood memo ries the longst anding ME contribu to r, LBSC, drew pictures of the ex te rio ra nd of the inte rior wo rkingsofs uch a toy, figs. 1 and 2 in Vo l. 83, 2068. His depic tion of ah ot air engine with finned cy lindersfor cooling differed from the wate r- cooled model ow ned by AlexP ro cy ks hown in my article. Th ankstot he help of GerdM aier in Germany, who has collected many examples of hota ir engines, an air cooled ErnstP lank locomotiveh as been fo und. It seems thatt his is one of seve ra lk nown, with the wate r cooled example being even ra re r. Howeve r, this to od iffersf ro mt hat draw nbyL BSC from memo ry in 1940, at leastforty ye arsl ater.I th as just one displac er and one powe rcylinder rather than twoofe ach depicted by LBSC, photo 1.U nfortu nate ly the cy linder fins arevery small and wo uld have probably been ineffectivefor cooling
Fig2:The mechanism of the locomotiveasrecalled by LBSC.
As no ot her example has come to lighti ts eems likely thatw hi le LB SC’s memory wa sc orrect abou ta ir cooling,h ewas at fa ult with re ga rd to the num ber of cy linders. Whath ed rew looksl ikeam oree legante ngineering solution. It wo uld probably have wo rked better though wo uld have costm oretob uild, perhaps making it unsuitable fo rt he competitivetoy market .I ts hould be possible to make ah ot air loc omotivea pprox imating to LBSC’sd esign or even to re create the original Vu lkan design of Ernst Plank.
REFERENCE
GerdMaier, Alt Heisslufmotore,(9 booklets -1997-2006), also Compendium Heisslufmotore (digitale Hefreihe).
Fig1:The hotair poweredtoy locomotiveasremembered by LBSC.
We inviteentriesfor the twomodelengineering competitionsthat aredecided by apoll of readersofModel Engineer &Workshop andmembers of our forum, www.model-engineer.co.uk
THEBRADFORD CUP
TheBradfordCup is awardedtothe author of the bestarticle or series in Model Engineer during the previous year.Because of the changeoftitle and rangeofcontent,articlesappearing in Model Engineer in issues 4734 12 January 2024 to 4761, 24 January 2025 areeligible forthis year’scompetition. Next year the competition will cover afull year of Model Engineer& Workshop.Graham Astbury recounts the story of the cup:
At BradfordMES, we were always short of copyfor the BradfordMES Monthly Bulletin as members always
seem to hide their lights under their bushels. In an atempttoencourage people to writearticles forthe Monthly Bulletin,the Commiteethoughtthat some awardfor the bestcontribution to the Bulletinmightbeagood idea. I suggestedtothe Commiteethatit mightbring some publicity to Bradford MES(oneofthe oldestclubs in the country)ifweweretowiden the scope and thereweretobeanaward each year forthe bestarticle appearing in 'Model Engineer'. Martin Evans agreed to do this as he hoped it might encouragepeople to writearticles for ME.Hencethe name of the trophyand whyitis in Model Engineer.The cup
wasdonatedbyBradfordMES to the Society forModel and Experimental Engineers, SMEE, and laterly has been presentedatthe Midlands Model Engineering Exhibition.
Thecompetition first ranin2022 and waswon by MikeTilbyfor his series on steam turbines, photo 1.Subsequent winnershavebeen SteveGoodbody and RonFitzgerald.
Entry to the BradfordCup is by nomination by athirdparty only only, youcannotnominate yourself.Tomake anomination, please send the name of the author and the article in question to meweditor@mortons.co.ukby25 July 2025.
Photo 1: MikeTilbyreceives the BradfordCup from Grham Astbury
THESTEVENSONTROPHY
As well as being acontributor to MEW, John Stevenson, photo2,was known forhis larger-than lifepresence on the Model Engineer forum and his willingness to advise on practical issues and ofen ofer practical help.Funded by manydonations in his memory, the Stevenson Cup wasfirst awarded in 2018. Thecup is engraved“John Stevenson, 1948–2017.Remembered
by his manyfriends”with “Awarded forExcellence in Practical and Useful Workshop Equipment” on the plinth.
TheJohn StevensonTrophyis presentedfor justthat, awell-made and usable piece of tooling,amodification to amachine or an accessory fora tool wherethe fact it workswell is more importantthan makingitlook good.
The lasttwo competitions were won by Bernard Towers, photo 3. Laterly the trophy is also awarded at the
BradfordCup Entry Rules and Conditions
1. Nominations from readersshall be invited in Model Engineer &Workshop magazineinthe July issue.
2. Nominations shall close on the 28 July
3. Nominations should be sentto the editor of ME&W stating:Thatitisa nominationfor the 'BradfordCup'; The author'sname; Thetitle of the article; Theissue number in which it starts; The name, postal address and email address (if applicable)ofthe person nominating the article.
4. All nominations mustnot have been enteredintothe competitionbefore.
5. Anyreader of ME&W maysubmitonly one nomination whichmustnot be their ownwork.
6. Thearticle musthaveappeared in issues 4734 to 4761 and maybeasingle article in asingle issue;asingle article published overmorethan one issue; or a series running in severalparts which may run into or from another year
7. All entriesmusthavebeen nominated by at leastthree people to be eligible. When nominations close, theeditor of ME&W will listall the articles in orderof numbersofnominations.
Thesix articles with thegreatest number of nominationswill be deemed to be theentries to be selected forthe judging.Ifthereare fewerthan six entries forthe Trophy, then the editor mayselect, at his or her sole discretion, additional articles to makethe nominations uptosix.
8.Ifthe editor of ME&W suspects that anyunfair or undue influence has been brought in to atempttoinfluence the selection of entries, then that entry maybe disqualified.The editor'sdecision will be final on this mater.
9. Theeditor mayrejectany entry if it fails to meetadequately anyofthe criteria forinclusiononthe shortlist. These will be that: the article is well writen; it demonstrates some original thinking or design; it reports experimental work undertaken by the author; it is wellresearched; or describes something of interest to model engineersnot published in themodelengineering pressbefore.
10.Articles whichare asimple narrative of building someone else's design willnot be eligible, unless the building involves a noveltechniqueorprocess
11.Priortopublication of the listof entries available forvoting,each author will be contacted to confirm thattheyare willing fortheir article to be enteredinto the competition. They maywithdraw their consentatthis time should theywish to do so.Ifthis occurs,the editorofthe Model Engineer shall select the next article in the listormay substituteanother article of his orher ownchoice.
12. Theentries forthe competition will be listedinnoparticular order in ME&W in suficienttime forreaderstovote. and the date forthe latest submission of votes will be published also.Votes cast afer this date will notbecounted.
13. Voting shall be by an on-line vote by forummembersonthe Model Engineer website(www.model-engineer.co.uk). Readerswho join the forum specifically in order to vote will be allowedtodoso. Voting will be strictly one vote per person. Anyreader of Model Engineer who does nothaveon-lineaccesswill be allowedto vote by writing to the editor of the Model Engineer clearlystating that it is avote forthe BradfordCup and shallname the selected entry and the author.
Midlands Model Engineering Exhibition. Thecompetition is open to all Model EngineersWorkshop readers and Model Engineer forum members, who mayenter their ownwork.We encourageentries of itemspublished in MEW, but unpublished itemscan be entered. To enter, send four good photographsofyour entry with up to 500 wordsofdescriptionbyemail to meweditor@mortons.co.uknolater than 25 July 2025.
cast, or thatanatempthas been made to unduly influence the result of the vote,any questionable voteswill be disregarded and those entries maybedisqualified
15. Thewinner from the six shortlisted authorswill be announced atethe Midlands Model Engineering Exhibition, or other time or venue as decided. Thetrophywill be presentedbya member of the Society of Model and Experimental Engineers.
16. Thetrophywill remain the property of the Society of Model and Experimental Engineers. Thewinner will take responsibility forensuring safekeeping of the trophyuntil the next exhibition. The trophymustbereturned in good condition, in the supplied packaging,ingood time for awarding to the winner of the subsequent competition. However, an A4 certificate of the awardwillbepresentedtothe winning author fortheir retention.
17.The winner mayarrangefor their name and the year of the awardtobe professionally engraved on the base of the Trophyattheir owncost.
18. No alternativeprizes, cash payments or awards will be made. In all maters relating to the competition, decisions made by the editor arefinal
Stevenson TrophyEntry Rules and Conditions
All entries mustbeapiece of practical workshop equipmenti.e.a tool, jig,fixture or amodification to or accessory foran existing piece of equipment. One entry per person.
All entries to the competition must be materially your ownwork (commercial parts etc. areallowable but please be clear about whatthese are) and nothavebeen enteredtothe competition before
Ashort listofentries will be selected by the competition organisers, agroup of peoplewho knewJohn and arefamiliar with his views on workshop equipment.
Criteria forinclusion on the shortlistwill be thatthe tooling is practical and capable of being used foraccuratework in ahome workshop seting.Itshould demonstrate ingenuity,good design, economical use of materials and be appropriately finished for its function.
By entering youconfirm your permission to featurethe entry in the magazines or on the forum.
If practical, youmay be invited to displayyour entry at amodel engineering exhibition in the future.
Thewinner will be selected by apopular online vote by forum members. Readers who join the forum in order to vote will be allowedtodoso. Voting will be strictly one vote per person. In the eventthatthe judges consider invalid voteshavebeen castorthat an atempthas been made to unduly influence the result of the vote any questionable voteswill be disregarded, or entries maybedisqualified.
Thetrophywill remain the property of the competition organisers. Thewinner will takeresponsibility forensuring safekeeping of the trophyuntil the next exhibition. Thetrophymustbereturned in good condition, in the supplied packaging, in good time foraward to the winner of the subsequentcompetition.
Thewinner mayarrangefor their name and the year of the awardtobe professionally engraved on the base of the trophyattheir owncost. No alternativeprizes, cash payments or awards will be made. In all maters relating to the competition, decisions made by the organisersare final.
Photo 2: John Stevenson
Photo 3: BernardTowers with the Stevenson Trophy.
AWorking ScaleAshpan fora Princess Royal
CliveFenn feels that just because acomplex mechanism is hidden, it’snot areason to avoid modelling it. His problem solving required manyinterestingoperations with other applications.
You maybewondering,why write an article about making an ashpan?Well notall ashpans aresimple boxesstuck under thefirebox of alocomotive. Forsome of the largerengines the ashpans could be rather complicatedafairswith very elaborateoperating mechanisms. The ‘Princess Royal’ Pacificsofthe London Midland and Scotish Railway were one such class of locomotive. Theashpan wasofthe hopper type and because
theyhad wide fireboxes it meantthat the sides had very litle depth and the slope wasvery shallow. Also thedoor operating mechanisms involved many rods and cranksand wasvery complicated. Due to the lack of depth on the side slopestheywerefited with two doorsoneach side. These were operated by alever on the fireman's side, thatisthe right-hand side of the cab forLMS Stanier engines when looking forward. Thereason forthese side
Clive’shand-draughted drawingsfor theashpan.
doorswas so thatarakecould be used to push anycompacted ash down into the hopper and makedisposal easier Themechanism to these side doors proved very troublesome, particularly during thewar yearswhen maintenance waspoor.Soitwas decided to remove it and replace it with asimple locking mechanism on the outside of the engine. Whatfollows is adescription of the building of the ashpan for my 5" gaugePrincess Royal, referred to henceforth as a‘Lizzie’,asthis wasthe nickname given to the class
Photo 2
Pho to 1
Photo 3
by railwaymen.
Iamnot abig fanofworkingwith stainless steel and thereforeonlyuse it whenabsolutely necessary.Isay this because there willbethose of youthat maybecriticalofmyuse of mild steel throughout its construction. My first task wastoproduce adrawing and forthis Iconsulted LMS Locomotive Profiles No 4, ThePrincess Royals.
Istill work on an old Rolls Royce drawing board; IknowI am abit of a dinosaur so thereforea bit long in the toothtolearn newtechniques. When onesetsout to build a‘Lizzie’one needs all the sparetime one can muster and Ithereforedid notfancy wasting time learning newideas. Photographs 1, 2 and 3 showthe drawings(these areincluded to showClive’sdrawing skills andare notpresentedasworking drawings-Ed.).
Afer this it wastime to start construction and my first task wasto makethe support studs thatsecure the ashpan to the fireboxfoundation ring.Onthe full-sizeengine there were sevenextra-longstuds down each side whichsupportedthe ashpan and gave the necessary gapof4"between foundation ring and slope of the ashpan. Iopted to use four of these studs down each side as Ithought these would be strong enough to do the job on the model, togetherwith twomorenormal studs front and rear wherethe ashpan comesflush with the foundation ring.These four normal
Photo 6: Hinges test fitedtothe foundation ring studs.
Photo 4: Fixing studs with wedgeshaped coters.
Photo 5: The ashpan fixing studs atached to the fireboxfoundation ring.
studs have flatcotersinthem as per full size, photo 4.Dummy visual efects will be provided forthose long studs thathavebeen omited. Photograph 5 showsthe studs screwed into the foundation ring
Theeighthinges came next, four down each side and these were made from brass. Theconstructionfor these wasvery simple. Ihad no 3/32" brass tube to hand so Ichucked alengthof 3/32" brass rod, faced of the end, then lightly centred with a1/16" centre drill. This wasthen followedbydrilling out to 5/8" depth with aNo. 56 drill at the highestspeed on my MyfordSuper7 (2150). Notall the holes came outdead on centreand the bad ones,onlytwo, were discarded -but Idid notknowthis untilIhad silver soldered the flats on and had cut them of the bar to shape them to size; photo 6 shows the hinges in place on the foundationring
Inow began to construct the ashpan itself using 1/32" mild steel sheet and photo 7 shows the twohopperside sheets squared up using twospacers My next task wastomakeand silver solder in place the curved base, the forwardand rear bases and also the frontand rear ends. Photograph 8 shows the formed plates. Note the mild steel 1/16" x3/16" strips riveted to the
base.These had twopurposes on the full size, first to strengthen the base at the doorsand second to giveagreater door sealing area. Ihaveextended these strips slightly so as to prevent
the platesslipping during the silver soldering operation. They were filed of flush before finalfiting Photograph 9 shows the hopper nowsilver soldered and ready forthe side slopes. Before Ibegan to makethe slopes, Ihad atrial fit of lowering the boiler in place onto the chassis with the hopper in position. All seemed to be fine, so Iproceeded to makethe side slopes, again madefrom1/32" plate With the boiler back on the bench and in the upsidedownposition Ibegan to makecardboardtemplatesofthe tworear horizontalplates. When happyI thenmade themfromthe mild steel plate using the templatesasa former.These were thensecured to the foundation studs and silver soldered to the hopper sides. Photograph 10 shows the tworear slopes inplace.
Inow made templatesofthe forward slopes, photo 11 and when satisfied converted these to steel plate.These
