RMweb Premium Chas Levin Posted October 26, 2023 RMweb Premium Share Posted October 26, 2023 Nice work Mike - and fast, too! Link to post Share on other sites More sharing options...
mikemeg Posted October 27, 2023 Author Share Posted October 27, 2023 (edited) 12 hours ago, Chas Levin said: Nice work Mike - and fast, too! Thanks Chas, Has to be said that I did use some of the parts from the first build of this chassis, described in the first page of this thread - coupling rods, gearbox, motor and wheels - so that allowed this build to be done more quickly. The sandpipes have yet to be painted and 'rusted'. I do often repeat the final photographs, as I have on the previous posting, as I find the magnification feature on the RMWeb postings does help to get the weathering right. So below is the latest iteration of the weathering process, with everything below the footplate getting a 'diluted' coat of muck and rust. Even so, the loco superstructure is still probably too clean for mid 1950, though a layer of 12" to 1 foot dust does help!! Regards Mike Edited October 27, 2023 by mikemeg 10 2 Link to post Share on other sites More sharing options...
mikemeg Posted November 6, 2023 Author Share Posted November 6, 2023 (edited) LNER B4 So after the brief interruption, to build a new chassis for a J72, it's back to the B4. I have started this phase with the gearbox, which is a High Level Models HiFlier - 60 :1 ratio. While I was in the 'gearbox department' I did take the opportunity to build a new gearbox for one of the A6's, this time using a High Level Models RoadRunner Compact Plus - 60 : 1 ratio. Both motors will have the non-business end of the drive shaft cropped off before the chassis' are fitted The B4 motor is a Mashima 1428; the A6 motor is a Mashima1424. Both of the Mashima motors are from my own stock of Mashimas which I bought some years ago, before Mashima ceased production. So the photos below show the two drive trains B4 (HiFier) and A6 (RoadRunner Compact Plus) with an end on view of the HiFlier to show the various gear stages between the motor and the final drive. Cheers Mike Edited November 6, 2023 by mikemeg 11 Link to post Share on other sites More sharing options...
Popular Post mikemeg Posted November 14, 2023 Author Popular Post Share Posted November 14, 2023 (edited) LNER B4 So after a long period of component assembly, now time to start the final assembly. Five of the six mainframe springs have been added to the chassis, with the remaining one assembled but not yet fitted. The etches for these springs are quite something to behold, with the sheet containing multiple layers for the spring hangars and the springs themselves with the outer layers having half etched detail. Thus the springs can be built to whatever thickness the builder desires; I used two layers on the spring hangars and three layers on the springs. Any more might impinge on the movement of the eccentrics around the centre driving axle. So after 'teasing into place' the various assemblies which sit on or surround the front driving axle and then supporting the inverted chassis on a suitable cardboard box to prevent the whole lot falling out, a quick photograph before I add the last of the front springs. The 'ubiquitous' cocktail stick - I use these things for all manner of jobs - is simply there in lieu of the middle driving axle. There have been a number of areas where I have diverged from the instructions, not least in the assembly of the internal valve gear. I actually soldered up all of the various joints on these two assemblies rather than leaving one unfixed, which meant that slotting them over the front driving axle was made much more complicated. This was a conscious choice to try and avoid those joints from later disintegrating. The brakes and brake linkage have all been assembled but are not yet fitted until the wheels and drive train are fully assembled and checked out. At last I can see the completion of this build approaching!! Cheers Mike Edited November 14, 2023 by mikemeg 20 1 Link to post Share on other sites More sharing options...
mikemeg Posted November 15, 2023 Author Share Posted November 15, 2023 (edited) LNER B4 At this point and before the coupling rods and connecting rods are fitted, time to do a little simple mathematics. For this I use a digital calliper and vernier gauge, which is accurate to around 0.02 mm. a) The ruling measurement for clearances is the distance between the two sets of slide bars, which is 26.2 mm. b) The overall width of a correctly gauged (P4) set of driving wheels is 22.8 mm over the outside bosses. c) Thus the maximum space available for the outside motion is 26.2 - 22.8 = 3.4 mm or1.7 mm per side at the slide bars. However, this dimension would give zero clearance between the slide bars and the motion. d) The thickness of the front journals on the two coupling rods is 0.85 mm. These were assembled without the journal overlays which were applied to the middle and rear journals. Thus, the crankpin nuts on the front journals must be fitted flush i.e. the reverse of their normal fitting, to preserve enough clearance between the front coupling rod journal and the rear of the connecting rod. e) The combined crossheads and connecting rods are assembled such that the connecting rod does not protrude beyond the crosshead and is, in fact, slightly inset. So the positioning of the connecting rod, within the crosshead, does not compromise the 1.7 mm of overall clearance and, in fact, adds a little to it; but how much? Conclusion is that with very careful assembly and attention to these clearances everything will fit and will rotate. Perhaps worth mentioning that on the prototype the footplate steps, initially fitted between the leading and middle sets of driving wheels, were removed because the connecting rods hit them when the locomotive was at maximum speed. So even the real things were very tight for clearance - too tight!! I had a similar problem on the two B16/1's which I built - also to P4 gauge - where the clearance between the connecting rod and the back of the front set of footplate steps was very tight < 0.4 mm or .015". However, on these B16/1 models, the clearance issue was made easier by virtue of the connecting rod being located on the front set of driving wheels. Cheers Mike Edited November 15, 2023 by mikemeg 6 1 Link to post Share on other sites More sharing options...
mikemeg Posted November 15, 2023 Author Share Posted November 15, 2023 (edited) LNER B4 There are some days when, despite many hours of toil, there is precious little to see for all the effort. On other days, a few short processes and the model takes shape; it begins to live! So having fitted all of the mainframe springs and painted and weathered them - much easier to do without the wheels - then the wheels can be added. Suddenly the model, which has inhabited all sorts of containers and utilised various supports, can stand on its wheels and it begins to resemble a locomotive. Still quite a bit to do but the essence of a Great Central 4-6-0 is now clearly visible, though for this photo it's a 4-5-0 as the rear axle will contain the drive train so needs to be removable. Cheers Mike Edited November 15, 2023 by mikemeg 13 1 Link to post Share on other sites More sharing options...
mikemeg Posted November 15, 2023 Author Share Posted November 15, 2023 (edited) LNER B4 With a trial fitting of one of the coupling rods plus a connecting rod and crosshead, then the efficacy of my mathematics, in the posting above, can be checked out. Are the calculations correct or just so much rubbish? Seems that the measurements and suppositions in the above posting are about right. Phew!! I must extend my thanks to John Bateson from whom I bought the kit originally and who has since supplied so many new or revised components, as well as a wealth of advice and copious drawings. So another photo, a little more complete and a little more of that essence of the prototype. They were lovely things, these early 20th century locomotives! Cheers Mike Edited November 15, 2023 by mikemeg 16 2 Link to post Share on other sites More sharing options...
billbedford Posted November 15, 2023 Share Posted November 15, 2023 The B4s had a recessed nut on the leading drivers. This nut shows as a polished ring in early photos. I also think the coupling rod boss was thinner than the trailing one. Link to post Share on other sites More sharing options...
mikemeg Posted November 17, 2023 Author Share Posted November 17, 2023 (edited) On 15/11/2023 at 16:09, billbedford said: The B4s had a recessed nut on the leading drivers. This nut shows as a polished ring in early photos. I also think the coupling rod boss was thinner than the trailing one. Thanks Bill. Seems that Mr Robinson, the CME of the Great Central, had the same clearance problems with the connecting rod and the front coupling rod journals on these locomotives. It is one of the inherent disadvantages of P4 that these clearances are simply scaled down without any augmentation through a reduced gauge (EM or OO), so require a great deal of care. Saving the odd 5 or 10 thou (0.125 mm or 0.25 mm) here and there, by using slightly thinned metal sections, becomes the order of the day. I've pretty well sorted the motion clearance issue and am now checking the extent of the lateral movement of the front bogie wheels. The model does provide for a 'pinching in' of the fronts of the mainframes but only by a small amount. My minimum radius curve is 4' 0" so I will need to establish this, mathematically, before I put it to the test. The B16/1 models had this issue, even more, due to the distance between the front driving wheels and the front bogie wheels; similarly the D20's. The obvious answer is to create bogie wheel cut outs in the mainframes but such an approach just 'goes against the grain'. Regards Mike Edited November 17, 2023 by mikemeg 1 Link to post Share on other sites More sharing options...
mikemeg Posted November 18, 2023 Author Share Posted November 18, 2023 (edited) So, doing the maths - Pythagoras equation for right angled triangles - on the lateral deflection of the front bogie wheels, using the distance between the centres of the front driving wheels and the front bogie wheels (50 mm) gave a deflection of 1.03 mm; just within the profile of the pinched mainframes. Then, trying out the unpowered chassis on a 4' 0" curve, the front bogie wheels did touch the mainframes. So, something was wrong with the maths!! Then a eureka moment (Pythagoras and Archimedes in the same posting!). The point on the locomotive chassis which is truly tangential to a curve is not the centre of the front driving wheels, it is the centre of the middle driving wheels which, on this loco, are 80 mm behind the centres of the front bogie wheels. Redoing the calculation using 80 mm rather than 50 mm gives a deflection of 1.73 mm. So the pinching in of the front of the mainframes is not enough to allow 4' 0" curves to be traversed. So now a little rework of the front end of the mainframes will be done to increase the extent of the pinching in to allow the locomotive to traverse these 4' 0" curves. Cheers Mike Edited November 18, 2023 by mikemeg 1 2 2 Link to post Share on other sites More sharing options...
RMweb Premium Compound2632 Posted November 18, 2023 RMweb Premium Share Posted November 18, 2023 38 minutes ago, mikemeg said: Then a eureka moment (Pythagoras and Archimedes in the same posting!). The point on the locomotive chassis which is truly tangential to a curve is not the centre of the front driving wheels, it is the centre of the middle driving wheels which, on this loco, are 80 mm behind the centres of the front bogie wheels. Redoing the calculation using 80 mm rather than 50 mm gives a deflection of 1.73 mm. So the pinching in of the front of the mainframes is not enough to allow 4' 0" curves to be traversed. This could be eased a bit if the rear axle was given a bit of sideplay, so that the tangential point becomes the midpoint between leading and centre drivers, giving you 65 mm and a deflection of about 1.4 mm. Maybe too late for that now but worth remembering for when you move on to building a Jersey Lilly? 1 Link to post Share on other sites More sharing options...
mikemeg Posted November 18, 2023 Author Share Posted November 18, 2023 (edited) 2 hours ago, Compound2632 said: This could be eased a bit if the rear axle was given a bit of sideplay, so that the tangential point becomes the midpoint between leading and centre drivers, giving you 65 mm and a deflection of about 1.4 mm. Maybe too late for that now but worth remembering for when you move on to building a Jersey Lilly? Stephen, thanks for this. I actually revisited these calculations, just to double check. The revisit changes the game, for I had mis-read the result for the 80 mm separation and then did the calculation, again, for the 65 mm separation :- Deflection at 50mm separation = 1.03 mm Deflection at 65mm separation = 1.74 mm Deflection at 80mm separation = 2.64 mm Where separation is the distance between the centre of the front bogie wheel and the tangential point of the chassis on a 4' 0" radius curve. As can be seen, simply increasing the pinch of the mainframes to accommodate the 80mm deflection isn't a goer; they'll just look wrong. So, adding a measure of sideplay on the rear driving axle, to move the tangential point forward, in conjunction with increasing the pinching of the mainframes is the only way this will work and even then the frames may need to be pinched in by up to 1.25 mm as there is around 0.75 mm of play between the main frame and bogie wheel, each side. I hope this short dialogue hasn't bored any readers of this thread but even on 4' 0" radius curves, which are generous on most model railway layouts, not providing mainframe bogie wheel cut-outs does cause problems. And this would be the case for any 4mm gauge, OO, EM or P4. Cheers Mike Edited November 18, 2023 by mikemeg 3 2 Link to post Share on other sites More sharing options...
mikemeg Posted November 23, 2023 Author Share Posted November 23, 2023 Just to round off this series of postings around the cornering / bogie wheel deflection issue, a combination of maximising the sideplay, both on the rear and centre sets of drivers, coupled with increasing the pinching in of the fronts of the mainframes by an additional 0.5 mm per side has solved the problem. The unpowered chassis - though with the motor / gearbox mounted on the rear driving axle - will now traverse a 4' 0" curve without the front bogie wheel(s) actually touching the mainframe. Cheers Mike 1 1 Link to post Share on other sites More sharing options...
mikemeg Posted December 5, 2023 Author Share Posted December 5, 2023 (edited) LRM LNER B16/1 Some time ago I did a couple of test builds of a London Road Models kit, which LRM took over from Steven Barnfield, some years ago. The kit was actually drawn and developed over thirty years ago and was not fully released by LRM until four or five years ago. This after some additional etches were developed to allow the kit to represent the entire class of B16/1's, including the last twenty which had different splasher fronts (these were built by the LNER) and to cover the alternative LNER designed boiler which was fitted to most of the class at some point in their lives. In fact the original North Eastern boilers continued to be overhauled and fitted along with the later LNER designed boilers right up until the withdrawal of these locomotives in the late 1950's/early 1960's. As the original artwork no longer exists for any of the etches in this kit, no modifications can be made to those etches, so any errors or omissions can only be made good by the provision of additional etches. Anyway, two test builds were done on this kit, with both builds being taken to fully powered models, though not yet painted. There were, on both builds a couple of details missing and a known error on the tender in that the coal rails were some 3mm too long on the 4125 gallon tender. Prompted by another modeller building this kit - MickLNER - and documented within his thread, I decided to finish the detailing of these two builds, correct the error on the tender by removing a 3mm section out of the coal rails and then resolder and reattach them and then send both off to the paint shop. The photo is the first of the test builds, with the tender coal rails modified by reducing their length by 3mm and then re-attached. The tender has also now been primed. The raised plating rings around the lower washout plugs have also now been added leaving just the plugs themselves to be done. The steam reverser piping also needs to be done, which is the next job. So, the photo shows the state of the first build after a day spent working on it, representing a loco carrying one of the original boilers, though as the prototype would have appeared around mid 1950. Cheers Mike Edited December 6, 2023 by mikemeg 18 Link to post Share on other sites More sharing options...
Popular Post mikemeg Posted December 6, 2023 Author Popular Post Share Posted December 6, 2023 (edited) LRM LNER B16/1 And then there were two, with the second build featured. This one carries the LNER designed boiler and the plain fronted splashers and represents one of the last twenty to be built, under the auspices of the LNER. This is the first time that both have been featured in the same photo. As can be seen, the second tender still needs a little more work, though the modifications to the coal rails have been done and the loco also needs a few details adding. The chosen prototype for the second build - 61462 - was unusual in that as late as mid 1950 (I have a photo of this loco dated mid 1949) and possibly beyond, it carried the very flat smokebox door, as originally fitted to these locos, but with an LNER designed boiler and it also retained its cylinder tail rods. Cheers Mike Edited December 9, 2023 by mikemeg 20 Link to post Share on other sites More sharing options...
mikemeg Posted December 8, 2023 Author Share Posted December 8, 2023 (edited) LRM LNER B16/1 A couple of photos of the prototypes for the two models above. 61413 carried an original North Eastern boiler (pattern 49) from 5/1940 - 1/1952 and then from 1957 until its withdrawal in September 1961 The photo was taken during late 1960 when the loco was stored at Hull Springhead prior to its withdrawal the following year. Worth noting the external condition of this loco, which is very good for a loco awaiting its final journey. The second photo taken at the coaling plant of Hull Dairycoates shed, in 1949, shows one of the last batch of twenty locos built, identifiable by the plain splasher fronts. This loco carried the later LNER designed boiler (pattern 49a) from 10/1947 to 12/1951, though with a much flatter North Eastern smokebox door. Note the condition of the front footplate, which was noticeably bent and which 'feature' I haven't actually modelled. This loco was withdrawn in 5/1961. The two photos are shown courtesy of Mick Nicholson, whose collection of photos of North Eastern and many other locomotive types, continues to be an invaluable source of information for model makers. Many of these old black and white photos have been seriously edited by Mick to remove foxing and fading but, as Mick says, none of these photos can be taken ever again. Cheers Mike Edited December 8, 2023 by mikemeg 9 1 Link to post Share on other sites More sharing options...
mikemeg Posted December 8, 2023 Author Share Posted December 8, 2023 (edited) LRM LNER B16/1 The detailing of the second tender is now progressing with the addition of the Dave Bradwell axle boxes/springs and long spring hangars and the castings of the later style of toolboxes. Now the scratch building must be done for the tender water filler and the detailing of the tender front and draw beam. Looks like the join, where I rejoined the coal rails after removing 3 mm, isn't too prominent, though the nearest coal rail needs to be eased down onto the tender flare just a little. Cheers Mike Edited December 8, 2023 by mikemeg 9 1 Link to post Share on other sites More sharing options...
mikemeg Posted December 9, 2023 Author Share Posted December 9, 2023 LNER B16/1 So not being able to find a suitable casting to represent the tender filler, then one more time resorting to scratch building. The photo shows one completed and the first processes for the second; representing about thirty minutes work in total. As this is only 5.5 mm high with the top being 6.0 mm diameter, then photographing it/them isn't that easy. The first one still needs a little cleaning up before I prime it and fit it. Cheers Mike 6 2 Link to post Share on other sites More sharing options...
mikemeg Posted December 9, 2023 Author Share Posted December 9, 2023 (edited) LNER B16/1's A quick coat of primer; I have already primed the tender top so opted not to add another coat but just to prime the new component. Anyway, it looks ok and matches the drawings from which I am working. The 'dodge' on the coal rails is now clearly visible but will be totally obscured when the loco is coaled. What is also visible in the coal space are two pieces of 1/16th inch thick lead sheet, to add weight to the tender. Yet another 'addition' which will be hidden by the coal! Also worth adding that both of these 4125 gallon tenders have fully sprung 'chassis' using continuous springy beams with 2 mm high level axle boxes and horn guides. This isn't essential though if the tender is to be used for pick ups, then springing does help that process. I probably should have also mentioned, earlier in the builds of these two, that both locos are also compensated on the middle and rear driving axles. I made the compensating beams from scratch. Cheers Mike Edited December 11, 2023 by mikemeg 7 1 Link to post Share on other sites More sharing options...
mikemeg Posted December 9, 2023 Author Share Posted December 9, 2023 (edited) Someone asked me, via the private mail facility, where do I get the 1/16" lead sheet from. The answer is no, our local church roof doesn't now leak; I bought a 'roll' of 6" wide lead flashing - as used on roofs, etc. - some eight or nine years ago from a builders merchant. From memory there was some 30 feet of it, when purchased, and it cost around £60. This stuff can be cut with tinsnips or sawn using a junior hacksaw and can be bent, rolled or otherwise shaped very easily. Almost all of my locomotive models have a coil of this stuff glued inside the boiler and forward of the motor, usually somewhere over the front set of driving wheels. Even though I've used quite a bit, the roll is still b----y heavy!! Cheers Mike Edited December 9, 2023 by mikemeg 3 Link to post Share on other sites More sharing options...
drmditch Posted December 9, 2023 Share Posted December 9, 2023 Re: Lead I do have two lumps of lead (from a boatbuilder friend many years ago now). Offcuts can be produced with a heavy hacksaw, and then further cut and hammered into shape. Lead is of course the ultimate malleable metal! In one of the autumn storms last year, a part of my roof was damaged and had to be replaced. I was able to persuade the roofer to let me cut some of the 'waste' lead before he took it away. My heavy duty tinsnips allowed this quickly and should provide for several years of model ballasting. I do not have as much as @mikemeg describes above, but it cost less! (Well, the roof didn't but that's a more complex story.) I should point out the safety requirements (in terms of cleaning hands etc) for working with lead, 1 Link to post Share on other sites More sharing options...
mikemeg Posted December 9, 2023 Author Share Posted December 9, 2023 (edited) LNER B16/1's The drag beam detailing is all done and the basis for the tender front detailing is also now added. Just the representation of the brake and water scoop standards housings plus the floor extension and this one will match the first one, which was done some time ago. The front handrail stanchions will be added next to avoid damage to the further detailing as the holes are broached out for the stanchions. Cheers Mike Edited December 11, 2023 by mikemeg 12 1 Link to post Share on other sites More sharing options...
mikemeg Posted December 11, 2023 Author Share Posted December 11, 2023 (edited) LRM LNER B16/1's With both tenders now complete then just the final few details on build #2, nearest the camera, and they can both travel to the paint shop. The wisp of smoke, from the one in the foreground, is just a little discolouration of the artists card, which I use as background for the photos. For a very old kit, which has come in for some criticism, they haven't turned out too badly though, as has been said before, many of the castings I've used are from much more recent ranges and there is a fair degree of scratch building in some of the detailing. All of the original castings, which I replaced with newer offerings were from either Arthur Kimber's North Eastern Kits or from David Bradwell, both of whom have on-line catalogues of their castings. The error (and the only one on the tender) with the tender coal rails can, with care, be rectified, as above. The omission of the lower firebox washout plugs can be rectified by using a Markits product or, as I did, by turning down some .010" nickel silver or brass 2.0 mm inside diameter washers, leaving a .015" annulus, which can then be soldered onto the firebox sheeting using the ubiquitous cocktail stick to hold them in position. Cheers Mike Edited December 12, 2023 by mikemeg 17 1 1 Link to post Share on other sites More sharing options...
Dylan Sanderson Posted December 17, 2023 Share Posted December 17, 2023 Hi Mike, Just discovered your thread by chance after buying a High Levels J72 chassis for my first attempt at modelling P4! Looks like a really impressive kit, one I'm looking forward to getting stuck in with over Christmas. Don't suppose you know if the chassis fits the latest Bachmann offering? Link to post Share on other sites More sharing options...
mikemeg Posted December 18, 2023 Author Share Posted December 18, 2023 20 hours ago, Dylan Sanderson said: Hi Mike, Just discovered your thread by chance after buying a High Levels J72 chassis for my first attempt at modelling P4! Looks like a really impressive kit, one I'm looking forward to getting stuck in with over Christmas. Don't suppose you know if the chassis fits the latest Bachmann offering? Hi Dylan, No, I don't know whether the High Level J72 Chassis fits the latest Bachmann J72 but if you go onto the High Level Models website, there is a contact option. This allows the user to contact Chris Gibbon with queries or enquiries and he always responds pretty quickly. So ask him the question. Regards Mike Link to post Share on other sites More sharing options...
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