Izzy

I think the J15 & E4's ran with the same size/type of tenders at times, but as for the loco I don't believe that trying to convert a J15 would be the way to go. It's not just the larger driving wheels and splashers but more importantly that the boiler was pitched higher with a different style cab. These two aspects alone would make it a no-no for me because it just wouldn't look right with a lower pitched boiler and nothing would match up either, cab, splashers etc. Izzy

Thanks Edwin. I had looked at some of the exGE terminus plans on John Hinson's site and noticed several had electric tablet release GF's for loco release crossovers but wondered whether it was feasible for my particular plan given it's small nature and the impact on the rest of the pointwork. My very grateful thanks for that Mike. It helps an awful lot in that I now know what I need to have and where to place it. This is doubly useful as it now also means I can plan out the point rodding runs etc. Wonderful. I will use colour lights of the exGE searchlight pattern, indeed your suggestion for that on the main platform road pretty much replicates the 4mm one I made here : http://www.rmweb.co.uk/community/index.php?/topic/116233-theatre-indicator-on-platform-starter/ I know that a lot of lines had semaphores until quite late, in fact my local one went from them to LED's just recently, but using C/L's is easier for me on a constructional level with this particular layout, which is 2mm/2FS, although I do hope to make the theatre indicator work this time, but not perhaps the position light. kind regards, Izzy

Thanks Ray, Part of the problem I have arises from the small size of the track lengthwise, e.g. the distance between positions 1 & 2 being just one coach length. This seems a real issue with Platform B where if as you say the starter needs to be clear of the fouling point ( which I had wondered about), then it's only just long enough to take a 2 car DMU or a couple of MK1's. It is these kind of aspects where I really get stuck and don't have the knowledge to come up with a solution. Perhaps there isn't one and it's just a consequence of squeezing the track layout down too much to fit the space available and it's too 'wrong' to work reasonably correctly. As far as platform usage goes, like Bodmin St Boltophs has always been a single platform, but with a couple of carriage sidings. As well as local services between Clacton/Walton - Colchester (North) calling/reversing there, some services have originated there, e.g. Brightlingsea branch trains, and still do today, (some Sudbury line services at weekends now I think). Thus while the main platform A is intended to cover most passenger trains and B parcels traffic, I had thought that at peak times B could be used with occasional DMU services using the upper line to the 'main' station. You will understand that I am using St Boltophs as the general basis around which to run/use the layout, but being totally fictitious it's just 'somewhere in Essex'. I had thought the ground discs were in roughly the right places to cover moves regarding the release and sidings, but perhaps this is not so. regards, Izzy

Hello all, I have recently started building a small secondary town terminus station layout after spending a long period trying to come up with a design that meets my needs of being small and easily moved around yet gives some scope for operating. It is intended to be exGE in the 1960's/1970's with (hopefully) early searchlight colour signals rather than semaphores. The ground discs will still be mechanical and all the pointwork worked by rod from a box. The general premise of the design/location is based on St Boltophs, Colchester (Colchester town) exGE, along with Wells-next-the sea exGE and Bodmin General exGWR, in that it is served by two separate single track lines but which like St Boltophs form a triangular junction with a 'main' branch line, a bit like I believe was once proposed with Bodmin if perhaps with longer lines. It has a rather unusual track plan of a main platform with a shorter second one for (mostly) parcels traffic with a siding (C) accessed from the main platform head shunt via a single slip. I doubt any such design ever existed in the real world, but has been used to enable the maximum use of limited space. Since getting the track built/laid and working I have struggled to work out how best it should be signalled. Can anyone offer any advice as to where signals should/might be placed? Here is the track drawn as best I can. I am not sure if it is correct. I think I might have the ground signals where they need to go, but as to the main signals for the two platforms well, that is where I get stuck. Would main platform A have a starter/route indicator/junction on its end at 1, or at 2, or a starter at 1 and an advanced/junction at 2? It's a similar question with B and 3&4 and the relationship with the siding behind it. As far as the loco release/access to siding C goes I presume a fouling bar would exist on the Platform B road to prevent use when stock sat in it past such a point. Would any of this be feasible or am I way out with my thoughts. It would not be unusual! thanks, Izzy

I believe motors need an odd number of poles to enable slow controlled starting, 3,5, or 7 being most common. When I saw these I did wonder, if the spec was correct and not an error, just what kind of slow speed control they would have. Izzy

I find that track designs in one scale don’t really easily convert to another whether it’s say, 7mm going down, or N going up. Partly it’s because it’s all done in the same scale real world at 1:1 so always looks different, but also as a result of fixed sizes, our hands etc, needing the same space to operate things. Generally with any layout I find you need a balance of about the same length of track in the off-scene fiddle areas as you do the visible parts, otherwise it might look pretty, but the limitations on what you can actually do when you ‘play’ with it become very limiting if not unworkable. One downside of using a smaller scale is that things often look smaller/tighter/cramped compared to a larger one and this is most noticeable with smaller curved track and points in N, so what may look good in say 4mm might not in N. In the space you have, a visible area of about 100cm/40” and a fiddle of 60cm/20” ( a sector plate will probably be easiest to make in my opinion) would be my suggestion, and coupled with a run round loop and/or a shunter to marshall the trains brought in by another loco. Izzy

Hi Nigel, I have now checked the gears for any discrepency between them and can't find any, the overall OD and tooth depth being the same with all of them. I did wonder if this might be another area where the problems might be, given that gear forms can be over or undercut where needed for a particular situation. However, in going through all this I feel I might have discovered what might - I can't prove it now - have been the cause. It is simple, and leaves me feeling rather red faced. The P/B wiper pickups. Those on the 31 are wide flat strips which run horizontaly along the bogie moulding. In fitting the 2mmSA 7mm carry wheels I had to modify them behind the centre axle to prevent shorting against the axles. Whether this was a contributing factor I don't know but the rear of the 2mmSA geared wheels have a large boss on which the wheel is fitted. I think the position of the pickups were such that their lower edges pressed down on the top edges of these bosses and allied with the slop in the axles in the bogie allowed them to act as springs, raising up the loco as a result. Mostly the weight of the loco compressed them, but not all the time. Had I realised this I could have tweaked them to stop it. It is noticable that the second 31's pickups sit slightly higher up, not by much, but enough to show. The original's ones don't seem to have been fitted/soldered on as well, the same level of quality, and I will now redo them. So another little lesson learnt. regards to all Izzy

Thanks for the gear tooth thought Chris. Just double-checked this aspect - used a white gel pen as the gears are black - and the 31’s are 16 tooth, and so are the 24’s. Should also say there is nothing wrong with the 2mmSA drop-in wheels. The geared 7.5’s have been re-fitted into a recently bought Farsh 24 where it works as expected and they run absolutely fine. It’s all rather bemusing. I feel I must be missing something quite obvious, but I just can’t see what. Thought it was the disparity between the geared non- geared wheels re the size difference error, but with the centre carry wheels removed it stayed the same. Ah well. Cheers all, Izz

Class 31 conversion Some while back I posted details of a 2FS conversion I had undertaken on the new version Farish Class 31 using the 2mmSA 'drop-in' diesel conversion wheels. This loco uses different sized wheels in the bogie as per the prototype and so required the use of 7.5mm geared wheels and 7mm un-geared ones. These were very slightly larger in diameter than the Farish originals at 7.35mm and 6.75mm respectively but otherwise the conversion seemed fine, the difference in overall diameter seeming small and something which it was supposed would make little real impact. The use of the non-geared wheels with their smaller diameter axles (1mm v 1.5mm) did mean however that the centre carry wheels needed springing via fine wire to ride properly on the track At the time a question was posted as to whether re-machining the Farish wheels to 2FS would be an easier/better route. Later on I acquired another new version 31 and machined the wheels to see if this was indeed a better solution for this particular model. With a lathe it was, for me, an easy task to undertake and the results proved that it did work well. Without a layout at the time a couple of differences between the conversions went unnoticed and have only recently come to light under the testing of a newly finished layout, (well the track is built/laid/wired and it all works but that is all). The re-machined wheels converted 31 works fine, it sits at the correct ride height and the body is firm and upright on the chassis. The original 31 using the 2mmSA wheels however, while it ran fine, had body issues in that the ride height was about 0.5mm more, and the body would keep leaning/listing to one side or the other. A complete strip-down of the chassis did not reveal any reason for this. The springing to the carry wheels was removed in case this was the issue, lifting/raising the chassis/body. It made no difference. Finally the original wheels were re-fitted. This cured the problems, the loco now sitting at the correct ride height with a stable upright body. I am now currently machining these wheels as per the second 31 conversion. I have no idea why fitting the 2mmSA wheels gave these issues as it doesn't seem logical - especially the increased ride height since the whole diameter difference was only 0.15mm - but there we are. Finding these problems I thought it best to warn others wishing to convert their 31's. regards, Izzy

With my PA2 the lights flash when there is a short, and will do this for a while as it tests/re-tests whether the short continues to exist. If the short is temporary then the lights and power return to normal. However, if the short continues to exist then after a while the unit stays with both lights on. When this happens I usually either switch of the at mains power, or hold the red ‘stop’ button on the handset for a couple of secs, which cuts track power. I then sort the short out, and pressing the red button again restores track power. This latter method prevents having to shut the base/command station down and I have read somewhere that it is not a good idea to leave the base station with both lights on under a continuous short. Izzy

I'm not sure the large axle frame bushes would be suitable. They are a very easy running fit on 1.5mm axle shafts (as you might expect) and also on the motor sleeves. Although the use of Loctite 601 or similar might centre them on the shafts I would worry about any vibrations caused by any excentricty as already stated. Izzy

If you look on the youchoos website, for the Zimo MX644D 21 pin decoder the stay-alive connections are via pads at the opposite end to the pins. It appears you can connect speaker wires to pins 16&20 if these are not provided via the connection pcb board. Is the capacitor you are concerned about a stay-alive unit, or perhaps something else? Hopefully someone with knowledge of the J11 will be able to offer information. Izzy

Straight cut spur gears will mostly be noisy/whine when run at higher speed due to the on/off loading transfer from one tooth to the next. This can be overcome by using helical cut teeth, but they need decent widths and angles to be effective in this respect along with good side thrust bearings to minimise frictional power loss through this aspect. I agree with others who feel worm gears get a ‘bad press’ simply due to their alleged inefficiency. It’s a generalisation that has so many caveats that it becomes meaningless in many respects since one gear train design may have quite different primary needs and objectives to another. Little mention ever seems to be made for example of the materials from which gears are made or their size relative to the power input/output. Izzy

I always use methfix where possible in preference to other types of decals, but first apply them using water to get the position right and remove the top paper, and then give a quick thin wash of pure meths after to melt/glue them into place. With this method I can get multiple numbers/letters etc all lined up and square first, and re-wetting with water allows repeated adjustment until they are because they remain firm/hard, before they are permanentaly fixed in place using the meths, which of course softens them until they go off. Izzy

I recently visited a local show where one stand had various flavours of these small motor/spur gearbox combos (N20's?) for sale. These were being sold as suitable for scenic use, powering windmills etc that kind of use, and not as powerplants for locos. The stated voltage seemed to be allied to the gear reduction. I can't remember the actual details but broadly they were 3v, 6v, and 12v, with the later having the highest reduction - 300rpm IIRC - and the lower voltages rather less, 100rpm and 50rpm I think. The actual motors looked identical, as you might expect, so getting those of the right voltage might be something of a lottery if there isn't clear indication of their actual specs, and especially if they come sans gearbox. Similar sized motors are used in smaller servos, will of course be 6v rated, and could well be what is often available on e-bay when sold motor only. A word of warning if I may. Having tested the 6v servo motors one fact that stands out is the high current they draw, running both off and on load, compared to the more normal motor usually used with model locos. Anything around 100mA light, and 900mA under stall. This may be one reason among many why some are frying themselves, and especially if they are 3v ones. By comparison, a Mashima 1833 I recently transplanted into a Bachmann 08 ( the original motor died for no apparent reason and I had the 1833 spare (they are almost the same size), couldn't be persuded to draw more than 0.5 amp stalled at any voltage up to 12v ( I wanted to ensure the decoder used could cope with the Mashima current draw given I kept reading they were higher than other motors). Izzy

Hi Scott, A suggestion. You're a bit of a wizz with plasticard going by your great coach thread, so why not build an F4/F5 chassis using it and fit the wheels/motor out of the Airfix 14xx? The 14xx wheels are about the same general size, 5'-2"/3'-8" viz 5'4"/3'9", so all you would need would be another set of carry wheels. along with some brass top hat axle bearings. Nile has built a F4/F5 using printed parts for both body and chassis (can't find the thread at present) and I can't see any reason why plasticard couldn't be used instead. Indeed I have done it myself in the distant past - simple motorization of Airfix plastic kit locos. You'd have to alter the F4/F5 wheelbase to suit since it's 7'6" x 8'-0" x 7'6" and the 14xx is 7'4" x 8'2", but I guess you would have already decided to work with the compromise needed, unless you got/made up some replacement etched rods (Gibson perhaps?). While weight is needed to give a bit of traction with a loco chassis it isn't absolute weight that is the most important factor, but having it in the right place. In this case it means over the drivers where the side tanks are situated so plenty of room to put some there. If you put the drive off the front axle the motor would be over them as well, and probably clear the cab. In saying this I am just not sure if the Airfix motor would fit between the wheels. It's been an awful long time since I fiddled around with OO gauge and XO4 type/size motors. I say this with the thought that it might be easier trying this than seaching around for and altering another RTR chassis to get what you need. Of course you could always get a couple of K&S brass strips and use them instead of plasticard, so no bearings would be needed and you could just drop the 14xx wheels into the chassis.......... Just some thoughts, cheers, Izzy

Here's a couple of shots of locos I built for a friend from Jim's kits. I made quite a few others for myself, J15/J67/F7/tram etc and would say they are probably some of the best kits I have constructed in any scale in that they go together properly without issue. Yes, you can always 'improve' them by replacing any of the castings with alternative ones ( I found the main ones to be quite good enough for me although I usually made replacement sprung buffers and bufferbeam hoses etc), and add extra detail as you feel neccesary but there is no tussle with trying to get the basic parts to fit. The G5 & 4F were left for my friend to finish off, coaling, crew and other small details to taste, I just did the main construction and painting while the F7 is mine in it's raw state. I don't think anybody regrets getting any of Jim's kits, why would they! cheers, Izzy

I have encountered your frame issue a few times in the past in a variety of scales. Almost inevitably it has proved to be a frame spacer not truly square or sitting dead square in the correct position, especially with the etched/bent 90degrees type. Occasionally it has been the frame twisted or bent a bit, but not often. The errors have been small, tiny in some cases, but enough to throw things out. Your description says to me that one or more of the PCB frame spacers is not aligned correctly on each opposing frame, a mis-match between the sides. Could I suggest you remove all the spacers, clean up the frames, make sure all bits are true, and start again. Sighting along the flat sides of the frames will show up the slightest kink/twist, which is all such a problem needs to exist. Placing them back-to-back will show any differences in spacer location points. It can be slight enough that they will still drop into the jig. I have found that the spacers don't need to be a very tight fit as if there is the slightest error in them this will stress/twist the frames. I take it you are using the PCB frame spacers from shop 3? Izzy

I first tried BRM digitally in 2014 when I was visiting family in Australia. For those overseas I can see the advantages both in terms of having a current issue of a mag rather than being weeks/months behind quite besides the lower costs, but I am afraid that despite trying a few since then I just don’t like trying to read a digital version of a magazine designed for the printed page. It doesn’t work for me at all and I won’t get any more. Izzy

I believe extending the inner check rails will have no beneficial effect as they will not reach as far as the crossing nose if I am looking at the overhead shot Ian provided in post #65 correctly, and doing this could well introduce electrical isolation issues needing a re-working of where the rai/sleeper cuts are made i.e. as with a diamond like this both stock rails and check rails must be isolated from each other up until the cuts for the crossing unit itself. I fully agree with Jim, leave well alone unless running issues - hitting/riding up of the crossing nose - are encountered. Izzy

It's looks to me like there is lower beading around the doors, the inside corners look rounded so it's not clear whether the beading is actually on the doors or by the side of the openings or both, and I am sure that is a ducket behind the guard poking his head out. Izzy

Don't know whether this is of any help, Yeadons might give this info, but RTCS pt4 states the six received their larger side sheets/single window cabs at Doncaster after their transfer to the NE at various times through 1936. 7408 - 9/36. 7411 - 5/36. 7416 - 10/36. 7463 - 8/36. 7478 - 7/36. 7496 - 12/36. Sadly, what isn't clear is whether these were further modifications on the newer/higher steel roof or full rebuilds of the original low cab one. However, as the text states in two places they were given new sides sheets and single cab windows in time for the winter of 1936 I would guess they already had the higher steel roofs. Izzy

I'm afraid you won't find quite the same kind of inherent strength that ply and rivet construction provides, but using just small strips of tape at the outer edges as suggested, and then using turps/white spirit applied with a brush at each sleeper in turn will ''kill' the tape glue bond for a while and allow the template to be slowly and gently peeled away from the trackwork. I actually use rivets under the crossing nose and wing rails for strength and electrical bonding, and also do the same at the first chair position past the slide chairs on both the blades and closure rails for the same reasons, covering them with half chairs afterwards as you normally would with ply/rivet construction. The worst part with this type of construction is that there isn't that much of a bond between slide chairs and rail, they must of course be glued to the rail sides, while the others can move along the rail. I now paint both sides of the rail inc the chairs while the track is still on the template. This creates an extra bond between rail/chairs which aids removing the completed work and placing it on the baseboard. This is using ply sleepers but I would guess it would work just the same with plastic ones - I have never used them. Izzy

Ah, thanks. I hadn't realised that the K's had ever been given the square riveted type or the fluted cover. When I built my I the only reference material I had was those articles by Don Townsley in the MRJ's 8/12 and the compendium, and even then it seemed a minefield trying to work out what features went with a particular class while trying to allowing for repairs/rebuilds etc. I had gained the impression that by the time the K's started appearing the tanks were of the more rounded rivetted type before being flush as with the cover, but obviously I got this wrong. I just hope I haven't made any similar serious errors with the model. Izzy

I also looked at the kit for these from Marc models, but at £60 is more than I can justify. The parts to make it are not as far as I can tell available from Comet at present, so I got the etched sides/ends for the Gresley Dia 120 4-wheel instead. I will scratchbuild the rest of it. As simple drawings of both the Gresley 4-wheel and Thompson 6-wheel BZ are in the two volumes of :- Rolling stock worth modelling - D Bradford Barton ISBN 0 85153 453 8/ 454 6 (V1/V2) I have, I will probably have a go at scratching the 6 wheeler at some stage. The one fixed axle +inside bogie certainly is to my mind the easiest way of getting a 6 wheeler to run okay. I have a feeling someone used to make a design - Slaters perhaps? - with one full bogie and one 'half' bogie, both pivoting about their centres and linked together. I'm sure I remember making one once which ran quite okay too. Izzy