GarrettTheThief Posted January 20, 2014 Share Posted January 20, 2014 I have a question about these. On some models (especially the DMUs and Mk2Bs), the bogie pivot is so large there's a visible gap between the bogies and the body. What's the best way of eliminating this? Because I think it looks rather odd. Does it actually suit some models too? Cheers. Link to post Share on other sites More sharing options...
standardblue Posted January 20, 2014 Share Posted January 20, 2014 Some Lima bogies are actually HO gauge and therefore under scale, hence the gap. I've got some DC Kits bogies lined up to replace those on one of my Limby 101s (Hornby didn't change the bogies, so still HO) when I finally get a round tuit... Hope this helps. Link to post Share on other sites More sharing options...
RMweb Gold Dagworth Posted January 20, 2014 RMweb Gold Share Posted January 20, 2014 Some Lima bogies are actually HO gauge and therefore under scale, hence the gap. I've got some DC Kits bogies lined up to replace those on one of my Limby 101s (Hornby didn't change the bogies, so still HO) when I finally get a round tuit... Hope this helps. Don't bother, the Lima bogie is scale The HO bogies on OO models were on the deltic and class 50 only Andi Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 21, 2014 Share Posted January 21, 2014 Don't bother, the Lima bogie is scale The HO bogies on OO models were on the deltic and class 50 only Andi Hi, I can confirm that the Lima bogie on the DMU's (and the Hornby re-issues) is an almost perfect size match for those on Bachmann DMU's and those are most certainly not HO scale. Andi is absolutely correct in what he sais regarding HO bogies on OO models. The large pivot on the Lima bogie results in the gap and caused the buffer height (and thus overall height) of the vehicles to be aprox 2mm too much. I have solved this on my DMU's by totally removing the Lima pivot, replacing it with a flat plate (80thou plastic card) glued to the bogie, using a turned brass spacer (can be replaced with layers of plastic card just as well) and using an M5 bolt as the actual pivot - the M5 bolt will 'self-tap' into the plastic of the chassis and can be set to give a bit of movement for good running. As a safeguard against it working loose (they don't normally) an M5 nut can be placed on the end of the bolt to lock it to the chassis if it might be needed to remove the bogie again or simple supperglued if its removal again is not likely. Hope this might be of some help or interest. Regards, Robbie Link to post Share on other sites More sharing options...
GarrettTheThief Posted January 21, 2014 Author Share Posted January 21, 2014 That's VERY helpful, thanks for sharing that with us! Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 21, 2014 Share Posted January 21, 2014 That's VERY helpful, thanks for sharing that with us! Hi, you are very welcome. I'll get one of my dmu's out of its storage box a bit later and take a couple of photos to show what I've done and will upload them here for interest. Robbie Link to post Share on other sites More sharing options...
RMweb Gold Ramblin Rich Posted January 21, 2014 RMweb Gold Share Posted January 21, 2014 Part of the reason for the larger gap is probably that Lima used rather smaller wheels than scale (seem to remember around 11mm, when should be 14mm?) Link to post Share on other sites More sharing options...
stewartingram Posted January 22, 2014 Share Posted January 22, 2014 They needed to use smaller diameter wheels to compensate for the pizza-cutter flanges! Stewart Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 23, 2014 Share Posted January 23, 2014 They needed to use smaller diameter wheels to compensate for the pizza-cutter flanges! Stewart Part of the reason for the larger gap is probably that Lima used rather smaller wheels than scale (seem to remember around 11mm, when should be 14mm?) Hi, Sorry to contradict you but although the Lima wheels in the DMU's were undersize this was by only just 1mm (11mm used) when in fact the correct size should have been 12mm - the wheels in almost all BR 'first-generation' DMU's were actually 3' 00" diameter (12mm at 4mm to the foot scale). 14mm is equivalent to 3' 6" diameter at full size - the size of the Mk.1 coach for example and the wheels in DMU's were very clearly smaller when observed from the lineside (or as a guard working on them) - plenty of published sources also confirm this as well including BR works drawings. If you look at a Lima vehicle it is clear the there was no need for the amount of compensation allowed - had Lima used 12mm wheels, and even allowing for the very overscale flanges two paths were open (1) to provide a clearance 'notch' in the chassis frame members (as I have done as shown in the attached pictures) or (2) to have raised the 'ride height' (buffer centre height) of the vehicle slightly to gain the required clearance - however there was no need for the great big gap and excessive ride-height actually allowed by Lima (and easily dealt with). My person opinion would suggest the excessive ride height allowed for upward movement of the tension-hook of the coupling - although to some extent this is negated by the fact that the coupling on these vehicle (and many other Lima) is somewhat excessively far forward of the buffer-beam line. Perhaps the actual reason is simply another example of Lima not getting dimensions quite right in this respect. Remember the Lima high density DMU had other dimensional error that included the first passenger window behind the cab being too long(should be the same as the other large bodyside windows) and the profile of the bodyside (the 'tumblehome) not being quite right - the first is easy to deal with and the second isn't noticeable unless one deliberately checks so is in most modellers eyes acceptable. I described earlier in this thread how I reduce the excessive bogie to solebar gap but to better illustrate this reply I've photographed another method I sometimes use that involves a bit more work making an alteration to the underframe instead but achieves the same reduction with good results. I should perhaps add that if it is desired to replace the undersize Lima wheels with scale size wheels (12mm) this can be accommodated simply at the same time by adjusting the setting of the ride-height whichever reduction method is used. Photo 1 : Shows an unmodified Lima TCL (centre coach) on the left with a modified and ride-height reduced TCL on the right - note that the modified coach still retains the original Lima wheels at the moment - due to the matter of the Lima axle being shorter than a standard pin-point I have successfully turned Lima wheels down in the lathe to bring the flanges to a better profile and narrowed the tyre to a nearer scale width - this requires the wheels to be opened up on the axle slightly to widen the back to back and make running on finescale track far better. Photo 2 : Shows the method of 'dropping' the bogie mounting area of the Lima chassis further into the chassis to effect the reduction to the bogie to solebar gap and at the same time bring the ride-height to virtually correct height. Photo 3 : A closer view of the modified chassis - note the clearance 'notches' cut into the chassis members to allow full bogie swing - needless to say this 'notching' will of course vary depending on the curves on your layout and whether you fit scale 12mm wheels or not. I hope the above is of some use to someone and please ask if you'd like to know any more. Regards. Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 23, 2014 Share Posted January 23, 2014 Hi again, Sorry to do this but just after I sent my last post I realised that there was something I missed that perhaps it would be better to mention. You will see that the modified TCL is fitted with Roco type short couplings. I use these on my DMU's as they remove any slack between the vehicles and make the running more realistic - BR didn't run 'loose-coupled' DMU's (although a bad one could feel like it was !) so the tightness of these couplings is a big improvement - I set them so the buffers are held just enough apart to allow running on my layouts without the conciderable work needed to fit expanding cam equipment on the Lima underfames. Although we need to reduce the excessive gap between bogie and solebar on the Lima cars its worth noting that on the real thing there is actually a larger gap than on (say) a BR Mk.1 coach (unless fitted with B4/5 bogies)and this is noticeable both on the real thing and a model so the gap must not be reduced too much or this will look un-realistic as well as making the coach too low overall Regards Link to post Share on other sites More sharing options...
Baby Deltic Posted January 23, 2014 Share Posted January 23, 2014 On the MK2b's, drill the pivot hole out at 4.2mm, tap it M5 and fit Bachmann B4's using a short M5 screw. Link to post Share on other sites More sharing options...
RMweb Gold Ramblin Rich Posted January 24, 2014 RMweb Gold Share Posted January 24, 2014 Weatheringman - thanks for your information & photos, my mistake on the wheels sizes! So 3ft wheels would (I presume) cause that larger gap on full size DMUs compared to coaches... Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 24, 2014 Share Posted January 24, 2014 Weatheringman - thanks for your information & photos, my mistake on the wheels sizes! So 3ft wheels would (I presume) cause that larger gap on full size DMUs compared to coaches... Hi RamblinRich - thanks for your reply. Yes indeed the use of 3' wheels in DMU's plus the fact that the actual bogie frames were were a bit shallower than many other types (and due to the smaller wheels ran at a lower centreline from the rail) did cause the somewhat larger gap between the top of the bogie frame and the lower edge of he solebar. Just to pre-empt the obvious question as why did the DMU's use a smaller diameter wheel - from conversations with drivers I worked with and fitters at Southall and Reading depots I have always understood that the smaller wheel was used in order to keep the mechanical drive-line as near horizontal as possible due to the nature of the final drive on the axle having to accommodate the turning of the bogie on track curves (especially pointwork) - I cannot say for certain that this is correct but what I was told does seem perfectly logical. I hope this is of some interest. Regards. Link to post Share on other sites More sharing options...
GarrettTheThief Posted January 24, 2014 Author Share Posted January 24, 2014 Thanks again for the replies. As it seems, I think I only have to see to the DMUs. Which raises the question on how to lower the motorised bogie. Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 25, 2014 Share Posted January 25, 2014 Thanks again for the replies. As it seems, I think I only have to see to the DMUs. Which raises the question on how to lower the motorised bogie. Hi again, I did wonder if someone might ask this question !. The lowering of the motorised Lima car is actualy quite simple albeit a little more work - i'll explain the method I use in the hope that it will appear clear from my explanation. The Lima power bogie is retained in the chassis and prevented from moving fore and aft by a moulding at each end that has a 'lip' at its upper edge to prevent the bogie dropping out. The ride-height of the coach is set by the 'upstands' moulded at each side of the bogie frame - these 'upstands' have a curved outer face (to aid bogie swing on curves) and a curved top to aid bogie 'rock' to accomodate track imperfections. The 'lip' at the upper outer edge of the mouldings rides above and clear of a moulded housing in the chassis such that if the coach is lifted the 'lip' comes against the 'shelf' and prevents the bogie from falling out of the chassis. Needless to say the 'lip' provides the clearance necessary for the bogie to 'rock' fore and aft as above. To lower the coach at the power bogie end all that is necessary is to carefully reduce the height of the side 'upstands' by the required amount (aprox 2mm) with a sharp scalpel - NOT A FILE due to the material type - making sure to retain a slightly curved top to aid bogie 'rock'. When replaced into the chassis the chassis itself will now ride at a reduced height on the shortened 'upstands'. The 'lip' as mention above will now simply ride at a slighty greater height above the 'shelf' - this is normally no problem but on odd occasions it may be necessary to trim the seat moulding slighty to gain clearance - this seems to vary between mouldings i've found. All that will happen will be that the bogie will now 'drop' that bit more when the coach is lifted from the track - still being retained in the chassis as before. It is also worth taking note that some Lima mouldings can have some flash at the outer centreline/bottom edge of the mouldings that prevent fore and aft movement (below the 'lip') and this can cause tightness when this modification is made - a few strokes of the scalpel will sort this out. The unpowered bogie is best dealt with as described and illustrated in my previous post by 'dropping' the chassis mounting area in a bit - the top of the unpowered bogie has a moulded boss but (experience at work here!) it is not desireable to cut this away as the running of the bogie will be seriously impared and anyway this will not provide enough lowering. Make the modification as per my pictures and all will be well. Again it may be necessary to make minor alterations to the seating above the pivot/power connector for clearance. Also it may be necessary at the unpowered end to create the 'notches' for flange clearance as shown in my pictures. At the power bogie end it may be necessary to very slightly trim the area of the chassis moulding near the gears but both off these last matters depend on the curves on your layout. There you are Gentlemen - I hope that this is of some interest and help - a pleasure to share my findings. Regards Link to post Share on other sites More sharing options...
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