Chuffer Davies

Whilst I would have to agree that the clarity of dialogue on many recorded broadcasts is poor we should recognise that as we age our hearing also deteriorates. In particular it is typically the high frequencies that are increasingly attenuated and it is these frequencies that are required to decipher consonants. Although I can still function day to day quite well without hearing aids I decided I would invest in a pair none the less. I now not only hear birdsong and music clearly once more, of relevance to recent comments here, I can better decipher tv dialogue than without them. Perhaps it is time for some on ‘hear’ to consider a hearing test? Now back to some modelling… Regards, Frank

The EMGS's flexitrack (manufactured by Peco) is a match. This is available mail order to EMGS members from the club's stores, or can be purchased from their trade store at either of the Expo events by both members and non-members.

The only models that are unsuitable (without significant modification at least) to convert to DCC are locos where one or both of the motor’s brushes are earthed directly to the chassis. The models I know to have such motors are the Hornby Dublo, Triang Rovex, K’s and Mainline split frame locos. Any motor where the terminals are (or can be) isolated from the frames can be operated under DCC so I would expect the O4/3 to be suitable. Frank

A real quandary indeed! Logic demands that the locos must have been getting traction current from somewhere other than the DCC command station when on the scenic section. Did you try unplugging the DCC from the mains whilst the train was traversing the scenic section? My guess is that the train would have continued to run until it got back to the fiddleyard. If it happens again give me a call and I’ll try to help you diagnose what’s happening. Frank

I too have experienced the ‘Sir’ effect when operating exhibition layouts. As soon as Sir appears you can be sure chaos in one form or another will ensue. Nearly as bad is the appearance of a video camera when previously silky smooth running locos start to stutter and wagons that have trundled successfully countless times around the layout spontaneously fall off on a piece of plain track.

Hi Stewart, As you will appreciate it is difficult to generalise and I was hedging my bets with regards these estimates because of the vast range of motors that have been used by the hobby over the last 60+ years. A loco kicking its legs upside down in a cradle will draw far less current (amps) than the same loco hauling the maximum of which it is capable. Mashima motors under max' load would probably be in the range you suggest but the Hornby Dublo loco under max' load would be getting towards 1 amp. The message I was trying to get over is that when selecting a transformer/controller combo (for analogue) you should not exceed 12volts max on the track. The more amps that the system can support the better especially if you are running multiple DCC locos on a single power supply. Frank

There is frequently confusion regarding the relationship between controllers and locomotives. There are two components at play, volts and amps. The maximum volts available are directly the result of the transformer’s windings and would typically be around 15volts ac (alternating current) for an analogue system. This reduces to around 12volts after being rectified to dc (direct current). If the voltage supplied is too high then you can end up burning out the motor so you would be ill advised to use e.g. a 20 volt power supply on a typical OO analogue system. The amps are dependent on the efficiency of the motor, I.e. the demand the motor makes on the supply. Modern coreless motors typically draw between a quarter and a third of an amp. Older soft iron cored motors will draw between half to one amp. An under powered controller may not be able to supply sufficient amps to the motor, in which case the motor will not perform to its full potential. Conversely a high powered controller (e.g. one designed for O gauge being used on a OO layout) will permit the motor to work to its maximum potential with no risk to the motor. I am not fully up to speed on DCC systems but the rules above will still apply. The lower the available amps delivered by the supply the less power will be available to be shared across all the locos running on the system. LEDs and sound systems will increase the demand that an individual loco will place on the control system, but traction current will always be significantly more than the additional power demands of lights and sound. The size of the layout is unlikely to impact this significantly although it is good practice on larger layouts to run a copper wire power feed to every individual rail rather than rely on fishplates to conduct the current. Nickel Silver track has a higher electrical resistance than copper wire and fishplates can also introduce further resistance. A layout wired with only one power feed to the track will exhibit a loss of voltage the further away from the feed you get, whereas a layout with a copper wire feed to every rail will have very little resistance so it is unlikely you would notice a voltage loss unless the layout was enormous.

I have now serviced/repaired another of the Hungerford locomotives that had to be retired at the start of the Abingdon Exhibition earlier this month. This time it is model of a City class locomotive that must be well over 40 years old. It was originally built from a Nu-Cast kit in OO gauge by the late Michael Bradley of the Wakefield Model Railway Society. Michael later converted it to EM by simply changing the Romford driving wheel's axles to an EM pair and then pulled out the bogie and tender wheels on their axles to EM. In this guise it first ran on Wakefield's Kingsbridge layout which featured in several 1982 Model Railway Constructor articles. When this model was first exhibited on our Hungerford layout is 2002 we experienced a problems with the Romford gears stripping. Michael died in 1997 and so it fell to me to deal with the issue. I decided that the best option was to dismantle and fully rebuild the chassis. The modifications introduced at the time were: Ultrascale (Beuler) motor and gearbox replacing the XO3 type motor and Romford gears that came with the kit. Compensation: Simple compensation of the leading driven axle and a new functional set of compensated frames for the tender. American pickup - All 4 wheels on the offside of the loco and all 3 wheels on the nearside of the tender. Ultrascale wheels with modified Markit outside cranks. Replacement Coupling Rods - Made from a set of Gibson's Universal Rods. Rather than use Ultrascales' plastic outside cranks I decided I'd prefer to experiment with a set of Markit's metal cranks. I drilled out the threaded axle holes in the cranks to 2.5mm. I then rebated the ends of the Ultrascale extended axles reducing their diameter to 2.5mm to a depth of 1mm matching rge dimensions of the modified cranks. I know that the 3 jaw chuck on my Unitmat lathe does not run perfectly true and so the axles were held in a home made brass collet inserted in a 4 jaw chuck. The positioning of its jaws were then adjusted using a Test Dial Indicator resting on the axle's end to ensure that the axle was running dead true before turning. The cranks are fixed to the axles using Loctite 603 which I can confirm provides a rock tight fixing. This loco has now run reliably in its rebuilt form for 20+ years but recently the motor has started to fade and at Abingdon it could do no better than crawl when attached to its train of parcel vans. The loco was retired for the duration of the show and I have now had a chance to repair it. Rebuilt chassis with the Ultrascale Motor and Gearbox as installed in 2002: Rather than just replace the motor I took the decision to replace both the motor and gearbox with a superior High Level 1230 coreless motor and RoadRunner gearbox. This necessitated removing the outside cranks from the rear axle in order to release the wheels and axle from the frames which in turn allowed the gearbox to be released. I was amazed how little the coupling rods and frame bearings had warn so repairs could be limited to the replacement power unit. Chassis with replacement High Level 1230 coreless motor and 60:1 RoadRunner gearbox: The model is now reassembled and runs even better than when first rebuilt in 2002. The High Level drive system is silent with the 60:1 gearbox ratio providing excellent low speed control under analogue operation. With 6' 8" driving wheels the top speed is more than adequate for Hungerford's main line running. Whilst the model is crude when compared to modern etched brass offerings I still think the model is a fair representation of its prototype and worthy of appearing on our Hungerford layout.

I am currently servicing three locos that unexpectedly misbehaved at the Abingdon exhibition and couldn't be used over the weekend. One of these is a Malcolm Mitchell 517 class auto tank. This is a rather unique model having been built by Guy Williams for a Model Railway Journal article. Shortly after the article was published the model was put on sale and I was fortunate enough to purchase it. Guy built the model in P4 but as our Hungerford layout is built to EM gauge Malcolm sold me the etches so that I could build a second chassis in EM. On the Abingdon weekend the loco ran perfectly at low speed but when trying to run it at main line speed it ran erratically. Once I got the chance to investigate the problem properly I initially concluded that the motor was to blame so I swapped it out only to discover that the problem remained. I was certain that it was an electrical problem because there was a faint smell of ozone when I ran the chassis. I then tried connecting wires from the controller directly to the chassis and turned the loco upside down to examine it closely. Low and behold I could see sparks emanating from between the gearbox and one of the horn blocks. I have always had a dislike for wire pickups for current collection. Most of my tank engines are built with split frame current collection whereby the rims of the wheels are shorted to their axles. The axles in turn are made with a paxillin bush to isolate one end from the other so that the current can pass from the axle through the horn blocks into the frames. The frame spacers are made from double sided printed circuit board with the copper track cut through so that the frames are electrically isolated from each other. The motor’s leads can then be soldered directly to the frames. Whilst an amount of extra work is required to machine the axles the end result is a simple and reliable means of current collection. The position of the paxillin bush in the axle on which the gearbox is mounted is critical because it has to sit in a very small gap between the gearbox and one of the hornblocks. A fibre washer is inserted over the axle between the gearbox and the hornblock to stop the gearbox from shorting against the hornblock. In the case of the 517 the gearbox is mounted on the middle axle. This axle requires a small amount of side play to help the loco negotiate curves. This creates a further complication when obtaining the correct position for the paxillin bush in the split axle. It appears that I hadn’t quite got the split in the correct place on the 517 and the end of the axle running through the gearbox was coming into contact with the horn block on the other side of the fibre washer. I had no option but to remove the axle from the chassis and using my lathe I removed a small amount of metal from the split end of the axle so that it could no longer make contact with the horn block. The fix appears to have worked and the loco is now running smoothly once more. Why this problem suddenly manifested itself after many years of trouble free running I have no idea but at least its now resolved and the loco will once more be seen on Hungerford the next time it is exhibited.

Hi, the power bogie has pickups and so should run when the non powered bogie is off the track. My powered bogie is only picking up on one side so your’s is not unique. You can check which wheels are picking up by lying it on its back and testing each wheel in turn with some flying leads off a controller or clipped to the track. Frank

This weekend just gone we had a now rare opportunity to play trains on our Hungerford (EM) exhibition layout which had been invited to appear at Abingdon's 50th Anniversary show. I say rare because the previous time w exhibited was at Gaydon in 2019. Hungerford has been on the circuit for 22 years and has been to almost all the shows that might want to invite it. Most of the time it is packed away in a dark attic flat in the top of the building that hosts the Shipley Model Railway Society. Despite its age the old girl performed well with only a handful of problems coming to light on the Saturday morning. Fortunately almost all faults were 'round the back' so did not impact the viewing public's pleasure. This event at last gave me the opportunity to run the GWR model locomotives I have built since Gaydon, these being the modified Heljan 47xx, the Dapol Mogul for which I designed and built a replacement Motor-In-Tender (MIT) chassis, and the MIT converted Mitchell Mogul acquired from the estate of my late friend Tony Stoker. The Moguls operated faultlessly. The 47xx ran almost faultlessly but occasionally exhibited a 'shudder'. I am not convinced the Heljan R-T-R chassis is man enough to haul a heavy train of metal kit built rolling stock. It was pretty much on its limits and if I had time I would be very tempted to design and build a new chassis similar to that I built for the Dapol Mogul. I took the opportunity to shoot some videos of the layout which included shots of the 47xx and Dapol Mogul both of which still require weathering (apologies). I hope that those unable to attend Abingdon, or have never seen Hungerford in the flesh, will enjoy these very amateurish shots of the layout. I have also included a photo of the well stocked fiddle yard where the 22 trains that run in the layout are stored . Enjoy!

You do not normally need to secure the crank pin screws in the wheels as they are a screw fit in their holes. If you over tighten them then they will slip but all you require is sufficient grip to stay in place when the crank pin nuts are tightened. I am concerned that you are reporting that the RH rear driver already slips, did you remove the sharp edges from the axle ends before first inserting them into the wheels? If not there is a likelihood that the axle end has cut into the wheel hub removing a sliver of plastic as it did so thus compromising the grip of the wheel on its axle. I would recommend you replace this wheel. I have used these wheels successfully on several models but the trick is to try to minimise the number of times you fit them to avoid over stressing/stretching the holes in the wheels. When you are carrying out the final assembly (typically after painting the model) I recommend you use Loctite 603 to adhere the wheels on their axles. This will pretty much eliminate any risk of their slipping under normal use. Regards, Frank

The valve itself is in a box into which the vacuum pipe enters. When the emergency cord is pulled the valve open allowing air to enter the vacuum pipe thus destroying the vacuum causing the brakes to be applied. I think the items that were referred to are (red) flags which are normally horizontal but when the chain is pulled they move to vertical allowing a guard looking down the length of the train to determine in which coach the cord has been pulled. The chain is reset by manually returning the flag to horizontal.

Oh wow…. It’s even worse than I feared. I’m going to have to wait until I’ve got a clear bench to attack this particular project. Many thanks for your feedback and the very informative photo. Frank

Did you drop the steam bogie out completely and if so how difficult was it to do? I’m going to have to dismantle the model to convert it to EM so it would be good to hear your comments. Frank

Hi Keith, I would have to challenge the logic of including wheels in with a kit. Inclusion of Markits wheels would be a wasted cost for P4 modellers or EM/OO modellers with a preference for plastic centred wheels. I don’t know enough about 7mm wheel options but would imagine a similar situation exists. Perhaps if wheels are offered as an optional extra then fine that might be of benefit. Frank

No, I gave the Fulgerex chassis away to a friend who had a OO layout. He then installed it under a Hornby body. My king has a large Portescap motor/gearbox combo. Frank

Hi, my understanding is that the castle had some dimensional inaccuracies but the King was a better model. The King’s chassis was rather crude but with a replacement chassis from the likes of Comet (or in my own case Malcolm Mitchell) the model is transformed. Fulgerex Original: And with Mitchell Chassis - painted by Ian Rathbone. Regards, Frank

Oh Err Missus, something looks very wrong in the bottom photo. The valve spindle should be horizontal rather than leaning up at a jaunty angle. I can’t offer any advice on how to sort it though. If it were me I’d be returning it under warranty rather than risk damaging it. Frank

Any chance of a photo please?

I’ve had an initial look at the model to get a feel for what will be needed for the conversion. There isn’t enough clearance to just pull the driving wheels out on their axles and do I’ll be ordering replacement wheels from Ultrascale or Gibson. The Kernow wheels are a fairly typical thickness for RTR at 2.5mm but Gibson wheels are more like 2mm which will gain 1mm of the 2mm required for the extra back to back of EM. Using Ultrascales type C crankpin nuts should gain me enough to get the crankpins in without hitting the backs of the crossheads. It looks like the model has 2mm axles which might mean I need to bush out the replacement wheels if I can’t get them with 2mm axle holes. That’s as far as I’ve taken it so far. Frank

Hi, mine is awaiting conversion to EM but your comment prompted me to at least spin the wheels on its back to check it was a runner. In doing so I’ve discovered that the pickups on the nearside of the power bogie aren’t conducting current so if your model has a similar issue it might explain what you have reported. I’ll sort the pickups out when I do the gauge conversion, which won’t be for a while yet. Frank

The decision as to how/where the coupling rods are hinged is typically determined by the kit designer rather than the builder. Where I have designed the kit myself I have chosen to reproduce the hinge away from the crankpin so that the crank pin baring surface is uninterrupted rather than divided across two halves of the coupling rod - just a personal preference but I don’t think there is any mechanical benefit one way or the other. Frank

Hi Jeff, I believe it to be a mistake to elongate the crank pin holes in the coupling rods associated with the driven axle. The driven axle is my reference and everything else is adjusted to be compatible with that. However, If the driven axle is coupled to the other axles via a hinged joint in the coupling rod life is slightly more complicated and in that case I may choose to adjust the crank pin holes of the driven axle having first ensured that the next two axles have been sorted and run smoothly without binding when turned manually. Most of my 6 or 8 coupled models are driven off the rear axle and so this is the only way I’ve come up with sorting binding. Regards, Frank

Can J suggest that a simpler way to check if this is the problem is to remove the coupling rods and then put power to the motor to test that the driven axle turns smoothly when not connected to any other axle. Regards, Frank