Chuffer Davies

According to Hatton’s site this model will have upgraded tooling with modifications to the rear pony truck. So hopefully this will sort out the problem associated with the previous release of the large prairie. Frank

I’ve always felt that the RTR coaching stock for Great Western modellers has been disproportionately under represented when compared to the wide range of locomotives produced by the major manufacturers. The GWR tended to mix their coaching stock up more than the other regions and so, other than the top flight expresses, any given train might consist of a variety of coach styles and this is hard to reproduce using RTR vehicles. Why hasn’t any manufacturer produced top light coaches or a decent representation of clerestory stock? The original clerestories from Hornby were basic although their saving grace was that if you replaced the under frames and bogies you could cut and shut the bodies to produce some respectable models. Hornby’s later reliefless attempt at clerestories was an appalling attempt in my opinion. Fortunately, when we were building Hungerford, the late Mike Bradley built a significant variety of GW coaching stock which meant we had no dependency for RTR. Frank

Hi Simon, In the case of the ROD I've used two devices. The first is my universal solution for pony trucks and comprises a simple coil spring made from fine phosphor bronze wire wrapped around the shank of a drill to form the coil. Crude but effective. The top of the spring is soldered to a chassis spacer directly above the body of the pony truck. I then solder a brass washer to the bottom of the spring to act as a skate that presses down onto the top of the pony truck. this provides downward force only but does not have any impact on side control. In the case of the ROD I noticed that the wheels were getting very close to the front drain cocks on the cylinders and might cause a short if they touched. The loco's chassis is live to the nearside and so the offside pony truck wheel would be where the problem could occur. For this reason I have also added a side control wire acting on the back of the pony truck below the axle’s centre line to avoid any adverse tipping action when the truck deflects on a curve. Hopefully the following pictures will better illustrate this: Frank

Building a locomotive chassis to a specific brief is different to building one for yourself. The 'Brief' was to build a chassis that was capable of hauling the long mineral train on Pendon's Vale Scene. Whilst this train is normally hauled by Guy William's famous 28xx, currently Pendon has no suitable substitute loco if the 28xx needs servicing. I had tested the ROD as far as I could on both my test track at home and on the club's Clayton layout but eventually it needed to be tested on the train for which it is being built. On Tuesday morning I set off to drive the 190 miles to Pendon Museum. Fortunately the weather was kind to me, the sun was shining, the traffic on the M1 was for once moving freely, and I was able to enjoy the four hour drive to Pendon's car park in the beautiful Oxfordshire Village of Long Wittenham. After a private tour of the museum, including a look around the back of the layouts to see those areas that the public don't normally get to see, Tony Sheffield (the Pendon locomotive CME) invited me into the fiddleyard of the Vale Scene to give the ROD its long awaited test run. I was first given a demonstration of the 28xx hauling its famous train. You need good sight to see the back of the train sitting in the fiddle yard. The train is well over 20 feet long and its back stands under the scenery of Pendon Parva village. The power was applied and after a slight slip of the driving wheels the 28xx dug in and started its train. The 3 link couplings remain taught when the train comes to rest in the fiddleyard and so the 28xx doesn't have the luxury of picking up the train one wagon at a time, it starts the whole train at once. After this amazing performance by a locomotive that is now over 50 years old, Tony removed the 28xx from its train and invited me to place the ROD in its place. The controller was turned and ------ the ROD polished the track. Tony gave the train a slight helping hand and after a couple of feet the ROD dug in and away it went. It then hauled the train all the way around the Vale back to the fiddle yard only slipping momentarily as it went up the short gradient at the entrance to the fiddle yard. Tony explained that the fiddleyard has another slight gradient at its exit, just where the locomotive stands, and this is why the ROD couldn't get the train started. He then went to his work bench and returned with some offcuts of lead flashing. These were incrementally placed on the boiler of the ROD until there was sufficient additional weight to enable the ROD to start the train. This is how much additional lead is needed to allow the ROD to meet the Brief: I now have to find a way of hiding this lead in various crevices of the chassis and/or Guy's loco body. Once installed I will then return to Pendon to try once more. So close but no cigar! (yet). Many thanks to the Pendon team for their hospitality and for their kind words of encouragement. Better luck next time, hopefully. Regards, Frank

Now that is an interesting question! If I'm being totally honest I don't precisely know what the solution was. As I have already documented, the symptom I was experiencing was that, although the wheels appeared to rotate freely in their individual horn blocks, once I added the coupling rods the chassis stiffened up significantly and the wheels would no longer revolve if I pushed the chassis along the track. The stiffness was not as you would typically expect. There was no one tight spot to suggest that the crank pin holes needed opening out or the quartering adjusting. The one thing that I was certain of was that the spare set of coupling rods I'd built were now worse than the original set, so I dismantled the chassis one more time and....... Firstly, instead of the 1/8th inch reamer I'd been using, I replaced it with a 1/8th inch drill bit in my mini drill and gave the horn blocks yet another seeing too. Secondly I checked the fit of the connecting rods in the crossheads and made sure they were a nice floppy fit. Thirdly I filed the crossheads to make them a looser fit in their slide bars. I then reassembled the chassis with the original coupling rods, re-quartering the wheels by eye (as I always do), et voila it was suddenly working. Was it one specific thing I did, I don't know, but in combination the problem was at last eradicated. I normally try to keep everything as close a fit as possible when building my chassis, but in this case by loosening everything up slightly it has resolved the problem I was having. Frank

Coincidentally I have just completed the following: The eccentrics are mounted on a brass tube which is attached to the axle by a grub screw. The gear box is mounted on the rear axle so does not prevent the eccentrics from being installed. Of course its almost invisible once installed, but I know its there which is all that matters..... Frank

Meanwhile four months later! The build of the ROD chassis for Pendon is now complete and it is ready for final testing prior to it being dismantled one last time for cleaning and painting. The completion of the build has been problematic and has taken me far longer than I expected. Despite numerous attempts to adjust the quartering I just couldn’t get the chassis to run smoothly. Individually the wheels rotated freely in their horn blocks but as soon as the rods were fitted the chassis appeared to stiffen up despite there being no obvious tight spot to indicate a quartering issue. After a while I got so annoyed with both it and my inability to sort it, that to get some respite I set the chassis aside and started another project. This is very unlike me because normally I try to work on one project at a time. This new project has been equally frustrating for a completely different set of reasons, but that is a story for a future time. Returning to the ROD a few days ago I started thinking about sourcing a replacement etch and starting again, but over the weekend I had one last attempt at getting the chassis to work and finally its running sweetly. I previously mentioned that I planned to include a representation of the inside valve gear. I already had a set of Martin Finney eccentrics in my spares box and had designed the etches with the intention of attempting to make the valve gear work. The build has turned out okay and the chassis now has working valve gear. I decided to mount the eccentrics on a thin walled 1/8” inside diameter brass tube connected to the axle by a grub screw. In the event there is a problem with the valve gear in the future, removal of the grub screw will permit the chassis to be run with the valve gear remaining static. Of course, despite all the effort, in reality the valve gear can only be seen under a strong light and when viewed from a particular angle. Visitors to Pendon will be hard placed to even see that there is any valve gear between the frames, let alone whether it is moving or not, but that is not the point when it comes to Pendon modelling. So far the ROD has been tested at home and I have also carried out an initial haulage test on the gradient of the club’s Clayton layout. The ROD successfully hauled 40 mixed goods wagons up the 1:50 gradient on a 4’ 6” radius. Critically this loco has to be capable of hauling the long mineral train on the Vale Scene at Pendon which I believe is around 90 wagons and so, before I once again dismantle the chassis for painting, it is my intention to visit Pendon and try it out. I’ll let you know how I get on. Thanks for reading, Frank

How on earth did I not know that? I’ve only ever known the station as Bath Green Park, and I’ve never heard of a Queen Square in Bath, only the one in Bristol I cycled through every week day on my way home from school in Brislington. And now I understand the origin of the queensquare handle. Thanks for the explanation. Frank

Surely we are talking about Bath Green Park? My childhood recollection is that Queen Square is in Bristol and being square faces the 4 points of the compass. Frank

Looking remarkable Jerry… The layout that is, although I suppose Glastonbury is remarkable for completely different reasons. Frank

Oops, how embarrassing…..,,, checking my order I didn’t actually put the J50 chassis in the basket which is probably why Chris hasn’t sent it….. Expect a new order Chris…. Frank

No one can be sure without someone trying it and reporting back, but the earlier slide bars are a single casting with the piston rod gland and is a friction fit into the plastic cylinder end plate. I would expect the new and old castings are interchangeable. Frank

Hi Chris, firstly many thanks for the amazingly fast (48hour) turn around on my order. Outstanding service as always. I assume the J50 chassis is on back order which is fine because I wont need it for ages yet but the motor and gears will be test installed tomorrow? Secondly I just wanted to say that, now that the penny has dropped around its design, how I enjoy using your CSB jig. It’s a brilliant piece of kit making the drilling out for the CSB supports near (if not completely) idiot proof. Finally, I’d like to offer my support with regards to your proposal to provide kits without stock wire, tube, etc. Having designed a few kits myself I know how time consuming it is not only to source the materials in the first place, but also to prepare and include all the bits of wire in a kit. The (time) cost to you must be significant and yet most of us kit/scratch builders will already have suitable wire and tube in stock. Regards, Frank

Looking at the samples I’m pleased to see that they have re-designed the slidebars and have removed the flared ends which had been a major bone of contention when the earlier model was released. I think I’ve also read that this model has the revised higher gear ratio which delivers better control at low speed (especially on analogue layouts), and a more prototypical top speed. The earlier model was good but with these improvements the new model has the potential to be very good. Frank

Hi Jerry, Tie bars for double slips are a challenge in my scale of 4mm so I can’t start to imagine how much harder they are in 2mm. Looking at the double slip in the photo I notice that all four blades are fixed solidly at the ‘k’ crossing end. This is problematic and creates significant forces at the tie bar. When I build double slips I cut the rail of the inner blades and install them using fishplates so that they can slide laterally. The outer blades are therefore equivalent to those on a standard point controlling the position of the tie bar between the sleepers, and the inner blades move for and aft eliminating any stresses that would otherwise be created on the tie bar.

Hi Tony, the 28xx chassis is completely different to the 47xx series. The 47xx is an extended design of the 43xx Mogul. Brassmasters sell the Finney 47xx kit and might be a able/willing to provide you with a chassis kit… Regards, Frank

As previously reported, I have been assisting Paul Craig with the development of a new LRM kit for the J52/53. My role has been to test assemble the model using the etches and castings supplied by Paul. A few months ago I showed the completed first test build of the model in bare metal on WW. I have now received this back from Ian Rathbone (many thanks Ian) who has kindly painted and weathered the model for me, and thought it would be of interest to followers of Wright Writes. The model is based upon a loco that was based at Bradford in 1930 which retained its condensing gear despite it being unnecessary for working around West Yorkshire. The model has been built with High Level CSB suspension, Gibson Wheels and a High Level 1219 coreless motor mounted vertically in the firebox. In this instance I didn't want to deviate from Paul's primary design principals and so the model has conventional (back scratcher) pickups to the offside wheels with the chassis live to the nearside wheels. We still have some minor corrections/enhancements to make to the CAD work and I will then test assemble the corrected components before this can go into production. It will still be a while before this becomes generally available but I think it will be well worth the wait. Frank

I concur, it does seem a somewhat extreme decision to have a flat plate across the whole of the coal space looking nothing like the prototype as a result. It would have been more appropriate, perhaps, to provide an alternate moulding with a more accurate representation of the coal space that could be removed/replaced for those minority (?) of modellers wishing to fill the whole of the tender with loudspeakers for DCC sound. Frank

Hi, thanks for the suggestion but I’m thinking High viscosity would not be drawn into the wheel/axle interface whereas a low viscosity glue might be better drawn into the joint by capillary action. What would be your take on this? Frank

Hi Bill, I’m confused…. Can you restate for clarity please? After your earlier comment, I’m going to do some investigation around Loctite products and superglues. My concern with superglue is that I’m not sure it would provide enough time for tweaking the quartering (I do it by eye) before it goes off. Frank

Hi Mike, that is useful information about the Gibson tyres. I have occasionally had a problem even recently but it’ll be because I abuse the wheels by soldering shorting tags to them. The heat no doubt causing the tyre to expand and break away from the wheel. No matter, as I have said previously, a quick dab of Epoxy sorts it as it would for tyres on the early wheels before Colin took over. My experience of less grippy Gibson wheels has definitely supported my observation that grip degrades as the wheel diameter increases but I defer to your greater experience on this matter. I must say that some of his smaller wheels are so friction tight on their axles that I have to put my Marigolds on to get enough finger grip to shift them. Frank

Hi Tony, you have indeed illustrated on many occasions that Markit wheels can readily be used in EM and often without modification to the kit/commercial model being built. None of the contributors to WW have ever said anything to the contrary. What we have said is that this is not universally the case and SOME models need adjustment to allow for the extra width of the Markit wheel that is not necessary when using plastic centred wheels in EM. However: several equally experienced modellers have said that plastic centred wheels can be used just as successfully if certain precautions are taken. These are: - ensure that any sharp edges are removed from the axle end before attempting to press a wheel onto its axle. This prevents any risk of plastic being shaved away from the hole in the wheel which will introduce an incurable wobble. - in the case of Gibson wheels, if the wheel’s date of manufacture pre-dates Colin taking over the business from Alan Gibson, check the tyre is firmly attached to the wheel. If it is loose it can be refitted with Epoxy glue. (Not an issue for wheels purchased today) - keep to a minimum the number of times wheels are fitted and removed from the axle during the build process - with (perhaps) the exception of the smaller Gibson wheels you should never rely on friction alone to hold a wheel permanently on its axle. Wheels can be reliably locked onto their axles using Loctite 601 or by methods such as knurling with a file, or pinning. Plastic centred wheels require a back to back gauge to ensure correct spacing. Quartering can readily be achieved by eye but some modellers prefer to use a jig. There are commercial b2b gauges and quartering jigs available. Be aware that (unfortunately) some Gibson wheels run eccentrically to a lesser or greater extent. In summary Markit wheels are by far the easiest to use but their width is sometimes a problem. Plastic wheels require care when fitting but are often visually closer to the prototype and the axle ends look better than the nuts on a Markit’s axle. Their thinner width as compared to Markit wheels in general avoids the need to reposition slide bars or splasher fronts. Modellers currently modelling in OO but with aspirations to model in P4 might benefit from experimenting with plastic centred wheels because Markit do not sell P4 wheel sets. Frank

The wheel centres on Markit’s wheels are approx 0.5mm thicker than those of Ultrascale and Gibson. In EM this causes the crankpin on the leading wheel to hit the rear of the cross head/slide bar. Modellers either have to find a way to move the cylinders out or re-drill the positions of the piston rods and slide bars off centre to adjust for the extra width. Ultrascale provide a special crankpin nut for leading wheels to help overcome this issue. I use this Ultrascale crankpin nut even when fitting Gibson wheels for this very reason. The other problems in EM with the thicker Markit wheels are that the splasher fronts on some kits and proprietary models are set at the prototype distance and Markit wheels are too wide to sit between them. This can also be an issue for locos with narrow cab sides. In the case of the Bachmann Atlantic (above) it would have meant removing the cast footsteps on the side of the footplate to get clearance for the connecting rod. Regards, Frank

Whilst Markit wheels are excellent for the inexperienced modeller, plastic centred wheels are not the disaster that is often portrayed here on WW, and Markit’s wheels cannot be used if modelling in P4. Several of the regular contributors on WW have reported considerable success with plastic centred wheels because they have taken the time to understand the pre-requisite actions needed for success, as well as being willing to take the small amount of additional time and care required to fit them. The positives with plastic centred wheels are that the modeller can more often obtain the correct one for the prototype being modelled and it also more often avoids the need to reposition slidebars and splasher fronts when modelling in EM due to the narrower wheel profile. As to the suggested simplicity of using a nut to attach a wheel to its axle, I can only see a minor distinction between using a nut or applying Loctite to fix a wheel firmly. With practice quartering without a jig, and setting the back to back accurately, are easily acquired skills. I think it is unreasonable to suggest that all plastic centred wheels share the same issues. Ultrascale wheels are flawless, tyres cannot come off, and they always run true if fitted correctly. I acknowledge that the delivery time for Ultrascale products is 8 months but if you plan ahead this is rarely an issue. Gibson’s wheels occasionally have problems but are much cheaper than Ultrascale’s as well as being considerably cheaper than Markit’s. Their quality reflects their lower price and they sometimes suffer from loose tyres but these are easily cured with an Epoxy glue. Some Gibson wheels wobble slightly but under normal running conditions the loco doesn’t ride any more roughly than the prototype tends to do. In summary plastic centred wheels can, with a bit of care, be used successfully as long as the modeller has taken the time to learn how to fit them properly. Markit wheels are the best wheels for an inexperienced modeller but are expensive and be prepared for other problems if modelling in EM. Frank

Hi Mike, Just for clarification, do you knurl the axle ends as well as using, or instead of using, Loctite. Frank