What About The Bee

Hilariously, I forgot that a metal wheel can bridge the gap between an auto-reversed block and a fixed polarity block. My error! Bee

Agreed NTP. I used the 9F as an example only. Wheelbase extends to rolling stock, for example, lighted carriages. Bee

Extracting a steel shaft from a brass worm will require quite a bit of force to overcome the retarding frictional force of the interference fit. That is, the ID of the worm is typically 0.002" (50 um) smaller than the OD of the shaft. In this way, the torque of the motor can be applied to the gear to gear interface without the motor shaft slipping. It also happens to be the most economical way to do it as well. Most gear pullers in this size will not have the material strength (Youngs Modulus of Elasticity) to resist deformation and bending. The puller reaches yield and bends like a pretzel, unable to overcome the extraction force necessary. If all you want to do is save the brass worm, then applying heat primarily to the worm will expand the worm relative to the steel shaft. The motor is likely burnt out anyway. It cannot get anymore burnt out than it is. Bee

Hi Dukedog I think you will find much greater utility in that fiddle yard. Very lengthy sidings mean parking longer trains. Further, the wells are much more spacious. It will be easier to work on the layout and much more comfortable to operate. Plenty of room for grandkids. Well done! Earlier in this thread, we discussed reverse loops. It is quite clear you need 4 auto reversed track blocks, for the four leads to the center double crossover. There is an issue you need to resolve with the current design. The two highlighted leads are quite short. One is ~130 mm (5 inches) whilst the other appears less than 75 mm (3 inches) . Consider a long steam locomotive with tender pickup, like a 9F. The power is drawn from the front pickup to the rear pickup. This can easily exceed the length of your auto reversed leads. Dead short. For the following, we are moving left to right. As the locomotive transitions from the fixed polarity scissors crossover to the auto reversed block, the highlighted auto reversed block flips to match that polarity. The locomotive continues on, and encounters the transition out of the highlighted zone. The auto reversed block will flip to match the polarity in that fixed block. The problem is that if a locomotive can span the auto reversed block the auto reverser can be required to supply both polarities to both tracks, which occurs when you run the layout as a figure 8. RULE: Auto reversed blocks must be longer than the longest powered wheelbase of anything you put on it. Bee

This is the kind of stuff that drives an engineer round the bend. An engineer specifies a product, gets it quoted and vended. First samples seem just fine. In this case, both wheels insulated from the axle. Then, without bothering to mention it, the vendor changes what is supplied, to no longer compliant to specification. In this case, Going Spare, you were working under the specification that stated "Insulated wheels". Except they weren't. Even Hornby was not aware. Based on some very old comments on another train board, this has flip flopped several times now. Hornby should make up their mind and enforce that with the vendor. To be frank, I would be having a very strongly worded conversation with that vendor. Vendors should not engage in these shenanigans. At the very minimum, differently specification parts should have different product codes. The specification should be clear to us, the clients. There should be two types, as clearly, situations can arise where both wheels should be insulated, and as in Ian's case, one wheel live. Bee

@Dukedog.Hi! You mentioned, at one point, a more extensive fiddle yard on a lower layer, accessed by a helix. If properly done, you can walk into the center well, as opposed to crawling in. Why not give that a twirl? In the end, the only person you must satisfy is yourself. Please remember that my comments are from the cheap seats far, far in the back of the room. My comments are intended as food for thought, and only that. Bee

Even with the best of intentions by software engineers, unexpected outcomes occur. The most obvious example here is the metadata driving the pages. Hornby cannot really want numerical sales data exposed to public view, nor the expected date certain instead of the 'season'. It is clear that the implementation meets requirements. The availability of a model (pre-order, in stock...) and the season are displayed to clients. Yet exposing internal data is a side affect, and obviously not a stated Hornby requirement. Hornby - "can you fix that Mr Subcontractor?" Subcontractor "Yes, how much money do you have. Give it to me" And on to the next cash cow, ad infinitum. Correct Colin. Bee

Hi NTP 67 mm / square, so yes, just under 7 cm. Dukedog did mention one hole is accessed by a lift out section near the door, so that will easier to access. @Dukedog.Those holes need to be bigger. Putting aside operations, you will need to build the layout. It is one thing to pick up a derailed vehicle at maximum arm's reach, yet quite another to work on scenery at arm's reach. You could make the bench work more robust. Then you can sit on top of it and crawl on it during construction. This has obvious limitations. ÷÷ If you remove the central double track with double cross over, you can have one central well. The one central hole becomes much bigger. Seating now becomes available for you and the grandkids in the center well, something that may be very tight in your current design. Easier to work on scenery, easier to run trains, particularly through the constricted zone. Bee

Hi JJ None of them ran on the LMR. And so, I will never have them. That doesn't mean I do not like the look of them on your layout though. Crack on JJ!! Bee

Hi Dukedog, At first, I was going to suggest moving the fiddle yard to the top (outside of the loops), as then it could be double ended easily. But, with the walls now defined, that's not feasible. I will make a firm recommendation before you build a single thing. Get a large piece of cardboard and cut out the openings shown. Support it horizontally at the height you intend for that board, and get into the openings. Literally crawl under and stand up. Try turning and moving around. Move from one opening to the other. Get the feel of maneuvering yourself in those spaces. Why? I think they are quite tight. I'm not convinced you can turn around in some, as they may be too narrow. You will also be required to bend like a pretzel to get into these holes. Before you paint yourself into a very constricted corner, trial those openings. Further, if this is for you and the grandchildren, will they fit with you in those spaces? Its the interaction with the kids, the talking, pointing and sharing you will want. Can't have that if you are locked in one hole, they in the other. ++++++ As to the layout itself. I think it is just fine. NTP rightly notes the 4 into 2 tracks as a limiting factor. It might be, but it also might be the perfect challenge to stimulate the Train Master (you) to keep them from crashing. Ditto all the potential conflicts when switching those scissors crossovers. Stimulation via conflict. As to the upper level? I've come around to your point of view. If that is for the grandchildren to run, then a simple layout will be better for them, age dependent. You can always add interlockings and inclines later, as they show more interest. But try the cardboard test. I think you may make a few slight changes 😉 Bee

I am enthusiastic about Hornby's web pages coming back in house. Finally, errors will be corrected, or so I hope. With direct sales up 18%, and the webpages the store, it behooves Hornby to get this bit correct Bee

7P6F P = Passenger F = Freight The higher the number, the stronger the locomotive 7P means seventh category of strength for Passenger 6F means sixth category of strength for Freight

Hi Dukedog Is the layout wall to wall in the room? Which sides are accessible from the outside? Can you sketch in the walls? Bee

Re: warped prints. I had some. Asked about it on Shapeways message boards. Was told to put in warm water. Rational was that items are bagged when warm, hot off the press. They are deformed by packaging. Placing them in warm water allows the item to de-stress/relax. Never tried it but others reported success. Bee

There are other 3D printing services 81F. I have noticed them while working with Shapeways. A quick search reveals their names. I will just pick another one. You may wish to consider this. No need to abandon everything. There were rumblings of dissatisfaction on Shapeways message boards. Shapeways had, within the past few years, changed print technologies in fine detail plastic. The fineness of unsupported walls and wires had become coarser as a function of the print technology. So a product that someone was already selling suddenly became unprintable. The design would be kicked out by the Shapeways software. The designers of said products were not informed, except when a customer ordered the part. That lead to unhappy designers, unwilling to re-engineer their catalog. Imagine going through each CAD model, adjusting dimensions, leading to a cascade of other changes and test prints. In other words, spend time to re-engineer and spend money on trial fitment. For a proven product. That was a firm "No!" from many. Only designers can say "print the thing anyway, it is a test print". 3D prints for third party customers must pass all print criteria. With the spec change, many designs were out of specification. So no print for them and unhappy third parties Someone at Shapeways chose poorly. Shapeways wrote that they were switching to a new printer because the old printers were wearing out. In my view, it was a terrible idea to reduce print quality. Keep it the same or improve it. There were likely other issues to cause bankruptcy, but an interruption in revenue stream is not helpful Bee

Hi Ian Thank you for clarifying. No one is disputing your input. Clearly, one wheel is live to the axle, else the circuit would have an open / would not function. To my understanding, the specification is being confirmed internally, as there may be a technical glitch in the firmament. We will sort this, never fear! Bee

At this viewing distance, it looks fine. If anything, like a well used, well worn wagon. Bee

@Deem The return crank must be properly positioned for the oil pump rods to not kink, fatigue and snap. When it comes to this positioning, Atom has written extensively about the task. Based on what he has written, it seems like there is a bit of finesse required and that it is tricky to get correct. Fortunately for me, this didn't exist for my railway of choice, so I need not worry about it. But you do. Do not just replace the part. Make sure to get the return crank positioned just so, as well. Bee

Hi Dukedog Much bigger fiddle yard. Can't have too much fiddle yard! Still room for one or two industries for your freight service, if industrial switching is your interest. The scissors double cross-over is kept as its own feature, instead of buried in a complex interlocking. Your change will preserve the complexity of working trains and managing conflicts at the crossover. Lots of engagement there Here is where your insulated rail joiners should go. The four tracks that come off of the scissors double crossover should be isolated at each end. Your image was too small for two fushia lines at the scissors double crossover, so one line for two tracks will have to do. Both tracks are insulated, even though only one fushia line is present. These four isolated tracks will have the auto-reverser feed. Yet the scissors double crossover itself and remainder of track can all be fixed polarity. You can never have back to back auto-reverser tracks. So the scissors double crossover should be that fixed polarity section in between the two auto-reversed sections on the route your train takes. There is a complexity in wiring the frogs itself, in that the frog should not itself be on an auto reverser, but work off your switch machine. This preventing back to back auto reversers for longer locomotives bridging two auto reversers. I think this is a definitely improved layout. It preserves the features you originally sought with a bigger fiddle yard. Any thoughts of making that fiddle yard double ended? Bee

Electricals The next challenge was how to bring power from one rail, through the motor and then back to the other rail. Enough with the art of a chimney door, determine how to power the motor. OO Twin Sisters is just over 49 mm long and roughly 33 mm from front to rear wheel contact points. With such a short locomotive, I want all wheel pickup. A commercial part exists to bring power from the metal tire, across the plastic insulating wheel, to the metal axle, but this demands the live/insulated wheel axle regime. I have but three axles. No matter how I distribute this commercially available part, one side of the locomotive may have two pickups, while the other side of the locomotive will be limited to one. Or simply one on each side, skipping one axle entirely. That is a recipe for stalling on track, as Twin Sisters will lose connection to electrical power. I measured the pickup foil on an existing model and found it to be 0.08mm. Sheets of 0.08 mm beryllium copper foil are readily available in consumer quantities. Beryllium copper has a higher mechanical yield than pure copper, making it more suitable for springs, while retaining the vast bulk of the conductivity of pure copper. There will be two main bus bars down the length of Twin Sisters. Each bus bar has three fingers which contact the back of the metal tire of the wheel at top. As I intend DC¹, a simple wire from each bus bar is brought to the motor. The circuit is complete. While the bus bar is inside the cart, the fingers will go through slots to the outside of the cart. A dimple plier will be used to form a hemispherical bead on each beryllium copper finger. The bead will be held against the tire by spring pressure. As the 1st and 3rd axles shift side to side to accommodate 2nd radius (438mm) curves, the fingers can either follow the wheel out or tuck completely back into pockets formed into the sides of the cart. The fingers will not interfere with the full range of side to side travel of the axles. Will the fingers be noticeable and obvious? Even if you know where to look, and have the benefit of the contrasting colors of a CAD model, the pickup fingers are not obvious when the complete locomotive is presented Once camouflaging paint is applied, the fingers may disappear altogether. With the proposed model now complete, I can proceed to parts ordering. Obviously, some features will need revision due to actual dimensions, instead of estimated dimensions on some parts once they arrive. Artistic rivets and flanges will be definitely added, whilst coving up those flathead screws in the top of the boiler. While the design is far from complete, the proposed model is most definitely feasible. I can get power to a motor. The gearbox is duck soup simple. The mechanical parts are largely purchased Romford / Markits components. The crosshead and crosshead rods are commercially available stock. It all seems to fit together without worry. I think its time to commit! Bee ¹ For the foreseeable future. The boiler that does not have a motor is completely empty. It could readily fit a decoder and small keep alive. Vent heat right on up through the chimney. But for now, DC it is.