Rabs

I think that the breed must have been in the UK before WW1. UK breeders decided to change its name to Alsatian because "German Shepherd" wasn't politically acceptable during the war. They wouldn't have needed to change it if they weren't already in the country.

I'm interested in pre-grouping in N it but can't claim to have done any modelling of it yet! I'm still stuck in the 40s for my main layout. I'll look forward to seeing what others have been up to...

Sorry if this is egg-sucking but one thing to watch out with if you get into printing your own is to make sure you have a very good idea of how much of your time it takes to print a model. I had several people asking me about using my B9 to print models for sale. At first glance a print time of a few hours on the machine made this look quite viable. However, when I sat down and worked out sensible estimates for my time to do: Set up Machine maintenance Cleaning the printer after printing Cleaning the model Post-curing P&P And then I thought about how much extra time I would need if a print fails (which they do from time to time). Considering all of this and even putting a pretty low value on my time it quickly became clear that the asking price would have been no better than ordering from Shapeways. This was before their recent price changes though. I suspect that someone with your skills will have thought this through anyway but if not it might be worth speaking to someone who uses the machine regularly so that you can get a realistic estimate of how much of your time it will soak up.

I did see someone recommend drilling a couple of holes in the mounting plate of the coupler. Then, if you use epoxy, some of the adhesive will come through the hole and firmly secure it. This way you aren't just relying on the interface strength of the adhesive.

I can recommend Tippex for small gaps like that. Flows well and is easy to scrape the excess off, unlike many putty fillers.

I draw my rivets as small cylinders rather than domes in 2mm. It's quicker to draw, easier for the computer to process and seems to cause less problems with automatic wall thickness checks. When they are printed they come out a bit rounded anyway and they are so small that, as long as there is a 'pip' there, it doesn't matter too much the exact shape of them.

Looking good! Just so you know, you can turn off the lines in the 'styles' menu. I find it useful for taking images of fiddly shapes, such as bodies with lots of rivets in, so that they aren't just black blobs from the lines.

Ah, ok. I've not peeled apart one of these tiny batteries myself - sorry, I didn't mean to spread disinformation.

This would probably be fine if you pick up and place the loco on and off the charging track, or you flick a switch when it's stationary. Driving the loco onto an active charging point would cause problems I think. The extra current of the motor could confuse the charge management IC and make it think that the battery was short circuited, so it would then automatically turn off. No way to know for certain though without knowing what chip your charger uses, it could be fine. Nearly all lithium ion and lithium polymer battery packs have the following safety features built in: PTC thermal cutout (basically a thermal switch to disconnect the battery if it gets too hot because of a short circuit, usually set at about 80C) Undervoltage protection (to prevent you over discharging it, which causes crystal growth on the electrodes of the batteries, which destroys the capacity of the batery and greatly increases its resistance. This is usually set at about 3.5V) Overvoltage protection to prevent it being over0charged (causes swelling and rupture in some battery chemistries, usually set at about 4.3V) Some also have a dedicated current measurement to prevent excessive discharge and charge current, in addition to the PTC. This is rarer though. If anyone is concerned about safety and wants to peel back the cover over the electronics in their batteries to take a photo I'd be happy to help identify what's there.

I've wondered for a while - why did the railways put pointy bits on the top of signals? Where did the practice come from and did it serve any purpose other than aesthetics?

The hardware for charge management is very small, particularly if the supply voltage to the tracks is regulated to 4.2V. Basically you need a BMIC and a back to back FET package. These can be as small as about 1mmx1mm each. If the track voltage available is 12V or DCC then you also need a rectifier (already in the circuit somewhere) and a regulator, so add another 1mm^2 for a linear or ~2.5mm^2 for a switch mode. It's not an easy hobby solution, but it would be very achievable if someone like Deltang wanted to add the functionality into their receivers.

Simply stunning. I particularly like the choice of a quite subdued Indian red (not trying to re-open that debate, I just like the tone you have chosen ). Are the chimney top and whistles turned in metal or painted?

I can promise you that you won't look back when you get the B9 set up to print fiddly bits like that. In the last few months I've printed things that have saved, quite literally, days of my life. That's even including the time taken to draw it and set it up!

Unfortunately I'm fairly sure that the 'precision' setting in Sketchup just affects the display of numbers, not the precision that it actually performs the computations to. I do the same as Quarryscapes but at 1000x times (draw in meters with 1m on sketchup = 1mm on the model) then scale it down with netfabb after exporting from sketchup.

Ah, I hadn't spotted that one!

Err, where on earth did that particular titbit come from? Making sweeping statements that the 'laws of physics' mean that your argument is right and others are wrong is nonsense. It isn't a matter of what is scientifically possible - the demonstrations on this thread show that either option (with or without batteries) is viable. It is a matter of personal preference and whether for an individual the amount of hassle associated with batteries is more or less than the present alternative of regular track cleaning. If you are unable to see that there are obviously arguments both for and against it then you're guilty of the very same dogmatism that you are criticising others for. The underlying tone of your posts above is that you believe that everyone you are talking to is an idiot. I hope that it is unintentional but perhaps it explains why you have been getting negative reactions.

Perhaps a 'complete this kit' button in the shop which adds the right ancillary bits you need to go with the chosen chassis? Probably easy to suggest but rather harder to implement!

Good luck . I've not gone up to the better resolution yet so I'm very keen to see how you get on.

I agree completely. How many mobile appliances do you see that are connected to mains? The only mobile applicance can think of is a robotic vacuum cleaner, which is, not-surprisingly, battery powered. Since when was 'non-portable' a relevant requirement for a model railway locomotive? Unless I unknowingly moved up to a much larger scale... I also don't think that a comparison to prototype practice is relevant to the discussion, surely nobody sane would think that the same reasoning would apply to both the prototype and a small scale model (unless the intention is to perfectly recreate the prototype, in which case we better set about finding some very, very small people to drive our trains).

What do you think of seafoam/seamoss for tree armatures? I've always thought that they looked very effective and appear to be easier to make than twisted wire. Not done any tree making myself yet though, so I'm not in a position to say for sure.

Hi Tom, It was very nice chatting with you on Saturday. Hope we meet again soon. Robert

I had a look at the hattons stand and they had Makerbot replicators on show which, in my opinion, and only good for 7mm or bigger. I didn't ask if they are planning to do anything else in the future.

Thanks, that's very helpful. I'd tried a few fluxes but ran out of time to experiment. The pellets I have are pure bismuth, but hopefully the same will work for me. Most of the levitation videos show the carbon levitating over the ferromagnets. This works well because the carbon is much lower density. The issue with levitating ferromagnets over diamanets is that the ferromagnets tend to be too heavy for them to levitate properly. The experiments I've done since then, and a more careful read of SRI's patent, leads me to the conclusion that the diamagnetism thing is a bit of a red herring. In their videos they seem to have several sections where they aren't even using it. I suspect that the main advantage is from the low friction of the graphite. PTFE (teflon) would probably work just as well. True, windings would provide a more powerful magnetic field but I think that you are right, the cost would probably be prohibitive. I think that I've come up with a grid arrangement which allows 2D translation and rotation of the magnets and where the PCBs could be tiled to give an unlimited running area. The cost is likely to be in the region of 50p per magnet set for the vehicles (need a particular pattern of poles) and about £10 per 10cmx10cm road tile. If I can program the control system right this would allow any shape of motion for the vehicle. Early days. When I have something to show I'll start a new thread. For now: back to Bath!

Just saw this. Glad you're happy with it. A van like this with sheet metal sides is probably about the hardest thing to print because any warping or stepping is immediately obvious - if anything I think that the beetle came out better. When I said similar to injection moulded plastics I was thinking HIPS and I only meant in terms of stiffness. In fracture toughness the resin is far worse than any thermoplastic, I'm still trying to make up my mind if it is good enough or not. Have you painted it yet? How did it come out?

Hi, Thanks, that's very kind. I'm near Bedford. Fortunately I do actually have space to set the layout up in my dining room - but that can only be temporary before my wife arranges a party just to make me clear the table! I've also recently joined the EBMRS in Sandy, where a group of us are starting a new N gauge layout (the club's first foray outside 4mm). This will be a more substantial layout using similar methods. When we create a thread for the new project I'll put a link here.