Gordon H

The bits that need to conduct are usually made of metal, these ones aren't. Possibly so. However, they wouldn't have to concern themselves with posing at all if they were constructed properly.

At Peterborough Hornby confirmed both types are made of plastic, are unsprung, and have no linkages to make them move correctly, even in the mechanical sense. As a result, in the strict sense of the meaning, they are not pantographs at all, just bits of pivoted floppy plastic. Looking at the Hattons picture posted earlier, seems the Brecknell Willis version can't be posed properly either. However, they will come ready assembled (for what that's worth).

Which components do you mean? Nothing need be particularly overscale if the right materials are used. Hornby ran a series of seminars at model railway clubs when they first announced Zero-1, one of which I attended. However, it was quickly pointed out to them that the 16 loco limit would not work very well in a club environment where chances are collectively there would be considerably more than this wanting to run. For me, 'ease' and 'simplicity' are rarely considerations. 'Realism' of operation comes far higher - and what better than a model of an electric loco, itself using an electric motor, then using the appropriate method of power pickup for that motor? 'Reliability' is a debatable point. From extensive exhibition experience of club layout operation using live wires, the wires themselves are very reliable once erected correctly, and the system is effectively self-cleaning due to the wiping action of the pan head. Most problems were actually caused by derailments causing pans to de-wire. Can't deny the locos themselves look the part.

Our original club layout 'High Gill' used this arrangement, long before DCC became an option. Each of the hand controllers had an extra switch fitted to the end of the diecast box which selected between track and overhead common returns. Electrics all ran via the overhead, and diesels via the track. When it came to 'Carstairs' with its triangle, I created a special board located within that area's control panel which took all the relevant point position information, and decided which polarity to apply to the track on the Edinburgh branch. These things are all do-able if you put your mind to it.

That was certainly a selling point they latched on to in the early days, but at least it allowed overhead electric locos to derive their power 'as nature intended'. Now we don't even get the option. By forming an alternative common return current path, the original system could easily be expanded using conventional track sectioning techniques, so was by no means limited to just two independently operated locos.

Looks like you are reading it in the wrong direction. 240 Ohms would be red, yellow, black, black (+ tolerance band) in four banded terms.

That is the point - it should not be non-functional in this day and age. If they managed to do all these functional versions dating back 60 years, why take yet another a step backwards now? The rot started to set in when they produced the ridiculous 86 pan about 30 years ago. If you don't want to get involved in pantographs and OLE, why model AC electric outline at all? It has already been mentioned that some of the other 'continental' makes that Hornby now own seem able to produce working pans - and Japanese models have had working cross arms for years, even in N Gauge. Why should it be so difficult to produce them for British outline as well?

The orientation most certainly WAS implied, and not just to me it seems. As the orientation of the cranks is the only crucial factor in this discussion, it was reasonable to assume that it was this you were referring to when using the term bottom to identify their location. Obviously the linkage will be at the bottom of the pantograph as a whole, within the base area, but what matters is that one crank is on the top of one cross member, and the other crank is on the bottom of the other cross member.

It is definitely the case that this cross-arm pan design will not be in contact with the wire. There is no springing, and if it did touch the wire, it would just flop over as there is no linkage (already mentioned) to maintain the shape of the pan. Maybe good for posed pictures, but totally impractical for anything else.

The contact wire registers for each adjacent track need to be able to pivot or swing independently, otherwise they will interact. Just like the real thing...

Ironically, the diamond frame pans they fitted to their EM2 model back in the 60's were pretty good - and operational, both mechanically and electrically. You might think that 50 years of progress in all the various fields of manufacture would allow them to produce something at least as good by now, but sadly not it seems.

I think the point being made is that you said (above) the linkage goes between a crank at the bottom of both sets of arms, where one of them should have its crank on top, as per the picture. otherwise it would certainly not work.

Whether they work or not (i.e. whether they conduct) is indeed a contentious issue. However, they at least ought to operate in the correct manner mechanically - which neither of these new versions would appear to do. The real cross arm does have a linkage between the lower rotating tubes. How else do you think it works? It is the general way they are presented by Hornby in the display case (see the previous pictures) that gives the impression they are self assembly - otherwise why even bother to show the bits as being part of a sprue? That would be of no interest to customers if they come ready assembled on the model.

Having also had a look at Peterborough today, it definitely looks to me as if Hornby have completely copped out of the working pantograph issue by producing simple plastic sprues, which it appears you have to you assemble yourself. Although it looks OK at first glance, the cross-arm pan in particular appears to have no linkage between the two halves, meaning you can't even have it raising symmetrically by itself as it should. It looks as if it's is only poseable, and then only until it receives its first longitudinal knock which will immediately put it out of shape if it survives at all. The Brecknell-Willis version wasn't even assembled on the demo model, which only the base fitted, so no observations were possible. Of course I could be misinterpreting the situation, but I suspect not.

The best value to use would depend on the sensitivity of the particular track circuit detector design you are using. You really need to establish that figure first.

Do you use only one button to toggle the position? If so, you must already have an electronic circuit in place capable of doing that, so it ought to be a simple matter to add a relay to provide the polarity switching, controlled by the circuit with no more than a few extra components.

Minor correction, actually £21 for the first year: https://www.merg.org.uk/membership.php

It all depends on what resin is being used, hence my original query. When I used polyester resin for my own 508 nearly 20 years ago, I found that the resin itself was the best adhesive. Other resins I have tried since do not seem to stick together so well using the same principle.

What adhesive is used to assemble the parts?

When I looked into it quite a few years ago I discovered it to be based on a relatively conventional 4800 Baud serial link chain, but using current sources and sinks rather than voltage controls to provide better noise immunity over extended bus lengths. I didn't have any kit to try it with, so my investigations went no further.

Better not to think of them in terms of 'working off' a voltage like a filament bulb. LEDs require a controlled current through them to operate correctly, typically about 10mA. The voltage often quoted in LED specs is a feature of the LED when it is operating normally because it is a semiconductor device. It 'drops' that voltage when powered from a current limited supply, so you need a bit more voltage than that in your supply to allow for the current limiter (usually a resistor) to operate. LEDs should not be connected directly to an unlimited current supply such as a battery, in spite of any advice you might see to the contrary from certain people.

The concept implies that every physical position over the entire layout would have to produce a different result to prevent ambiguity of interpretation. How one might set about designing a layout against this requirement is unknown, and would probably be more involved than producing the circuitry needed to implement it. Also, what happens when more than one train (or current sink) is present on the layout?

To be truly universal, surely the flat pack loco should come with a selection of pantographs too? :-)

Better to replace the circuit board with one that operates the signal in a sensible manner. MERG have a kit which does that job.

I saw it yesterday at the museum, most impressive. Whilst there I had to explain to another visitor what 'HO' meant as a term, as the layout operator didn't know.