Things appear a lot more complicated than they are.
Take a look here
tomikawaTT As everone else has mentioned, the connection between the end of the swinging arm and the fixed body tracks is the critical point for alignment. However, the rail ends don't have to come within a few thousandths of an inch of touching. At the rather slow speeds appropriate for entering and leaving hidden yards, a gap of a millimeter or more can be allowed if the ends of the rails are beveled slightly. To keep from collecting swing problems, the swing arm could be carried on a couple of spacers, one at the pivot and two side by side close to the free end. That would go a long way toward avoiding problems with junk interfering with the swing arm. I would devise some kind of positive lock on the rail ends of the fixed track, interlocked with an electrical switch or switches. If the swing arm isn't properly aligned, whether by a millimeter or a foot, the storage track should be electrically dead. If the switch is a DPDT, the other contacts could operate red and green LEDs for at-a-glance alignment/lock status. (There are a lot of ways to do this, some simpler than others.) Actually, it's a clever idea. I almost wish I could use it. Chuck (Modeling Central Japan in September, 1964)
As everone else has mentioned, the connection between the end of the swinging arm and the fixed body tracks is the critical point for alignment. However, the rail ends don't have to come within a few thousandths of an inch of touching. At the rather slow speeds appropriate for entering and leaving hidden yards, a gap of a millimeter or more can be allowed if the ends of the rails are beveled slightly.
To keep from collecting swing problems, the swing arm could be carried on a couple of spacers, one at the pivot and two side by side close to the free end. That would go a long way toward avoiding problems with junk interfering with the swing arm.
I would devise some kind of positive lock on the rail ends of the fixed track, interlocked with an electrical switch or switches. If the swing arm isn't properly aligned, whether by a millimeter or a foot, the storage track should be electrically dead. If the switch is a DPDT, the other contacts could operate red and green LEDs for at-a-glance alignment/lock status. (There are a lot of ways to do this, some simpler than others.)
Actually, it's a clever idea. I almost wish I could use it.
Chuck (Modeling Central Japan in September, 1964)
I don't see why with careful design and the right materials that it shouldn't work. I would keep it more simple. If this area of the staging won't be sceniced, the sector/ flexable track could just ride/ slide on a smooth roadbed like 1/4" styrene etc. A surface throwbar long enough for controls whether underlying or surface controled. "U" staples or some other means of holding the throwbar down while still maintaining tie clearance would be nec. Atlas flex would be the best to use in this case, it is probably the most springy yet durable track to use for constant movement. By not having a break @ the pivot the sector/ movable flex is powered right up to the assorted storage tracks. Instead of a compclicated indexing and power routing, I would just control on/ off power to each of the tracks. The last few inches of the flexable section should be ridgid. Glueing the rail/ tie would do this. Having the end ridgid would alway allow for consistant indexing to each of the storage tracks. What you need to figure in the design is just how much the track will flex and still maintain some stability and still keep it relatively flat on the riding flat surface. You may find that it will only accomadate the swing to handle 4-5 tracks, additional bemding to added tracks could cause far more difficulty/ dependability of the sector use. You may find that instead of just using sliding restriction for the flex that some sort of slightly adjustable indexing may be incorporated into the design. It's not going to be anything easy and there will be quite a bit of tweaking, yet I think it could be done. If the staging tracks aren't going to be that long, have you considered using a drawer slide tranfer table instead. Of course you need room @ both sides of the lead to make this happen, but it would be much easier and far more dependable.
Modeling B&O- Chessie Bob K. www.ssmrc.org
I think your system, as you depict, will work, but it will be fussy. First, you will need a long section of flex to avoid the very tight curve that Byron is worried you will experience at your pivot section. Additionally, you will need to keep it sweeping both a clean and a smooth surface so that you don't get snagging [which will impart a different curve]. Finally, your various staging leads will have to be terminated carefully so that your sweeping flex end that meets those staging leads does so with minimal gaps. Will you rely on joiners to keep the flexed end securely aligned? If so, I don't see it being very reliable.
Crandell
Sector plates are commonly used in British "railway modeling" and actually not that difficult to construct. A search in British railway modeling forums will give you plenty of information on how to build a sector plate.
cuyama What most folks consider a sector plate is the opposite of what you've posted (or maybe I am just not understanding your drawing). The staging tracks would be on the moving section in a typical sector plate, with the approach track fixed. Have you built anything like this before? A few folks have done something like what you describe, but if you are thinking of making the movable track out of flex track, for example, note that the relative lengths of the two rails will change constantly for each track you try to align to. That could be a bit tricky and would require some significant engineering. I'm not seeing how your planned pivot point will work -- seems like that would create a very sharp curve in the track when aligned to the outside staging tracks. If it did work, it would likely need to be curved over a much longer length, near as I can tell. Here is a more typical sector plate. All the staging tracks are on the section that moves to align with a fixed feeder track. From this thread on another forum. Best of luck.
What most folks consider a sector plate is the opposite of what you've posted (or maybe I am just not understanding your drawing). The staging tracks would be on the moving section in a typical sector plate, with the approach track fixed. Have you built anything like this before?
A few folks have done something like what you describe, but if you are thinking of making the movable track out of flex track, for example, note that the relative lengths of the two rails will change constantly for each track you try to align to. That could be a bit tricky and would require some significant engineering.
I'm not seeing how your planned pivot point will work -- seems like that would create a very sharp curve in the track when aligned to the outside staging tracks. If it did work, it would likely need to be curved over a much longer length, near as I can tell.
Here is a more typical sector plate. All the staging tracks are on the section that moves to align with a fixed feeder track.
From this thread on another forum.
Best of luck.
I agree with what Cuyama has said. That sector plate only needs one track on it if you are basically using it as an escape track for a locomotive. However, it can be made train length if you have the space. But I gather from the explanation that what you are trying to do is have the sector plate replace the yard lead turnouts.
I did find a link to a site where there are pictures and an explanation from someone that did exactly what you want to do. See: http://model-railroad-hobbyist.com/node/6401
The joint he cobbled up to eliminate the rail length changes Cuyama referred to is very innovative.
I notice you posted on this same topic a couple years back. A that time, folks were telling you about sliding drawers, which is also a possibility, but still different from a sector plate. Again, the feed track would typically be fixed.
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