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Sector Plate Setting Up & operation.


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Is there a prescribed way to lay out the tracks that link a multi-track sector plate with connecting tracks on the scenic part of the layout?

 

I would like to have a two track sector plate on a layout that I've just started. Either of the two tracks will be able to access each of the three tracks leading to the rest of the layout.

 

The fiddle yard will be separated from the scenic section of the layout in front by a partition/backscene and I want to make sure that I can get the maximum space I can for the aforementioned scenic section.

 

I understand the concept but wonder if there is a formula or calculation for spacing the tracks on the sector plate correctly so that one track can be aligned to one scenic section track and the other sector plate track can be aligned to an adjacent scenic section track.

 

Many thanks.

Edited by Ray H
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12 hours ago, RexAshton said:

Does this help?

PLan1.jpg

 

Thank you. It does, but not completely.

 

The key thing that I'm missing is how to determine how far apart (and at what angle) the tracks need to be at the end of the scenic section (and the mating end of the sector plate). 

 

Logic suggests that the track spacing for the greater length of the sector plate needs to be the minimum allowed for the gauge of the railway e.g. for O gauge I take this to be around 80 mm apart.

 

I appreciate that the tracks at loose end of the sector plate need to be curved outwards slightly to align with the rail ends on the scenic section. 

 

I get the impression that we could be in a chicken and egg situation. You can't set the sector plate track end curves at the loose end of the sector plate until the tracks on the scenic section are in situ but equally you can't position the tracks at the edge of the scenic section until the sector plate tracks are in place.

 

Puzzled of MK ;)

 

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I THINK  the logic is. . . Lay two of the three scenic tracks, then lay the middle and left, fiddle yard tracks so they align with the scenic tracks, move the sector plate over until the left fiddle yard track aligns with the centre scenic track, now lay the third scenic track so it aligns with the MIDDLE fiddle yard track, move the sector plate back so the middle and left track again align and you can now lay the right fiddle yard track so it aligns with the remaining scenic track. I COULD be completely wrong though and I'm sure I will be swiftly corrected :read:

 

 

   P.S. Ahh just re read it and you want to do 2 into 3  b%@&&#r  got it wrong again, but I'm sure I'm close !

 

P.P.S. na still works as you just dont lay the third fiddle yard track and at the extremes only one line would line up anyway and you peg the traverser at that point

 

 

P.P.P.S. ignore all the above by me, I'm thinking traverser. . Where did I get traverser from ? !:read:

Edited by Mattc6911
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All your presumptions are correct. Bear in mind though that the distance between the tracks need to be wide enough apart to handle stock if necessary. As you can see from the plan the centre track on both the sector plate and the scenic section are dead straight and form a datum. If the sector plate is then swung so that the centre (straight) track is aligned with the position you want the next track to align with it, it will allow you to calculate the approach angle of the track on the scenic section. Once that has been laid you will then be able to calculate the curve needed for the next sector plate track to align correctly with it. I've attached a somewhat ropey sketch to hopefully show what I mean. The method works but does require both the scenic and sector plate sections to be laid together.

IMG_20191024_0001.jpg

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The basic principle is that the end of each track on the sector plate should be aligned so that, if the rest of it were straight, it would pass over the pivot point. This is easiest to visualise by looking at the centre, straight track. Consequently, all the fixed tracks leading to the sector plate must also be aligned such that, if you projected them in a straight line, the projection would pass over the pivot point. 

 

If this principle is followed, any track on the sector plate should be alignable with any of the feed tracks. 

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Many thanks peeps.

 

My critical track on the scenic section is the one with the point in the image below. The above responses will hold good for that.

 

231019_2.jpg.d503f89b7d186fee7830dc485e04f04a.jpg

 

This where I'm at currently - before I penned (and read) the above. The two tracks on the left foreground simulate the sector plate.

 

The vertical plywood piece is pretending to be the backscene between sector plate and the right hand siding. I was keen to see if I could move the backscene a little further away from the (scenic) siding as the two look a bit close at the far end.

 

The layout is basically rural as I haven't got (storage) room for too much height on the layout.

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I think we're there. The cardboard bottom left represents the sector plate.

 

241019_1.jpg.d552e51f2b8eae08bf51d1d6b3a06252.jpg

 

I tried several different pivot points to try and open up the distance between the siding - right foreground - and its back scene but what suited that pushed some of the left hand track - middle left - off the side of board. I also tried varying the distance between the three tracks fed by the sector plate. That didn't provide a solution either.

 

The baseboard closest to the camera is now to be reduced in overall width by approx 100mm to match the other two boards. Every thing will then be shifted to the right by about 15mm to increase the space between the right hand baseboard edge and the nearest track to it.

 

I'm also cheating a bit! the outer end of the right hand sector plate track will actually slide under the back scene by about 10mm. It loses about 30mm of usable track but the alternative would be to only have a single track sector plate.

 

I don't intend to have a huge amount of stock so most of it (other than an occasional loco change) is liable to remain on the layout although there is just a possibility that I might add a hinged side extension to the left hand side of the board that will be behind the back scene. That will only facilitate a link to the left hand track on the sector plate and would accommodate a cassette to facilitate stock addition to or removal from the layout.

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When I built a sector plate, I placed the pivot point close to the end away from the rest of the layout.  I then laid the tracks on the sector plate parallel until they reached the curved end.  The curve on the sector plate was centered on the pivot point and the tracks were adjusted to be perpendicular to the curved end where they met it.  OK, I did have 5 roads on the sector plate and one leading off which makes things easier.  But the key point as I see it is that the tracks should be perpendicular to the sector plate curve.  (Rather like on a turntable as the sector plate is in effect a large turntable that doesn't turn the full 360 degrees.)

 

So in your case, I'd lay the sector plate lines parallel at normal running distance apart except at the curved end of the sector plate where they'd diverge slightly to be perpendicular to the curve.  The layout track can then be laid to align with your 2 sector plate lines.

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That's largely what I've done -  and thanks for re-assuring me.

 

I spent much of yesterday adjusting the pivot point relative to each of the three entry/exit roads and also tried manipulating the position of those entry/exit roads.  I tended to run out of baseboard on one side or end up with the back scene board too close to the siding track that runs parallel to the sector plate.

 

I did plot the centre lines of the exit tracks to assist in laying them out so I'm reasonably content that there aren't too may options that I missed.

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Your welcome.

 

The  track was only down loosely in the last image and the third board needed its width reducing. That's now all but been done and I hope to be able to put the track back down in the morning. That may just throw up a better arrangement but I think I'm all done on that front now.

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Maybe these might be of assistance?

 

One of them shows how I ensure the rails stay aligned when soldering them at the joins by using an upside down rail joiner on TOP of the rails. Excuse messy soldering but it works!

 

steve

 

 

IMG_1610.JPG

IMG_1611.JPG

IMG_1612.JPG

IMG_1613.JPG

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The baseboard has been re-modelled and the sector plate made.

 

One question that I hadn't thought to ask before is what methods people use for the pivot. I'm thinking that a screw will gradually wear it's hole over-size.

 

What other options are available given that I don't have any form of workshop to make metallic things in.

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15 hours ago, Ray H said:

The baseboard has been re-modelled and the sector plate made.

 

One question that I hadn't thought to ask before is what methods people use for the pivot. I'm thinking that a screw will gradually wear it's hole over-size.

 

What other options are available given that I don't have any form of workshop to make metallic things in.

I usually use a coach bolt, which then has a washer and 2 nuts on the under side of the board the sector plate is attached to. The first nut is to hold the board and washer in place (not too tightly, you want it to move without snaging) and the second nut to stop the first one coming undone.

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On 28/10/2019 at 05:36, Ray H said:

The baseboard has been re-modelled and the sector plate made.

 

One question that I hadn't thought to ask before is what methods people use for the pivot. I'm thinking that a screw will gradually wear it's hole over-size.

 

What other options are available given that I don't have any form of workshop to make metallic things in.

 

It will, but given the very limited angular movement and negligible load, possibly not fast enough to cause a problem. Would depend on the amount of use the layout gets, of course. One simple option would be to drill the clearance hole in the sector plate oversize and either glue or force fit a sleeve of K&S brass tube in to provide a bearing surface against the screw.

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Several years ago I had a brief encounter with (amateur) radio such that I ended up collecting all sorts of electronic bits and bobs to break down as a source of components. I still have a number of bits including springs, spacers, screws and washers. Within the spacer box I found what I will class as spacers with a flange and one that fitted snugly inside the other with the two flanges at opposing ends, The smaller piece had an internal dimension of approx. 2.5mm. From elsewhere I found a 2.5mm "bolt" with locking nut.

 

I drilled the sector plate pivot point to take the smaller diameter and the baseboard to take the larger item - I also had to recess the underside of the sector plate slightly.

 

The larger piece has been glued into the underside of the layout - because the diameter of the drill I mistakenly used was 0.5mm too large. The bolt passes through the top of the sector plate and emerges to other side of the baseboard where it now has a locking nut to hold it reasonably tight.

 

The layout will be dcc controlled so the sector plate will just have two wires ! ! !

 

The untethered end of the sector plate is within about 15mm of the baseboard end at the narrowest point. I plan to replace the various sleepers with parts of a copper clad PCB sheet to which the rails will be soldered. Whilst I can relatively easily cut the PCB in a straight line I'm wondering how to shape the curved side of the PCB given that the dust from PCB isn't good for ones lings.

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4 hours ago, PatB said:

 

It will, but given the very limited angular movement and negligible load, possibly not fast enough to cause a problem. Would depend on the amount of use the layout gets, of course. One simple option would be to drill the clearance hole in the sector plate oversize and either glue or force fit a sleeve of K&S brass tube in to provide a bearing surface against the screw.

 

Agreed, I planned to use a 1/4" jack socket and plug for the pivots on Summat Colliery, electrical connection and movement in one. Temporary screws were used to prove the design and yes, they are still there and working fine after 10 years LOL. I've not noticed any wear at all.

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The sector plate has been built and well tested in operation from what many may see as the conventional position i.e. the rear of the layout.

 

However, I'd like to give myself the opportunity to operate the layout from the front as well as the back. This presents a problem of its own in that there is a siding in front of the sector plate.

 

I've exhausted my supply of ideas relating to ways the sector plate can be operated from either side of the layout.

 

Has anyone any suggestions as to ways that it could be done given the fact that I've only got a small range of tools and little engineering skill.

 

Thanks.

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On 04/04/2020 at 03:22, DavidCBroad said:

Could you post some pics of what you have built so far. There are a few ways to do it but it depends on what you have in place.

 

Thanks David.

 

The layout's dismantled at present (so that I can use the bench underneath) but this shows the layout when erected - it is still largely bare boards save for the track at the moment.

 

090320_1.jpg.71978f49203479d1603f5aef65dbbd14.jpg

 

The sector plate is bottom left and the back of the layout is also on the left. The sector plate  does not move any further to the right and there will be a backscene board either where there is a step in the baseboard surface, at the right hand side of and adjacent to the sector plate or somewhere in between.

 

The remaining backscene boards are waiting to be fixed to the rest of the layout. I think it would be nice to be able to see and operate the layout from the front especially as I endeavour to add some scenery to it.

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Something along the lines of this - a transverse rod or dowel through the baseboard. A vertical pin from this locates into the end of the sector plate. It will need a slot cut into the surface to allow it to move, about 2 inches long at a guess. Stick a knob on each end of the rod and you can operate it from either side.

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Thanks.

 

Alas the layout is O gauge and the sliding end moves around 150mm. I can reduce this slightly by locating the drive pin nearer to the hinged end but I'm concerned that the projection of the rod/dowel out of the front of the layout when I'm operating from the rear is so great.

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