What are the recommended methods of installing/cutting/maintaining electrical gaps?
Here on the NEBW, we use hand laid trackage, but we still have a large number of gaps, especially since we use solid metal frogs. In addition, what do we do about the gaps? The answer is...nothing.
That's right, nothing. Our gaps are just that, gaps. In fact, a little over a week ago I cut a curved number 10 turnout into the mainline, and there is a 1/8" gap right off the frog on the mainline
route. And it ran perfectly during all twelve hours of our weekly open houses. In fact, the only problem we had with it was due to the angle of the frog. Being such a shallow angle, I had to install
the guide rails to keep the wheels from taking the wrong route in the frog. After I did that, there were no further problems. And, all of our curved mainline turnouts are superelevated, which makes
it all the more difficult.
On a layout like ours, where we have no humidity control, the gaps should be left open to allow for the expansion of the rail and the benchwork. As long as the rail is spiked securely in place, open
gaps will prove no problem.
It also means that areas like turnouts, crossings, etc. and other special trackwork won't be knocked out of gauge by expansion problems.
I have a small (3' X 4') N scale layout with mostly hand-laid track. Generally, I cut gaps using a motor-tool cutoff wheel, which makes nice straight, narrow gaps. I usually use a small shim of
styrene that is epoxied in place to fill the gap. The styrene is easy to file down to the contour of the rail and can be painted to become invisible.
As the layout is small, gaps are only about 2-4 feet apart and the amount of expansion and/or contraction would be minimal. For longer sections, I would probably leave the gaps open as the plastic
filler might not be flexible enough to take the compression and rails between the gaps would buckle slightly out of alignment.
Here's a technique that works for me:
1. Spike track securely in vicinity of gap
2. Cut gap (if it wasn't built-in in the first place)
3. Fill gap with epoxy cement
4. When set, paint over epoxy with rail color [Some railroads fill their own rail gaps with epoxy. Painting is optional]
If the gap is on a curve, (to be avoided if possible) I puddle some epoxy on around where the joint will be, let it cure.
I allow for expansion by allowing the "normal" rail joints on straight track to be a little loose and only solder joints on curves, to keep the rail ends in line. I then run a pair eighteen gauge
wires under the track to serve as a bus and run feeders up from this to connect to EVERY piece of rail on the layout. Nickel silver doesn't oxidize very quickly, but it is not a very good
conductor.
I cut my gap, usually using a Dremel cutoff wheel. Then I take a flat or square, not round, toothpick and push it into the gap. I then "set it" with some white Elmer's or furniture glue. Next day, I
trim up the toothpick to conform to the rail contour and have a permanent, fixed gap. Have some that are still good, AND, for all purposes unseen, for over 20 years.
I have a question regarding wiring my layout for block (cab) control. I'm not ready for DCC yet, so this is the route I want to take.
I want to have 3 cabs. One (Cab A) will have control over a certain section of the layout (let's call it section 1), another (Cab B) will have control over the other section of the layout (section 2), and the third (Cab W)will share control of both sections (W will share with A in section 1 and share with B in section 2). Cab W will be a walkaround handheld controller. So cab A won't be able to control in section 2 and cab B won't be able to control in section 1 but Cab W will be able to control in both sections. Each section will also be broken into smaller blocks.
I wired my last layout for two cabs using DPDT toggles, assigning block power to the different cabs by throwing the toggle switches. My question is, how can I accomplish the setup I describe above, hopefully still using the DPDT toggles?
Instead of using toggle switches you can use a plug and 3 sockets for each block. Then any controller can operate any block. if you use multi pin plugs and sockets you also can interlock your signals to your block cab selection.
My club was faced with a similar problem to yours, and we came up with the following solution.
Two throttles were wired to a dpdt switch the way one normally would. The output wires from this first or primary switch were routed to one side of a second dpdt switch. The other side of this second switch connected to the third throttle, and the output went to the block as per normal practice.
If the second switch was thrown toward the primary switch either of the two throttles connected to that switch controlled the block.
Throwing the second switch the opposite way gave control of the block to the third throttle.
Thus, we could control any section of the layout from any of the three throttles.
It was hard to operate the panel at first, but we did get used to it. In practice the club members found that the third throttle was unnecessary and was subsequently disconnected.
Another and possibly simpler solution would be to use a rotary switch to select the appropriate throttle.
DCC is the third option. I can't comment on this, as I have no practical experience with this system. Judging from what I have read, seen and heard about DCC it would seem to be a much more practical and certainly a much more flexible system of train control.
Andy
I do something similar with "ganged" throttles. From the track the feeders go to a dpdt toggle that connects to either cab one or cab two. At Cab two it hits another dpdt to actually connect it to cab 2 or send it on down to cab 3. At cab 3 it hits another dpdt to either connect to cab 3 or send it on down to cab 4. You can daisy chain as many cabs as you want.
In operation, cab one can take any block he wants. Cab two can have any that aren't used by one, cab three can use any that aren't in use by one and two etc. Since, on my layout at least, Cab 1 will usually operating the main, cabs 2 & 3 the trolley line, and cab 4 the yard, it works out well.
The "down" side is you have to have a dpdt switch at each cab for each block, which can quickly get you up to price of a starter DCC system. (FWIW, I have about 24 blocks, means I need 96 toggles once all the cabs are in. Fortunately I have about 50 salvaged from previous layouts so it's not as bad as it sounds))
When I eventually DO go DCC, I'll just subsitute the DCC unit for cab one. That will leave conventional cabs to run the trolley line or any none DCC equipped locomotives.
Don