Tuesday, January 12, 2021

Electrical considerations for a lift bridge

When adding a removable section of tracks to span a gap in the layout such as the entry door to the layout room some thought has to be given to a few problems. 

How will any needed wiring pass through the bridge ?

My train room was built in the back half of a garage that is about 70 years old.  The concrete floor was in poor enough condition that I elected to build a raised floor which ended up being about 9 inches above the concrete garage floor.   Anticipating that layout wiring may need to span across the doorway I included a 1 inch diameter electrical conduit that connects each side of the doorway.  This conduit travels down the wall on each side and under the ramp that leads from the garage floor at the door up to the raised floor if the layout room

A pull line had been left in this conduit when it was installed so it was easy to pull in an 8 conductor, 18 gauge cable at this point in the layouts development.  Each end of the cable was terminated on a terminal strip.  A new pull line was also pulled in at the same time so future cables can be installed the same way.


How are the tracks on the bridge itself connected to track power ?

In this case there are 2 tracks that go across this bridge with each being connected to a different DCC Specialties PSX-1 DCC circuit breaker.  While there are special door hinges used for electrical door locks that could be used, these are quite expensive so I am just using 4 flexible wires.  These wires are 18 gauge but are made up of many smaller strands and that is what makes them more flexible.  The ends are connected to terminal strips so can easily be replaced if movement eventually causes any of them to break.  

What prevents a train from approaching the bridge when the bridge is open ?

At the end of the bridge that does not have the hinge,  there is a magnetic switch within the frame that the bridge fits into and it's activating magnet that is within the end of the bridge itself.  The bridge has to be fully closed for the switch to activate.   

The magnetic switch controls this group of 5 single pole relays.  4 of the relays control track power, 1 for each rail of 2 tracks.  When the track is installed, it will have an additional isolated gap a few feet from either side of the bridge.   This will stop a train from approaching the bridge when the gate is up.  The 5th relay will be to control a warning light outside the door indicating that the gate is lowered.


Sunday, January 3, 2021

Adding wifi throttles to the layout

I had been considering adding another utility throttle when the Digitrax LNWI caught my eye.  The LNWI is a Wifi module that connects to the Loconet and will allow a smart phone with a throttle app to be used as a throttle.   These cost about the same as a wired UT4 throttle and will support several smart phone throttles.

There was nothing to installing this new module, I just plugged in the power and connected it to the existing Loconet and it was ready to go.  There are several free throttle apps available and the one I am using is called WiThrottleLite.  It worked the first time I tried it, no problems.  I found the WiThrottleLite app very easy to use and it also has a flashlight function built in which may be handy when uncoupling those cars in the shadows.

Thursday, December 31, 2020

2020 - A year devoted to the home layout

This past year of course has been a very challenging time for almost everyone.  I do feel fortunate that I have this layout to keep me busy doing something creative and that helps ease the feeling of "cabin fever".  With all train shows and conventions being canceled this year and being home all of the time I have been able to enjoy more model railroading time than I would have normally.  And with no shows I was not motivated to work on any modules so all of that time went into this layout.  Besides working on the continuing expansion of the layout I was also able to finish some side projects on various other parts of the layout.  Here are some of those projects with links to posts made on them:

This winter I am again participating in the annual Trainboard.com Winter Layout Party.  I have noticed that there seems to be more people participating this year so I must not be the only one spending more time with their layout.

Already the N Scale convention in Sparks, Nevada that was scheduled for next June has been canceled and I suspect that it is going to still be some time before it will be safe to travel or have train shows again.   Until then, I'll just keep working on my railroad.

Happy New Year !

Wednesday, December 23, 2020

The crooked path across the bridge

Back in June I posted about the lift bridge I had constructed across the entry into the train room, that post can be seen HERE.  After six months and changing seasons it has remained quite stable.  With this current layout expansion the bridge will be needed so now to put some track on it.   The idea of my bridge is to use tunnel portals and hillsides to hide the bridge being in the scene.  

The actual Palisade tunnels that this part of the layout represents on are on a straight alignment but I am going to take some liberties with the track alignments through these tunnels to make my track plan work.   The tunnel portals on the right or west side are angled to allow for a larger radius curve around the corner.   

At the points where the tracks meet at the gaps I am using copper clad PC board as these will hold the track very stable.  I was able to buy the material on ebay in a 2" x 6" size and then cut it into 1" x 2" sizes.   These were then cut at the angle that the track will cross the gap.  Each of the 4 track / gap angles are different.  Holes were drilled on both sides for track nails and a groove was cut through the copper cladding to isolate the rails.

On the lift bridge we built many years ago at the Ntrak club, we used Atlas code 80 re-railer tracks at the gaps.  The idea was that if a set of wheels gets derailed at the joint it will get re-railed right away.  This has worked out well so I wanted to try the same idea on my layout's lift bridge.  A friend had recently given me some Atlas code 55 re-railer tracks and the rails were a perfect match for the Mico Engineering track I am using.   Traffic will move mostly in one direction on each track so the re-railers are placed the side after the train crosses the gap.   Another lesson learned from the Ntrak bridge experience was to round the tops of the rail end a bit.  This helps with smooth running but also with a shirtsleeve being snaged when someone goes through and pulling up the track.

The gaps were done in pairs on the work bench with the second one being done with a tracksetta tool in place to hold the alignment and the track gauge was carefully checked with both an NMRA track gauge and a caliper.

So at this point the   track is in place and everything seems to roll smoothly over the joints with no derailments.  After the holidays I will post about the electrical aspects of the bridge.

Friday, December 11, 2020

River bottom and land forms for Palisade Ranch

The sub-roadbed has been completed through the new Palisade Ranch section of the layout and the cork roadbed is well underway.  So now I am also working on adding the river bottoms and the land forms.  This needs to get fairly far along before I install the track and bridges especially toward the back and under the bridges.  The bench work frame is only 2 inches thick here and the river will be at the top of that frame so strips of scrap were glued onto the existing structure of the bench work to create support for the river bottom.

Next the river bottom made of hard board was glued into place on top of those supports.  The river will round the corner around the corner to the right and disappear behind the built up track.

I am using similar methods for the terrain as I have before on this layout.  For some of the terrain I am using building insulation foam board.  Along the back of the scene the hills will be built up to blend in with the backdrop.   This will then be covered with a layer of plaster cloth.  A long sheet of .030 styrene is slipped in front of the backdrop to protect it while all the scenery work is going on.

In some larger areas I use the plaster cloth over cardboard strip method.    The cardboard that works best for me is from Postal Service Priority Mail boxes that items sometimes come in.  It is corrugated but thinner than most corrugated cardboard.  I cut it into strips about 1/2 inch wide across the corrugations so it will bend easily without any sharp kinks.   The ends are glued with yellow carpenters glue and either pinned or clamped to the surrounding structures.  Areas like this usually get 2 layers of the plaster cloth.

Thursday, December 3, 2020

Plan and start for the new section

In a post on October 31st I had shown a prototype photo of what the next section of the layout will represent.  Here is another photo of the same area taken from just above the tunnels on Palisade Ranch Road that I like to use as a reference.  I suspect that the road access is the reason that this is one of the most photographed areas on this line and so I am calling this section of the layout the Palisade Ranch section.  The through truss bridges in the distance is in the spot that the concrete trestle will be on the layout.   

 In planning this new section I used some red rosin paper left over from a painting project and cut a section of that to match the shape and size of the new area to be modeled.    Laying it out on the floor I bent some track to the desired radius and laid them in place along with the bridges and tunnel portals that had already been built to get an idea of what I could accomplish in this space.  With Sharpie pen I drew in the key features.

Of course my model of this scene is going to have to be quite compressed and is going around a corner.  I want to include Palisade Ranch Road in this scene and that is indicated by the yellow line drawn in with Photoshop over the tunnels.  The location of the curved concrete trestle is also pointed out with yellow.

Construction on this new section is moving along.   There was already the basic structure in place that was supporting the temporary turnaround loop so working off of that all of the sub roadbed for both lines has been established.  Cork roadbed is now being installed and next will be the river bottoms and then some terrain can get started. 

Thursday, November 26, 2020

Building a curved concrete bridge

In the next expansion of the layout I will need a bridge where the WP line again crosses the Humboldt River.  The bridge that is actually in that location on the prototype is a 4 section through truss bridge.  My bridge in going to have to be part of a curved section of track so I am going to use a ballasted deck, segmented concrete bridge.  I already have a straight version of this type of bridge that I installed on the Golconda section in February of 2017 and is featured in THIS POST.   For that bridge I had a couple of good prototype photos I was following.  This bridge is going to be more freelanced.  I had considered the BLMA kit which is similar to what I wanted but it was too short for my application so I decided to scratch build this one.

I started by making several bents using some of the poles from Rix Products highway bridge kits.  These are 1/8 inch in diameter so I am only using 3 per bent.  The horizontal beam is cut of pine strip with holes drilled into it for the poles so they are quite sturdy.


The curve is going to be 18 inch radius so using an 18 inch radius Tracksetta tool as a guide I marked out a curved section on a large sheet of .030 styrene sheet.  Then I cut the curve out with a pair of scissors.

.030 thick styrene was cut into five 20 x 17 n scale foot sections and glued onto the curved strip.  The outer edge has small gaps between the sections.  The excess of the original curved sheet of styrene was cut off at each end.   Then .060 x .060 L channel strip was glued along both edges to covers the gaps on the outer edge between the two sheets of .030 styrene. 

The longitudinal beams were made from 1/8 inch Plastruct square tube stock cut into lengths that matched that section along the edges.  To give the bridge deck some stiffness, short lengths of .040 music wire that had a slight bend were glued into the holes of the tube.

On the straight version of this type of bridge I had used 1/8 inch thick acrylic to make the bridge deck stiff but not being able to cut a curve in the acrylic I used 1/8 inch hard board.  Between the music wire joints between the beam sections and the hard board the bridge deck got quite stiff.

.040 x .060 styrene strip was added along the top near the edges of the deck to retain track ballast.  Bridge abutments of the correct height to match the adjoining sub roadbed plus the thickness of the cork were made from 1/4" plywood.   All the pieces were painted with Model Master aged concrete acrylic paint.

The bottoms of the poles were cut and angled to sit on top of 1/8" thick footings on the bottom.  The bridge is shown here set temporarily in place after all the parts were glued together and receiving some weathering.  Once more of the surrounding terrain is built up and the river get at least a basic finish then it can be permanently glued in.

Wednesday, November 18, 2020

Upgrading wheels on old Kato locomotives

I have quite a few of the older Kato SD40, SD45, U30C, and C30-7's and I really like them for their reliability and durability.  One thing that has bothered me is the way they would rumble through any of the code 55 turnouts that I have had on my last two layouts.   No such problems with code 80 like on the Ntrak layout or the staging yards of my current home layout.   Apparently the older releases of these models have what in the hobby are called "pizza cutter" wheels as they have a flange that is almost as deep as the rail code 55 rail is tall. 

So I decided to see if I could do something about this and found that Kato USA sells packages of 6 locomotive axles with low profile wheels so I order several sets of these.

Once I got the new wheel / axle sets I wanted to make a side by side measurements of all the dimensions of both new and stock.   My first impression of the new wheels is that they look more like railroad wheels.  I also noticed that they also appear to be the same or similar as what are on some of my newer Kato releases.   Below are two photos with the dimensions I measured on each type of wheel set.


The main difference between the two is that there is a .013 difference between the flange depth.  The old wheel flanges are actually slightly larger that the height of the code 55 rail which is .055 so no wonder the wheels bumped.  The wheel itself is .015 narrower than the stock wheels but since flanges on both are right on gauge I don't believe that would make any difference but it does look better.

To change the wheels the trucks needed to be removed and then opened up to expose the axles and gears.  Then those are popped out and the new ones popped in, they are a perfect fit.  It's a good idea to clean out the cups in the brass contact frames that the axle points go in before re-assembling the trucks.

It is an $8.00 investment in each locomotive but I feel it's worth it as they are otherwise such great runners and already have DCC decoders in them.  Little by little I plan to got through the fleet with this improvement.

Saturday, November 14, 2020

Yard sequencer

In previous posts I had mentioned the use of some automation in the staging yard, here is just a bit more detail about how that works.

I am using Aztrax IR sensors to sense when a train arrives on one of the four staging tracks.  The sending units are in stands made from brass while the receiving units are in the tracks between the ties.  These are positioned near the departing end of each staging track.

The post on one side of the stand is 1/8 inch hallow tube and the wires for the IR sending unit are fed down through it.  The post on the other side is 1/8 inch rod that has had the end threaded for 6-32 sized nut.  Before the IR sender LED's were installed, the stands were spray painted white.  After the IR sender LED's were installed white heat shrink tubing is slipped over after a hole is punched on one side for the sender.

Referring to the control panel photo and diagram below I will attempt to explain how this works.  When a train arrives at the IR sensor pair it triggers a one second closure of the relay on the Azatrax board. The relay contact outputs of the Azatrax units are wired in parallel with the push buttons on the control panel associated with the next track but first pass through a toggle switch labeled Auto / Manual in the photo.  In the auto position the contact will trigger the turnouts for the next track and the train on that track will leave.  In the Manual position that track will be skipped and the closure will go to the next track.   This allows the flexibility to use any of the tracks and skip others in the case there is no train on that track. 

In the photo below one of those IR sensors between the ties is pointed out.  This system has been working out fairly well.  I did have to move the sensors around a bit to allow for the arriving train to coast to a stop before reaching the end of the siding.   Also it does occasionally happen that the train stops with the sensors being right between the first and second locomotive.   If this happens then when that train goes out again, the second locomotive will be mistaken as an arriving train and cause the sequence to move to the next track.