Monday, January 24, 2011

Fixing the Grade

As this is my first layout, almost every aspect of the construction of model railroading is new to me. Most tasks are trial and error, and the amount I’m learning is extraordinary. At the same time, I’m also seeing where I went wrong, and the biggest error is the grade leading off of my trestle down to the 60 degree crossing. This has been a huge issue since I first designed the layout. Engines would high center at the top of the hill, and the cattle-guards would catch on the crossing, always causing derailment. This grade had to go, so back to the drawing board I went. With a little better planning, I managed to take the grade from almost 11%, down to just over 6%.

Track grades before and after

I removed the entire grade to start fresh. I took two things into account when re-planning the grade. The first was that I needed to try to make the distance from the 60 degree crossing to the end of the trestle longer. Second, I had to decrease the height of the trestle. These two items were essential in making a more successful grade.

Track grade adjustmentTrack grade reduction

To do this, I removed about 4 1/2 inches of the structure leading up to the trestle, thus allowing me to move the trestle over. Second, I had to lower one end of the trestle. I had almost ¾ inch clearance above under-passing trains, so with a few modifications, I lowered the trestle about 1/2” on one end. The trestle now has a down grade of about 2%.

Foam grade risers from Woodland Scenics

For the rest of the grade, I used a 4% foam starter grade from Woodland Scenics. This allowed me to easily transition from the crossing level up to the edge of the trestle. I then used custom cut foam supports to make sure the grade stayed in place and had proper support. I then added foam roadbed and once continuous piece of flex track to ensure a continuously smooth track. The end result was flawless! No more derailments and no more high centered engines!

Reduced track gradeReduced track grade

A lesson about grades: I’ve done a bit of research about grades, and most prototypical modelers say nothing over 2%. For small layouts such as mine, this just isn’t possible, as I would prefer a slightly less prototypical railroad with lots of curves, elevation changes, bridges, mountains, etc. before I would a simple oval with no grades at all. However, with grades come great challenges, especially if it’s your first layout, such as mine. A few things I learned which might help you:

1. Plan first and know your limits! When designing your layout, try to give yourself as much room as possible for up/down grades. There are physical limits to how steep your train can travel.

2. Keep your grade as consistent as possible, with smooth transitions at each end. This is a problem I ran into. My transitions at the top and bottom of my downgrade were very extreme, resulting in my engine getting high centered at the top of the grade and bottoming out at the bottom of my grade.

3. Crossings require level track leading up to them to prevent couplers and cattle-guards from catching on the crossing track. If you have a grade leading to a crossing like I do, make sure the grade is no more than 2% for at least 8” before the crossing.

4. Experiment. Play around with different grades with actual track and engines before you make anything permanent. Allow for adjustments, and if it doesn’t work the first time, find what’s causing the issue and retry.

5. Don’t let anyone ruin your fun. Most professionals would laugh at a steep grade over 2%, but don’t let that discourage you. Make a layout as you see fit, after all, it’s your train and your imagination! Do what makes you happy and proud.

Control Panel Winch System

With my electrical and control panel system complete, the last thing to do was to create a method to lower the control panel under my layout when not in use, and to raise it and keep it upright when needed. For this, I decided on a winch system. Simply turn the winch to raise the control panel into place, and reverse the winch to lower. The winch even holds the control panel up while in use.

Control panel winch cable system

The system was quite easy to build. First, I purchased a mini-winch from a local hardware store, as well as a couple cable pulleys and other hardware to fasten it to my benchwork. For the cable, I used 1/16” aircraft cable covered in PVC and aluminum sleeves to create loops at each end. I planned a path for the cable to run, then drilled the necessary holes through my benchwork supports so the cable would come out centered right where I wanted it to lift the control panel to. I used 2 small pulleys to guide the cable to this point and to also ensure the cable was not contacting and of the benchwork.

Winch bolted to 2x4 table legControl panel winch

I then used a fixed pulley bolted to the underside of my table top and ran the cable overtop, as seen below. This was then attached to a ‘U’ bolt that was fastened to the control unit. The cable is rated for 95lbs safe working load, so it’s more than enough to lift and hold the unit.

Control panel winch cable systemControl panel winch cable system

Wednesday, January 12, 2011

Holiday Wiring - Part II

My wiring and control panel are finally complete! The challenge over the last week and since my last post has been to move the control unit down to the basement and to hook it up to my layout.

Model train control panel

I first attached the back of control unit base to the three 4x4” hinges with six ¼” bolts. This allows the control unit to fold under the table when not in use. However, for the moment I have not yet made a final decision on how the unit will latch when in its upright position, so for now I fastened it up with 3 screws.

Control panel base hingesInstallation of control panel

Installation of control panelInstallation of control panel

I ran the leads from the control unit and hooked them up to the corresponding terminal screws on the previously installed terminal strips. The terminal strips made it very easy to detect any crossed over wires, and even easier to correct the problems as I only needed to swap the crossed wires to the correct screws. Remember, it doesn’t matter how organized or well planned your wiring layout is, mistakes will happen, so leave room to make corrections!

Terminal stripsModel train wiring

I kept the layout wires attached to the benchwork using small metal cable fasteners. These can be purchased at Canadian Tire for about $1.99 for 20, which compared to other products and retailers I found, is not a bad deal. Small zip-ties also help to keep wires organized and looking neat.

Model train wiringModel train wiring

While testing my control unit, I realized that I needed a higher powered AC power source to power my switch machines, separate from my MRC Tech 4 280 power pack. For this, I mounted an older MRC power pack to the underside of my benchwork, and ran the new AC line back into my control box. This 2nd power source can also act as an additional 12VDC source in the future.

Extra cab controller used for AC accessory power sourceMain power bar and surge protector

To provide reliable safe power to the different components, I installed a surge protected power bar below my benchwork for all the components to plug into. This is then connected by and extension cord to the wall outlet.

Master power switchMaster power switch

I didn’t plan a master on/off switch into my control panel design, which is something I most definitely should have done, as I have no way to turn my components off (not including the power pack). To solve this, I purchased a rocker switch ($2.99 from Princess Auto), rated at 120V 20A, which I tapped into the cord on the power bar. I then mounted the switch into a standard light switch cover panel that I painted dark brown. I drilled a hole into the front of my benchwork beside my control unit so the rocker switch panel could fit flush against the bench. This switch now cuts the power off to the power bar, so I can leave my layout plugged into the wall outlet at all times.

Master power switch installationMaster power switch installation

Master power switch splice into main power

The track signals are still all displayed together on a temporary paper panel. This is purely for testing and making sure the signals work correctly when switching tracks. They will eventually be positioned on standards in the necessary positions along the tracks.

Finished control unitTemporary trackside signal holder

Other than a few small required adjustments, everything works great as far as the electrical system goes. The dual cab control works awesome, and I couldn’t be happier with how everything turned out. The next step will be to find a method to easily raise and lower the control panel and latch it when it’s upright. I’m also going to start smoothing out flaws in my track work and most importantly, take out the steep grade coming off of my trestle.

Model train control panelModel train control panel

Model train control panel LED

Also check out my Design and Planning page for updated schematics for different systems on my layout so far!

Thursday, January 6, 2011

Holiday Wiring - Part I

The last 2 months have been insanely busy for me, so up until last week, I haven’t had much time to concentrate on my layout. My goal was to complete my wiring and my control panel by new years, and even though it’s the 5th of January now, I’m not that far off of my goal! My work was closed over the holidays and this gave me almost enough time to really concentrate and complete my control panel. I managed to battle the weather last week and made it to Calgary to purchase the last of my supplies for my electrical system. I purchased a MRC Tech 4 280 dual cab controller for my power, as well as 4 Atlas snap-relays to power my x-section, track signals, indicators, etc.

MRC 280 Tech 4 controller
As mentioned before, my control panel and controller need to be able to fold away under my layout when not in use do to the small space. I purchased a 1/2” thick hardboard panel to use as the base to which my control panel and controller will bolt to. The rear of the hardboard panel will attach to hinges located under my bench work, allowing the entire unit to swing under the layout when not in use. I used ‘L’ brackets bolted to the sides of the control box to fasten the control panel to the base. Below you can see where the controllers and control box will sit on the base and where the base will be cut.

Control panel bracketsMRC 280 Tech 4 controller

Once the base was cut, I cut a large opening to allow access to the inside of the control box. I also drilled holes at this time for the controller wires and power cables. A scrap piece of aluminum the same colour as the control panel was used as the base for the cab controller, and glued to the base. I used small black metal eyelets around the drilled holes for the main power leads to make them look more appealing. At the same time, I attached my 4 snap-relays to the bottom of the base.

Controller base with Atlas Snap RelaysController base with control panel

Only the first 8 inches of the base will protrude out past the layout, and the majority of it will be covered by the control box. To cover the visible hardboard, I attached ¾” titanium L molding around the edges, just as I did on the control box itself. As before, I used PL Ultimate construction adhesive to glue the trim.

Controller base with titanium trim and access hole

While the trim dried, I used this time to start wiring everything together. The first item on my wiring list was to connect all the leads from the 8 turnout signals to my resistor board. I also started connecting leads to all of the LED lights and volt meters inside the control box white it was still detached from the base.

Trackside signals connected to resistor boardTrackside signals connected to resistor board

The leads from all of the LEDs were then connected to their appropriate leads on the resistor board and all connections were soldered together and insulated with electrical tape. As I made connections, I tested each circuit to make sure everything worked. One advantage of having all the resistors together on the PC board is that it was very easy to test each resistor anytime I had a short circuit. It was also at this time I decided that the resistor board would be mounted outside of the control box, as it would be to cramped inside.

Turnout position indicator LED wiringResistor board installation on control panel

I then mounted the control panel to the base panel with 4 bolts which were fixed to the 4 ‘L’ brackets fastened to the control box. I mounted the resistor board to the bottom of the base using brass bolts and used brass nuts and foam blocks to support the PC board. At this time I also made a schematic on my computer, showing which resistor is which on my PC board, making it much easier when testing.

Resistor board installed with brass bolts

The cab controller also needed to be attached to the base, however did not have any brackets or holes to do this. With a little research and testing, I discovered that the MRC cab controller is quite hollow, as the printed circuit is located right below the top panel, leaving the bottom entirely open. I started by drilling 2 very small holes through the bottom to inspect to make sure I wouldn’t hit any important electrical components. I then drilled larger holes to accommodate a large threaded screw. I drilled 2 holes through the base; passed the large screws through and screwed each screw about ¼” into the controller. This worked great, and securely attached to cab controller to the base. I ran the power cord through a drilled hole below so it would not be visible on top.

Control panel wiring

I spent about 4 entire days wiring everything together. This included making all the connections, soldering, and insulating. Once each circuit was made, I needed to test each one. Everything worked well with the resistor board for all the LED lights on the system, with only a few shorts that were located and fixed relatively quickly. I spent a lot of time setting up all of the snap-relays as well, making sure that the correct indicator LEDs and switched were activated/lit when the switch control was flipped.

Control panel internal wiringAtlas snap relay wiring

Atlas Short Circuit Note: One of the most frustrating shorts I had to deal with had really nothing to do with my wiring at all! It had to do with the actual Atlas controller, selectors, and switches on the top of my control box. It turned out that the screws supplied to attach each lead to each Atlas device protrudes further then the base, which in turn contacted the aluminum surface of my control box causing a large system-wide short. I resolved this by making a small copper washer for each screw.

Terminal connectors on Atlas selectors

Testing everything as I went along took a lot of extra time, but was worth it in the end as problems could be fixed immediately and could easily be identified, opposed to having everything together in the end and having to sift through everything. Another problem I found was with my switch overload indicator lights. I didn’t take into account that when one AC lead was powered, that the second AC lead would also be powered as both were connected together where they contacted one of the bridge rectifiers AC posts. This was easily resolved by putting diodes into each converging line, preventing current from traveling down the other lead when powered from either side (as seen below).

Diodes for switch machine overload indicatorsPower block electrical leads

I put all of my future track signals in a temporary holder at this time as well so I could easily view them when testing, as seen below. They all worked perfectly fine and matched the switch positions perfectly. A switch on the control panel turns the center amber lights either on or off. I then attached my accessory 12V rectifier to the bottom of the base with handmade brackets. This 12V DC power source powers all of the future accessories and LED lights.

Control panel wiring12 volt laptop inverter

I used small brackets to fasten all the cables to the bottom of the base. There was such a large amount of wiring that it was sometimes difficult to keep everything perfectly organized, or at least as organized as I wanted it. All the main wires that connect to the layout run off the back of the base where it will be hinged, and will connect to their appropriate screw on the layouts terminal strips.

Control panel wiring almost completeControl panel wiring

Completed control panel wiring

Now that the control panel and all the wiring is completed, I plan to have it attached to my layout by the end of this week. Once I complete this, I will post the second part to this update.