Large Scale Central

Signals

Modeling
#1

I finally had a free day that didn’t involve ceramic tile, kitchen cabinets, paint, or spackle, so I retreated to the shop and dove into the pile of acrylic that I bought for signals. After about half an hour, I had a working prototype for my outside signals. The main body is 3/8 and 1/4" acrylic tube. The signal head is a disk 1 1/2" diameter. Two color LED, and led mounting will let me replace them as needed. Im still working out the shade. The signal is a scale 20 feet in height. I cant paint today since its about 30f outside, so I had to take pictures against a dark background to get the acrylic to show up.

Total cost for the signal is about 70 cents. -=Bob

#2

Nice! For a shade, slice a piece of tubing at an angle and glue it on.

#3

Pretty slick!

-Brian

#4

That’s a great idea Bob! I was thinking of a few signals just for scenic effect myself. I was planning on using metal washers for the signal reflector.

I like your choice of materials. Where did you get the two color LED’s and what would I need to wire in to use a 12 volt DC source?

#5

I got the 2 color LEDs off ebay. There are literally hundreds of dealers selling them. I got 5mm leds, and mounts (the black bit) so i can replace an LED should it burn out.

Run them off 5v, not 12v. They have 3 leads coming off the back. Wire a 180 ohm resistor to the center lead (common) and one lead is red, the other is green.

#6

Today’s progress. A hundred or so holes later

(http://zbd.com/photos/OnePoint20/Signals%20and%20Equipment/CTC1.jpg)

(http://zbd.com/photos/OnePoint20/Signals%20and%20Equipment/CTC2.jpg)

Well, its a start!

#7

Ohhhh Shiney!!!

#8

for the CTC panel, I now need to design the trackplan for the top of it, and work out the blocks for this section of the mainline. That’ll tell me how many signals I need to build, and give me an idea of how complex the interlocking logic will be.

#9

Painted up one of the CTC signal plates. A coating of flat black, let it dry, then some 400 grit sandpaper flat on a table brings out the raised details.

(http://zbd.com/photos/OnePoint20/Signals%20and%20Equipment/CTC3.jpg)

#10

Those look really neat!

It looks like you’re planning on more than just a few?

#11

I think I’ll have about a dozen OS sections, so that means two of those panels. Eventually it’ll be set up to auto-clear signals when the blocks are clear, but first pass will be manual detection and signals. Step at a time!

#12

Basically, and each end of a passing siding on the main, you’d have something like this for signals:

(http://www.ctcparts.com/figs/fig2.gif)

R174 is the eastbound signal approaching the siding. The upper head will show red yellow and green. The lower head only red or yellow. The upper head is the signal for entering the mainline, and the lower is for entering the siding. L174 is the westbound main signal, and LB174 is the westbound siding signal.

#13

Bob,
Is this for your outside garden railroad?

#14

Yup… for single-operator, the signals will be automatic, and the mainline switches locally controlled. For dispatcher controlled sessions, the signals and controlled switches will be controlled by the CTC board.

#15

I think I’m learning why you have no time to come to Canada. :slight_smile:

You might find hitting the back of your hand with the claw side of a claw hammer more enjoyable. But, its your railroad, so you make the rules. And this is suppose to survive New England snow storms, also? Wow!!!

#16

Bah, this is the easy stuff. Reliable block detection is going to be a tad difficult outdoors.

#17

How do you plan to detect the blocks?

#18

To detect a car or locomotive in a block, its generally done by passing a current across the rails, and having some sort of detector looking for the current draw. The trick is to not quickly toggle between ‘occupied’ and ‘empty’ states when the track is dirty and contact is intermittent. Its pretty easy to jumper the insulators on metal wheel sets, and a simple detection circuit works OK. I’ll have to jumper all 4 axles on a car for redundancy. 4 chances of a completed rail-to-rail circuit instead of just one.

The problem arises around switches. Since I’m battery/rc, most (all) of my switches are metal frogged, so both rails on a switch show up as connected electrically. So, I’m pondering some sort of visual detector.

Probably do that second, after the main blocks.

#19

IR is a possibility, but not so much in the sunshine.

#20

Yea, and its for the “Dont throw a switch under a car” scenario. Id like to have it, but its not necessary out of the gate.