Monday, July 20, 2020

My homemade searchlight signals

My last post went through a quick review of a few ready to run and kit searchlight signals that are available and mentioned that I was going to try to make some of my own.  In this post I am going to present how I am making these.   I am using only red and green conditions for my signals.

These are the LED's I am using on my signals.  Dimensions are shown in this image that was part of the ebay listing that I purchased them from. 

These are similar in size to bright white LED's I have used in the past for locomotive lights or street lights. Small but still big enough for me to handle and solder the magnet wires to.

The wire I am using is from a roll of  wire that I have had around for years.  It measures at about .011 inches in diameter which is about 31 gauge.

This is the type of wire that is used for motor armatures, relay or solenoid coils, etc.  The darker red color is actually an insulating enamel that is very thin. so this type of wire is commonly know as magnet or enameled wire.
Surface mounted LED's and other surface mounted components come on a tracked strip like the one shown in this photo.  The individual components can easily be cut out with a hobby blade and the part drops right out.

The enamel on the wire can be scraped or filed off on the ends so that solder can stick to copper wire itself.
I am using 1/16 diameter brass tube for my pole which has a large enough interior diameter to allow for up to 5 wires of the type I am using to be threaded through without much trouble.  The target support piece was made from brass strip.  1/16 holes were drilled and the support was shaped with a dermal tool and files.
Here is the signal assembly after the magnet wires have been fed down the tube and the LED attached to the back side of the support aligned so that both red and green colors go through the hole in the support.  It is really important to have the edges of both ends of the tube filed smooth so the magnets wires won't get scraped.

Before installing the LED and wires a short section of 3/32 brass tube and a brass washer were added near the bottom setting the finished height of the signal.

A section of 1/8 inch diameter heat shrink tube is placed over the bottom end of the pole and extends past the end of the tube to create a bit of a strain relief for the delicate wires.  After shrinking the overall diameter of the bottom of the pole will be about 3/32 inches.
To make the wires easier to connect under the bench work I splice the magnet wires onto 22 to 24 gauge wires.  The splices are staggered so that only one splice at a time need to pass through the hole in the bench work.

The signal targets are 3D printed items I ordered from Shapeways.  I painted them black first then glued them to the front of the support with ACC being careful to align the hole on the target with the hole on the support and to have the shade on the target on the top.

I found it necessary to first build up the area around the back of the target with thick ACC before painting to keep the paint from creeping in between the target and the support.  After the ACC was fully dried, the entire signal was painted with Testors aluminum.

To mount these signals I drilled a 1/8 inch hole in the bench work and after feeding through the wires the pole was secured with E6000 adhesive.

These signals were connected to the same relays for the helix that control the oversized signals at the other end in the staging yards.

My signals have been in place for a few weeks now and are working great doing the job of showing occupancy on the tracks within the helix.

These signals were rather inexpensive to make, maybe 5 or 6 dollars each for materials but they are a bit of work and are not as good looking or detailed as some that can be purchased.  As I expand signaling to other areas of the layout I may also try out some of those ready to run signals.

Sunday, July 12, 2020

About N Scale searchlight signals

Signals in general and searchlight signals in particular have always been a bit of a challenge in N Scale.  In more recent times the availability of surface mounted (SMD) type of Light Emitting Diodes (LED) have improved the chances of getting something to scale.   The development of 3D printing has made it possible to include more accurate detail parts.

This prototype photo from a post on the Jersey Mikes Railroad Adventures blog shows the type of searchlight signals that would be common along the line in the era that I model and would be similar to what I would like to have on the layout.  Below is a quick overview of three brands of searchlight signals that are available.
This is an example of a N Scale searchlight signal offered by Layout Dynamics.  These are made with brass tubing for the pole that appears to be a 1/16" diameter with all of the other parts made from 3D printing.  They come fully assembled, painted, and wired with a 3 color LEDs.  They are offered in 1 or 2 head versions and with or without relay cabinets.
Some of the best to scale models I have seen are offered as kits from Showcase Miniatures.  The kit uses a 1/32" brass tube and detail parts of etched brass and white metal.  Each kit comes with 2 signal heads and can be customized by the builder.  Very tiny 3 color LED's with really fine wires can be ordered separately.
Another brand of ready to run searchlight signals is from Custom Signal Systems.  Here is a screen shot from the Corn Country Rails You tube channel that covers these signals quite well including their installation.

I decided to try making some of my own using 1/16" diameter brass tube and some 3D printed signal heads from Shapeways.  As I had already established the helix as a block on both lines and installed oversized signals in the staging yard, I installed these at the layout end of the helix.  This one is on the WP line.
Here is the signal on the SP line just before it enters the helix.  The signal to the left is from a Showcase Miniatures kit.  It is not lighted as it could not be seen anyway.  The 3D printed signal heads I am using are the same size as the ones on this kit and I am making my signals the same height as this kit is.  In a future post I will cover in more detail how I went about making, installing, and controlling my signals.

The ready to run signals are not cheap but after making a few of my own I now have an appreciation for what it takes.  My reason for making my own was not so much the cost but how delicate they looked.    I wanted to gain some experience handling and installing some of my own first and may be using some purchased ones in the future as they are more accurate and detailed than I can make.

Thursday, July 2, 2020

A new brand of turnout motor

Well, new to me anyway.  A friend recently introduced me to a brand of turnout motor that I had not hear about before.  These MP5's are slow motion motors that run on AC or DC, and 2 sets of double pole contacts.
This photo shows the comparison between one of the existing Tortoise motors on my layout and of of these new MP5 turnout motors.

Another feature I like about these is that the wires are connected to a removable plug which would make things easier when working under a layout.
I have been testing these motors out with some new Peco turnouts.  Using the stock rod that comes with the turnout motor, the movement is strong enough that there was no need to remove the over center spring in the Peco turnout.  On other types of turnouts I would use a more flexible wire linkage.

The turnout points need to move about 3mm.  The amount of movement on the motor the way it came was too much so I needed to change it from the stock 6mm to 3mm.

After removing the two screws on the bottom, the bottom can be hinged open and the slider part removed.

The cam inside rotates a half turn with voltage in one polarity and then another half turn in same direction when voltage is reversed.  If the cam cannot continue it's rotation because it has reached the stop on the turnout, it cannot be reversed by reversing the polarity.

A pin on the cam fits into a slot one the slider and the rotation caused the slider to move.  The holes on the cam are at 3, 6, 9, and 12 mm from the center of the cam which correspond to how much the slider will move.  The pin is installed at the 6 but can be pulled out and moved to the 3 for N Scale turnouts.

These seem like great little turnout motors and they cost about the same as a Tortise motor.  The small size makes them great for modules or layouts with shallow frame bench work.  They are made in the Czech Republic by MTB Models and are sold in the US by Model Railroad Control Systems.