Staging Yard Points

As you recall, the staging yard is on a wide window sill, and that means there is no room for Bullfrog or other switch machines below the roadbed. Because the room provides a number of functions in our house, we want to be able to make the staging yard look like a clean window sill, which means there is no place for a ground throw above the window sill either (although perhaps if they were painted white, they wouldn’t be too objectionable.

I decided to think about flick switches, similar to Peco and Micro-Engineering. Actually, I’ve only operated with Peco in N Scale, but I do find the flick switches are very convenient and intuitive. Of course, being on the cheap side, I’m not about to go out and buy a bunch of turnouts and convert them to Proto:87. So, I spent a few days thinking about how I might achieve an over-center spring of my own.

IMG_1683.JPG

The other change I’m making for the staging yard points, is in the switch rod. There is no need to use the 3D printed parts as on the visible layout. So, I’m going to use PC board throw bars. Others have found that the joint between the PC board and the rail is prone to failure, and so, I devised a method using pins. The points are soldered only to the pins, which means they can rotate freely.

Tonight, I spent about three hours putting a prototype example together. It worked superbly on the first try!

IMG_1681.JPG

Some things I learned:

  • You need to be careful to get the second headblock perpendicular to the track. Otherwise, you’re putting pressure on the point-throwbar joint.
  • The nub on the throwbar that interacts with the spring is .020″ brass wire.
  • The spring was formed by pressing it around a piece of .064″ wire. It is not especially precise.  It is .008″ phosphor bronze sheet.
  • As I’m doing six turnouts, it’s going to be worthwhile to come up with a fixture for making throwbars and springs.
  • It might be easiest to assemble the headblocks and throwbar on a piece of shim stock before having to worry about rail.
  • The pin idea works well, but they’re a pain to solder without soldering to the PC board as well. On one side, I filed away the copper at the pivot point, and that simplified matters substantially.
  • The pins want to turn sideways. I shall consider drilling through the point to improve this behaviour.
  • I tried simply bending the points, rather than providing a hinge at the heel. While this worked, I find it makes forming the wing rails even more challenging. I think I will go back to hinging the heel (in which case, do I still need to pins?

IMG_1682.JPG

Advertisements

4 thoughts on “Staging Yard Points

  1. Neat spring idea. This should work quite well in the zero vertical area along the window sill staging yard.

    I like the hinged points idea – using the pin as the hinge. On my N scale turnouts, I’ve used a similar arrangement though with a piece of phosphor-bronze wire folded first into a “L” shape and soldered to the web of the point blade. With that joint complete I then bent it down to drop through a hole in the throw bar to the base. Once through, the tail was bent over in a 90 degree angle and the tip of that was soldered to the underside of the throw bar. Compared to just solder the narrow base of the point blade to the throw bar it feels like it should be a stronger hinge and offers just a bit more flexibility. Using the pin head certainly makes the first bit easier, compared to my bent wire approach.

    However, the above relies on using a full tie width PC board tie as the throw bar and I’d like to narrow this up. I’m impressed with your 3D printed parts for this part of the turnout and I’m starting to wonder if something similar could be done for N scale.

    Finally, that sketch is just neat. Thanks for posting it. We often post photos of the work itself but not of the plans that lead to it. It’s neat to see this extra step – I like it.

    1. Hi Chris,
      Good idea about beefing up the point-throwbar joint. With the heel of the points loosely hinged, I don’t think the toe needs to be hinged too. So, I might steal your idea for stronger points.
      For scale switch rods in N scale, you might want to check out Proto87 Stores design (proto87.com). Also, you might want to click on Andrew’s blog on the right: he may be a kindred spirit.
      Rene

      1. I looked at Andy’s idea regarding the switch rods in N. I think it’s rather quite innovative. The big thing I’d like to see changed is his reliance on a simple friction effect joining the rod to the point blade. I find smaller height rail tends to lift upward from the ties and I worry that eventually they’d find their way free of the point rods. At its heart, it’s a good idea and one I’ll keep coming back to.

        I never made the connection to Andrew’s blog but realise that I already subscribe to it:
        http://cascadedivision1964.wordpress.com/

        He does terrific work and is already immersed in a finescale version of N scale that is where I think I am ultimately going with my own work. I’m ready for the track but lack the machining capacity so feel limited in my ability to convert motive power to finescale wheels. Excepting the diesel wheels issue, I’m ready to make the leap.

        Thanks

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s