Guest post

Tonights guest is Worzel.

"I'm building a NZ120 layout using hand-made pointwork. Something I had always pretty much taken for granted with Peco points is that they have a throw bar with spring built in, so now I had to come up with something to throw the points with and keep them in position. I wasn't keen on fitting out every point with a Tortoise or solenoid so set about producing some manual linkage systems. After a bit of googling I came up with a couple of designs - one based around a slide switch and another around a toggle switch. Both use a vertical rod going up through a slot in the roadbed to move the throwbar on the points from below - much like a Tortoise or solenoid switch machine does. Maybe it says a lot about my lack of mechanical prowess but neither of these worked as well as I would like - too much flex in the vertical bar and/ or adjusting the amount of throw was fiddly. The other thing was that in order to get the vertical rod stiff enough it had to be big and that required a large hole in the throwbar, and the PCB sleeper would break where the hole was.

Fast forward a few months and I found another design described in the September 2008 Model Railroader. Fast forward to this month and I have finally got around to collecting the various materials and putting one together. In this design the vertical rod going through the roadbed doesn't slide sideways, it rotates and an arm moves the throwbar. I've just finished installing this and it seems to work pretty well. It is more complicated to build but is easier to install and works better. You end up with the arm being visible above the ties but I think that's a small price to pay for better buildability and reliabilty, and hopefully not too noticeable from 2 feet when the track is ballasted. This design also has two advantages over the other systems. The main one is that the control bar (that comes out to the fascia with a knob on the end) and the switch don't have to be in line with the throwbar. The other is that the switch can be positioned so that the knob on every point can be in against the fascia when in the main position and pulled out when set for the secondary route.

This might be old news to most of you, but this is all new to me. I've attached a couple of pics - one from above and one from below."