I’ve done that on both ends of my layout.

Mine happens to be HO but could be 1:1 also.  An Arduino and three of Dr. Geoff Bunza’s DAPDs, a couple of transistors, batteries or a wall wart, switch machines some wire and some time and you’re in business.

Nick

NIck I would prefer NOT to

NIck I would prefer NOT to run any power to the wye but I want to make sure the points don't cause a derail when the train is coming back toward the wye.

Hard to explain, but a 90

Hard to explain, but a 90 degree bell crank set up so it's spring loaded to stay snapped one side or the other, but not in between will fill the bill. The lead wheelset trailing through the points will be used to push it over-center thus snapping it into the correct position for a facing point move coming in the opposite direction. The prototype uses a similar principle (lead wheels move the points and they stay put) on variable switches, but they accomplish it with the use of an internal clutch inside the pumpkin.

Andre

So I am looking at the

So I am looking at the Gargraves wye manual switch.  I wonder how hard it is to do what you are talking about Andre

I know the Peco N scale track

I know the Peco N scale track uses that snap like I think youre talking about.  I just don't know how to do that LOL.  Maybe the O gauge track switch is a bit more heavy duty that it will stay in place once it is moved by the loco.

Hopefully this helps...

  < ------- PR

A1         c/l                 A2

Okay,  for the above illustration:

* We're looking DOWN ON. (Top view)

* The wye switch is to the LEFT.

* PR-to-c/l-to-A2 is the 90 degree bell crank. "c/l" is the pivot point of the 90 degree bell crank.

* "PR" is where the Push Rod is attached to the bell crank arm end and goes to the throw bar of the switch.

* A2 is where the spring hooks to the bell crank arm end.

* A1 is a fixed anchor (screw/hook/etc) where other end of the spring is anchored.

When the lead wheels trail into the closed switch, the wheels will move the points over top dead center, and the spring will snap it to opposite side and thus hold the points against the stock rail, ready for a facing point move from the opposite direction. Bear in mind that the only time such an arrangement will enact is when the switch is trailed through. You would have to manually move the points for a facing point move to diverge from the its current route.

Obviously, some experimentation will be in order. The most crucial part is adjusting the throw travel so that the points MUST cause the bell crank to pass through top dead center. 90 degree bell cranks of all types are in supply for the R/C model airplane hobby.

Hopefully this helps to understand the principle?

Andre

Turn of (last) century street cars did that

with a spring switch... softly, yet firmly forcing the points to one setting and allowing wheel flanges to press the points away when entering from  ONE of the diverging routes... the heel of the switch would always direct the train one way. 

Street cars making the circuit the same direction could enter the wye and include a stop on the wye, then exit on the other track.

I find it impressive doing historical searches into this era... local transit maps, patents for state of the art track...

There is a very easy way to

There is a very easy way to make a switch a spring switch. See the attched two photos which depend on using a piece of lite, tension, spring/brass wire to keep a point rail against the stock rail but not too much to prevent the litest car from springing through it or derail. This also depends on using a free moving points switch like an Atlas or Walthers one. A Peco or Micro Engineering one might work after removing the point lock.

The spring wire is bent into an "L" shape on one end and inserted into the hole on the throw rod. The other end is bent slightly, along its length, toward the frog (but not touching it or other rails) to create the spring tension and should be fastened using small spikes to allow for adjustment before gluing it in place. 

This is a geat, easy, economic way to create a spring switch which has worked, flawlessly for years. Just another way to handle a challenge.

Barry

O scale wye

Has this been done on O scale as I see it a lot on HO and N.  The O scale 3 rail might pose me a problem but seeing as I am not using the middle rail I might be able to make this spring switch work.  I ordered the wye so I just have to wait till it gets here to give it a try.

Can you use the Dynamite Canyon set-up or gravity??

Hi Toyzfrome (??) and all,

First suggestion: Gravity-weighted or kangaroo point By varying the size and distance of the weight from the pivot point, you can fine-tune the amount of force to hold the blades over so that when you push through the blades, the blades return to a known position. For O-scale rolling stock, you should be able to weight your wagons so that they can push through the blades and still have enough adjustment on the weight to shove the blades back. I'd be also using graphite to lubricate all sliding parts to minimise the weight needed to shove the blades back to where they came from.

Second suggestion - Dynamite Canyon always-straight points with no moving parts. This will work if you exit the each leg of the triangle track on the straight path or as shown for a reverse loop. To see them in action have a look at

This might give you some other options,