Powering a frog when there is no switch machine

[Lemosteam]

For cost savings and arm reach ability, I have decided to use over center phosphor bronze springs for my turnouts.  They work very well but I have one dilemma: How to power the frog. These are atlas code 55 switches.



Should I run a wire from each point pivot rivet to the frog eyelet and let the contact of the points provide the power?  The contact is fairly robust in both directions due to the spring.

Thoughts please.

[mmagliaro]

I would not do that, John.
It will work, but my experience with ME, Atlas, and Peco turnouts is that sooner or later, those rail points
always get dirty and start failing to complete the circuit annoyingly.  You can keep cleaning them, and if you don't have too many turnouts, maybe you could stand it.  But it seemed like it would be a big headache once you got 10 or more turnouts
on a layout.

When I used over-center sprung turnouts, I bent a Z-shaped piece of piano wire, hooked to the throwbar,
passed through the benchwork, to the underside, where the other end of the "z" would press a small microswitch
screwed to the underside.    The micro switch was a SPDT.  Wires are run from the two main rails coming into
the turnouts, to the two contacts on the SPDT, with the center contact of the SPDT going to the frog.

I had to first bend with wire just in an "L", get it through the benchwork, and then make the final "Z" bend underneath,
up against the underside of the benchwork.   I hope this is making sense.

It took about an hour for each turnout, but it is dead reliable.

[Van Horne]

I have three words for you.  Hex Frog Juicer.

Dave

[Lemosteam]

Max, I just knew you were going to say that!

Dave, please elaborate.  Will it work with DCC?

[Van Horne]

Absolutely it will.  I have been using them for years.

Dave

[Scottl]

I use the same spring mechanism, and ended up using a frog juicer.  It works flawlessly.

[peteski]

Yes, FrogJuicer is designed for DCC.  But when you start using those then the cost of them will most likely be the same as if you uses a switch machine.

How about using a slide switch connected to the throw bar to throw the switch?  That way you can use the switch as both mechanical and electrical way of selecting the route.

[wm3798]

I think I just answered this on your facebook post.  I'm with Max.  Use a cheap slide switch.  They're dirt simple to build and install, and will serve you well.

Lee

[mmagliaro]

I wasn't talking about a slide switch.  Actually, without the over-center spring, I DO use a slide switch
on my current layout.

I was talking about a Z-shaped piece of wire hooked to the throwbar, with a micro switch, not a slide switch,
mounted under the benchwork.  When you flip the turnout from above, the wire rotates under the benchwork
and hits the microswitch.  The SPDT microswitch has feeds from each incoming rail, and the common going to the frog.

This is not a new idea.   It works great, doesn't care about DC or DCC, and is really cheap.

I wish I had taken a photo of all the ones I installed on my old PRR layout.  I kept meaning to do it and never
took a photo.

[Lemosteam]

Yes, I saw those Leee, thank you.

Max, with a micro switch, how was it able to switch polarity?  If the wire flipped the lever to the diverging route, and flipped the frog, how did it flip back? Or did you cave a switch on eac side of the wire?

[Ron McF]

I use a cheap slide-switch operated by a push-rod from the layout fascia:
http://gulflines.blogspot.com.au/p/turnout-pushrods.html

I have several dozen of these on my layout. They're easy to install and they work flawlessly.

Regards,
Ron McF

[peteski]

Yes, I saw those Leee, thank you.

Max, with a micro switch, how was it able to switch polarity?  If the wire flipped the lever to the diverging route, and flipped the frog, how did it flip back? Or did you cave a switch on eac side of the wire?

Micro switches have spring-loaded plungers. SOrt of like miniature doorbell push button switch. If there is no pressure applied to the plunger, it snaps back to its at-rest position.  Since the contacts are SPDT then the at-rest position connects the common lead to the normally closed (NC) lead.

[Joetrain59]

Uh Max, the worst pictures are the ones not taken
 Joe D

[mmagliaro]

You don't care about polarity.  All that matters is that the frog is connected to the correct rail.

Let's call the two rails "+" and "-" (although for DCC they really aren't, but...)

Coming into the turnout, let's say "-" is on the left and "+" is on the right.  And let's say it's a RH turnout,
and you are going through the straight route.  So we want the frog powered as "+".  Okay.  We connect
it to "+" and the train runs through.   Flip to the diverging route, and now we want the frog
connected to "-".  As long as we do that, the train will branch right, go through the diverging route,
and it works.  As long as the frog is connected to nothing else, this all works fine.

[Lemosteam]

Thanks gents!

 Max I understood your design right away.

Here is what I am thinking of doing.  The layout doe not have conventional construction, so no fascia, or room for cables or solid wire activation here.  The reason I did the over center springs and no switch machines was because I will not have direct access.  The elevated berm presents another problem in that I want it to look clean and as prototypical as possible, see the LIRR IS layout thread.

This design presents a sliding PRR switch machine that mounts to the micro slide switch with a 00-90 screw over a styrene plate that will keep ballast out from between the throw bar guides.  The slide switch holes will be tapped for a 00-80 screw that will attach through a plate into the switch.  That assembly will be glued to bottom of the throwbar guides.  A U shaped pin will connect the throwbar to the switch post. The plate under the machine casting will be glued to the tops of the throwbar guides.  This will trap the throwbar' movements between the fixed parts.

Not sure if I will throw the switch machines on shape ways or scratch one and use it as a casting master.

I like the idea of a larger "handle" to move the switch.