Key Operated Ground Throw

I've been as busy as a bee looking for some type of mechanism to open and close the turnouts on the Santa Fe and Cajon Pass Railroad. I searched and searched but, what was available was either to expensive or was to big for my tastes.






Today I made a drawing of a model of what I really want. As a child I used to play down by the railroad tracks, and learned a great deal about how the railroad built things and why.. The padlocks on the switch stands were very well made and have influenced the design of this switch stand.

How does it work:

1. A key with a square socket can be fitted over the Red/Green lamp holder and turned to activate the switch stand. A clockwise turn will move the points towards the stand, and a counterclockwise turn will move the points away.
2. The key rotates the red/green lamp holder to indicate which way the points are thrown.
3. The only visable portion of the switch stand is mounted about 1/2" from the centerline of track and extends about 3/16" above the ties.
4. The wire is under constant tension. As I will be using these with my homemade Fast Tracks Turnouts, the point rails will be automatically energised with the proper phase of current. There will be no need to supply power to the frog.
5. The switchman on the train crew will have his own key to the switchstands just like on the trains I rode on when I was a kid.

Your comments as always are appreciated. I still have some time before I have to deliver the drawings to the mold makers.

Jerry

 

How large (or small) will the post and the "nut" be? Could it be possible to recess the nut below grade, still accessible by the key, and perhaps put a small detailed switch stand on top?

I really like this idea. Simple, clean, and the key idea is really cool.

Keep us posted.

 

Interesting concept. I look forward to seeing your next drawing.

Ben

 

Paul,

You and I should work together! We are on the same wave length.

The big cylindtical post is about 3/8" in diameter. In the picture I poster, it is just tall enough to penetrate 1/2" pf plywood sub roadbed, 1/8" of cork soundeadening material and a railroad tie that is 1/32" thick. When the Switchstand is installed, I envision that a jig will be used to precisely locate two holes in the sub roadbed. One hole will be for the throw wire and the other for the big cylinder. Next the throw will be fastened to the underside of the raodbed with two small brass wood screws. Then the actual turnout winn be fitted on top of the cork. A small grove has beem cut into the cylinder so that it will cover the end of the turnout throw rod and hide most of the ends of the two adjacient ties. The last thing to do during installation will be to poke the wire through the throw rod hole in the celterline of the track.

The cube is 3/16" (0.1875") or aprox 5mm on a side. I thought about recessing it below grade but lost interest in that when i considered that small things might fall in the hole where they could possibly muck things up.

Originally I was going to mount a replica of a tall switch stand on top of the cube. Allas, that idea went buy the wayside also when I began to consider how the key would have to be carefully fitted over the stand before it could engage the cube. The key needs to fit loosely enough that it can be engaged and disengaged without hanging up.

I think you are going to like the Key when you see it. I'm going for a shiney brass look. Maybe even a watch fob for those who want to have one to go with their steam locomotives. :angel:

Thanks for your very good questions.
I hope I have answered them in enough detail. If not, I can provide more information if you want.

Jerry

 

This thing looks like a winner so far.

To All:

You can see the latest study rendering below. The height of the lamp stand may have to be reduced some in order to get more clearance between the Lamp stand and the train. I will work on that tomorrow.



I,m also going to experiment a little with different forms for the Lamp Stand. Maybe some kind of trackside electrical box can be made to substitute in place of the Lamp Stand.

That's all for today folks!
Jerry

 

Paul,

I think it would. The mechanism that moves the points is capable of generating a lot of force. Without some limits on the thing, It might just move the track right off of the roadbed. mg: To prevent that from happening, I designed a built in stop mechanism which prevents the user from exerting excessive force on the points.

Thanks for asking,
Jerry

 

Bottoms up... BUT you first!

:shade: :shade: :shade: :shade:

GM, a really intriguing idea!

 

Paul,

The final design might take some time. I have only been tossing this thing around for three whole days! :teeth: Sometimes it takes me a whole week to get these things right.

Good things take time. This one just might have some merits.

Jerry

PS: I really have to get another keyboard. This one doesn't spell any better than the last one!

 

Mathew,

If you were in charge of the Engineering Department, what would you do that is different from what is shown?

Jerry

 

Just looking here...It's going to take two holes and it would be better to install it before the track is down. That is, install the turnout after the machine is installed. There won't be any limit on tight spaces or bending control wires. You will have to be able to reach all the turnouts unless you devise a way to control it with a control wire.

I think that a prototype switch stand on top would be fragile.

 

Flash,

I have eight turnouts that will require remote operation. This device can easily be modified to work with them.

You nailed the installation procedure. I don't know whether you have been following the design of this railroad, but; the sub roadbed will be machined from plywood using a friends CNC router. In conjunction with the sub roadbed machining, I plan on having the machine draw the centerline of track which will provide an exact location for the turnouts. Then all I have to do is drill the mounting holes. To facilitate installation I plan on building a precision drill jig so that the holes are exactly where they need to be.

Thanks for the constructive criticism. I appreciate that.:embarassed:
Jerry

 

Ground Throw With Ties Under Rails

To All,

This morning I made some more changes to the size of the Lamp Stand and put some ties under the rails so that I could get a more realistic image of the installed switchstand. For the moment, the lamp stand size in now a 4.0 mm cube which should provide an adaquate perch for the key.


Click to Enlarge

I think this will work! what do you think?

Jerry

 

Jerry what is the distance from the rails to the closest part of the switch stand?

 

Owen,

You may have just found the whoops in the design!

According to the NMRA Standards S-7 I think it might have enough clearance. The top of the circular disk is designed to be level with the top of rails. Dimension F = 15/32" or 0.46875" and Dimension G = 3/16" or 0.1875" With the face of the "cube" being 0.490" from track centerline and only 4mm or 0.157" tall, I think the clearance might be OK. To verify that, I will draw a cross section of the device through the Throw rod.

Good catch!
Jerry

 

Jerry in your last rendering of the switch it just looked a little close.

Even though the Kato turnout has a switch on the molded ballast, I still want to engineer a proper ground throw for that as well. So I am following this thread closely.

 

Owen,

I know!:embarassed:

Let me tell you something about the rest of the problem. I would have used the Caboose industries ground throws except for their height. That becomes a real issue when tracks are installed as close together as mine.

In every area of the layout I have either met or exceeded the NMRA standards for Class 1 track separation. In the classification yard I decided that the tracks should be just a bit on the tight side. Using a distance of 1-1/16" where the Class 1 standard calls for a distance of not less than 1-1/32"

What this all boils down to is that I need to check everything again. The design as it exists today means that I will have to install that thing at an almost perfect half distance between track centerlines. Normally when I design something I allow a tad bit more wiggle room than I did this time.

Thanks for being so observant! I wish everyone would look as close as you did.

Jerry

 

Paul,

All is not lost yet!:embarassed: I still have one ace up my sleeve. Unlike the real world, I can always choose to put the whole thing underground and out of sight without having to worry about the debris falling into the switch stand pit. Only once have I had to resort to that trick in real life. Turnouts in a paved street are not fun to maintain.

If I cannot mount the key operated switch stand on the surface with those neat looking red and green panels visible, then under ground it will go. I have an alternate design that will use something like a TORX type screwdriver to spin the cylinder that moves the points. Think along the lines of using the same basic concept as I have presented here except take the CUBE off the top of the cylinder.

I have to go now. The snow has stopped falling and I want to clear the walk before we retire for the evening.

Jerry