Ground throws

[dave9999]

Nigel,

I appreciate all the help. I owe you one. You saved me $$, as I was about to
go out and purchase ground throws. I like this method better. Thanks again. Dave

[nfmisso]

QUOTE: Originally posted by dave9999

Nigel
I dont have any music wire, but I think I got the idea using a spring from a
ball point pen. When the spring is compressed slightly, it buckles off center,
causing a bow. This holds the points against the rail. When I flick the points
the bow shifts and pushes the points against the opposite rail. Is this correct?
What size music wire do you suggest? And can I get this at the LHS or do I need to
pick it up at a music store. Thanks again, Dave

Dave;

You have the concept !! <G> You may want to use ball point pen springs instead of music wire. You can music wire at LHS, you will need a cut off wheel in your moto tool to cut it, as it will severely damage diagnol cutter and similar (wear your safety glasses!!!). Music wire is very hard high carbon steel, yield point in the range of 250 to 300 thousand psi. Typical steel (not hardened) yields at under 50 thousand psi.

Size, depends on length, and force desired, some experimenting is required. I'd start iwth .005" diameter wire, 3" long, arranged to have about a 1/4" deflection at each end of travel. This is STRICTLY a guess on my part . Set up one on your work bench, and make adjustments until it feels right.

[cacole]

If you decide to go with the Caboose Industries ground throws, use the sprung version so the internal spring keeps tension on the points for good electrical contact. The easiest way to install them is to set the turnout points at mid-range and the ground throw's lever straight up, which is its mid-range. Temporatily pin the ground throw down using very small brads or sewing pins and check to make sure the turnout moves correctly in both directions, and that the ground throw's spring is keeping tension on the points. Then fasten the ground throw down more securely once it is in the correct position.

[dave9999]

Nigel
I dont have any music wire, but I think I got the idea using a spring from a
ball point pen. When the spring is compressed slightly, it buckles off center,
causing a bow. This holds the points against the rail. When I flick the points
the bow shifts and pushes the points against the opposite rail. Is this correct?
What size music wire do you suggest? And can I get this at the LHS or do I need to
pick it up at a music store. Thanks again, Dave

[nfmisso]

Hi Dave;

I could not find a reference on-line, so I will try to explain myself better. Here are three different methods.

Using a compression spring, attach on end to a fixed stop, and the other to a bar with a pivot in the middle (and away from the spring). The spring should be compressed bar is aligned with the fixed stop. It will not stay aligned, as the spring will push it one way or the other, adding limits (like the points against the inside of the rail) in either direction, provides two positions. The spring force is always pushing the points hard over to one side or the other. The pivoting bar should have a rotational radius smaller than is typical on our turnouts.

You can use an extension spring (or rubber band) the same way by putting the pivot between the fix stop of the spring and the moveable end.

Third method is a compression spring of sorts. The fixed stop is a dimple (like a polling pocket on a real train), the moveable end is a bar that is constrained to move side to side only with a similar dimple. The distance between the two stops is less than the length of spring wire (aka music wire) that you insert into the dimples. The bar that moves side to side has a limited travel. When the bar is at each limit, the spring has a 'C' shape to it, in the middle it has smaller radius 'C' shape, which it likes a whole lot less than the larger radius shapes. It still doesn't like the larger radius 'C', which pushes the points to one side or the other.

With a mechanism like this, you just have to flick the points over with your finger. Check out a Peco at your local hobby shop. Comrail uses this for the easily accessed ones, and Tortise motors for the inaccessible ones. A single Tortise is sufficent to move all four turnouts of a double crossover. See: http://www.comrail.org/

[dave9999]

Thanks Nigel,
I'm not sure I get the concept. Is there a web site that you know of that has an
illustration of the toggle spring set-up? The reason I was considering ground
throws is I've always liked their appearance. But it's not set in stone. I do believe
in listening to experienced modelers. What I really want, above all, is a reliable
means of switching without wiring the yard, which is easily assessable. Dave

[nfmisso]

Hi Dave;

Use sprung, you want there to be a force holding them over. Alternatively, instead of ground throws, consider a toggle spring, like Peco uses. It can just be a piece of music wire that is attached so that it is curved more when the turnout is centered, and less curved at either position. This will force the points against the rails one way or the other. All takes to change the direction is a flick of the points.

For your hard to reach turnouts, I'd like to suggest Tortise or Switchmaster machines, or mechanical linkages that you can reach.

[dave9999]

I am considering using ground throws for my turnouts. On my last layout
I used Atlas Snap Switches. This time I'm going with Customline # 4 & # 6
turnouts. The snap switches proved to be unreliable at best. I'm planning
to use ground throws in assessable areas. Has anyone used ground throws
and do you prefer the sprung or rigid? I have no experience with these so
any help would be appreciated .
Also, will my Atlas code 83 switch machines work with the Customline turnouts? Thanks, Dave