Question How do you switchmotors to the switches

Mzbringh Feb 18, 2013

  1. Mzbringh

    Mzbringh TrainBoard Member

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    How do you connect switchmotors to switches? should the title be.

    I start a new thread instead of highjacking Svein-Martin's thread.

    I'm getting to the part on my layout when I want to connect a Tortoise switchmotor mounted under the board to a stripped Märklin switch. Do anyone of you have any closeup photos on how I should do that? The risk is that my board is way to thick. But that's why I started my double pizza, double loop layout, to try things out in a smaller format.

    Cheers
    Mikael
     
  2. shamoo737

    shamoo737 Staff Member TrainBoard Supporter

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    Mikael, I used servos to switch the switches. They are controll with stationary decoders, and the frog is powered with a juicer. Its nice to see the switches move slowly instead of seeing it move instantaneously like the Marklins.
     
  3. SJ Z-man

    SJ Z-man TrainBoard Member

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    The Tortoise is sort of a crow-bar compared to the feather needed to flip the märklin turnout. The plastic used on the switch rod is really fragile so you want a way to limit the throw. The Tortoise does have an adjustable fulcrum so you can minimze the throw however, that is for a typical mount, say a 1/4" to 1" at the max and, an HO throw. How thick is your layout? Being 3" away makes the throw MUCH larger and then you have to deal with any bending of the wire that will make it get shorter at each end.
    As John suggested, the Servos, $5 to $10 each plus an Tam Valley or ANE Models SmartSwitch interface to throw them could give you more options. Both allow you to adjust the throw (both Left AND Right limits) so you can center it and throw it even asymetrical. You could mount the small servo just underneath (since you are just building the layout) or, use the wire-in-a-tube install to mount it remote and flex bend to the turnout location. Or, make a bell-crank (tube down through the foam, wire up through that you throw below and move at the top. Long throws at the bottom and short throws (the length of the horizontal bend) make for small movements above.

    http://www.anemodel.com/product.html#!/~/category/id=1299325&offset=0&sort=normal
    http://www.dcctrain.com/shop/item.aspx?itemid=3808

    http://www.tamvalleydepot.com/products/servosaccessories.html

    There are a lot of servo types out there, including this linear one:
    http://www.youtube.com/watch?v=k5EjmIaR8P4
     
  4. FrenchieZ

    FrenchieZ Permanently dispatched

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    Hello Mikael, I do not have answer to your question, but... the two links in your signature seem to be broken. Also, I am living in Haga... if you care to meet sometimes. I warn you now... I cannot speak Swedish.
     
  5. Mzbringh

    Mzbringh TrainBoard Member

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    Thanks for the links. Tortoise are the only nonmagnetic switchmotors that I have seen around here. I think they are very clumsy for Z-scale but I have seen others using them. The board is about two inches thick. I assumed that I use a thin wire that gently bend and that the switchmotor goes a little bit too far and the wire act like a spring at the ends. But it is, as you wrote Jeff, like using a crow-bar on a tiny fragile switch. I will start with trying to follow Svein-Martins example. My initial design used only three switches so I already got three switchmotors. Saying that I like the linear servo. And I will look at the other options too. My final goal is to build a yard with perhaps twenty switches. Trying to squeeze in twenty Tortoise switchmotors could be interesting.

    I'm sorry about the links. I though I had updated my signature. I have removed my WEB-page. I haven't given it much attention anyway and I'm moving away from my ISP. They haven't been up to the task lately and then I have been using them since 10-15 years or so. For videos I have moved to Vimeo instead.

    Haga you say FrenchieZ. That is a nice part of the city. I'm living not that far from HobbyCenter here in Gothenburg (there is a Gothenburg not far east from North Platte too). HobbyCenter is a Märklin store, among other brands, so they have to have Märklin Z-scale in store even though they don't like it. So I'm paying them a visit now and then just to annoy them. I only buy some track from them when I need it and scenery stuff. Send me a message. English is no problem for me. I use it daily.
     
  6. Garth-H

    Garth-H TrainBoard Supporter

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    there a number of ways to reduce the tension created by the tortoise machine on your switch. Use a much thinner piano wire and used the Z throw bar, which allows you to adjust your connection point to the throw bar and thus reduce the spring tension plus using a very fine piano wire can considerably lighten the load on the throw bar. There is also the Hoffman switch machine. which you can adjust the travel of the throw arm. Hoffmann is mostly available in Europe, but quite economical even with shipping, not sure if there are dealers in USA or not.
     
  7. SJ Z-man

    SJ Z-man TrainBoard Member

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    The Hoffmann's I had did not have any throw limit, only speed. And that was simply 'with added friction' or no friction. Too much current in either case so DC switching rather than from electronics like NCE Swith-it, Switch-8 or DCC Specialties' Wabbitt.

    Mikael, if you are building only a small area with such 50mm of foam, cut a square at the top to place a plate to mount the Tortoise up there. Then you can adjust the slider to be close to the track and make a small amount of throw. But still use a much smaller piano wire (K&S Engineering supplies a lot of Hobby Shops with these stiff wires). They are normally about .5mm. You should try more like .1mm or less !

    For the yard, Servos !!!!
     
  8. David K. Smith

    David K. Smith TrainBoard Supporter

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    The single greatest issue presented by commercial switch machines used for Z scale switches is that they generally have too much throw and/or apply far too much torque. The challenge this creates is in fabricating a wire link that applies just the amount of travel and torque required, and trying to do this where there are different thicknesses of benchwork increases the challenge exponentially. This is not to say that one shouldn't use devises such as the Tortoise; indeed, there are few options available to Z scalers.

    My recommendation is to avoid depending on the springy nature of steel wire to set the points. Instead, a classic "Z link" alleviates virtually all of the problems by relying on a tightly-controlled range of motion.

    Here is what I do:

    [​IMG]

    First, the Tortoise is mounted on a bracket so as to exploit the rotational motion of the actuator, instead of its linear motion.

    A linkage made from (relatively) heavy steel wire is formed to engage the screw hole in the Tortoise actuator on the bottom end; on the top end, it is formed to engage the switch throwbar.

    The trick is to establish the relative lengths of the linkage ends such that the range of motion at the throwbar is very slightly greater than that of the throwbar itself, in order to apply a tiny amount of pressure on the points to hold them reliably in place. This minute amount of pressure does not rely on the springy nature of the steel wire, but instead on the mechanical slop inherent in the switch point assembly.

    Adjusting the relative lengths of the linkage ends can be accomplished without too much difficulty by using a tight-fitting length of tubing to splice the steel wire together. Once the proper length is determined, the wire and tubing are soldered together. These dimensions can then be applied to any other Tortoise assemblies, with only minor adjustment required.

    One of the many advantages of this arrangement is that the amount of layout substructure through which the linkage must pass is irrelevant; it can be any length (within reason) and the switch will behave the same way, since it's actuated by rotational movement, instead of linear movement. It's also almost completely immune to the effects of ballasting, and it does not require a large hole under the throwbar to accommodate the typical Tortoise linkage. Yet another advantage is that most of the parts can be fabricated and assembled at the workbench, using an assembly-line process for all of the devices required. Soldering the splicing tube must be done in place on the layout.

    This is not an original design, but I don't see it employed that often.
     
    Last edited by a moderator: Feb 20, 2013
  9. yoshi98bc

    yoshi98bc TrainBoard Member

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    David.

    Have you figured out the linkage distances for z scale. I'm assuming it will be slightly different for every layout but a starting point would help. Also, do you have diamters of wire,brass tubing,etc that you use. Any photos of the actually setup? This linkage would is very appealing when different foam thickness are used. All info would be appreciated.
    Thanks
     
  10. David K. Smith

    David K. Smith TrainBoard Supporter

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    Linkage lengths are entirely dependent on each unique application; the empirical approach is really the best way to determine them.

    I can supply images, but the installations I have done are all on another layout, so it could be a while until I get a chance to snap some photos.

    Wire thickness and tubing diameter actually aren't all that critical. I can measure what I used on the installations, but there's a range of dimensions that will work.
     
  11. yoshi98bc

    yoshi98bc TrainBoard Member

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  12. David K. Smith

    David K. Smith TrainBoard Supporter

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    The mount is not "adjustable" but I do need to adjust it on occasion to get everything right. The best way to determine the wire lengths is to start with a simple ratio of throwbar movement to Tortoise actuator movement. I make the lengths of each end of the wire more or less match this ratio. From there I can determine where the tube needs to be installed relative to the switch. And the tube location will indicate where to mount the Tortoise. Finally, I will "fine-tune" everything by operating the switch.
     
  13. Mzbringh

    Mzbringh TrainBoard Member

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    Thank you David. I can't draw as good but that is one of three different option that I'm considering so far. Either do it as Svein-Martin is, perhaps with a thin wire that doubles as a spring. If the movement of the motor is too big for Z-scale then I thought I can put the wire inside a tube with a pivot point. That way I could get a smaller movment up at the switch. The third option is the way you describe David. That gives the smallest hole, easy to drill, and it basically doesn't care about how thick the board is. And you can have a ratio between the length of the bend at both ends and control the movement. The only problem I see is if you get a too big of an angle at the top pin maybe the throwbar is bent sideways. But for Z-scale the movement is minimal I guess. I will probably try both Svein-Martins method and yours David.
     
  14. ddechamp71

    ddechamp71 TrainBoard Member

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    Interresting post about Tortoises... Myself I'm only relying on them whith "from the box" hardware and I've not the slightest problem with them.. I first used them on modified Marklin turnouts I removed the ugly lateral mechanism from, and now I use them on my Wright turnouts (and I will use them on my future FT equiped layout). The given piano string works perfectly my my Z scale turnouts.

    However in some locations, as I had to set the Tortoises 2.5 cm lower than the benchwork´s underneath, I had to use a thicker string, as the sample from the box was too short, and as a longer string of the same brand was too light to correctly bend the points.

    Dom
     
  15. yoshi98bc

    yoshi98bc TrainBoard Member

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    David,

    How many ties away do you drill the hole from the through bar?
     

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