Double Crossover with one Tortoise

Discussion in 'FAQs' started by BigJim, Apr 12, 2007.

  1. BigJim

    BigJim Member

    After MANY versions I finally made linkage that works to control all four sets of points with a single Tortoise.

    The solution was to use a stiff push/pull rod connected directly to the Tortoise drive. I used a piece of NS rail with copper plated "wire feed welding wire" for the connections.

    Two wires at each end connect to bell cranks with a wire going up to the switch bar.
    Having both bell cranks movine the same direction the rod moves back and forth rather than having a "reversing" crank like one early version.
    One note of caution. Since the wire coing up to the points does not pivot like using a Tortoise per switch bar it moves further to the sides. The holes need to be larger or at least "cone" shaped to accomadate the outward bend of the control wire.
    Why bother? My layout has 4 Double crossovers. If I only had one it would have been easier to just use 4 switch machines. 4 versus 16 saving 12 made it worth the effort.
  2. MasonJar

    MasonJar It's not rocket surgery

    Looks like a great solution... Do you have a diagram of how it works? I (and maybe it's just me ;)) can't really make out the movement of the bell cranks.


  3. Gary S.

    Gary S. Senior Member

    Oh yeah! Good solution. If i had a double crossover, I would use that!
  4. BigJim

    BigJim Member

    Does this help?
  5. MasonJar

    MasonJar It's not rocket surgery


    I get it... Great solution! Thanks for the photo.

  6. eric halpin

    eric halpin Eric Halpin

    double xover

    Looks like a great idea and we need something for the Algoma and Rideaus 2xx. But what are you using for the four pivot end pieces? They look like some kind of porcelain device?

  7. BigJim

    BigJim Member

    [FONT=&quot]The base and pivots are made of high density polypropylene plastic. If I didn’t have a bunch of scrap I obtained years ago I would probably use pieces of hardwood. The pivots need to be thick enough to keep the wire up to the points straight. Mine are about 0.5 inches thick. I wouldn't go any thinner. The wire is wrapped around the black screws to secure it. The pivots turn on short pieces of ¼ inch brass tube.

    All four 2xx are done and working perfectly. With a little of adjustment there is quite a bit of tension on all of the points in both directions. I suggest you put a very small "Z" bend in the four wires from the rail to the pivots. (90 degree twist with the tip of needle nose) This makes the pivot "throw" center easier to adjust by opening or closing the angle of the "Z".

    As with all Tortoise adjustments put the Tortoise in the center position and adjust each wire so the points are mid-throw.
  8. MadHatter

    MadHatter Charging at full tilt.

    That looks really cool! I'm not sure if I'm going to have any double cross overs one day, but if I do I'll use that idea.
  9. MasonJar

    MasonJar It's not rocket surgery


    You could use hardwood, or UHM plastic (Ultra High Molecular weight - very dense) from might work instead.

  10. BigJim

    BigJim Member


    The UHMW plastic looks perfect for the job. Considering the number of uses I have found for the HDPP plastic (appears to be very similar) I rescued from the trash, on a daily basis, from a business near my work 15 years ago I am sure you will find additional ways to use it.


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