Steppers

It sounds like a job for a stepper motor and pic controller.  Maybe Tam Valley has something that would work?

Tam Valley for sure

 Again I recommend Tam Valley products. They use Servos to drive turnouts. In N scale, Fast Track switches can be thrown very easily with a 9G servo. Larger scales may need hinged points.

With a Quad P system you can set up routes within the QuadP and have different servo motors thrown in particular directions and all it means is you select a route instead of a switch.

If you go to the Fast Track site, you will find on the new items list that Tam Valley now has a single Frog Juicer. So for a few bucks you can buy automatic frog control depending on how many juicers and frog points you need to control. Or, the Quad P hooks up to daughter boards that will accept DPDT relays.

I am not affiliated with Tam Valley, but I do use his stuff. It is very good and easy to set up[. And reliable. More modellers need to investigate Tam Valley products, they have some very good products available.

servos

Hello - I am in the same position trying to find drivers for a crossover in n scale.  I have decided to use four servos from Tam Valley.   See the article in the 2009 3rd quarter MRH and the Tam Valley website http://www.tamvalleydepot.com/  This is the  simplest connection and most reliable  driver in my opinion.  Use their Octous II board with four servos and micro-switches to contol the frogs..  Total cost including power supply around $80 or $20 per turnout. You still need something to control the diamond.   I plan to have all turnout points move simultaneiously. 

Actually there are only two positions -straight and crossed.  If one path is crossed you can't use the other straight position.   

My ex-yardmaster Terry (aka

My ex-yardmaster Terry (aka Crusty) used a single Tortoise to run all four turnouts in a double crossover. Mechanically either both tracks are set to straight through or both routes are set to crossover.  Perhaps this is not quite prototypical, but it will save you close to $40 in tortoises!  Sorry, I don't have details on the linkages but I'll see if I can get him to post on this thread.  The real trickiness comes in setting the polarity of the frogs in the crossing.  EIther do it by having a 3-position switch to control the tortoises and the frog polarity, or use a frog juicer or auto reverser circuit to automatically switch polarity (if you're running DCC).

Cheers,

Charlie

double crossover

Only a two position tortise is necessary.  There are 4 routes through the dbl crossover--two straight and two crossing over.  If either straight route is used then the 2 crossing routes cannot be used as a turnout is set against it.  The same is true for the crossing routes-a turnout is set against the straight routes.

 I used one tortise and home made linkage for the mechanical point control and a 4p dt relay controlled by the tortise for frog polarity.  There is the potential for 4 different blocks to be connected to the double crossover.  The relay provides the necessary block isolation.

I developed a circuit to use push buttons to control tortise machines from multiple locations so my panel had two buttons for the straight routes and one for the crossover routes.

Crossover linkage

Brilliant,

Yes, there really are just two positions -- open and crossed. So I see that one motor should do it. Would it be possible to post a picture of the linkage?

Thanks,

greg

Photos of Terry's Double Crossover linkage

Terry's current layout has no double crossovers, but being the supreme pack-rat he had a section from a previous layout that did. It was sunny yesterday, so he took it outside and had at it with his camera.  Here are the results.

photo 1

photo 2

photo 4

 Perhaps Terry will post again and explain how all this works...

Best regards,

Charlie

Double Crossover one Tortoise

 I built this for a Shinohara D/C and am in the process of building one for a FastTrack #8 D/C.

dbl crossover linkage explanation

Somewhat random notes--

The white plastic pieces are model airplane bell cranks, two "L" shapes trimmed and rivited together (rivits are track nails peened over.

Linkage to the tortise is model airplane parts.

Linkage to the points is through a "Z" shaped linkage that was used for years with twin coil machines.  The connection to the bell crank has a strain relief circle to limit the force on the points.

Wires shown in and around the bell cranks are track feeders and track connections to the frog polarity relay and frog wires from the relay.

The actual track is a Walthers code 83 double crossover with some modifications--the point throw was changed to a fiberglass throw bar, points isolated from the frog and connected to the stock rails (makes much more DCC friendly)  The crossing was left stock as it is properly insulated for operation.

The relay that fits in the socket is an AMP R10-E1397-1 or R10-E1-X4-S450.  Manufacture date is1978 so I don't know if it is still available.  It's a 4p DT with a 12V coil.

The circuit board is a convient way I had on hand at the time to gather the various connections--no other electronic components are on board.  The white cable is a piece of CAT 5 used to bring in power and control the tortise.  The relay is controlled by a set of the aux contacts on the tortise.

The mechanial linkage of the tortise had to be strengthened to transfer the necessary force to throw all 4 points,  I used a piece of the model airplane linkage to do this.  It was installed by drilling out the tortise fulcrum to accept the wire size.  The other end has a loop of wire soldered to it for the screw mount.  This loop was wrapped with another piece of wire and soldered.  The throw rods have a similar linkage, strengthened by soldering.

The various mechanical pieces were bent, warped and otherwise abused to prevent interference with the various pieces.  The pictures show my solution.

Yes, piano wire can be soldered with regular rosin core solder--I cheated and added some external rosin flux.

Terry

Mechanisms

Thanks to both Terry and Les for posting their mechanisms. I am going by the local RC model shop today to look at what is available. Both approaches are ingenious and the responses are exactly what I had hoped for.

greg

photos in posts

photos in posts not showing - what is wrong?

Photos are back ...

WOW!!

Photos of Terry's Double Crossover linkage

Charlie, the guy stated he was a "new guy" to railroading and you post these pictures. "run for the hills"!!!!