Wiring Tortoise motors

[mwalther]

I am a novice. I have been busy mounting my tortoise machines and now it is time to wire them. I have 36 tortoises so far and would guess I will eventually have 72-100. I think that I will use control panel switch position to indicate turnout position. Is it necessary for trouble-free operation to use DT-Center Off or is just a DT okay? Also, various swtiches are rated at various amperages (ie. 6A at 125VAC). What should I be looking for? Any opinions as to which is best: DPDT w 1 power supply or SPDT w 2 power supplies? Of course I want to save money where I can, but I want to be as trouble-free as I can too. Any recommendations for suppliers? I guess I am asking how do you guys do it?Thanks

[mcouvillion]

Mark W,

Its been a while since I wired one of these. They are stall motors, so that they draw a minimal current when stalled (at the end of their throw), and are intended to have the current applied all the time. You do not need the center off position on the switch, but you will have to get a power supply that can handle the total stall current of all your turnout motors and the current of any/all the motors moving at any one time. I wouldn't put 50 - 100 motors on the same power supply (all your eggs in one basket, so to speak). I would use several small power supplies around the layout for motors in different areas. The Tortoise installation instructions show you several ways to wire them up, including using diodes. One layout I run on has installed bi-color LEDs in the straight and diverging routes such that we can determine the routing from a distance (green for selected route, red for other route). The LED is wired in series to the frog power from one of the single pole double throw s

[cwclark]

use the DP/DT center off type....I get them from a place called parts express at @$1.30 ...you need only one power supply for up to 20 machines ...a 12 v DC (do not use AC unless you want to burn up all the motors)..the switches?..any rating is ok...they don't make the switches with ratings so small that it will cause you problems...the 6A 120V will do just fine...the #1 and the #8 (the first and the last contact) are the ones that wire to the tortoise...when you wire the DPDT switch, the power source will go to two outside posts...then add two more wires and cross the wires and wire them to the other two outside posts at the opposite end and then the middle posts will go to the tortoise motor....http://www.partsexpress.com/ type in DP/DT and it will take you to the page..I like the ones with screws on the posts...beats all that soldering!...Chuck[:D]

[mcouvillion]

Mark W,

Its been a while since I wired one of these. They are stall motors, so that they draw a minimal current when stalled (at the end of their throw), and are intended to have the current applied all the time. You do not need the center off position on the switch, but you will have to get a power supply that can handle the total stall current of all your turnout motors plus the current of any/all the motors moving at any one time. I wouldn't put 50 - 100 motors on the same power supply (all your eggs in one basket, so to speak). I would use several small power supplies around the layout for motors in different areas. The Tortoise installation instructions show you several ways to wire them up, including using diodes. One layout I run on has installed bi-color LEDs in the roadbed of the straight and diverging routes such that we can determine the routing from a distance (green for selected route, red for other route). The LED is wired in series to the frog power from one of the single pole double throw switches on the Tortoise. When the route changes, the LED indication changes. (Great from a distance when your eyes are failing!)

With so many turnouts, and being a novice, you might consider using edge mounted connectors for your Tortoise wiring. There was another thread a few weeks ago that mentioned this specifically. If you have trouble with a turnout, it makes it easy to disconnect the Tortoise from the wiring and replace it (though Tortoises are practically indestructible). There have been several small articles in Model Railroader over the past 10 years that show modular ways to install switch motors, especially on layouts with a bunch of them. Modular installation allows you to change out a problem quickly, then work on it in a comfortable place (read "workbench" rather than standing on your head underneath the layout).

Most any of the toggle switches, or pushbutton switches, you might use are easily rated for the current of the motor. Buy what is aesthetically pleasing, a size you are comfortable with, and what you can afford. Good luck on your (large) project.

Mark C.

[mwalther]

Thanks for the replies so far. As indicated by two of the replies it is still unclear to me whether I should use the Center Off switches. I still wonder WHY I should or should not use Center Off switches. I've heard that there is a problem with the Tortoise shorting when switching (Is this true?) and that the Center Off provides a momentary ALL OFF while switching. I am using edge connectors for the reasons suggested. As an aside I have burned out 3 power supplys shorting out in the installation -testing mode and after the 2nd added a lamp to the test lead edge card to indicate short circuit, but still shorted one out. Thanks

[rrinker]

The problem using edge connectors is a) they can fall off and b) it's hard to get ones with the right amount of conductors. The standard sizes that edge connectors come in have 2 extra pins than the Tortoise. If you don't use what's called a blanking insert to block off the unused pins, you can easily put the edge connector on incorrectly, and this MIGHT cause problems dependng on what you have wired to each terminal.
A better solution is to use 8 terminal barrier strips and solder a short harness to the Tortoise. This still allows you to easily disconnect the Tortoise if it ever has to be removed, but is more reliable and cheaper than the edge connector.
For operating them, it was suggest to use multiple power supplies, a very good idea. Not for capacity, even 100 Tortoises is < 2 amps. Just for reduncancy, so your whole layout doesn't come to a screeching halt. Plus if it has > 100 switches, I assume it's fairly spread out, so rather than run yet another power bus to supply the Tortoises, divide them up across multiple power supplies. Even better - use a standardized wall-wart type power supply, and have at least 1 extra on hand in case one fails during an operating session.

Center-off toggles are not needed. Power should be applied to the Tortoise at all times, this is what holds it in position. They are designed to work like this.

As for the 'shorting out' this usually refers to using the Tortoise contacts for frog polarity, if not adjusted correctly the Tortoise contact can connect one side while the point rails are touching the opposite side, causing a short. However, careful adjustment can resolve this. There is a modification you can make to the Tortoise contacts as well, but that would void the warranty. Note that if you are using an insulated frog turnout like Atlas it won't be an issue anyway, provided a train is not sitting on the frog when you throw the turnout.

--Randy

[cacole]

No, you do not use center-off switches with the Tortoise, because it needs to have power applied continually so it can maintain tension on the point rails. When stalled, if you have the proper resistors wired into your circuits, a Tortoise only draws something like 10 milliAmps of current, which is very low. They use more current when they're moving from one position to the other, but still not more than about 30 or 40mA.

A good power supply for Tortoise machines is one from a computer, since they provide 12 Volts regulated DC power, but you need to know something about electronics in order to connect one of these. One 150 Watt or bigger power supply should be more than sufficient to power all of your Tortoise machines.

[rrinker]

There's a link that was posted a while ago on how to make a computer power supply work outside of the computer. Basically you need a load resistor or the power suppyl won't regulate.
Keep in mind that a 150 watt power supply can't supply all 150 watts on the 12V line, however it will probbaly do a good 8-10 amps on the 12v side. That's enough for several hundred Tortoises, AND probably lights in all your structures. I always knew there was a reason I kept all these old computer power supplies I have in the closet.. Too bad they don't put out 14-16 volts, they'd be good power supplies for DCC boosters, too.

--Randy

[richhotrain]

Mark,

I have installed 38 Tortoises on my layout and I use the Miniatronics DPDT switch but I did not install the Center Off version and all works fine. The thing that I don't like about Center Off is that it is one more position to worry about. If you are not paying close attention, you may think that you threw the turnout when in fact you didn't because you only managed to kill the current without doing anything else.

I have not had any problem with short circuits with the Tortoises. I do agree that you ought to use separate power supplies throughout the layout. I use two separate power backs with half of my tortoises on each power pack. Also, I have wired dwarf signals from Tomar Industries along side each turnout to visually confirm the direction of the turnout. Works great and looks great.

One other bit of advice. My LHS dealer convinced me to replace the cable wire supplied with the Tortoise with a heavier gauge piano wire and I did that with very good results. The best thing about the Tortoise is its "forgiving" nature. Unlike the Atlas Under Table Switch Machine, the Tortoise does not require exact, precise positioning to work flawlessly.

Rich

[SP4449]

Wiring the Tortoise is no problem. Just follow the directions on the sheet included with each motor. With the motors each using power while stalled, a transformer of adequate size is needed, again, follow the directions for that, and don't scrimp on the wire size. 22 guage is the absolute smallest you should use. For the long runs from the power supply to the terminal strips, use 18 guage. The motors will respond more positively to the toggle switch changes than if you use smaller wires. rrinker mentioned using terminal strips - [tup]. The terminal strips will make wiring and troubleshooting much easier. Good luck. The tortoise is a good solid performer and pretty much dummy proof.

[novacoach]

Buy one and play about with it. I got a 8 position connector and it worked fine after I cemented some 1mm/1mm styrene to the motor connector strip.

[nslakediv]

I use answering machine power packs for mine. I also use 22 gauge wire for all of them. My choice of toggles was DPDT center off because I had several hundred left when I converted to DCC. A tip: wire the toggles at the work bench then all you have to do is hook up the 4 wires at the layout, I clamp the toggles to work surface and strip all wires first, than I tin them and make up my assemblies quickly. Tortoise is the best invention since flextrack.

[Anonymous]

I run about 20 of the Tortoise machines on my layout. When I bought them the dealer told me to use a plain double pole double throw. No center off position. I don't usually run my layout more than a couple hours at a time, but I haven't had any problems with the machines. I don't believe you need the center off position switch.

[SP4449]

If I may offer another post on this subject:

The modular layout that we run at train shows has 26 tortoise motors controlling the ends of a yard. We have found that the turnout point position does not change until the toggle switch position is changed, even if the power is removed. This is due to the gearing inside that little green box. We use this to advantage by lining all routes for mainline running at the end of the show then we disconnect the control panel from the layout. At the next setup, the turnout control panel is connected only after the layout is totally operational so if we had experienced difficulties getting set up and are pressed for time, we can still run trains when the show opens. The layout is powered at least 6 hours each day the show runs. No problems with the power being applied to the tortoise for that length of time have come up.

The stalling feature is to allow elimination of the cutoff contacts other slo-motion turnout motors have. The cost of the unit is kept down and it is simpler internally which means more reliability. Using center off toggles does no harm but may have a side benefit that power drain on the power supply will be less, thus each tortoise will respond better to toggle switch changes. We use two wall mount transformers from Radio Shack (model number 273-1652D, 12VDC, 500MA), to power each end of the yard, connected as "bi-polar DC with SPDT switches". Instead of SPDT, we use DPDT to control led indicators in the future.

We were experiencing problems with reliable point positioning and thought the tortoises were beginning to break down. Upon closer examination, we found the problem was caused by the small wire that the system was wired with. All motors were rewired with 18 gauge wire and the problems went away. There is a two position barrier strip mounted near each motor which the 18 gauge wires run to from the control panel then a smaller gauge wire is connected from the strip to the tortoise, soldered directly to the connection.