Most of my turnouts are in the yard in places where close-set tracks prevent me from putting a Caboose Industries manual throw. So I bought a few Tortoise machines to try out. I’m going to run a bus around the yard, hook up the Torts to a single power source, like a 12v wall wart.
So far so good.
But I was talking to a guy at a swap meet yesterday about how the Tortoise machines are designed to be powered all the time, and that I had heard they actually use more power while sitting idle than while moving the points. He recommended some kind of powering off mechanism – he said it too quickly for me to get – so that the machines didn’t overheat. I told him my understanding was that they were designed to be always powered and that I’d never heard any talk of it being a problem. “It’s a problem,” he said. “They do overheat.”
So my question to my esteemed fellows here is manifold: have you experienced Tortoises overheating? If so, what did you do about it? Does the idea of some shut-off mechanism make sense to you? How does one do this?
My initial setup will be four Torts on a bus, with a wall wart powering the bus. Would a throttle be useful instead so that I could throttle down after the switch is thrown? Or would throttling down even have any effect here? Remember, I know almost zilch about electrical stuff (although I am proud to say my eight DC power blocks work perfectly and the whole layout works in DCC as well, but mostly that’s because of the excellent help I have received here).
You don’t use a bus to power a Tortoise. They need constant power, if you disconnect power to a Tortoise it will slack up the pressure on the moving points. The Tortoise is a designed stall motor.
Use constant power from a DPDT reversing switch.
A Tortoise will not overheat unless you exceed the voltage specs, I’m sure there are members on this Forum that have dozens of Tortoise switch machines in service for many years without overheating.
My Tortoises are powered by a DC power pack. My layout, including the power pack, is powered up for hours at a time. I have never experienced a Tortoise overheating.
I have only one Tortoise on my layout, on the stub end of a turning wye, and also powered it from a wall wart. The switch, a simple double pole one, was labelled to allow me to access the turnout from either the north or south tracks. It worked well for years, but a couple months ago it seemed to be dead.
I checked the wall wart, which was working fine, but started to wonder if the Tortoise was damaged due to me working in the layout room with the power on for up to 20 hours a day.
I’m not sure why the idea popped into my head, but I decided to change the switch on the layout’s fascia that controlled the turnout.
I replaced it with a similar switch but one which also had a centre-off feature, and as soon as it was connected, the tortoise worked as it had originally. When I’m not using the wye, I leave the switch on “OFF”, and the points remain in the position last selected.
To be honest, I don’t know why it had stopped working, and I don’t know why changing the actuating switch fixed the problem.
I run my Tortoise machines at 9 volts. The slightly lower voltage causes them to move at a slower, more realistic speed. No problems with overheating.
I have a few Tortoise machines in more isolated areas. I run them with stationary decoders. They work fine, but one of these days I’ll replace those decoders with the slightly more expensive ones that also allow a parallel toggle from a control panel. After living with controlling turnouts from the throttle for a while, I definitely prefer panel toggles.
@Mel, maybe I’ve misunderstood all the videos I’ve been watching where people connect their Tortoise wires to a bus with a suitcase connector. Maybe that’s the main layout bus that they’re connecting into for constant power?
@Sheldon. I’m all ears. What are some of them and which have you used and which do you favor?
@Wayne. Can you tell me or link me to the exact precise product that you chose for your reversing center off DPDT? I’m unsure whether all DPDTs have the crossing wires or if that’s something you have to specifically choose. Also, is this a button you push or a toggle you throw, and does it matter? Also, it sounds like your experience is different from Mel’s, that your throw bar did not relax problematically when you turned off the power to the Tortoise?
@Mr. B. I did read in several places that 9v works better for Tortoises b/c it makes them slower and quieter, but I wasn’t sure if you can START with 9v. I thought I read also that if you start with 12v and have a number of switch machines or lights or other things on the circuit, it lowers the power that each Tortoise gets to about the ideal voltage. Do you instead recommend getting a 9v wall wart? Would the switch machines work right if each is not getting the full 9 volts?
If you wire all of your Tortoise to a bus when you reverse the polarity every Tortoise with operate. Each Tortoise has to have it’s own reversing switch. The buss can’t go directly to a Tortoise. You can Buss the reversing switches as the power source but not the Tortoise its self.
You can set up a pair of bus wires to your DC power pack or wall wart and run multiple DPDTs to that pair of bus wires. But the outer two power wires (#1 and #8) on each Tortoise need to connect to the center tabs on its own DPDT.
if a power supply is rated at 12V 200ma, it may start out above 12V but will be at 12V when delivering 200 ma (~10 Tortoise machines)
rather that using and wiring DPDT reversing switches, another approach is to use a pair of power supplies so that you have a V+, Gnd, V- bus supplying the layout and using SPDT switches.
the SPDT switches are wired to V+ and V-, supplying one to one terminal of the T machine and connecting the other side of the machine to Gnd.
Wait, no, that would switch the polarity of the whole string of switches, like someone said earlier. I guess the DPDT has to be up the line toward the switch machine, eh? Or…no… that’s no good… I think I don’t understand this very well.
The Tortoise is a stall motor drive by design. With power applied to the Tortoise the motor stalls with pressure on the spring wire going to the turnout points. Removing the power from the Tortoise lets the gears turn freely as the spring tension equalizes to 0 pressure. If you put your ear close to the Tortoise you can hear the gear movement when the power is removed. The spring rod to the turnout points will have 0 pressure on the spring rod without continuous power.
You are going to want to do a little research on various types of turnout control. There are advantages and disadvantages to the various types of control systems. It can take a while to decide what you want to do. The guy who told you that tortoises overheat was not accurate. There was some sort of a problem with the set-up if the machines were overheating.
The simplest control method, as Sheldon mentions, is a mechanical linkage of some sort. There are limitations to this approach but the various set ups can work quite well. Possibilities range from caboose throws, to choke cables, to slide switch arrangements, Bluepoint controls, to Joe Fugate’s door bolt set up and controls such as the OOP Hump yard products. Peco and Micro engineering turnouts use a spring in the points so they can be thrown by simply flicking the points with a finger.
Then are electric options that run the gamut from solenoid (“crash and bangers” as some of us used to call them) to stall motors to servos. I’m not familiar with servos, so I leave that up to you to research.
The solenoid options include Atlas and Peco switch solenoids as well as older Kemtron and other devices. Solenoid devices want momentary power application to throw the solenoid and then shut off. This can be accomplished with a push button or a momentary on-off-on toggle switch (there are also lots of other momentary contact switches that can be used).
The advantages of these machines is cost and ease of wiring but they can be hard on points and can be difficult to install in a way that you won’t see them (ie under the layout). Peco requires a hole cut in the layout surface under the turnout or a linkage. Atlas require a linkage for under the layout installation.
Stall motors are another category of control. These motors are designed to stall with
When power is removed, the Tortoise will “relax” slightly (the sound you hear), but there is still plenty of spring rod tension to keep pressure on the points.
The Tortoise would have to roll back to (almost) it’s centered position t
I had a pair of Atlas Custom Line code 83 #6 turnouts that the points would move enough with heavy traffic to derail without power on the Tortoise.
Actually I’ve been experimenting with servos for my turnout switch machines.
I remove the electronics from the servos (Tower SG90) and wire the motor like the Tortoise (Stall Motor) and use a resistor to limit the current to 20ma. They have a lot more torque than a Tortoise and at $1.50 each a bunch cheaper, no tweaking either.
Using an Arduino for a controller is a lot more effort than just using the servo as a stall motor. I have two servo (stall) motors installed and both are working very good.
So far you have received several excellent answers. Rich’s wiring diagrams are spot-on. They should help a lot.
I have used Tortoise switch machines exclusively for my last four layouts. These responses are to your original post from my experience:
No.
No.
Not for the use you described. That said, as Mr. Beasley suggested, I use an old power pack to supply electricity to the Tortoises. I adjust down to 7-8 volts or so just so the motors move slower. I never adjust this setting once it is where I am happy with the speed.
For what it is worth, yes, the Tortoise will draw more current when the motor is stalled and not moving, but we are talking milliamps here. In application, it makes no matter, they will not overheat. One small power source can run several of these machines.
