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Powering Tortoises - issues I'm pondering

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Powering Tortoises - issues I'm pondering
Posted by crossthedog on Sunday, September 12, 2021 2:08 PM

Hi guys,

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).

Thanks in advance,

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by RR_Mel on Sunday, September 12, 2021 2:20 PM

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.

 
Mel


 
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Posted by richhotrain on Sunday, September 12, 2021 2:25 PM

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.

Rich

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Posted by doctorwayne on Sunday, September 12, 2021 2:33 PM

crossthedog
...So my question to my esteemed fellows here is manifold: have you experienced Tortoises 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.

Wayne

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Posted by ATLANTIC CENTRAL on Sunday, September 12, 2021 2:48 PM

Matt, if you want manual turnouts in the yard, there are many less bulky alternatives to the Caboose ground throw.

Sheldon

    

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Posted by MisterBeasley on Sunday, September 12, 2021 3:12 PM

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.

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Posted by crossthedog on Sunday, September 12, 2021 3:32 PM

RR_Mel
You don’t use a bus to power a Tortoise.

@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?

Thanks all.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by RR_Mel on Sunday, September 12, 2021 4:02 PM

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.

 
Mel

 
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Posted by richhotrain on Sunday, September 12, 2021 4:17 PM

RR_Mel

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.
 
Mel

Agreed.

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.

Rich

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Posted by ATLANTIC CENTRAL on Sunday, September 12, 2021 4:33 PM

I use subminature slide switches and little spring rods. I don't have a photo handy, but later I might be able to post a drawing.

Sheldon

    

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Posted by gregc on Sunday, September 12, 2021 4:40 PM

crossthedog
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.

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.

greg - Philadelphia & Reading / Reading

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Posted by crossthedog on Sunday, September 12, 2021 4:50 PM

richhotrain
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.

@Rich, do you mean something like this (red and black are bus wires)?

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by crossthedog on Sunday, September 12, 2021 4:52 PM

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.  :(

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Posted by RR_Mel on Sunday, September 12, 2021 4:58 PM

crossthedog

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?

 

-Matt

 

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.

 
Mel


 
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Posted by richhotrain on Sunday, September 12, 2021 5:15 PM

Wire it this way.

Rich

Wiring-DPDT.jpg

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Posted by richhotrain on Sunday, September 12, 2021 5:20 PM

Multiple Tortoises/DPDTs.

Rich

Wiring-DPDT-2.jpg

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Posted by trainnut1250 on Sunday, September 12, 2021 6:46 PM

Matt,

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 the power on - they draw very little current when stalled @20 ma or less. These machines need a constant power supply to keep the points locked solidly against the rails – not all stall machines will back off pressure on the points all the time but this happens often enough that they are not reliable unpowered. These machines need an on-on toggle to work correctly.

There are several brands of stall motors in use in the hobby – Tortoises and Switch master (hankscraft motors) are the main contenders.

Tortoises mount under the table and need a 1/2’ hole to move the points. You have to drill this hole before you permanently install the turnout. These machines work well and come with several contacts that can be useful for powering frogs and other things.

Switch masters also mount under the table using a crank assembly that does not require a large hole. The disadvantage is that you do see the crank on the throw bar in the ties – Not noticeable to me, but I am biased as I have lots on the layout so I might not “see” them anymore. The motors can be installed after the switch is in place on the layout and are very reliable. They do not come with contacts.

If you choose another brand of stall motor than the two listed above, check the stall current – several vendors a few years ago were selling stall motors with high stall currents (something to be avoided).

As far as wiring there are several schemes that have been already discussed in this thread. If you use a wall wart – use a REGULATED supply that won’t drop voltage as the supply’s amp capacity is reached. Run the system at 75% of the amp capacity of the supply (when motors are stalled) for longer supply life. I have several friends who run their tortoises at a lower voltage to reduce noise and to slow down the motion of the throw- it works reliably.

My layout uses switch masters (70+), hand throws and solenoids. I use a dual polarity power supply as Greg mentions above for the stall motors and it works well. I laid all the track and used temporary ground throws while I tweaked the track arrangement and then I went back and installed switch masters after everything was the way I wanted it.

I chose stall motors because I have lots of remote turnouts and I didn’t want operators to damage things by reaching into the scene to throw a turnout. I chose switch masters due to the ease of installation and because my friends use them, so I have a pool of expert advice on their use and installation.

All of the methods and machines/setups can work well – your choice.

Sorry this post is so long, I'm sure I'm leaving some stuff out - Opinions vary on this subject – good luck with the project,

Guy

 

 

 

 

 

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Posted by MrMe on Sunday, September 12, 2021 6:56 PM

RR_Mel

 

 
crossthedog

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?

 

-Matt

 

 

 

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.

 
Mel


 
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I'm beginning to realize that aging is not for wimps.

 

 
Nope, that's not necessarily true.
 
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 to remove all the spring rod tension from the throwbar, and certainly none of mine have ever done that.
 
I use Digitrax DS64's to control my Tortii, and they even have a setting (OPSW 9) to turn off power to the switch machines after 16 seconds for power conservation.
 
I have that setting active on all my DS64's, and in a quiet layout room you can hear the Tortii "relax", one after another, after I run the JMRI script to set all my turnouts to their default position.
 
But never in that "relaxed" condition have I had an issue with points not firmly in one position or the other (and I use Atlas Code 100 turnouts, which don't have built-in springs).  
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Posted by RR_Mel on Sunday, September 12, 2021 8:00 PM

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.



Mel


 
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Posted by SeeYou190 on Sunday, September 12, 2021 10:34 PM

Matt:

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:

crossthedog
Have you experienced Tortoises overheating?

No.

crossthedog
Does the idea of some shut-off mechanism make sense to you?

No.

crossthedog
Would a throttle be useful instead so that I could throttle down after the switch is thrown?

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.

I hope this helped.

-Kevin

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Posted by Lastspikemike on Monday, September 13, 2021 8:22 AM

Walthers turnouts now also have spring loaded points. You need spring loaded points in order to use solenoid type turnout motors.

Peco makes an E extended rod version of their solenoid motors and has done so for a long time. That requires only a 3/8" minimum diameter hole in the benchwork under the turnout throwbar. It's a bit tedious to line up and I find a 1/2" hole gives enough extra wriggle room to be worth using instead.

The standard under the points Peco is very reliable in operation and automatically lines up the motor by being secured directly under the throwbar by 6 metal locking tabs, the two centre ones are removed for the Code 83 application. This requires a square hole about 40 mm x 20 mm to be cut into the benchwork exactly under the turnout motor. Put it slightly in the wrong place and the motor only throws one direction. The end of the solenoid bar must pop out of the end of the coils at the end of its throw. 

Peco also now makes a Twistlock version of the E turnout motor which is somewhat easier to install and comes with a paper drilling template as does Walthers new Layout Control System. This latter system is obviously aimed at competing directly with Tortoise. Walthers includes (or at least did originally) a little V shaped plastic spacer to insert into the points to center them in order to drill the alignment holes in the correct spots. Quite handy.

I prefer the Peco E version if there's room under the benchwork. The newer Twistlock is easiest to install. 

For my next under the table Peco E installation I think I'll just drill a pair of alignment holes through the center hole in the throwbar, one at each end of the throw, to find the center of the 1/2" throwbar clearance hole. Peco throwbars also have handy holes in each end of the throwbar to allow alignment holes to be marked and drilled exactly across the throwbar throw line from end to end. It is fairly critical to get this line accurate in order that the throw of the motor actuating rod be correct. 

We're also planning to just use a finger to throw turnouts in easy reach of the operator. Remote turnout operation seems to be desirable but manually flicking the points turns out to be more practical.  In some sense more prototypical in many cases....

Alyth Yard

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Posted by MisterBeasley on Monday, September 13, 2021 10:46 AM

I do use a separate power supply for my Tortoise machines.  It has plenty of capacity, so there is no reduction of voltage as I add more Tortoises.  If I put on too many, exceeding the capacity of the supply, then I would see a voltage drop.

The diagrams you mentioned with multiple Tortoises connected to a bus are likely using the bus power to drive the turnout's frog power, not the motor to move the points.  Powering the frogs provides more reliable operation at slow speeds with smaller engines.  The frogs must be metal to do this.  It's a lot easier to power the frogs when you install the Tortoise than to retrofit them afterwards.

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Posted by crossthedog on Monday, September 13, 2021 12:44 PM

I'm sorry I can't respond to all the good suggestions and info here. I'm following up on threads where I still have questions.

One question is about Kevin's comments, but anyone feel free to jump in... it sounds like you're saying that the throttle on a power pack can actually be used to modify the voltage output... (I mean, now it occurs to me that that's what we're doing when we run our trains and use the throttle, eh?). If so, that's good news. I have an old MRC Trainpack gold box that outputs 14 volts. I could use that separately and throttle it up only 3/4 to power my Torti, sounds like?

Otherwise, I found these two old battery chargers in my box of stuff that we can't throw away or recycle and it all has to be taken to the hazmat or some other approved repository. But they each output only 7.5 volts. So that would not be enough to power the switch machines, right? Would the Torti not work at all or would they just be very slow?

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Posted by crossthedog on Monday, September 13, 2021 12:49 PM

richhotrain
Multiple Tortoises/DPDTs. Rich Wiring-DPDT-2.jpg Ad

@Rich. I forgot to say last night: thanks for this. It's extremely helpful. At this point this is what I plan to do... just have to determine a power source.

-Matt

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Posted by gregc on Monday, September 13, 2021 1:14 PM

crossthedog
But they each output only 7.5 volts. So that would not be enough to power the switch machines, right?

The Tortoise Instructions say no more than 12V and don't specify a minimum voltage.   

crossthedog
Would the Torti not work at all or would they just be very slow?

slow

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Posted by ATLANTIC CENTRAL on Monday, September 13, 2021 1:59 PM

The guy at the swap meet is wrong, he likely tried to run them on some cheap power pack turned up full throttle and was putting 18 volts on them.

9 volts is nice, it gives them a realistic speed.

Trust the instructions that come with the product, this is a product with a 34 year track record......

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Posted by CSX Robert on Monday, September 13, 2021 2:22 PM

crossthedog
I found these two old battery chargers in my box of stuff that we can't throw away or recycle and it all has to be taken to the hazmat or some other approved repository. But they each output only 7.5 volts. So that would not be enough to power the switch machines, right? Would the Torti not work at all or would they just be very slow?

I've never seen anyone mention what the minimum voltage is to drive a Tortoise, but I would think 7.5 would easily be enough.

The power supply on the left would only handle three switch machines (16 ma x 3 = 48 ma, the supply says 50 ma max), while the one on the right could handle 18.

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Posted by crossthedog on Monday, September 13, 2021 2:30 PM

Thanks guys. The last question no one has answered (it was back a ways) is... is the reversing of the polarity in a DPDT something that you have to specifically look for -- like a "reversing DPDT switch?" or is the reversal a function of how you wire any old DPDT switch? Rich's wiring diagram makes me think it's not the latter.

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Posted by Lastspikemike on Monday, September 13, 2021 3:07 PM

A DPDT switch can be made to flip polarity usually by wiring the two sets of end terminals together kitty corner style. The center terminals then connect one end at a time to whatever you're trying to reverse polarity for. You can wire one end to the power source or the center terminals to the power source, it works either way.

A DPDT doesn't have to be wired and used only to reverse polarity. For example,  Atlas snap relays act as DPDT switches without reversing polarity.

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Posted by CSX Robert on Monday, September 13, 2021 3:10 PM

crossthedog

Thanks guys. The last question no one has answered (it was back a ways) is... is the reversing of the polarity in a DPDT something that you have to specifically look for -- like a "reversing DPDT switch?" or is the reversal a function of how you wire any old DPDT switch? Rich's wiring diagram makes me think it's not the latter. 

It is the way you wire the switch.  The red and black X's in the center of each switch in his diagram is the wiring you add to make the switch reversing.  The input is wired to one of the outer sets of terminals and then crossed as it is wired to the other outer set of terminals.  The output is wired to the center set of terminals.

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