FAQ—Page 2

Why is my TORTOISE™ not moving my points?

The first thing to check is whether the TORTOISE™ is making its full motion under the layout.  If it is, then the problem is not with the machine.  If your turnout has an over-center spring such as PECO, this might be the problem.  See Application Note AN-6000-03 for more information.  If it does not, it may just be that your points are “sticky” from an application of ballast or glue.  The TORTOISE™ is a very forgiving mechanism, but it will not compensate for poor turnout action.  Check to make sure your turnout points move freely without bind or sticking.  Use a little powdered graphite to lubricate the sliding parts and correct any other binds you might find.  If the points still move stiffly regardless of these measures, or if you have a subroadbed thickness greater than 1”,  you can increase the diameter of the spring wire that is actuating them.  Try going up to 0.032” or even 0.039”.  These are stock sizes carried by K & S Engineering or their internet outlet, www.SpecialShapes.com.  You will need to drill out the small hole in the TORTOISE™ arm and the fulcrum as well.  Note the cautions in the TORTOISE™ Instruction Sheet.

It is also possible that your access hole is either too small or possibly drilled off center which is allowing the spring wire to hit the side of the hole as it moves, impeding its complete motion.  It is very important that the TORTOISE™ be properly centered with the throwbar hole above in order to impart equal tension in both directions.  It is easily possible to mount the TORTOISE™ far enough off of center that it will properly close the points in one direction but not the other.

What is the proper position for the TORTOISE™ fulcrum?

In almost all situation, the fulcrum should be placed at the very top of the case, right under the surface of the sub-roadbed you are mounting to.  Moving the fulcrum down in its slides will increase the throw at the points, but will reduce the tension on the points.  This is not usually a good thing.  Sometimes, if you can’t get the spring wire to throw the points fully to both sides, it might be suggested to TRY moving the fulcrum down.  If that solves the problem, great, but it is then likely that you have not mounted the TORTOISE™ properly centered and moving it to the correct position would be preferable.

Can I mount my TORTOISE™ on top of the layout?

This is perfectly acceptable in situations where the TORTOISE™ cannot be mounted conventionally due to obstructions.

Do you have room for the Remote Mounts' Actuator Mounting plate under the layout?  If so, mount the TORTOISE to the RTM following the instructions and then route the drive cable through a hole in the layout down to the Actuator.

If not, you might be able to just use the stainless steel wire and teflon tube by themselves to directly drive the throwbar.  Select the drive arm hole that gives you just a little more throw than the points' motion.  Likely the first or second hole.  Then just run the tube and wire across the layout surface to mate with the end of the throwbar.  We recommend putting a V bend in the wire near the throwbar so the wire can flex to take up any excess motion. 

One other method that has worked well for us is to mount the TORTOISE directly to the layout surface on the top with the circuit board pointing UP.  Before mounting, bend the spring wire following the instructions, then cut the spring wire to be 1/8" longer than the top (mounting) surface of the TORTOISE.  Using a 1/4" or 5/16" spade bit, drill into the layout surface to a depth of 3/16" or so centered at the location that the wire will be when mounted.  This location should be straight out from the throwbar.  The distance does not matter but the closer, the better.  Now measure from the center of this hole to the opening in the throwbar you will connect to and cut a piece of 1/16" brass tubing to a length 1/2" less than the measurement.  Take a piece of .025" spring wire/music wire/piano wire and cut it to 1/2" MORE than your measurement.  Now form a tiny loop in one end of the wire.  Make this as small as you can by bending it around the TORTOISE wire with needle nose pliers.  Coat the wire with Teflon or Graphite powder and thread the straight end of the wire through the brass tube and lay it on the layout surface with the little loop centered over the hole you drilled.  The straight end should be extending over or alongside your throwbar.  Make a mark on the wire where it will have to be bent to engage the hole in the throwbar.  Then cut off all except 1/8"-1/4" beyond the mark and make the bend at the correct angle to properly engage the throwbar hole.  Now check that you can move the points by moving the horizontal wire and that when the points are at the center of their motion, that the loop is perfectly centered over the hole.  Set the height of the brass tube so that there are no binds and fix in place with epoxy adhesive.  Paint it black to simulate steel conduit or hide it under foliage/ground cover.  Now set the TORTOISE fulcrum about 1/4" down from the top surface and place the TORTOISE while you make sure the TORTOISE wire enters the tiny loop.  Test operation and make sure that the points are held tight at both sides.  Adjust the fulcrum if necessary.  Fasten the TORTOISE down with screws when you are sure of the operation.  Hide the TORTOISE under a structure.

Can I get replacement parts for my TORTOISE™?

Circuitron does not sell replacement parts for the TORTOISE™ except for the fulcrums, spring wires and screws.  Send us an email (Support@Circuitron.com) with a street address and the number of pieces you need and we will get back to you with the cost, if any.

Why are my TORTOISEs™ making noise (humming) when they are not moving?

An unfiltered DC power source, such as we show on our instruction sheet as an AC transformer with Steering Diodes (or a traditional power pack with pulse power) will generate half-wave DC power (or worse) to the motors.  This is a "noisy" power source and will make the switch machines hum at 60 hz.  Depending upon the mounting and how many machines there are all humming in unison, this may or may not be audible.

The solution is to add an electrolytic capacitor across the power supply output.  If using a single supply, this is fairly straightforward.  If using a split (+ and -) power supply, two capacitors are required and you must be very careful to note the proper polarity of them when connecting.  Connecting an electrolytic backward will cause it to vent or explode, sometimes quite spectacularly.

A problem that occurs by adding the caps is that they will "peak-charge" and smooth the output and the voltage will rise as a result.  If the capacitor is large enough, this will amount to a 1.4 times increase in voltage.  This may possibly result in an overvoltage condition with the TORTOISEs "seeing" a voltage higher than their 12 volt maximum.  So, the goal is to use the smallest value capacitor(s) that will reduce the hum to inaudible, but at the same time cause the voltage to rise the least.  The amount of filtering required is also going to depend upon how many switch machines are connected (the total current draw).  Larger caps will be required as the number goes up.  So it is difficult to suggest a starting value as every layout is different and the number of machines and the way they are mounted will all contribute to the hum.

We recommend that you purchase some 220 mfd. 470 mfd. and 1,000 mfd. caps.  They should all be rated a minimum of 25 volts.  We can provide these for a small fee, if you do not have a Radio Shack or equivalent nearby.  Start with 220, have a listen, then go up from there until the system is quiet.  Then, measure the voltage at one of the TORTOISES.  If the reading is over 13 volts, I would recommend that you find a different, filtered or regulated power source.  See the question about finding a good power supply on Page 1 of the FAQ.

How do I retrofit a TORTOISE™ to a turnout that is already installed?

This is a lengthy and detailed answer and we’ll take you to it by CLICKING HERE.

          

 

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