As I understand it, there are basically 3 types of switch machines.
5-finger method (manual)
Selonoid (2 magnetic coils wrapped around a steel rod)
Switch machines like Tortoise and several others.
As I understand it, the selonoid is basically an all or nothing method. Once you activate the coils, the rod basically has one shot at bringing the point rails together with the outside rail.
Switch machines like tortoise have an automatic clutch or some sort of gizmo that gives the motor a few whirls to secure the point rail to its mating rail; then the clutch disengages. The advantage is that extra nudge is so the point rail (a) actually closes the gap, and (b) doesn’t hit and then bounce back a bit; thus preventing the train from “picking the points”
Oh, & btw, I may have forgotten, but I believe there are several other nifty types of switch machines.
The air controlled one are really sweet because they keep the point rail secured in the proper position by the force of air. The down side to the system is that it’s a bit pricey; but relative to the high cost of locomotives, its extra cost may not be too high.
I’m planning for manual switches to spurs and automatic, motorized types for the mainline reverse loops and turnouts leading to the lower level of the layout. I haven’t decided yet which motorized unit is best and least costly. Would be interested in finding some comparisons.
Air is the least used method. There’s a nice website out there on just such a system. My understanding that the pressure is always on, thus, the points are always being held in position.
Some notable modelers like Tony Lash, use the system.
Hmmmmmm. I’m just wondering out loud if the same air compressor that powers your turnouts could power an airbrush (my daughter bought me an Aztec air brush for my birthday last year and it came with a can of air but I’d like to eventually acquire a compressor).
dav
Oh, btw, I’ve seen some ingenious manual control switches, using clutch cables and an assortment of other contraptions. I actually prefer manual, but when I just want to sit back and watch the trains run, it’s nice to have an automatic (non-derail) type turnout on the turnout loops so the trains can be run in a hands-off mode.
Manual switches can be operated directly or remotely, using something like a choke cable, wires, or rods and bell cranks.
A switch machine can also be built using a single coil instead of two solenoids, to move an armature, much like a relay. This kind must be continually energized in one of the two positions.
Most solenoid machines have some provision for locking the points into position. The Lionel O switches have a “lock hinge” that provides a detent. The older O27 switches use an over-center connection to the pinion of a rack-and-pinion arrangement. The newer ones have a plastic cam plate.
Tortoises are “stall-motor” machines. There is no clutch. Instead, the motor simply stops when it reaches the limit of travel. The motor is designed to withstand this.
I have also seen a switch machine that used heated nichrome wire to move the points. This strikes me as a little bit dangerous.
I’m using mostly Tortoise machine and I’m very pleased with them. I had two NJI selonoid machines and have replaced one with a Tortoise. I hardly use the other NJI. I like the slow smooth action or the Tortoise. I took one apart and there is no clutch or limit switch. The motor just runs until the mechanism reaches the end of the stroke and then just stall in that position continually drawing a small amount of power.
I’m using a few DZ1000 machines on the upper level. Some are over other tracks. Unlike the Tortoise, they have a limit switch that shuts off power when the end of stroke is reached. I had a head on colision that broke a coupler when one limit switch killed the power before reaching end of stroke. I’m replacing a couple of DZ machines with Tortoise because I prefer the action and the auxillary contacts for operating relays.
Here’s what I use Dave. As always mall leftovers. This was custom built using mostly off the shelf stuff. The motor and limit switches were picked up surplus, the traveler, the base, and the coupling were custom machined. When you combine these with the pushrod linkage, that we discussed in another thread, you end up with a very easy to install, and reliable system.
I’m not familiar w/the 1122 but I believe that any of the devices we have been discussing can be made to work with your switch.
As a matter of fact, I once did an experiment by ripping out a selonoid switch to an HO turnout and used it to power an 027 switch. I have a K-line 042 manual switch that is a bit more difficult to convert but that could be done as well.
Ofttime, you will need to open the switch box and see how the mechanism works and perhaps make a special cable for it to connect with whatever remote device you will be using.
It is all automatic Dave, the micro switches cut the power to the motor when the traveler runs into them. The concept was borrowed from a commercial machine that was on the market, but modified into the monster in the photo. The contacts can be used for power routing on the longer turnouts or as a position indicator. It is actually possible to stack the micro switches if you needed extra contacts, or drive a relay. Lots of options.
This device could even be modified and lengthened to create motion for a home made animation. I was actually thinking of using something like this to move a 282 crane back and forth along its own set of rails. By popping out the small axlesand replacing them with set of piano wires that would go through a couple of slots, and connect to the traveler.
I built a traveling crane last year. It’s an overhead crane like you’d find in a steel mill to move heavy beams. Using a Plymouth HO diesel, I tore off the chassis and replaced it with a sheet metal frame. I then had it run overhead on HO tracks, powered by an HO transformer. When it got to the end of the track at either end, it would come into contact with a spring that connected to other HO packs that would turn a motor to let down the pulley.
It is kinda crudely built but it works and was fun to make. It doesn’t really look good enough for my layout, however.
I’ll make no secret that I’m not at all smart about electronics…just yet; but once my layout is completed, I’ll be devoting months to projects like yours and scratchbuilding things.
I’m pleased to see that there are some really creative folks on this forum who enjoy these things. Enough cool stuff was discussed today to fill an entire magazine.
Gee Dave that’s not such a bad idea about doing an article. I’ve always wanted to earn my Master Model Railroader title in the NMRA, and something like that would be a start on the author catagory. The layout that I’m working on would probably fill almost all of the other requirements. I don’t think that anyone has ever done this with 3 rail O as their primary scale.
Back in 1999 when the NMRA national convention was in St Paul, I sat in on a clinic about the master program, afterward I asked if doing handlayed track in 3 rail counted, and the guy looked at me kind of funny and said “I guess so.” The question about the track requirement was specific, because there are electrical issues associated with the requirement, that take on a very strange meaning with 3 rail.[%-)][:o)][swg]
Soleniod switches, like the 1122 and O22, have a mechanical latch that holds the frog in position once the switching action is complete. Try and move the frog on any of these. If it moves, the latch needs to be adjusted.
The O22 has a set of electrical contacts that turn off the soleniod when the frog is positioned; otherwise, the non-derailing feature would activate the soleniod when a train was on the switch.
Part of the difference is that soleniod switches are fast. Tortoise machines are slow. Fast is better for toy trains and non-derailing features. Tortoise machines require operational planning.
I might suggest a “routing” electrical mechanism if you decide on tortoise machines.
Correct me if I’m wrong but I plan to get some Tortoises on the layout to use in an elongated reverse loop with the non-derailing feature. I believe that the key to making it non-derailing and to account for the time it takes throw the points, is to insulate the track a couple of feet back instead of right at the turnout. Once the train (or cars) cross the insulated section, then the Tortoise is activated automatically.
Roger,
I’ve seen tortoises used in a variety of ways, connected to accessories by thin metal rods or piano wire, depending upon the application. In fact, I’ve seen them used on a fully animated HO layout, opening and closing lift bridges and opening the doors to the engine house and then closing them. I really can’t recall all of the other applications but there were others.
I have only played with one type of tortoise type switch machine, and it worked as follows:
There was only one DC motor, which operated in stall to hold the frog in position. The motor direction, and applied power polarity, was used to determine switch position.
Instructions showed using a DPDT electrical switch on a control panel for changing switch direction. The switch machine also had some contacts that changed whenever the frog was positioned one way or the other. These were intended to be used to control a train so it wouldn’t enter the switch until it had completed the switching action. All instructions assumed DC trains, so HO or O-Scale, no mention of AC trains.
I fooled around with it so I could run it off AC power (using diodes for the switch motor) and provide non-derailing using two relays. It worked well, but I decided to use high-rail track and Lionel O72 switches on the layout.
Does the tortoise switch machine you are using come with a non-derailing feature, or did you have to come up with a relay circuit?
The main problem is in locating the insulated track section to “account for the time it takes to throw the switch.” If your loop is large enough, no problem. But in situations where there are multiple switches close together, control gets tricky. Can be done, but a routing control mechanism is the usual result.
A “couple of feet back” may not be enough. It depends on the time to throw the switch and train speed.
I did find that I could speed up the switching action by applying a higher voltage, but this voltage was too high for stall mode. Another relay was used to drop the voltage when switching action was completed. This was too much complication for a bunch of switches, so I decided I would use O22 switch mechanisms (without the track part) to control the Gargraves switches I was playing with. I ended up using high-rail track, so never actually used either approach on a
As I mentioned above, “I plan to get some”. I don’t have any now. I may just get a few to play with to see how the timing works on them. I always can use them for other things on the layout.
However, in the case of a short turnaround loops where speed is of the essence, a selonoid-activated switch may be just the thing; esp if you run trains fast.
Interestingly, I am one of the slow-train runners, but the stretch of track I’m modeling on the Belen Cutoff, ironically, is one of the fastest speedways in the country with freights going upwards of 80 mph.
Thanks for your explanation and note of caution on the timing.
I don’t have my Tortoise machines non-derailing. It is possible to use a flexible actuating wire that will allow the flange of a wheel to force the switch open. A neat no cost approach for someone with heavy rolling stock.
I prefer to wire signals and center rail sections via relays to stop the train if the switch is thrown. I don’t want a train to throw a switch if I have another train approaching on the other track.
By the way Dave, 6 months to a year ago you inquired about operationing a semaphore in 3 positions using a Tortoise. I have successfully done this using one Tortoise with two relays. One relay for each of two blocks. One relay slowly moves the arm to the stop position. When the train advances to the next block, the next relay slowly moves the arm to the caution position. I use the internal contacts in the Tortoise with no modification to position the arm in the caution position.
Elliot, you probably have alread thought of this: A spring or a little deliberate elasticity in the linkage between switch motor and switch will allow a little overtravel of the motor and make adjustment of the travel much less critical than with a stiff linkage.
I have successfully used a Tortoise to actuate a Marx semaphore. I drilled a hole in the case to access the arm that the motor moves at a point where it has the right amount of travel, then mounted the machine on its side under the table, with a pushrod through the Tortoise’s hole and a brass tube through the table to push up on the vertical rod inside the semaphore mast that actuates the spectacle. By using the built-in electrical contacts, I was able to make it stop in the approach (yellow) position. The whole thing runs off 12 volts DC and uses no relays nor active electronics to replicate the behavior of a prototype block signal.
