Hi. There are 2 basic sw motors that I'm familiar with for HO: twin-coil types, and slow motion types like those you mention. The twin-coils are simple magnets that bat the points assembly from side to side rather violently. They are simple and somewhat cheaper than the slow-motions. There are some clever designs for manual turnout control that use things like automobile choke-cables and the like. That said, which you choose can depend on which turnout you are using.
If you use a turnout like Atlas, Shinhara or Walthers, you need a motor that will hold the points in the desired position. The slo-mos do this well, and the 2-coil types like Atlas undertable motors or Rix do too. I'm sure there are others like them. If you use a turnout like Peco that has the over-centre spring, the motor doesn't have to do the holding, the turnout does that for you. In this case, the simple Peco or Rix 2-coil job work well. I modified some of the older-style Atlas 2-coil motors to work here as well. If you soften the spring action a bit, the slo-mos are fine here too. A further wrinkle: power for the 2-coil jobs must be applied for only a short burst like a second or less, or you will fry the coil. The slo-mos are always under power, and are designed to stall and sit that way under power. If you are going DCC, there are stationary decoders that will control which motor you use.
Another consideration: will you want to power the frogs and point rails positively, or will you depend on the contact of the points to their respective running rail to do it? Some motors have built-in switches for that, and some need help from a relay or other external switch. I use some of both motor-types, and will likely gravitate toward the slo-motion ones when they need replacement, whenever. My control circuitry will have to be modified when I do. Mine is a DC layout, and I use a probe-and-stud method to control the turnouts; it doesn't allow for continuous power to the motor in its present form.
Sorry for the treatise, hope some of this is helpful. Your local hobby shop should be able to show you what is available too. By all means, ask questions. We all love to talk shop!
Have fun, George
Good answer, George, but can I get you to elaborate on one of the situations that you mentioned? I am planning a new layout in HOn3, Using fast track turnouts-code 70. I have a couple dozen peco two coil motors that I would like to use if I could overcome the problems of holding the points in position and powering the frog (I'm planning DCC). Any thoughts?
Thanks, Steve
Steve, I don't have experience on narrow gauge turnouts, so I'd recommend a trip to your LHS and a chat with someone who has. ...Maybe someone can join in here to help us out...??
In HO, there are micro-switch attachments for frog powering that sit astride the pin that moves the turnout of the Peco magnet assy. In cases where I've powered the frog, I've used either an Atlas relay, or Rix motors (mounted flat, under the subroadbed). The Rix have 2 dbl-throw contacts that are useful. The throw of that motor is adjustable to fit several sizes of track. If you use a motor with too much throw, you'll have to allow for some spring action of the throw so you don't overwhelm the points assembly. That's not too difficult if part of the linkage from the motor to the points is piano wire; just put a Z-fold (kink) in the wire so it can act as a shock absorber if the wire is push/pulling the points. If it is used as a bat like in the example of a Rix mounting bracket on Pg313 of 2007 Walthers catalogue, the flexibility of the wire is all you need.
None of this addresses the need to hold your points; at a show/market I picked up some mechanical brackets that might have been able to turn the Peco magnets into something that may have done the job, but I think there are simpler ways, like using a different motor. Remember, you cannot keep the coil powered for very long, or you'll fry it. The slo-mo motors can be used with DCC decoders, and I think there are now decoders for 2-coil mach as well.
Guess I'm not a lot of help here, sorry about that, George
durango wrote:Good answer, George, but can I get you to elaborate on one of the situations that you mentioned? I am planning a new layout in HOn3, Using fast track turnouts-code 70. I have a couple dozen peco two coil motors that I would like to use if I could overcome the problems of holding the points in position and powering the frog (I'm planning DCC). Any thoughts?Thanks, Steve
Steve
There are 3 issues with using the Peco motors on your Fast Tracks turnouts.
1) The mechanical joint (usually soldered) between the PC board "throw bar" and the point rails is usually the highest stress joint in most handlaid turnouts. Because most of us don't use hinges where the points join the closure rails, the joint of the points to the throwbar is in shear stress in both horizontal directions when the points are thrown. This is almost always the 1st joint to break (if any ever do) in a handlaid turnout. The stress can be overcome by strengthening the joint with tabs of brass, or letting the points pivot slightly at the joint.
Also, unless the stock rails are soldered in the vicinity of where the points impact them (mine are just spiked), the impact of a 2 coil switch machine throwing can gradually cause the stock rails to move out of position. Peco switch motors have very strong throws to overcome the latching spring built into Peco turnouts, which makes the impact stronger for our handlaid turnouts.
For this reason alone, most guys who hand-lay their turnouts tend to use something besides 2 coil switch motors. It's hard to watch your labor of love being violently assaulted by an electro-magnetic ram.
2) Most folks who hand-lay their turnouts want live frogs. This necessitates a contact on the switch motor or throw mechanism to change the polarity of the frog. Peco switch motors can have the contact added on at additional cost.
Tortoise switch motors have the contact built in. Since they are on continuously, latching of the points is also provided for.
Similarly, many manual throw arrangements use a toggle or slide switch in the mechanism to provide both the electrical contact for the frog and the mechanical latch for the points.
3) Finally, as you stated, Peco switch motors don't need to mechanically latch the points; the turnout spring does that for them. You will want some form of latch to hold the points in place once the turnout is thrown. It doesn't take much, just a little spring pressure is sufficient.
my thoughts, your choices
Fred W
George and Fred--Thanks to both of you for your responces. George-you may not have had the exact solution, but I'll use a couple of your comments to further my research. Fred-You have expanded on my concerns better than I could put them in words. I kinda know that I need to address the points that you made, especially para 3 RE;"latching". What I had in mind was to find or design a simple 'cam-over' device to latch the points and throw the electrical switch at the same time, using piano wire to provide some shock absorbing. Your comments about using a slide switch kinda sparked a thought--use the slide switch's latching action as well as the elec transfer to complete the changes at the turnout. Brings the question--is there a slide switch of sufficient quality to allow the peco motor to complete the throw and not cost more than a tortise? Keep in mind that I already own the pecos and I'm trying to use what I got without spending alot more money for less reliability.
As a side note, I was browsing Hobby Lobby's on line catalog and found that they have 20 ft control cables and tubes for RC airplanes @about $7.50. If any body is using this system for controls that seems like a heck of deal.
Thanks Steve
Steve,
Since you are doing research, I thought I would throw in a little info about switchmasters.
I use Switchmasters, and yes, they are expensive. Being the thrifty (some say cheap) modeler that I am, I bottom feed ebay for these. I have picked up used Switchmasters as low as $4.00 a piece. I'm sure that similar buys can be made on tortoises.
The motors and gearing in Switchmasters are made by a company called Hankscraft. The motor housing contains gearing to slow them down. Hankscraft sells many types of motors and gearing ratios. The main application is display animation (the beer bottle display that rotates etc). Switchmaster buys the correct ratio motors for turnouts and sells them together with the mounting hardware.
In addition to the other types mentioned already, Steve Hatch at Railway Engineering has a different design stall motor for sale. Check his website for details.
There are a couple of ways to install Switchmasters, the crank pin method (see photo) and the slot under the throw bar method, which is similar to the common Tortoise install. While I'm not crazy about the crank pin look between the ties, it is a very easy install (compared to measuring and cutting a slot) and can used in many awkward spots where the under layout geography is such that placing the machine directly under the turnout is not possible. Switchmasters are very smooth, last forever, are very quiet and do not slam the switch points like "crash and banger" solenoid style machines (Peco, Atlas, Kemtron etc). IMHO This makes them a better choice for delicate switches and hand laid turnouts,. Their use also eliminates the need for capacitor discharge systems.
Builders in Scale has picked up the Switchmaster line. Check the website for more info. In addition, they have a nice design for a bipolar powering scheme for these motors that is simple and very effective and allows for the powering of the frog and turnout from one DPDT with a minimum of hassle and no other contacts. It is a good powering scheme, I don't know why more people don't use it.
Typical motor install:
Switch powered by motor. Notice crankpin in center of points:
Same switch with ballast:
Guy
see stuff at: the Willoughby Line Site