Converting Richard Orr Brass Turnouts to DCC Friendlygreenspun.com : LUSENET : Wiring for DCC : One Thread
I am currently laying street track for HO trams and need help with the Richard Orr HO brass cast turnouts. These are the only turnouts I have found that look prototypical. The turnouts are intended to be used as common rail in conjunction with overhead cantenary wire. However, I am not going to power the cantenary but, instead will run DCC power through both rails....Some of the modifications to the ORR Turnouts seem basic but, others such as should I change the solid brass frog, are not. Should the cast brass frog be isolated with plastic spacers? Should the entire frog be changed to plastic similar to PECO's Insulfrog? Since the turnout throw bar slides on a piece of brass shim, should this be changed to a non-conductive plate? Any help would be appreciated.
The turnouts will be powered by either PECO PL-10 or Tortoise Motors and controlled by the Digitrax DS54 units.
-- Tony Britsky (email@example.com), August 11, 2003
I am not familar with Richard's turnouts. I did a quick check for a website, but didn't spot one. If you have a site, please post the URL.
I have not studied traction much, but the turnouts and track I have seen had both rails solidly soldered together. Make sure your track does not have the rails soldered together.
In general, your turnout should end up looking like something in 2-17 of my turnouts section http://www.WiringForDCC.com/switches.htm Whether you are making a DCC friendly turnout or not, at no time should the two rails be electrically connected to each other.
If you have a slider for the points that is brass, yes, you will need to do something. What that is may not be a big deal. Maybe you just need to cut the slider down the middle and then glue a piece of plastic underneath to hold the pieces together.
Your frog probably isn't hard to do, either. Yes, you will need to isolate the frog. You would have to do that anyway to power your traction from both rails. Just make it look like the first drawing in 2-17 and then power the frog from your switch machine. Since you are doing traction, I definitely suggest that you do not go with any kind of insulated frog. A little four wheeled trolley has a high probability of stalling on such a frog.
Do you need to replace the frog? I don't know what these turnouts look like, but I don't think you will need to. Cut the frog from the four rails going to it. Then glue a piece of plastic under the frog and the four rails. Glue it well. I suggest clear epoxy. Make sure everything is in proper alignment and gauge before gluing. I'm hoping what I am suggesting is simple. Given traction trackwork is hidden under a street, you can use big pieces of plastic that would not be acceptable to the typical modeler.
Don't forget the hinge for the points. On some turnouts, these are electrically tied together. Yours probably are. They will need to be separated in some way. You may be able to do the same thing as with the slider.
-- Allan Gartner (bigboy@WiringForDCC.com), August 11, 2003.
From the photo, I would suggest instead of cutting the four rails attached to the frog, only cut the two coming from the point rails. The rails leaving the frog are very short. So instead of cutting them, I would just put insulators at the end of the existing frog rails. There is no sense in making this any harder than it needs to be.
I am concerned about good electrical continuity to your one movable point. Normally, I would suggest that you attach a wire to it one way or another. Sooner or later, the pivot may make poor contact.
From the photo, the point appears to be sitting in a pocket. That prevents you from attaching a wire to it. With any luck, the pocket will provide longer term than usual contact.
I don't have any good suggestions as to how to ensure good, long term, electrical contact. Ideally, a conductive grease or gel that you could get under the point is what you need. A grease or gel will will prevent air from getting to the underside of the point and oxidizing it.
Rail-Zip isn't a gel, but it claims to retard oxidation. You will need to reapply it every two months.
A LITTLE anti-oxidant gel will retard oxidation. You can buy it at an electrical supply store, or use the gel you put on car battery terminals. Just make sure you put on only a very tiny amount and a thin layer in there. Too much and the thickness of this gel will interfere with the movement of the point.
If anyone has better ideas, chime in!
-- Allan Gartner (bigboy@WiringForDCC.com), August 13, 2003.