Turnout mod blues... Considering the half friendly routegreenspun.com : LUSENET : Wiring for DCC : One Thread
I have modified several Walhers Code 83 and older Shinohara code 70 turnouts following you recipe and beside being concerned about turnout switch motor control (posted in turnout section) the whole operation is getting quite tedious and I am considering going for the half friendly option.
My layout is medium size and will never have more than two operators so shorts taking out the whole operation will not result in getting me kicked out of a club.
(This is where you all insert all kinds of encouragement. The local hobby shops have never heard of these mods and can't figure out why I would do such a thing to a perfectly good $18 turnout!)
So to my question, in your half friendly design the frog is simply cut out and power routed with microswitches on the turnout motor. I know I still run the risk of some realy nice sparks as a derailed truck drags through the turnout.
Since part of the reliability concerns addressed in the full mods is power feeds to the point and closure rails, why cut the frog on the closure rail side? Why not cut the frog only on the diverging side and power the whole frog, closure rails and points with externally switched power? That way one gets the advantage of both the point contact and the point hinge contacts and this will increase the odds getting good power to the points. It does not appear to me this method makes the potential short any worse unless I am missing something. When it happens it will be a good one!
-- Bill Geiger (firstname.lastname@example.org), April 30, 2003
No doubt about it, "if you won't get thrown out of a club" is a factor in considering what you do to a turnout.
May I suggest that instead of lamenting over the effort of making a turnout DCC friendly, why not use a DCC friendly one in the first place? It takes time to convert those turnouts! I agree! That's why I use DCC friendly ones that I can buy without modification. I only use those that require modification when there is a coniguration I need that isn't available DCC friendly.
A number of manufacturers are waking up to DCC friendliness. Many can be made DCC friendly just by snipping a few jumpers on the back side.
Assuming you have a reason to use a non-DCC friendly turnout, here is the answer to your last question. Yes, I think you are missing something. As you noted, when you see the sparks, you won't be missing something anymore! :) The problem (assuming I am reading your question correctly) is that you end up with a situation where the stock rail has a different polarity than the adjacent open point.
If you decide not to use a DCC friendly turnout, for whatever reason, don't worry about making the cuts on the frog rails. Doing so, won't buy you much. Instead, you could put insulated joiners at the end of the frog rails. For all practical purposes, that is just as good.
Whether you are in a big club or a just a couple of modelers, and especially if you opt not to go DCC friendly, I do highly recommend that you do something to isolate your turnouts. You could put electronic circuit breakers (the most expensive choice), you could put a switch in series with the feed to the turnout (the second most expesnive choice), my choice of the seemingly unloved 1156 bulb (getting pretty cheap now), or simply attach the turnout through a terminal strip (so cheap it's almost free). Maybe I'm just paranoid, but little matches the frustration of a short that you can't isolate. Following the frustration, you may eventually have to resort to cutting your main bus into little pieces. That's a real bummer! Does this happen every day? Thankfully not. But do this once, and you will wish you had at least done the terminal strip thing.
-- Allan Gartner (bigboy@WiringForDCC.com), May 06, 2003.