Ivory Posted December 22, 2018 Share Posted December 22, 2018 Hi guys, I’ve just fitted the Hornby 070 turntable with the excellent information supplied by this forum regarding dcc conversion.At the moment I have one direct feed from my main track to the turntable, and four outlets to an engine shed. What I would like to do is have two direct feeds from the main track, so that locos can arrive and leave the turntable from two positions. My question is... will I need to install an automatic reversing module. Many thanks for any you can offer Ray Link to comment Share on other sites More sharing options...
Rog RJ Posted December 22, 2018 Share Posted December 22, 2018 No, you shouldn't need a reversing unit but it depends on exactly how you've converted it for DCC. Link to comment Share on other sites More sharing options...
2e0dtoeric Posted December 22, 2018 Share Posted December 22, 2018 We would need to see a photo or a drawing of your layout, showing where your track feed from the controller is, before we can properly answer that!And welcome to the forum. Link to comment Share on other sites More sharing options...
Ivory Posted December 22, 2018 Author Share Posted December 22, 2018 No, you shouldn't need a reversing unit but it depends on exactly how you've converted it for DCC.I used the info provided by Ray and PJ with the added extra photos.. which showed the top and bottom of the turntable in great detail.the reason I mentioned the reversing module was because the two paths from the main line ; which happens to be a tail chaser, to the turntable are different. .. the one leaves the “ circle “ at 9 o’clock and runs down to the turntable joining it at 12 o’clock.....the other leaves the “ circle “ at 6 o’clock and runs down to the turntable joining it at 3 o’clock.... which I suppose turns it into a “wye “ junction .... this was why I thought I would need the reversing unit ...hope that’s clearer .... Ray Link to comment Share on other sites More sharing options...
Chrissaf Posted December 22, 2018 Share Posted December 22, 2018 Wire it up, if you then get a short...fit a RLM.....simples. Link to comment Share on other sites More sharing options...
Fishmanoz Posted December 23, 2018 Share Posted December 23, 2018 You haven’t provided quite enough information Ivory but I’ll make an assumption; the one connection to the TT runs clockwise from the layout to the TT; and the other runs anti-clockwise. If this is the case, then you are right it is effectively a Wye reversing loop. However, given a TT is in the middle of all of this, it can only cause a short if there is continuity between each of the inputs through the TT. I can’t remember the Ray/PJ method of DCC conversion so don’t know if this will be the case or not, but if the method isolates the bridge then powers it from the DCC supply, then one of the inputs must be out of phase with it and a short will occur when a loco crosses, meaning an RLM will be needed in the bridge supply. But - if the 2 inputs go to opposite sides of the slip-ring, it will compensate for the out of phase meaning no RLM is needed. So, like I said, more info needed to be definitive - my 3 ifs need to be defined. Trust that is understandable and helps. With luck, Chris will draw that up with blue and red tracks as the proof of the pudding. Link to comment Share on other sites More sharing options...
St1ngr4y Posted December 23, 2018 Share Posted December 23, 2018 Hello Ray,Welcome to the Forum. The guys who have already answered are correct in saying that it depends on the exact configuration of the points which join to the main line. In Fig. 1 in the diagram below, there is one facing point and one trailing point on the main line, and if these sidings were then connected to a third point, then you end up with a classic Wye configuration which would require a RLM to resolve the polarity conflict at positions E & F. However, the R070 turntable has a feature which allows us to overcome this conflict. In Fig. 2 I have shown a turntable in place of the third point. On the turntable, there is a bridge position (marked with white lines on the picture) at which the polarity of the bridge rails is flipped as the bridge passes through this point. This means that the inlet tracks to the left of this position have polarities which are suitable for connection to track "E" and those to the right of this position have polarities which are suitable for connection to track "F"........ /media/tinymce_upload/a73d31aa06c1ac5441e5b83e84d2f54a.png I have placed blue and red dots at each inlet track rail to show the polarity at those positions. I hope this helps Ray Link to comment Share on other sites More sharing options...
Ivory Posted December 23, 2018 Author Share Posted December 23, 2018 Thanks guys for your welcome, and for the information. It was spot on and has saved me much heartache... when you see it in black and white in sketch form it drops into place ... again my thanks ..Merry Christmas .. Ray Link to comment Share on other sites More sharing options...
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