turntable wireing

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W

Woodstock

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Hello to every one in train land. I'am just getting back into HO so please don't make fun at the equipment I purchased to start with.:rolleyes: I have a walthers 90 foot turntable:mad: yep I know all about them….:confused: A little of this and some of that and I got it working. Now, I have a Bachmann E-Z command DCC control system.I control the Table with a separate power pack. Can someone show me how to wire the tracks and not create a short?????? :cool:
 


thank you MikeOwnby. I will look into getting the relay,will any type of reversing relay work? do you recommend any? I have the turntable working and are careful not to turn the engine to far. But, as the engine turns the sound drops out and back on every inch or so. the walthers 90 ft. has two metal straps that rides on the metal parts that hold the track wiring is this were the problem is. The voltage should be constant should it not?:cool:
 
I would think the voltage should be constant, but I honestly don't have any first-hand knowledge of any turntable other than the Kato. You might check that the contact strips and the turntable contacts themselves are clean, is about the only thing I can think of unless it is somehow making contact briefly with some of the rails and shorting out, but not enough to actually shut down the DCC command station. If you don't have a wire drop close to the turntable that's a very real possibility. Tracks can short out if far enough from a drop and not necessarily cause a shutdown. The inherent resistance in the nickel-silver rails after a certain distance act more like a large resistor instead of a dead short. That's one reason people recommend frequent power drops, to prevent that and the meltdowns that can happen because of it. You might try deliberately shorting the rails right next to or on the turntable and see if it does that same thing or if it does shut down your command station. Maybe someone else here knows more about the specific workings of this turntable and can give more specific info on it, but if that's somehow happening it would explain the momentary drop-out and return. If it is shorting out as it turns, then obviously the auto-reverse module will fix that. If it's something else then it won't. Obviously ;)

As for the reversing controller, basically any one should work. I've used the Digitrax AR-1 simply because I use mostly Digitrax. I currently have AR-1 units installed on four reversing loops and my turntable. It's been very hassle-free and I haven't even had to adjust its sensitivity on all but one of my reversing loops. That one is a very short section and has very little rail to offer any resistance, which is probably why I had to adjust the sensitivity down a bit, but it's a simple thing to do with the adjustment screw that's on the module. It's also very easy to hook up; two wires to the DCC power and two wires out to the reversing section. I think it's one of the less expensive units you can get, so there's that plus also. I've honestly never heard anyone complain of having issues with a reversing module for DCC, though, so I have a feeling whatever you pick (or whatever is available locally if that's a consideration) will work just fine. I'd look more at how simple it is to hook up and adjust than any other criteria.

Edit: I don't actually know anything about or have ever used Bachmann EZ command DCC. I'm making an assumption that you can hook up an auto-reverse to that system the same as any other, but you might want to ask Google about it and make sure.
 
Last edited by a moderator:
Hi,

Can you check if it is a recent Walthers 90' turntable with DCC build in (https://www.walthers.com/exec/productinfo/933-2849) , if it is then the wiring is a snap all you need is to connect the feeds from your DCC bus to the clearly marked input connections on the turntable. Reversing control is build in so no need to do anything; no separate wiring of tracks is required as loco enters or exits turntable build in reverse circuit adjusts the polarity. The only care must be that the sensor eye not be obstructed. I have one of these and a 130' and they work without any issues. Very easy to connect them.

Regards,

Vik.
 
Woodstock said:
I have a walthers 90 foot turntable:.... Can someone show me how to wire the tracks and not create a short?
Click to expand...
There are at least two different versions of that product. Do you know if you have an older ones or one of the newer ones? 933-1050 or 933-2849 or ??

In general for a turntable that gets power from a ring and the bridge, one would simply hook an automatic reversing unit as input to the tables track power.
 
If you built that turntable yourself, you know it has two copper wipers against two metal rings separated by a bit of styrene. They are constant, so when the turntable turns 180 degrees, its rails will be out of phase from the opposite side when metal tires try to bridge across the gaps. You must either wire in a reverser IN SERIES, or wire in a DPDT IN SERIES. Either way, they get wired into the turntable's feed wires, the ones rising to the bridge rails.

Most turntables us a split ring design below the pit. Those rings are always fed by the same wires, so they don't change. However, their are wipers running against them that feed the bridge rails. As the bridge passes over the split, the wipers change over to the rings that have the 'other' polarity or phase (depending on DC or DCC, respectively). That effects the reversal you need, so you need no reversers or switches. Not in this 90er's case, unless they have redesigned it completely.
 
Selector said:
If you built that turntable yourself, you know it has two copper wipers against two metal rings separated by a bit of styrene. They are constant, so when the turntable turns 180 degrees, its rails will be out of phase from the opposite side when metal tires try to bridge across the gaps. You must either wire in a reverser IN SERIES, or wire in a DPDT IN SERIES. Either way, they get wired into the turntable's feed wires, the ones rising to the bridge rails.

Most turntables us a split ring design below the pit. Those rings are always fed by the same wires, so they don't change. However, their are wipers running against them that feed the bridge rails. As the bridge passes over the split, the wipers change over to the rings that have the 'other' polarity or phase (depending on DC or DCC, respectively). That effects the reversal you need, so you need no reversers or switches. Not in this 90er's case, unless they have redesigned it completely.
Click to expand...

Hi,

this is from the Walthers instructions for Model: 933-2849

"INSTALLING THE PIT
Your new turntable automatically reverses track
polarity when turned. As a result, the unit has two
electrically insulated areas where the track on the
bridge is not powered."

Thus no reverse module is required for this model.

Thanks,

Vik.
 
We haven't heard back on exactly which model this is, but I have a feeling he's got the older model, guys. If it were the new one that's DCC-ready and auto reverses itself, it wouldn't be shorting out simply by turning the turntable too far in either direction, right? The current instructions for the newest model aren't going to apply. The only other explanation would be having the opposing tracks wired backward to the track they're facing. That's a possibility, but I'd think if one were dealing with a short the first thing they would obviously check would be to make sure the wire drops on the feeder tracks weren't crossed up.
 


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