I’m trying to get my Walthers turntable (933-3171) to function properly. So far, I’ve been able to get it to work using the Walthers motor and an old Tech II powerpack (18V). But of course, that isn’t an option as it spins the bridge a bit too fast. I’ve tried hooking up a Radio Shack 12V CT 450mA transformer, but all I recieve is a buzzing sound with no bridge movement. Can anyone offer any advice on hooking this up for me?
Also, I have a few other questions related to the turntable. I was planning on using a DPDT toggle switch, and wiring like a “reverse loop” scenario to power the bridge movement. My thinking was using the On-Off-On toggle switch, I could use the “On” functions based on which way to rotate the bridge/turntable. Will this work? Another idea of mine was to use a DPDT toggle switch for changing the polarity on the bridge track as needed. I figure the only time I’ll need to flip this switch, is when I turn my loco around 180 degrees, and exit the bridge back on to the approach track. Is this a common approach? I would rather not have to invest in a automatic reverse loop module if I don’t have to.
I used the track (DC) outputs from an old Tyco power pak to power mine. I even added a resister because the lowest speed setting was still too fast. What type of output does that transformer have? (it only says 120v input)
The DPDT switches will work like your planning. I’m using a momentary/off/momentary to control bridge movement. I’m using a DPST ON/ON for my track polarity.
If you have the motor leads attached to the correct terminals (variable DC…not AC!), your motor should be able to turn the bridge at a clock’s pace. Eighteen volts is too high, as you have learned. Try variable DC from the appropriate terminals on a DC power pack.
Most of us resort to a DPDT properly wired to correct the polarity of the bridge rails. You are correct, the only time you would flip the DPDT to change the polarity to the bridge rails would be when you swap ends to get the engine off the bridge at either end. This assumes the bay tracks or radials are all wired the same way as the lead(s) to the turntable.
The transformer I’m using, only has 2-wires for connecting to the turntable, and 2-wires for connecting to the power source (plug). Are there specific power packs/transformers out there I could use for this? I guess I’m not sure where to find one, and it seems the one I bought from Radio Shack is not working for me.
Interesting hookup. How do you add a resister to the power pack?..what connections do you make. I’m not the most knowledgable when it comes to electrical.
Steve, I had the same kit and motor (pretty sure) three years ago. I had an MRC DC power pack that had two pairs of posts clearly marked. One was for DC, the other pair for AC (switch motors and such). The DC pair are regulated by the rotary knob on DC power packs. The voltage can therefore be next to zero and up to the max permitted by design. The motor with the turntable is a DC motor that will speed up and slow as you rotate the knob controlling DC voltage, which would also be the way to get DC engines to speed up and slow to a stop.
The way it worked for me was that my tracks were controlled by a DCC system since my engines all have decoders. The unused MRC power pack came in handy to control solely the bridge motor on the turntable. If you are using strictly DC, and only the one power pack, then you will have to use more another switch to prevent other engines on the layout from moving as you increase voltage to get the bridge to rotate. You cut power to the layout, move the bridge, cut power to it with another switch, and then apply power to the engine waiting to move. This is why I went DCC…just the one DC power pack and only then to control the bridge motor. DCC engines would stay put until I directed them to do something via the hand-held throttle.
I just soldered the resistor inline between one leg of the power pak (track DC) and the turn table motor. Either leg will work. I think I used something like a 500ohm resistor.
Is your bridge a little jerky when it rotates? I had a hard time getting mine to spin smoothly.
I got it to work. I used my MRC Power Pack and hooked the wires up to Variable DC…set the speed at about 25-30, and tada!..I have a spinning bridge at a realistic speed…much quieter also. I then hooked it up to my DPDT toggle switch and it’s working fine with that also. This works out fine for me, as my main control system is DCC (Bachmann Dymanis). I’ll just rig up a platform/bracket to put in my benchwork for mounting the MRC Power Pack.