Help! Has anyone tried using the Rokuhan turntable on a DCC layout?

emaley Jun 2, 2015

  1. emaley

    emaley TrainBoard Supporter

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    I recently purchased the Rokuhan turntable and want to use it in a DCC layout. Having gotten a look at it now, I am stumped as to how to go about wiring it. Has anyone gone this route yet, or can you point to any resources that might help?

    Trey
     
  2. Garth-H

    Garth-H TrainBoard Supporter

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    Wiring this turntable for DCC is the same as wiring it for DC, including the observing the polarity of the feeds, I have asked Rokuhan to do a video of the turntable using Power cab, but so far nothing, I figure the biggest holdup on sales is is that only digitrax system was shown in original video using a special feature available on that system for controlling turnouts to control turntable rotation and no wiring setup.

    Rokuhan designed the turntable wiring with their pug and play wiring system in mind, so the Rokuhan turntable controller is placed between the train controller/power pack "track output" and the layout track whether on a DC or a DCC system, to power the turntable controller it must be snapped onto a Rokuhan train controller or a separate wall transformer, for power to operate and rotate the turntable excluding track power.

    So on your dcc system you need to connect "track power output" from your dcc system, OR power district to "track power in" on Rokuhan turntable controller, and "track power out" on your Rokuhan turntable controller goes to DCC track power district track input, on your layout, you need an insulator in your turntable entrance track between the turnout and the turntable. When setting up your wiring you want to keep your polarity on your DCC connections mimicking those shown on the DC wiring, if you do so then the instructions for handling reverse polarity will work, but I imagine a frog juicer could be used between power district and track input to Rokuhan turntable controller, the direction switch on Rokuhan controller works on DC as well as DCC as I use it as I have no installed a frog juicer. All tracks connected to pit receive power from pit track once aligned, and no power when they are not aligned. So any track going from layout power district to turntable, must have an insulator installed at pit edge or at another location between pit edge and the turnout leading to the power district. To cross this insulator you must have matched polarity to enter turntable pit bridge. Once your engine is on the bridge, direction control on your throttle is all you need to control your engine provided you have not installed additional or optional track feeds inside your round house on each track connect to the pit.

    I wrote an article for N scale magazine but it has not been published because the editor wanted to see a video showing turntable controlled by at least one other DCC system other than digitrax and I could not do that as the sample I have didn't have the final version of the eprom in the controller that works with DCC systems other than digitrax. The controls on the Rokuhan Controller work in parallel with the DCC system, so while I can not rotate bridge with my power cab everything else woks with DCC just fine. So if you need more information ask Rokuhan, they seem quite willing to respond to queries from users. Their web site has a contact page and they usually respond with a day or two.

    regards Garth
     
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  3. emaley

    emaley TrainBoard Supporter

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    Thanks Garth. I played with the meter today and came to the conclusion that you stated. I also emailed Rokuhan and will see what they had to say. I thought I was just over thinking things and that appears to have been correct. As usual, I have enough knowledge to be dangerous. It appears it will be much easier than I was thinking. The Rokuhan documentation states that the turntable has a fixed address of 200, so I should be able to control it through the Powercab. Thanks again for the clarification.

    Trey
     
  4. Garth-H

    Garth-H TrainBoard Supporter

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    Trey

    I believe the production Eprom brings up a choice of direction to move left or right, but I do not know if it allows you do multiple position moves or not or not, my pre-production unit has the address but does not provide any choice on that address so no action, I have to use buttons on controller to rotate my turntable. I would be interested in knowing just how they have programmed the Eprom once you get it going.
     
  5. RobertAllbritton

    RobertAllbritton TrainBoard Member

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    Guys,

    I just got done installing a Rokuhan turntable on our new DCC yard. I'm using a Digitrax system. Here is what I discovered the hard way:

    1) The turntable is sensitive to the polarity of the DCC track feed. I have no earthly idea why, but it is. I tried connecting just two things: DCC track power to the Track Power in socket on the turntable controler, and 12V DC power via the side plugs (rokuhan's use of 9v battery terminal connectors on the side of the turntable control box) There were NO other connections to the turntable (no track connections at all) For some reason, if the turntable controller did not like the polarity of the DCC track connection, it would re-boot when I tried to operate the turntable. Reverse the wires, and it worked fine.

    2) The turntable does respond to DCC commands right out of the box! It will detect switch commands sent to switch address 200. Issue a "Closed" command and it will rotate the turn table one way. Issue a "Thrown" command and it will turn it the other way. Issue three switch commands in a row, and it will rotate 3 tracks.

    Hope this helps!
     
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  6. rray

    rray Staff Member

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    Any updates on this turntable ran with with DCC? I ordered one yesterday, and plan on using my NCE DCC system to operate it, as well as using the panel.

    Specifically, I want to know if there are any programmed in tricks other than Opened (1 or L) and Closed (2 or R) to index left or right, features like press 3 and the turntable rotates 180 degrees to turn your loco around, or 01 to index position 01 or any other possible tricks .

    Also, since these turntables have been out a few years, are there any other tricks or tips to be made aware of?

    Thanks in advance,
    -Robert
     
  7. husafreak

    husafreak TrainBoard Member

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    Robert I had no trouble communicating directly with Rokuhan support via email. It wasn’t about turntables and they may not have experience with the NCE system but it’s worth a try.
     
  8. rray

    rray Staff Member

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    Well I sent Rokuhan my questions, we will see what the reply is. So, my turntable arrived from Japan yesterday. Plaza Japan shipped it FAST, ordering on Monday and receiving it on Saturday of the same week!

    I discovered it has no wallwart power supply, and it's not marked on the box or controller, nor in the instructions as to what it takes. No voltage and current info on the Rokuhan site either, but they did have a 12v 1.5A wallwart that is listed as discontinued for powering up their DC throttles and those snap together onto the turntable controller with what looks like 9v battery terminals. So it's possible that the 12V gets reduced before going to those 9v battery terminals, so I need to find someone who has a Rokuhan throttle that can measure those battery terminal connectors for the voltage level, or hope Rokunhan replies soon.

    There is also no instructions on connecting any DCC systems to the turntable, so I have to take it from Garth's post that I need a DCC auto reverser installed across insulated approach tracks. And I have a 50/50 chance of connecting the DCC track wires correctly or the TT Control unit will go into reset mode.

    Meanwhile I scowered the web for info on the Rokuhan turntable, and there are only a couple videos. One shows a user with a Digitrax Zephyr using the turnout throw buttons set to address 200 to index the turntable. A video of Rokuhan's own DCC system shows an Android tablet with a 24 position circle on it pressing a button and the turntable indexes multiple positions with 1 button press, SO, somewhere there is embedded code to operate it from BT or the audio out cable on a smartphone in a higher level than just emulating a turnout control signal for index left and index right. That tells me that it could be made to operate higher functions with JMRI, pressing a single button to move to a specific track, and pressing a 180 degree button to turn your locos around.

    So I went to JMRI, and they have no Rokuhan DCC support. Probably not a single Rokuhan DCC user in the world uses JMRI. It's above my skillset to write any JMRI code, but maybe someday. I'll wait.

    I suspect very very few people have these turntables, even though they have been out for 5 years, because there is only 1 video posted of a guys jewelry box layout with this turntable, absolutely NO teardown videos, and maybe 3 forum mentions of this turntable on the entire web!

    So, what do I think so far? It's ugly, but not for long as I DO intend on fixing that, converting mine into a replica of the Lester WA turntable. I'm afraid to take mine apart until I have actually powered it up and verified it operates properly, cause a bad from stock item can't be exchanged after I have at it. So first order of business is finding out what voltage window it can operate from. My guess is anything from 9V to 15V, as that is typical. I guess I can open the controller and look for the voltage regulator they used. Yep, that's what I will do. :D
     
  9. markm

    markm TrainBoard Supporter

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  10. husafreak

    husafreak TrainBoard Member

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    Yes Rokuhan is a little secretive in divulging their specifications. I think because they want us to use their complete system.
    Like you I was frustrated in my search about another product of theirs, their DCC controller, almost no information is available about that product. In the end I decided to just use DC.
    So, my Rokuhan RC-03 controller says INPUT DC 10V on the case but the Rokuhan wall wart supplied for it says 12V and measures 12V. The controller can pass this along to switches via direct connection or cable. Also the switches can be powered by the wall watt directly. I found that the switches are only completely reliable when powered by the 12V wall supply, using batteries the switches are less reliable and Get worse as battery health declines. So I think the switches are really designed for 12V. The controller has an output labeled ACCESSORY which can be used for lights etc, and I imagine for the turntable you got. It is a white plastic receptacle with a polarity plug using a circle and square shape plug. There may be something to this as the outputs on the RC-03 are different colors and shapes. This one passes 12V from the wall wart. The track power is obviously a smart circuit as it measures different voltages if it senses a loco, I don’t think it can be measured correctly with a voltmeter. But the switch and accessory outputs are probably not. I imagine they just pass the 12V from the wall wart.
     
  11. husafreak

    husafreak TrainBoard Member

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    Also the Rokuhan wall wart is 1.0A and center positive, 5.5mm if I remember correctly as it is easy to plug a Medvend supplied wall wart into a Rokuhan and destroy it. The snail speed controller is opposite plug polarity to the Rokuhan.
     
  12. rray

    rray Staff Member

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    Thanks. Yes I had read all their pdf's before posting here. Their lacking the basic pertinent info, and leave you to believe you need to use their DC and DCC systems together to make it all work.

    So, as far as their lack of power reversing, I can wire in an optical detector on one end of the bridge, to automatically filp their track polarity button on their TT controller in case of a 180 degree turnaround to solve that issue. I can't believe they did not think of auto reversing the track power when their bridge goes 180 degrees. They should have put in optical sensors that flip the track polarity between tracks 1 and 24 and beween 12 and 13. Even the $25 peco N Scale turntable has that functionality built in with their split wiper TT bridge pickup. They got lots of pretty lights though. :D
     
  13. rray

    rray Staff Member

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    I went ahead and connected my turntable to a 12v 1A power supply I had, with a 5.5mm/2.5mm positive tip barrel connector. I turned on the switch and nothing happened. I switched it off then unplugged it then re-plugged it in , and turned on the switch again, and this time the leds lit in circular pattern.

    I noticed that the operation was intermittant, requiring me to unplug the barrel connector and re-connect it to get the unit to power up again. But when powered up, everything operated fine, it indexes and otherwise operates pretty good. Alignment is not perfect on a 180 degree rotation, even after nudge tuning the position, but I think trains will navigate OK.

    So, It's time to take it apart. I took off the handrails, the bridge, the operators cabin, then used my mini table saw to cut off the operators cabin deck and the tabs that hold the arch. Now I can modify the bridge to look like the Armstrong type I will be modeling.

    There are 6 concentric wiper rings under the bridge. 4 are used for the stepper motor, and 2 (the orange wire and adjacent blue wire) are used for the bridge track contacts. If they would have gapped those 2 rings at 180 degree apart points, they could have cross wired the trace rings for auto polarity change per 180 degree rotation, saving the cost of the track polarity switch on the controller. Peco does this on their turntable. Simple, elegant, and functional.
    [​IMG]

    All the moving parts are on one side of the underside of the bridge, opposite the operators cabin. It's a simple enough, yet acceptable looking mechanism, but from what I see, should be priced closer to the $99 dollar mark instead of the $399 mark for what you get. There's definetly some greed going on in the pricing of this unit, because it's nowhere near as well constructed as a Marklin turntable. Still, it is what it is. At least it's a modern digital controlled turntable.
    [​IMG]

    The bridge has contacts that wipe under the approach track rails to power them with bridge power, so you don't have to wire them seperate. If you use DCC, do not wire track feeders to your approach tracks or roundhouse tracks, because as the bridge moves, these wipers will alternately short your DCC for each wired approach track per revolution. 5 amp arc's will disentegrate the bridge contacts in short order.
    [​IMG]

    As I mentioned above, I noticed I had to unplug and replug in the power to get the unit to power up each time. Something is not right so I decided to take a quick look inside the controller. Yikes! Much to my horror, it was another case of shoddy electronics workmanship. Rokuhan need to audit that vendor, showing up unannounced at midnight to see what's going on at that factory!
    [​IMG]

    Close examination shows what looks like a rookie used an Aero Duplex Acetylene Soldering Torch to rework a board in which all the leds were installed backwards, and blew several support components while testing.
    [​IMG]


    Flux is everywhere, as were tiny solder balls spattered all over. The power switch is both mounted to the frontside of the case, as well as the board soldered onto the switch terminals, so you cannot remove the board even after taking the screws out, unless you unsolder the power switch which has gobbs and gobbs on it.
    [​IMG]

    Also, the contact wires fell off upon opening the case, because they stripped 6 of the 7 copper strands and had 1 strand left to solder. Some careless inattentive teenager from some mainland sweatshop, forced to work 80 hours a week after school, obliviously assembled my controller. OK, to be fair I rant, but come on, this is unacceptable folks, at least spray the board with flux remover to remove all the glued on solder ball spatter and clean up the appearance of the board, and get a proper wire stripper instead of using your teeth or linesman pliers. And the power switch? Come on.
    [​IMG]

    I put it all together, and it still works intermittantly, maybe I need to use a different power supply than the 12v 1A.
     
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  14. JoshMurrah

    JoshMurrah TrainBoard Member

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    Garth, thanks for your writeup on this, and for the rest of the crew adding details.

    It would seem for worry-free DCC operation when entering the roundtable block, the turntable apparatus should behind a DCC auto-reverser, would that be right?
     
  15. rray

    rray Staff Member

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    Yes, after looking at the mechanism, and electronics, an autoreverser would be required on the lead track, probably just over a loco's length before the turntable so the short that triggers the autoreverse operation happens before the turntable pit.
     
  16. bostonjim

    bostonjim TrainBoard Member

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    YIKES!!! I won't be getting on of those. Jim
     
  17. rray

    rray Staff Member

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    If you do get one, buy it from an easy to return it seller. I bought mine from Plaza Japan to save $150, so it would be harder to return if it didn't work.
     
  18. bostonjim

    bostonjim TrainBoard Member

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    Thanks, Robert. It really doesn't fit into my scheme of things. I do appreciate the useful information. It makes decision making much easier. You really know your stuff. My hat is off to you. Thanks for sharing it with us. Jim
     

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