Rokuhan RC03 controller help wanted

[SwitchOnSwitchOff]

Hello All,

 

I bought a brand new Rokuhan RC03 controller to use with my Bandai B Trains and Kato Pocket Line layout. It seems defective and I should mention that I cannot return it. It is a long story, but I have no recourse in that direction.

 

The controller seems to output wildly variable power in the first 1/4 of the dial. In this first quarter, it is almost random if a train will speed up or slow down, regardless of whether the dial is increased or decreased. You can imagine that this turns a smooth departure into a convulsive, pandemonium of an affair. I can also explain it by saying that if this was a real train, the passengers would not be lodging complaints, because they would be dead.

 

It should be noted that this is at its most violent with two brand new Kato 11-105s. The Kato 11-109 steeplecab still exhibits the behaviour, but is much better able to handle the inconsistency. Similar with two Rokuhan Shorties, although the jerkiness is also still present here.

 

Have only run it with batteries and have tried brand new Eneloop Pro fully charged and a set of brand new alkalines. No difference. I am not interested in buying or running it with an adaptor as it should work with batteries and I bought it particularly to run from batteries.

 

As I cannot return it and I have paid $110 for it (with postage), I would welcome with open arms any suggestions on how to repair the unit. I am not afraid of opening it up and poking about, but I would need to know what to look for and what to try.

Edited February 9, 2022 by SwitchOnSwitchOff

[cteno4]

Switch,

 

could you take a video of this? Would be really helpful. Do you have any other regular plug in controllers or a power supply to test the track, train and connection to prove it’s the rc03 that is going wonkie. Might also help if you need to return it to plaza.

 

jeff 

[SwitchOnSwitchOff]

Hi Jeff and thank you for your suggestion. It is a little cumbersome right now to upload the video (I do have one), but meanwhile I was spurred on to do some further testing and I have solved the issue. I am pretty sure it's a temporary solution, but it confirms my theory.

 

What I noticed was that the random burst of speed were not random. They occurred at very specific points on the dial. This indicated to me that dial connection inside did not have a smooth connection throughout the range. I also noticed that the knob was very lightly attached and quite wobbly. 

 

As a test, I pushed down firmly on the dial and gave it 8-10 good grinds back and forth.

 

Lo and behold, all trains now start and stop smoothly, accelerate smoothly throughout the range and the insane engine noise from the Kato 11-105s is at least stably annoying instead of sounding like an angry chihuahua barking.

 

If the problem was caused by a poor connection as I suspect, this fix is likely temporary and the problem will resurface sooner or later. At least now I know where to look if I decide to open it up and attempt a permanent fix.

 

Thanks again!

 

Update: Fix didn't last long. After about 30 minutes it is slowly regressing back to its former behaviour. Dispute lodged with bank.

Edited February 10, 2022 by SwitchOnSwitchOff
Update

[cteno4]

Good, actually I was going to mention it might be a bad variable resistor once connections were ruled out (didn’t want to jump to the bad thing first). The variable resistor (pot) has a little arm that wipes along a circular contact. Sounds like it’s almost making a shorting contact at times to not get the resistance it should and thus speeds up. Only way to fix it is to replace the pot really, kind of thing the turn it back and forth will work for long in this case, but at this point it’s kind of the only thing to do. But does look like a defective unit. You sadly really got a lemon pile here, that’s pretty rare for Japanese equipment and plaza. Hopefully they will make this right for you.

 

jeff

[SwitchOnSwitchOff]

Tell me about it! Bad set of tracks, replacement power chassis with loose bogie and a defective RC03. All Rokuhan actually. I know they are usually known for their reliability and high quality and I'm sure that has mostly been the case, but this doesn't really give me a positive idea of their current QC. 

 

Thanks a lot for putting the technical terms on what I was describing. Very helpful! That seems to be exactly what is happening. Last night after it started going bad again, I had one test where the jolt from one of the problem spots on the dial caused the train to actually wheel spin with a dramatic whine. This spot is right before the point where power is cut, so you can imagine how un-train-like that particular stop was.

 

Unfortunately the RC03 wasn't from Plaza but from an independent seller who will not reply. The good news is that I've just had confirmation from the bank that they will reverse the charge.

 

I might go with a Tomix N600 controller as replacement. All the stuff I've bought from them has been quality in both feel and function and I think I can power it with the 12v battery pack I bought. I'd go for the Kato SX due to having CL, but it requires 13.6v input so I'm not sure the battery pack will drive it.

 

RC03 was just really practical in combining throttle, CL, two turnout switches and lighting output for buildings in one compact battery unit. Going with any other brand will significantly increase the space taken.

 

Anyway, I'll stop rambling here, thanks again for all the info. Highly appreciated.

Edited February 11, 2022 by SwitchOnSwitchOff

[cteno4]

Yeah that does sound like it’s shorting out. Usually they do the opposite and part of the wiper or the pad goes totally dead in some places.

 

sorry for the bad luck. Might look at hobby search, model train plus, and rg Rokko for suppliers. Super reputable and easy to deal with.

 

jeff