Question Rokuhan RC02 struggles with new MTL GP35

So I picked up a new GP35 and also a Rokuhan RC02 controller/track lot.

I previously purchased at a local train show an older gentlemans entire z collection including layout for $60, which included 9 rolling stock, 2 steamer locos and a dummy loco with parts that only needs brushes to make it run. Controller and few other bits.

Said GP runs really nice with the older blue Marklin controller on the old Marklin track layout. Can run really slow and take off easily.

Said GP requires me to turn the speed control to nearly 60-70% to being to move with the RC-02 controller on rokuhan track. It will not run very slow at all.

My lil Marklin steamer takes off at about 40% of the dial and can go a bit slower on the Rokuhan track with RC02.

Can anyone give me any guidance as to why the GP is running as it does on the Rokuhan track with the Rokuhan RC02? I am only running battery power(do not have a wall wart)

I'm stumped, and mildly bummed because I picked up a rather large lot of Rokuhan track and the RC02 at a great price and want to make a 2nd layout with it. Want to be able to run some turn outs and I like the size/looks of the RC02 with the turn out switch adapter, but I need to figure out how to get better performance out of it with my locos.

Thanks in advance for any guidance.

 

I'd get a snail speed controller for slower speeds. It's been my experience over the years different locomotives react differently to the different controllers like the markln controller and the MT controller. I was never satisfied with either of those. The jorger delux is what kept me in Z scale because it made running slow speed possible. Since they are hard to get I have a few snail speed controller as well and I think they are the next best. For about 35 dollars it is worth the investment, you wont dissapointed.

 

Welcome to the group. I'm sorry it isn't under better circumstances for you. This could be a bit complicated, so stop me if it starts to get away from me. If you have a good meter capable of measuring voltage and current in the milliamp range, it would help.

First of all, because your Marklin steamer is working on the Rokuhan configuration, I'm not very suspicious of it. My first suggestion would be to get a second Rokuhan feed cable and cut it in half. This would allow you to run the Marklin controller with the Rokuhan track and the RC02 with the Marklin track. Handy to have even when you don't have problems.

The GP35 is actually a somewhat old loco that hasn't been in production for about a half dozen years. They can be great runners, but they can also be a problem child. Most of the time the issues are related to cleaning, lubrication and some assembly issues (shell not properly seated, certain screws too tight). Since I don't have my GP35 notes at hand, I'd suggest you search this site for GP35 threads: a lot has been written here on care and feeding. If you know how to put an amp meter between your Marklin controller and track, a well running GP35 will draw about 50-60mA.

So why the difference between controllers? The Rokuhan and Marklin throttles are very different. If your Marklin blue is like mine, the output starts at 3V (check with a meter), where the Rokuhan actually starts at 0. The Marklin unit is capable to sourcing more power than the RC02. And Joe is right about different throttles supplying power differently, although I've not had any problems running the GP35s with the Marklin blue, RC02 or snail.

Hope this helps,

Mark

 

Thank you all for the great replies.

I've looked at the Blue Line snail and the Medvend panel mount. One the verge of purchasing one. I am not a fan of the Blue Lines side control knob.

Wonder is it possible to mount the panel mount in a small enclosure with a 9v inside?

I will do some testing with a multi meter and see what results I get.

The GP30/35 are my favorite locos. Living two blocks from a train crossing, I'm always getting stopped and looking at the trains. Through this, my fondness for these has grown as I used to see these style locos nearly once a day.

I am not a fan of the gaps under the gp38-2s from azl. The 30s I found were out of my budget at the time I bought my loco. Only by 50, but you guys all probably know about diversifying available funds....

I'll do some testing later tonight and see what I find.

 

The Jörger Deluxe is indeed a great controller. Still available, see e.g. here:
http://www.system-joerger.de/shop/
and here for tech data:
http://www.system-joerger.de/shop/beschreibung-fahrregler-deluxe/

Manfred does take orders in english and ships to US.

Matt

 

So I tested the output from the RC02 with a voltage meter. With the knob in the off/0 position, the voltage regestered 11.48. With it turned to max, it registered 11.52. As I turned the knob slowly, it increased from 11.48 to 11.52 in unison with me turning the knob.

Based on markm's comments, it would appear there may be an issue with my RC02. I did buy it 2nd hand on ebay but it was sold as working condition lightly used.

Does it appear there is an issue with the RC02 with the voltage readings I got? I did not bring my marklin tx to my store today, but will test it later tonight.

 

You usually cannot check voltage output on the RC-02 or any pulsed power controller with a simple DMM. That is the constant lighting voltage you are seeing. Try the ammeter option as that is a better test method mark proposed.

 

Frank is correct that unless you have some very specialized equipment (like the oscilloscope that Robert mention) you're not going to get much useful information on the pulse width modulation (PWM) controllers which are the preferred throttle these days due to superior low speed performance. Actually a very low-tech test would be to connect a filament 12V light bulb (not LED) across the track and watch the brightness vary with the throttle position. I assumed the RC02 was working correctly since it drove the steam engine properly.

I use the snail quite a bit and have been very satisfied. Using the 9V battery, you don't get as much full throttle speed as with the Marklin, but on the low end I get 1-2MPH scale speed which is nice. I typically get 4-6 hrs. of operation with disposable batteries. I been using rechargeable NiMH batteries of late. They have a slightly lower voltage (8.65V) and thus a little lower max throttle speed, and I get 2-3 hrs. of operation per charge.

Mark

 

I got home and did some more testing. I think, the rookie in me has allowed myself to be stumped.

Set up 4 Rokuhan 220mm tracks as a test strip. I move the controller and when I get almost to the first line, it moves! Back it down slowly and it slows way down. I get to the second line and it tops out at a rate equivalent of maybe half max on my Marklin controller.

It's fine to sacrifice speed as I prefer more scale speeds.

On the other hand, now my Marklin steamers, are performing how the GP35 previously was. Nearly all the way up before they move.

Results are totally backwards from what they were.

As for the rokuhan RC02, it takes micro movements...it's VERY sensitive. Is that normal?

And I stress my apologies as I am just learning stuff, so if I seem overbearing with my questions, I don't mean to I'm just trying to learn along the way.

As for the snail controllers, does anyone know if you can put a panel mount medvend into a small project box and just run it off a 9v rather than hooking a wall wart? Perhaps solder the leads of a 9v connector on the power leads?

One question sort of off topic. The tampos(I assume) for the graphics on the MTL GP35, are they difficult to remove? I'm a Norfolk Southern guy which is why I got the Pennsylvania version as it's black and has minimal graphics. Easiest to convert to a NS livery. If they are somewhat easily removed, what method should I use?

 

I believe the blue line is the same as the panel mount. So you should be good to go.