Hello,

I was wondering if the rokuhan and pwm controllers can be used on all marklin mini club motors (So the classic 3/5 poles, the "throw away" ones and the new brushless ones), without doing damage.
If yes, what are you experiences with them and which ones are/ do you recommend for use with marklin mini club.

Thanks for your 2 cents!
Kristof

Hey Chris,

First of all, thanks for the reply...

The only thing I indeed knew was that the peak power should be equal or less then the max allowed power for the motor, otherwise it would be jolting the motor too hard (there my knowledge stops lol).

It s that frequency what I was worried about, it also doesn t help that I have no experience to coreless motors, everything now has the classic motors, but since I m interested in the slow running charasterics that such pwm transfo can give, I was asking it was safe for all the miniclub motors... Sounds good that there are transformers/ frequencies that are safe for all miniclub motors, it would be a shame for the investment otherwise...

I guess the rokuhan voltage will be safe in any case (since they are made for z), but indeed, is the frequency safe too...

What are those snail controllers you refer to? I would like to find out more about them. Also, isn t all in life with a but :-P? The friction jump you talk about, that one is also there (at least here it is), with the standard marklin controller. The 3 pole motors have it the most noteable, but it s even there with the 5 pole motors, once you notice it, you ll always see it, beware :-).

I know rokuhan made the trip current in their latest controller indeed higher, but if it s high enough for the older motors even with this higher limit is still a good question, one I have too. Anyway, my locos are partly old, but well maintained and sufficiently oiled, so I think it would help with not tripping.

For now I have the normal controllers as well, although in my opinion, only the white ones with the transformer part build into the transformer itself work really well, I have a newer one with a seperate power supply, just like a brown and blue one and they all are disappionting :-(. But I m after the slow running charasteristics, with normal running (that last thing works great as well with regular controllers). Anyhow, if your controller idea ever gets to fruitition, let me know, I m really curious about it!

The willing to help, is help on it s own already, but still, it contained useful information, for which I thank you very much!

Kristof

Hey Chris,

Thanks for the explaination, I have watched the video, it s like there are some speed steps missing in the acceleration/ slowing down, if you control it manually, does it do the same? Doesn t seem like a good buy seeing the video s :-(.

That one looks nice, especially when you want to put it in a control panel, what did you have change/ fiddle with that one?

I like the white marklin controllers (the old ones), but the new ones I don t, which one do you find grainy? You solution does sound more fine tuned, do you have an example of it?

Kind regards,

Kristof

Hey Chris,

Seems we both don t like the same thing about it then. By physics, do you mean friction the locomotive encounters? The only emf sensing and feedback that probably should work, is the one build in in a decoder, but a one for all loco controller with the same probably won t work.

Well the non reversing is easily countered by a switch of course, but I have the impression it won t be much different then the snail controller, unless you change some things? Still, I like the slow running part, but the missing steps would be more annoying to me...

If you have one of those I can understand you don t like how it controls the train, I didn t like mine either and I m going to use it for lighting. It s a shame they don t made the older ones anymore.

Your layout looks very nice and everything seems to be working great, nice job! I see you have a br64, are you happy with it? It s on my wish list, but if it runs like my br86, I ll pass lol.

I only have one 5 pole bogie locomotive (br212), but that one runs closely to how the steamers run, even at slow speeds. But I guess it s mostly to what model you have? But in generals, the steamers run really well at slow speeds, but seem to lack a proper power pickup and pulling power, at least in my impression, my br50 and br86 don t get much done in any case lol.

That s too bad it doesn t work out, but that s the fun thing about a hobby, it s hasn t have to be done by tomorrow and every step you take, makes it worth the while. I hope to see more of the advancements in the future.

Kind Regards,

Kristof

Hey Chris,

Thanks for the reply and sorry for the delay.

I ll quote the parts from the topic, otherwise I m going to loose track of my replies :-).

"It’s been a long time since I studied mechanics, but my recollection is that there is static friction – the force that resists a stationary object from moving – and kinetic friction - which is the force that resists motion once something is moving. Kinetic friction is usually less than static friction and we see this all the time – for example you can but a block on a slope and it will stay where it is, but give it a push to get it going and it will then keep moving. We’re used to this with our locos, too – we turn the controller up to get them started and can then back the speed off and they’ll keep going. From this, I deduce there are two modes of movement – at very low speeds when the motor has to overcome static friction and at higher speeds where it has to overcome the (much lower) kinetic friction. My theory is that this boundary is where we see the sudden increase in speed of the snail controllers. (Apologies if this sounds patronising – that’s not my intention at all.)"

-> I see what you mean, I just tought about initial resistance, not the kinect friction, well thought off. Very clear explaination, thanks, I have something to think about :-). What I was wondering, snail controllers, do they actually have emf sensing? I thought they had a fixed pattern (changing with voltage), indifferent from how the train responds? I m for sure far from the expert, but I thought it worked like that? Don t worry about it, I love the explaination, it s very interesting and for sure not patronising to me :-).


"My theory further goes that with a PWM controller and in the low speed region the motor rotates in a series of short bursts coinciding with PWM signal. In between the motor is stationary and hence there is no back EMF to sense. Once the motor is into the kinetic friction region, it is rotating constantly and there is then a back EMF to sense for feedback purposes. (An additional factor, of course, is that at slow speeds any back EMF is quite low in level and hard to sense with adequate accuracy.) I don’t think there’s a fundamental difference as to whether the controller is in the loco as a decoder or feeding the track."

-> Like I said above here, are you sure those controllers have pwm sensing? I thought it was a fixed pattern, in function of voltage? If it was there, wouldn t it make a slow running train run worse since it couldn t sense anything and go haywire? Also brands like esu added slow running cv s to their esu 4 decoders, then there must be something they can get out of it, or is it just a wild guess in settings until you find something that works? This is a genuine question, not a mean comment :-).


"Anyway, that’s why I think getting smooth acceleration from crawl to full speed with a PWM controller is inherently difficult, even with back EMF feedback."

-> Just a train of thought, isn t there a way to go from pwm to regular dc when the train increases speed? Seems to me that pwm isn t necessary when running at normal speeds?


"As for the panel mounted PWM controller I mentioned, even with the changes I made (which I am very happy to share if you want to try for yourself) the performance is no better than the Snail controller, though no worse either, in my opinion."

-> It sounds interesting to know, even if only used in my train/ shunting yard :-). The pricing was still beter ;-).


"I have two br64s one with the 5-pole and one with the new coreless motor. They are very attractive locomotives but do lack traction. As you can see, most of my layout is on an incline and 3 coaches is about the most they can handle on it. I feel the coreless motor has less traction than the 5-pole and that would make sense as I would expect it to be a bit lighter, but they are both 21g according to my kitchen scales! I have my eye on the new br86 when it comes out, but am a bit alarmed by your reports of poor performance. I really like the 88942/88943 class 94s (forgive me I’m not familiar with the German locomotive classification system) which run very smoothly and could haul an elephant up my gradients. I was anticipating the br86 would be similar."

->Pfff that sounds indeed familiar, too bad, because I like them (at least the looks of them) a lot. Still it s easier to have a short train behind a br64 and not look out of place, then say a br86/br50, but 3 coaches isn t really much indeed :-(. I think it has to do with the weight distribution, the coreless motor is a little longer I thought? Maybe it hangs a bit more on the back, distrubing the balance front vs back a bit? I have the br86 from the coal train set (marklin 81379), she is a real beauty, great runner, but the power pick up and pulling power is a let down, it has 3 filled coal hoppers in the set and that s about what it will pull (to know they made a 4 filled coal hopper set avaiable to add to it, the thing won t get from it s place). One thing I also noticed is that the loco in reverse has less power (both br86 & br50), I m still to find out why. Maybe that is what is causing you br64 pulling power issues? It also confirms that coreless motors don t suffer from pwm, since you are running the br64 with coreless motor on it... You would have seen damage by now I guess.


"I’ve seen videos of the Maerklin articulated steam locos and they do seem to run a smoothly as the other steamers so I am confused as to why the diesels don’t as the mechanics are very similar. I have a couple of br218s and a br231 and none of the run as smoothly at low speed as any of my steamers. A pair of 218s pulling a 9 coach train is something to see, though!"

-> I think it s down to gearing, my br212 does run about as smooth as my 5 pole steamers (it has more power luckily lol), but it has some tiny gears in them, that from the top of my head a br218 doesn t have. I can t test further, since it s my only 5 pole loco that isn t a steamer. What here seemed to help with locos to make them run a bit better, is to reduce brush tension, it really can make a big difference, I didn t thought it was possible. Maybe it s an option to do? I love br218, must indeed be great to see those running with such a train (or a cargo train for that matter, power!!!!)


"I was a bit disappointed by the slow speed performance when I initially discovered it, but I have come to accept it now. As you say, the important thing is to have fun and find the hobby relaxing – which I certainly do! If I ever devise a way of uncoupling loco from train, I might be back to worrying about slow speed control. If I make any discoveries I’ll be sure to let you know."

-> I still have a lot of 3 pole locos, which do run great, except at slow speeds, so I know what you mean (well not bad for the type of motor, but still), but it s easier to accept then from a ho loco in my opinion (here most people are still impressed it even runs lol). Don t the stock marklin uncoupler tracks work? Here I use a plastic toothpick for places where there aren t any, it works a charm, due to having t tapered end (different from the wooden ones) and since they are made of soft plastic, they bend before the do damage. Please to let me know about the discoveries.

Kind Regards,

Kristof

I am new to this forum and train modeling so starting now with Z scale and a NOCH layout. I bought a Marklin 5 pole 2-8-2 steam engine manufactured in 2001. I tried the Rokuhan RC-02 controller as I will have battery power for my layout. The Rokuhan controller is ergonomically comfortable and very smooth in operation. I could run my engine at a crawl. I really like its DC operation. With fresh AAA batteries it can deliver 12.4v to the track though so be careful, and battery life is poor. I suffered the occasional current limiting shutdown with the RC-02 so I also purchased a Blue Line Snail Speed controller. This controller only puts out 9.6v max due to its single battery. It is not so nice in the hand but I was hoping ton use the naked version of these in a control panel. The train operation is a bit jerky as described, I especially dislike it’s tendency for the train to jump forward or backward before settling on speed. This is not very realistic. Worst case is usually if the train stops at slow speed it cannot be restarted except by physically moving it. That seems odd and makes it little better than the RC-02 in current protection mode. Battery life is even worse than the RC-02. Now I have added a Rokuhan engine of the DB line and it’s led lights come on full bright even stopped with the RC-02 but fade in with movement with the Snail Speed controller. I have decided to use Rokuhan controllers after this comparison. I heard that the RC02 is less prone to shutdown with wall wart power. But in keeping with my desire to run on batteries I intend to try a 3s LiFe battery pack which will normally output 9.0 to 9.9v with peak on fresh charge about 10.5v. And if the Marklin engine overloads it then a bit of cleaning is probably due.

Edited by user 14 April 2019 17:30:24(UTC)  | Reason: Not specified

Nice reply! Thanks. I believe the LED lights on feature is as designed by Rokuhan. And that the constant DC put out by the Rokuhan controller when switched into forward or reverse activates it. The Snail Speed controller puts out PWM and does not. I didn’t check how long it takes the 8 AAA batteries to settle down to their average working voltage but I’m sure it is pretty quick. So I’ll have to refrain from drag racing my trains immediately after a battery change.
FWIW I have noticed that after the voltage drops enough the Rohuhan turnouts I have on a Y connector become unreliable. I think a constant voltage source like a big battery or wall wart will make for more reliable operation.

We were having a discussion on another forum about controllers and one of the very knowledgeable members posted this in answer to my question about the lights:
"The light on the Märklin is 12V bulb connects across the tracks while the BR181 has an LED with a constant lighting circuit. There are upgrades for Märklin locomotives to a plug-in constant lighting circuit from HTM. I believe the ZTrack Center handles them. I upgraded my Mikado locomotives with them, but they aren't cheap."
I hope he does not mind my quoting him "out of context" here. You may want to look into the HTM lights, I haven't yet.
I only have one Marklin engine with the LED lights, it is the BR 233 Diesel Tiger from the 81451 set, its lights do not come on until the train is moving. I absolutely love Marklin cars and engines! But the Rokuhan BR181 loco distributed by NOCH runs really well, smooth and powerful with rubber wheels. A European engine with features and pulling power like the AZL trains. And those lights at rest ;)

Once you receive your Rokuhan AC adapter, I think the issue with the turnouts will resolve. I have seen flaky operation with battery power.

And yes I got the adapter today thank you for getting that out so quickly.

By way of an update, I now have a finished design. It works in PWM (at 5V) up to half speed and then switches to constant voltage up to full speed. I reckon that will be safe for all motors and give smooth control. Additionally, I have built in back EMF sensing and feedback (though I anticipate it will take a bit of trial and error to get that working correctly).

The prototype circuit boards are due to be delivered on Friday and I expect it will take a week or two to build and debug them, probably a bit more to get the feedback working acceptably.

Needless to say I'll keep you posted of progress and if the design works share it here.

Cheers


Chris

I believe that, to do the 5-pole conversion, some locos require that the worm gear be removed from the shaft. I have to say, that's not something I'd want to undertake! I also have to say that, in my opinion, the 5 pole motor has its own problems so I'm not convinced the conversion is worth the risk. Having said that, I don't have any locos with 3 pole motors so I'm not fully in possession of the facts!

As for my own controller design, I have it working, although without feedback which I've been unable to get working satisfactorily. My feeling is that the speed control is pretty smooth from crawl to full speed, which is what I was aiming to achieve. For one reason and another I have set the project aside for the moment, though. (I was distracted by an alternative design which seemed to promise successful feedback, and one of my locomotives started playing up. At the time I put this down to the controller (which is designed to be gentle on the motor), but I've since concluded that was just coincidental.) I'm also preparing for my first exhibition so that is taking up all my modelling time at present.

I'll certainly keep everyone posted of any progress I make. I have a general interest in controllers and have also been looking at other approaches on-and-off!

As for your problem with lack of control, I suspect that is a quirk with the Rokuhan controller (I presume you are also using the Rokuhan controller). It's quite plausible that its control characteristics suit the Rokuhan motors well but not Marklin. The Marklin controller gives fairly smooth control across the whole range, but does have discrete "steps" which I personally don't favour.

What is interesting is that there is no controller with everyone agrees works well, so whatever one chooses is a compromise in some respect!

All the best


Chris

Hi Jay,

Unfortunately, I have no experience of the original controller, so can't comment on that. Hopefully some other forum members can offer some recommendations.

In my opinion, the current model controller offers a pretty evenly spread range of speeds although I don't like its granularity, as I have mentioned. Gaugemaster manufacture (to order) a controller specifically for Z scale, though I don't suppose that will be inexpensive to have shipped to South Africa.

If you are comfortable using a soldering iron, I'd be happy to share the details of the controller I use on my layout. There's not much to it and would be relatively simple and inexpensive to build.

Cheers


Chris

If you are comfortable using a soldering iron, I'd be happy to share the details of the controller I use on my layout. There's not much to it and would be relatively simple and inexpensive to build.

Cheers


Chris

Drawing is clear Chris,thanks. Can't say the same for whats going on there though. But no sweat that's what the electronics supplier
is there for :). Will only get to him later next week.

Wishing you a good evening
Jay

Thanks Chris,
I have electronics supplier close by who is well stocked,however it won't hurt to list the part numbers anyway
for the benefit of those who do want to order online and experiment. Much obliged.
Best wishes
Jay

Thanks Chris,
As for the power supply, will the wart plug power supply work?
Best
Jay

This is from the latest issue of Trainini online magazine. In particular note in the second paragraph concern that PWM controllers (like the Snail Speed controller) could damage the new Marklin motors. I don’t understand why but it is not good news.

Editorial response: We have already directly replied to our reader, and, hopefully, been able to help him. It's true that both controllers mentioned are no longer available from System Jörger and Passmann. However, we will not be able to carry out the desired comparative test, as there is no access to at least one of the devices or to a suitable measuring tool to display and evaluate the transmitted current pulses.
Since our reader's expectations are based on the operation of bell armature motors that do not require pulse width modulation (PWM) and could even suffer damage (shortened service life), we have recommended the Heisswolf products, which allow locomotive-specific and storable settings. As far as quality is concerned, we rely on Bernd Heisswolf's acknowledged good reputation and third-party test reports.

So the Rokuhan is off the table because it won’t give gradual stops and starts running bell shaped motors, the Snail Speed because it may damage them.
Of the Marklin brand controllers we have the current (wall wart) version which is getting poor reviews, then the older hard wired #67271 of which I have acquired two and they work well but with rather large speed steps noticeable, and the oldest blue box controllers which I have on authority work the best of all with the new motors!
I have not yet looked into the Heiswolf controller and the new Noch controller is not released yet but hopefully the near future holds a controller that is adaptable to the demands of all Z scale locos regardless of their motor.

Oh my! I did not post the controller design you refer to. And yes the "husafreak" moniker is rather odd. But the first enthusiast website I ever joined was a Husaberg motorcycle forum, I chose "husafreak" as a pen name, and I have used it for every forum I have joined since :P.
It is hard to make a recommendation right now, every controller on the market has good and bad points. But hey, they all work. I will wait for the new NOCH controller until I buy again, I will also research this Heiswolf controller as it seems to be what the NOCH is aiming for also. Ultimately we may need a controller that can be switched to different power output settings depending on the loco in use.

Apologies all round its the senility creeping in . Of course the credit for the controller drawing should go to Chris (Poor Skeleton).
So sorry Chris.
I shall also wait till I am more informed about controllers. Right now I still do not know whether the new Z gauge Locos are digital or not. I
browsed the forum but am still none the wiser.

Best

Jay
PS I like the "husafreak" moniker,very clever considering its origin. I was not trying to be facetious in the comment and pray that no offence was taken

That's fine, I'm very happy for Husafreak to take the credit. At least until you've built it. If you like it, then it's all mine!

Cheers


Chris

Do you have any more information on (or a link to) the new Noch controller? I have not been able to find any information about it.

This week, I have been repairing a pair of (old, I presume) Noch 88181 controllers. It's a PWM design running at about 60Hz and is substantially the same as the "inexpensive" controller I refer to earlier in this thread. The only significant difference is some attempt at a thermal shutdown, though I have my doubts how effective it is.

My quest for the holy grail of controllers continues!

Cheers


Chris