It is well known that the models with these engines often have problems with the control electronics, so Marklin is
stopped working

The drive stand differs from the standard so it is not possible to put a plain engine in it

One such locomotive in the Backo Mini Express fleet damaged and Marklin's response was that
There are no replacement parts for it because it is no longer produced!

After numerous tests, they found a suitable stand with a standard engine

The plastic around the drive wheels has been attached to it

The decoder is also standard,sound
Comparison with the old

There are a couple of other models with problematic electronics for stepper motors in the layout fleet
and the crew is looking for other drive systems with a regular drive to replace them
If you have the same problems, feel free to contact http://www.backo.hr/en/

Edited by moderator 07 November 2017 10:39:16(UTC)  | Reason: Updated the title as requested

Hi Mike,
In 1Borna post, focus is how to repair valuable locomotive whit damaged Soft-Drive-Sinus motor with support driver which are not longer available. Company which produces SDS motors for Maerklin still offers them on request with customised flat cable but issue is quantity and price. Problem with particular and similar models with soft drive sinus motors is temperature issue with overheating which causes parts to melt down (bottom of spiral rotor with housing near support bearing) and destroy motor and its controller in most cases. If you drive locomotive a lot, temperature generated on the motor and on the controller plate is quite high. Whole concept in some locomotives with less internal space has some benefits but problems though. For all above mentioned issues, related problems and (financial)reasons, Mearklin stopped to use them in their locomotives and parts list as well and admit that use of those motors is an issue rather revolution like it was promoted when they introduce them.

At the end of the day, you have locomotive with no available parts and with no support form locomotive maker as they don't have this type of motors and controllers in their program any more. Also used parts are just temporary solution.

For that reason www.backo.hr offers solution with new replacement motor and boogie and support decoder board with speaker.
Mfx Sound decoder could be purchased as well.


Cheers,

Davor

Correct, backo.hr offers solution for damaged SDS motor or C-Sine motor or/and control board.
I'm not sure if C sine of that type is excellent for this application especially when EMF needs to be compensate.
Overheating is huge, definitely over allowable upper limit.

I know for many cases with motor issue. Recently on one 141 DB locomotive with same type of motor, whole plastic support has been melded down to the motor itself.. complete disaster.

I will post picture of that locomotive soon

Regards,

Davor

Great solution with Maxon motor :-)

A friend disassembled a C Sine motor that had pressed the loco against a bumper for possibly hours until it finally overheated and self-destructed by deforming the plastic parts.

In my experience this is a rare problem.

Reports about failing driver electronics are more common.

Back EMF is so old-school, those C Sine motors have Hall sensors for advanced motor control.
They ain't "stepper motors", they are brushless DC motors. I hear that type of motor is frequently used in RC models. They are not made for the variable voltages used with analogue operation and that surely was an issue, especially with DC operation.

The maintenance interval for those locos is typically 20 hours, not 80 hours.

After research I found that Marklin SDS Motor is produced by company PMDM or Precision Motors Deutsche Minebea GmbH from Villingen-Schwenningen.

It is BLDC 15 compact motor which operates at a voltage of 12 volts and achieves a no-load speed of 12900 rpm.
It has two high-quality miniature ball bearings.
I found that they use bearings form NBM company.
Connection (Kapton) flat cable (8 pins) needs to be customised.
Price of the motor is on request.
But at least it is available.

It is brushless 3 phase DC motor with 12 poles 9 magnets and 3 hall sensors.
70% efficiency at 10.000 RPM
230mA at 12V
Continues power of 2W

What is HAL?
Hall effect sensors measure the speed of rotation, Back-EMF estimates the speed of rotation. While the estimations from Back-EMF work well enough for MRR uses, I have more trust in measurements.

All worked well when Märklin introduced the C Sine motor in 2000.
The nightmare started when they combined the big C Sine motor with mfx decoders and untested electronics and brought the Compact C Sine motor with the same immature electronics.

I sent all my locos with those immature electronics back to Märklin to have them upgraded under warranty.

I'm sorry Dave, I cannot allow you to answer that

As far as I know the Hall sensor detects the strength of magnetic field (which can be static).

We are talking about brushless DC motors. AIUI the driver electronics animate the electromagnetic field of the motor and thus define the speed the motor should have - and the hall sensors verify that the motor turns as expected.

The new boards have a "csin3" label and consumers typically identify new boards by this label.

Can you clarify how the hall sensor is able to determine the WHY of the motor not turning?
The solution has to determine not only that the motor is turning and at what rate, which could be very slowly, but also why it is not turning at a desired speed.

How does the hall sensor detect that the rotation desired by the input drive current and voltage is not producing the desired rotation?

So does this not mean the C-Sin Märklin motors are doing almost no control of the motors themselves, and just applying the voltages at the right time? Control would indicate monitoring the rotation or back-emf to detect via the increased current or position that despite power being applied the motor is not turning, and then shutting down the motor when there is a stall condition when none should be. Either the current measurement or positional/rotation measurement solutions would allow for the same.

With all the talk on this topic I thought it might help to add Marklin's 'official' blurb about this technology just for those who may not have seen it before....

Enjoy - I hope it's interesting to some.



Cookee

Announcement Video



Announcement Brochure...

True. My poor writing. When I write motor I meant the physical motor and it's required drive electronics control circuit.

If you have a motor that can overheat there should be part of the control circuits that detects over current and overheating and halts power feed to the motor itself to prevent overheating. Based on the reports of motors melting the plastic the motor is bolted to that doesn't seem to be the case.



Voltage and current are two aspects of the same state that can be detected. Back-emf stall can be detected as a stationary rotor would generate zero back-emf as I understand it so the still applied supply voltage at high current could be detected on the motor inputs. Where you read the current or voltages to detect stall depends on how you build the motor body and windings, right?

In the end it doesn't much matter as the drive systems were designed the way hey were and they have some of the problems they have and the benefit they provide. So whomever buys then has to understand the issues and deploy accordingly.