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How many decoders?


WIMorrison
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I am thinking of buying a Halling railcar like this one

 

post-32397-0-98826700-1526936908_thumb.gif

 

which unfortunately has 2 motors, one at each end and the question is really quite simple - how many decoders?

 

clearly the model can only ever run as a single unit, so is it best to get a decoder that has enough power for both motors or should I get 2 decoders and try (somehow) to match them and run this one railcar permanently as a consist?

 

I can see advantages to both methods, I can also see disadvantages but I don't know which way will produce the better solution.

 

Any ideas?

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clearly the model can only ever run as a single unit, so is it best to get a decoder that has enough power for both motors or should I get 2 decoders and try (somehow) to match them and run this one railcar permanently as a consist?

 

 

 

If you do fit two decoders, no need to run as a consist - just give them the same address.

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Is it DCC ready? If so how many decoders does the manufacturer expect to be fitted? 

 

If you do go for only a single decoder then get one WITHOUT Back EMF, the two motors will confuse the hell out of a back EMF decoder.

 

Andi

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With a Multimeter - measure the CURRENT taken by the railcar.   It is probably below 0.5A, and therefore almost any decoder should do.

The use of 2 motors is a mechanical /  weight / assembly convenience resulting in good performance...

 

If you think the railcar runs too fast, you could even wire the motors in series.

A small decoder  6 pin or 8 wire can be fitted reasonably easily - but its years since I converted mine 8-)

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...Any ideas?

Is the same class available from another manufacturer more clued up on the idea that a single unit railcar only needs one motor?

 

If there is no alternative, does the assembly diagram suggest that one motor can be disconnected and disengaged such that only one motor operates the railcar?

 

Single decoder for a pair of motors is a poor plan, degrades the motor control.

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I have a twin motor bogie tram rigged for DCC using this method (credit BEC as marked).

 

Note socket (module) pin 3 is usually green wire not black/white as shown.

 

Rob

 

post-7193-0-55119200-1526983167.jpg

Edited by RAFHAAA96
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The current is not of any importance. As it is a DMU it will never pull any trains. I think you have the right answer already - given by dagworth in #3

 

Also I use Austrian stuff (I am made in Austria myself) - many of them have 2 motors. If the model runs fine on DC there is no need to use back EMF. And you save 20£ for a second decoder...

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My thoughts were definitely with a single decoder but I needed to test the assembled thinking before deciding to go down this route in case u was missing something obvious

 

Regrettably the thinking of everyone coinciding with mine is now liable to cost me a few hundred pounds!

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My thoughts were definitely with a single decoder but I needed to test the assembled thinking before deciding to go down this route in case u was missing something obvious

 

Regrettably the thinking of everyone coinciding with mine is now liable to cost me a few hundred pounds!

 

Why? Of course I do not know what the cost of the model is - but a decoder (Zimo MX600) is approximately 20£. So even if you take 2 it is far below a hundred... 

By the way - I will look into an Austrian forum to see what they are doing with multi engine locomotives. 

 

Sent a mail to Arnold Huebsch, who is very close to Zimo (he developed several adapter boards for them). Will see what he answers.  

Edited by Vecchio
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I think that you will find that current production of the 5090 railcar includes an NEM862 8 pin socket.  Just plug in a decoder and all will be well.  The small Mabuchi motors used do not consume a lot of current.

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Just got the reply from Arnold -

 

"Unbedingt die Regelung eingeschaltet lassen. Bei 2 Motoren sind diese über den Rahmen der Lok, Motor, Getriebe, Räder miteinander verbunden. Der Decoder schaut sich sozusagen den Mittelwert der Drehzahl beider Motore an. Genau das was er braucht um die Lok korrekt zu fahren.

 

2 Decoder sind für Anfänger heikel weil man 2 Regelkreise abstimmen muß, das braucht erfahrung und gute Decoder die die dazu nötigen Einrichtungen haben. Also ist man wieder bei den Guten Decoder Herstellern und da kann man gleich beide Motore versorgen."

 

 

I have to say google translations improve... I have tried to make the second paragraph a bit more understandable.

 

 
 
Be sure to leave the control (back EMF) on. With 2 motors, these are connected to each other via the frame of the locomotive, motor, gearbox, wheels. The decoder, so to speak, looks at the mean value of the speed of both motors. Exactly what he needs to drive the locomotive correctly.

 

 
Two decoders are tricky for beginners because you have to tune 2 control loops, that needs experience and you need good decoders which have the necessary facilities. So you're back at the "Good Decoder manufacturers" and with such decoders you can supply both motors from one decoder.
 

 

Arnold started also to make some comments about low quality decoders, I will save you from these comments... But I am happy he didn't use the word Zimo once in his reply...

 

Hope this helps

Vecchio

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  • 2 weeks later...

Finally plucked up the courage to buy the model and have found that the latest run of these come with a NEM652 socket which has removed all the concerns :)

 

I have ordered a Zimo MX622R which should be a simple plug and play - though I will need to learn another set of CVs as I have always used Lenz - hopefully no problems.

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Zimo’s documentation can look a bit daunting at first as there are so many things you can change if you want, but unless you want to play you only need to work with the normal CVs - Accelerator, Deceleration, CV29 etc and leave all the others at their default values. Since I started using Zimo decoders, I wouldn’t now use anything else.

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I am hoping it will only be CV29 which I set at 30 for 28 steps, DC, Railcom and a Complex Speed Curve which I measure using iTrain for top speed of 80kph and create a curve using Decoder Pro from JMRI.

 

When I do this I get my trains to stop within 1cm of where I want, which lets me fill sidings with trains that are only 3cm longer than the actual train!

 

This one will park itself up at the loco sheds when it isn't actually in use :)

Edited by WIMorrison
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I am hoping it will only be CV29 which I set at 30 for 28 steps, DC, Railcom and a Complex Speed Curve which I measure using iTrain for top speed of 80kph and create a curve using Decoder Pro from JMRI.

 

When I do this I get my trains to stop within 1cm of where I want, which lets me fill sidings with trains that are only 3cm longer than the actual train!

 

This one will park itself up at the loco sheds when it isn't actually in use :)

 

Set your ZIMO up with the Brake Key feature and you will be able to stop it wherever you wish. CV309 = X where X is the F key to assign to the manual brake, CV349 = Y Where Y is the braking force. Try values around 6. Best effects if CV4 is set rather high (100+) so you can have great coasting plus the ability to stop where required.

 

Best regards,

 

Paul

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