Does fitting a flywheel help or hinder quality (Zimo) decoders

[ROSSPOP]

Good morning all,

 

Hoping you are all safe and  well.

 

Just a Thought really.... for you real DCC boffins out there...

 

...........hard wire all my kit built locos with Zimo sound decoders for years now. I realise that decoders have an `electric flywheel affect` but if I fitted a traditional brass flywheel say for DC running would the  decoder  be `fighting` the mechanical flywheel effect when operating in DCC mode??

 

What do the panel think?

 

Cheers

John

[Happy Hippo]

Plenty of flywheel equipped locos out there running perfectly on DCC with Zimo decoders.

 

The decoder only manipulates the motor electronically and you can always 'tune' the momentum effect by adjusting various CV values.

[Enterprisingwestern]

 

A question I have often pondered.

My take on it is that electronically it probably doesn't make much difference as the decoder, as mentioned above, has an electronic flywheel but mechanically it will assist in "smoothing" the motor.

Probably totally irrelevant though as someone will no doubt be along to prove!

 

Mike.

 

[Oldddudders]

My assumption is that the flywheel will damp or slow the motors reactions, thus actually giving the decoder more time to assess and control. Hard to see a downside to having both. 

[RFS]

A number of more recent RTR models have flywheels, for example, the Hornby S15. I have two of these which run beautifully under DCC albeit with Lenz Standard+ decoders. 

[Dagworth]

I’m guessing that by Electronic Flywheel we are talking about Back EMF rather than energy storage? 
 

Andi

[Nigelcliffe]

If the mechanical flywheel is balanced, then it won't cause bad running.  If it is out of balance, by a small amount, then the decoder may end up fighting it because the back-EMF from the motor will be fluctuating due to the vibration from the flywheel.

 

I was once handed a scratchbuilt loco to "sort out the decoder setting".  Much messing around with CV's and I could not get satisfactory running.  I studied the mechanical side, took out the decoder, and found the flywheel was out of balance. Not by much, but could just feel it, and could see a small twitch in an ammeter with DC running.  Take flywheel out, and it was a doddle to setup the decoder.  

 

Personally, if building for DCC running, then skip the flywheel and fit a stay-alive unit in the space saved.  Reasons being:

Mechanical flywheels might be fitted for many reasons, including:  a - provides increased momentum for motor over minor pickup issues, b -  provides general "momentum" (though DC controllers with coast/brake offered this for at least the last 50 years).  But, mechanical flywheels effect is a function of speed; they only really work when the motor is going quickly. 

Stay-alive unit:  provides electrical continuity over any interruptions to pickup, and does this at any running speed (including coming to a stop with pickup not working, so nudging forward to regain pickup in Zimo's, a trick which a flywheel cannot emulate, no matter how its fitted).   The other factors, such as "momentum in model" can be set in decoder settings.   

 

 

 

- Nigel

 

[Crosland]

A seriously question whether one is needed, but a good decoder will cope.

 

One of the basic differences between coreless and cored motors is the mass of the armature. A flywheel will look like a (much) heavier armature.

 

You might need to tweak the CVs for the BEMF feedback loop.

 

[bgman]

All very interesting as I have ordered a flywheel to put on a motor in readiness for fitting into my 7mm Armstrong Goods build.

 

As  John states, I too use Zimo decoders in my builds so it will be interesting to see if it makes much / any difference to the running characteristics.

 

G