Achieving a Slow Start

[Right Away]

I run a Lenz LH100 system with Bachmann and Hornby steam locomotives fitted with a mixture of Lenz Standard and Zimo “budget” decoders.

Both decoder types have given exemplary reliability, however, straight “out of the box” and with just CV’s 3, 4, 5 and 6 adjusted to suit the individual engine, NO speed table set and with 28/128 control steps, it is the Zimo which always gives an extremely slow start, often with little trace of movement until “Step 2” is selected on the controller - very realistic! 

I would like to achieve the same result with the Lenz decoder fitted engines but even on Step 1, they move off immediately (I won’t say abruptly) but certainly not with the same minute degree as those fitted with a Zimo decoder. Tweaking of the above CV’s makes no difference at all to the Lenz fitted locos initial movement from rest.

Any suggestions re the configuration of the Lenz decoders to achieve the desired “slow start” would be most welcome.

Thank you for any help.

 

[Tim123]

CV2 controls what the motor sees as the starting voltage, so check that this is set to a value of 0. The output is a series of full voltage pulses that are varied in frequency, rather than a reduced voltage being supplied. There may be other "back EMF" settings you could change that might help. But I came to the conclusion long ago that Zimo decoders just work fine as supplied. The only Zimo CV I regularly change is CV57. This is the maximum voltage sent out in the pulses as my fleet includes some Lima locos with 9 volt CD motors fitted.

[Izzy]

Sadly my experience is that you just won’t be able to get other decoder makes to deliver the start from rest inertia movement that the motor control algorithms of Zimo (& CT) are able to provide no matter what cv’s you fiddle with. Sometimes with certain locos you can get close when the power train matches what the decoders deliver, but that is more luck than anything else I think. I long ago gave up the fight and just settled on using Zimo/CT.

 

Bob

[Pete the Elaner]

14 minutes ago, Izzy said:

Sadly my experience is that you just won’t be able to get other decoder makes to deliver the start from rest inertia movement that the motor control algorithms of Zimo (& CT) are able to provide no matter what cv’s you fiddle with. Sometimes with certain locos you can get close when the power train matches what the decoders deliver, but that is more luck than anything else I think. I long ago gave up the fight and just settled on using Zimo/CT.

 

Bob

 

From my limited experience, I have to agree.

 

I have 1 loco which needed a 6 pin decoder. It was a while ago that I bought it & the shop I was in had a Lenz Gold. I thought that was great because many on here used to rave about how Lenz Gold decoders were the very best. If I buy a decent decoder, I won't need to change it, right?

A friend of mine bought a similar loco with the same decoder. He was always frustrated about how jerky the loco was at very slow speed. It was no worse than mine, but he was dissatisfied.

He bought a Zimo. I can't remember what model but it cost about 2/3 of the Lenz. Its slow speed performance is noticeably better.

We both came to the conclusion that Zimo decoders provide better running. Their range is generally cheaper than Lenz too.

[Right Away]

Thanks Guys.

Yes, I have to say, some of my Lenz fitted engines are better than others in this respect of the initial starting. It is those “others”  which would benefit from a decoder change. From tiny 0-4-0 tanks to hunking great Pacifics, the Zimo wins out every time.

However, the hassle of opening up the engines involved, risking damage to intricate parts, not to mention the 300 odd quid outlay to re-equip them, is questionably viable at present.

 

Edited July 5, 2022 by Right Away
correction

[JimFin]

What works for me it to set CV2 to a value - say 40 and set the loco off on speed step 1. If it moves off, reduce CV2 by say 5 and repeat. Keep adjusting and fine tuning increments until it just begins to move on step 1. If it does not move off at 40, try 50 and just repeat until you can find the right value.

 

[Right Away]

Thanks.

However the engines’ initial start is the same if CV2 is 0 or 1. Acceleration, deceleration is fine, it’s just the initial movement from rest when the train moves off from standstill to a scale 2-3mph! Of course, other factors will come into play here, wheel diameter, gearing etc. I’ve tried adjustments with CV50 and others to no avail.

I’m becoming convinced that having been “spoilt” by the Zimo’s beautiful movement from rest, the Lenz cannot match it in this respect. This has probably made me a little too fussy and ultimately unless I am prepared to “cough up” for a decoder change en masse, I’ll have to live with it.

 

Edited July 8, 2022 by Right Away
correction

[JST]

I have two identical locos (Hornby Granges), one fitted with an ESU sound decoder and the other with a Zimo sound decoder. Both locos are excellent runners but I just cannot get the ESU equipped loco to start as smoothly as the Zimo loco. This just underlines the other opinions above that Zimo is the way to go if you want the best start off.

[Right Away]

Just to recap, as it could prove helpful to others ....

One of the Lenz fitted locomotives which has given the most discernible “sudden” initial start is a Hornby “Castle”. 

Still giving this some thought, I checked my list of locomotives fitted with Zimo decoders to see if one which might be suitable for donating its chip to the “Castle”, yet perform adequately when refitted with the Lenz from the latter. I decided upon pinching the Zimo out of an original “Merchant Navy” as this engine has a superb drive with flywheels, the starting of which might be more “tolerant” of a Lenz’s characteristic.

 

Having just swapped the two decoders over between the engines, I can report that the MN now, fitted with the Lenz, starts away nice and slowly, (clearly not as fine as with its previous Zimo) but perfectly acceptable to fussy me, and that’s what’s important.

And the “Castle” now Zimo fitted; this engine has been completely transformed. What a splendid model with running performance to match.

 

Regarding this previously errant “Castle”. I can only conclude, in this instance, that its mechanism, coupled with its big drivers are not entirely suited to the attributes of the Lenz decoder. 

 

I might add that not all of my Lenz fitted engines are problematic in the respect of smooth, gentle starting.

 

 

Edited July 9, 2022 by Right Away
correction