Consists and speed matching

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Sammo
Posts: 89
Joined: Fri Apr 10, 2009 9:58 pm

Consists and speed matching

Postby Sammo » Tue Oct 24, 2017 1:38 pm

I think I have quite a task ahead of me as I think I am going to have to set all speeds and accelerations etc individually if I want to run consists

However
Am I correct in thinking that if I have say 4 loco's which use the same chip and are of the same class that they can all be programmed simultaneously.
What do you think?

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Forfarian
Posts: 576
Joined: Tue Sep 13, 2011 2:16 pm
Location: Forfar, Angus

Re: Consists and speed matching

Postby Forfarian » Tue Oct 24, 2017 1:59 pm

What make of controller are you using?
I have a NCE power cab and can run consist from that OK, but you will need some patience to set up the speeds of the locos.
I have only successfully managed to run two Class 20 locos in consist, but it took me a while to get the two locos running at the same speed as one always seemed to be more powerful than the other.
No doubt some one on here will have more experience of this than me and will be able to point you in the right direction.
Tim
Tim
aka Forfarian

Bigmet
Posts: 5988
Joined: Tue Aug 14, 2007 2:19 pm

Re: Consists and speed matching

Postby Bigmet » Tue Oct 24, 2017 3:16 pm

Sammo wrote:...Am I correct in thinking that if I have say 4 loco's which use the same chip and are of the same class that they can all be programmed simultaneously.

You can do it alright!

I wouldn't though, unless they all happen to be perfectly speed matched, and are only ever going to run all together (like a set of four two-car MU's which will always operate as an eight car train) as they will not be individually controllable.

Sammo wrote:...I think I have quite a task ahead of me as I think I am going to have to set all speeds and accelerations etc individually if I want to run consists...

That's the way to do it. Really needs a layout with a continuous run to enable them to run over long distances when making the speed and acceleration comparisons.

First thing to do on the locos: take the couplers off. (Otherwise you will be forever having to uncouple them! Adding a soft foam pad on the ends so they cannot buffer lock if using small radius curves is a further refinement,)
Next make sure they are all running smoothly and stably, a couple of hours running using both directions equally is helpful.
Find the slowest loco during this process (it's annoying if you standardise on a top speed which another loco cannot achieve).
Then proceed to set up this slowest loco as 'baseline' for speeds (starting, top, mid speed) and accelerations.
Set accelerations (CV's 3 and 4) to zero, or disable on the controller.
Compare and adjust the other three locos to match this one baseline loco, so your four locos will have as close speed performance as possible.
You may have to write a speed curve if you get a motor that has a well off standard response. I have needed to do this on two RTR models and one kit mechanism out of a total of eighty, because the available speed curves didn't work well enough.
Accelerations (speeding up, slowing down) are done after speed curve matching. This is a decoder dependent function, and it is where decoders vary quite significantly from example to example. Don't expect to be able to put the same value in each decoder and have it come out the same in the running. Usually slightly different settings are required from decoder to decoder.
It's worth making a note of the settings by loco to avoid a complete redo, in the (rare) event a decoder reset is required.

Now here's something I cannot fully advise on. I have done this speed and acceleration matching on all my mechanisms, both kit builds and from the current manufacturers, and all with great success. But I have only used Lenz and Zimo decoders for this purpose, as I found these two decoder brands gave the stable performance I wanted. Not just when set up as locos alone, but more importantly for real operation, the stability of matched locos in speed and accelerations is maintained when hauling trains. I couldn't get the stable matching I wanted from the other brands I tried at the time: but that was a dozen years ago, and performance may have improved since then. But I don't know, as having found 'the right stuff' in Lenz and Zimo I have not looked elsewhere since.

Sammo
Posts: 89
Joined: Fri Apr 10, 2009 9:58 pm

Re: Consists and speed matching

Postby Sammo » Tue Oct 24, 2017 5:13 pm

More info
I am using the Digitrax twin throttle, hand held controller. With what I have, I am almost unlimited on the number of loco's in the consist.

However being practical I will probably have no more than 3
I will not be consisting an 0-6-0 with a 4-6-2
I may do a couple of 0-6-0 loco's together but in the main the consists will be either King class together or Jubilee class or Princess class together.

As for the decoders, I have Zimo in the escaps and a mixture of Zimo, Bachmann and Hornby in all the other loco's.

I purchased a few hornby DCC fitted loco's and they run fine which is why I purchased some R8249 chips to go into the Hornby unchipped loco's and Bachmann and Zimo chips for the Bachmann locos.
I have a few loco's with sound, so not sure of the chips used as they were purchased ready fitted from Hornby and Bachmann

Bigmet
Posts: 5988
Joined: Tue Aug 14, 2007 2:19 pm

Re: Consists and speed matching

Postby Bigmet » Wed Oct 25, 2017 10:25 am

Your choice how you apply the speed matching and consisting obviously.

My objective is to be able to consist 'any with any' within limits, to replicate a not uncommon feature of steam operation, which was to couple locos into 'trots' for moves like on and off shed, in order to reduce signalled movements taking up track slots. This could see quite mismatched locos together. By setting the bottom end of the speed curve - slow movement - to match closely I can do this; and it is realistic, as such moves were performed slowly.

At higher speeds, the locos are matched in one of three groups, based on their usual maximum speed out on the line.

Sammo
Posts: 89
Joined: Fri Apr 10, 2009 9:58 pm

Re: Consists and speed matching

Postby Sammo » Wed Oct 25, 2017 6:05 pm

Hi Bigmet
Thanks for that
I never considered, Because I didn't know that, what you describe actually makes sense. didn't know it happened on the railways of the larger gauge except for the double headers I used to see going through my old town of Aylesbury back in the 60s

I was considering just 2 or 3 loco's in the consist, and never even thought about consisting say 12 or 15 loco's together to move them away form a loco in the middle of them on the same track.
I would have moved them out one by one until I got to the loco I wanted to run then I would have put them back one by one.

As for speed matching I wouldn't have to worry too much when they are crawling as I would set the speed of the consist to just slightly faster than the slowest and would probably get away with that.

Going back to setting the speeds I think I am in for a long session and will write down the CV values for records and comparisons.


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