Cobalt motors and Z21 problem

[Jamie Smith]

I've just began with fitting my electrics and come across a rather bizarre problem.

 

Have my Z21 up and running and now moving on to assigning the (Cobalt digital) point motors. However, when I wire them up, the motors the just seem to zig-zag constantly back and forth!

I suspect this may be something to do with them trying to self-centre, but no idea why they are doing this.

I read that you can switch them off by assigning them an address of 198 or 202 but not sure if I've done this correctly as when I switch them from set to run mode, the zig-zagging begins again.

 

Have all the usual things, track bus bar, separate accessory bus etc.

 

Any thoughts?

[ITG]

You could do worse than ask DCC concepts. I found them very helpful when I had an issue with same point motors.

[Mick Bonwick]

The instructions on DCC Concepts website show you precisely how to turn off self-centring. I sugest you go and have a look. Follow the instructions and the problem will go away. I know this!

[55020]

Even if the self-centering was active, which they no longer are by default, then they will only do this on initial power up.  They shouldn't "zig-zag" at all.  It sounds like you either have some major interference in your accessory bus, or perhaps more likely you haven't wired them correctly.

Can you post a wiring diagram?

[Nigelcliffe]

Suggest trying with RailCom turned off on the Z21.   See if that fixes things.   If it does, ask yourself whether you'll do without RailCom, or return the Cobalts. 

 

 

[55020]

I use Railcom with lots of digital Cobalts, so there isn't a fundamental compatability issue with this combination.  I don't use a Z21 however.

 

Turning off Railcom is worth a try though, especially when programming anything "on the main".

[WIMorrison]

Been using a Z21 with Railcom and Cobalts for several years and never had an issue.

 

Have you tried issuing value 198 to the Cobalts? This deactivates the self-centering.

 

Also, as the default setting for the Z21 is +4 on the address you may need to issue 202 rather than 198 to deactivate the feature. You can turn off the +4 feature using the Z21 Maintenance Program.

[newbryford]

Are they Digital or Digital IP types? (You say Cobalt digital in the OP)

The older/original Digital type do not have the special address commands of 197-199

 

As a post above, auto-centre at power on is no longer the default new setting. It is disabled.

I think they've been that way for about three years or so.

[Jamie Smith]

Thanks for all the replies.

 

They are original Cobalt Digital points, not the newer IP versions.

 

Not sure It's a wiring issue/interference as I am simply running two wires from the Track Output at the back of the Z21 straight into ports 1 & 2 of the motor (DCC) and that's it. Nothing else...no frog out...not wired into the accessory bus etc. Thought I'd do it this way to keep any potential wiring issues to a minimum. Plus I've managed to program the next point 'down the line' so to speak and that one is working fine....so far!

 

I've tried all the usual things of disabling the auto-centre (198-202...and all combinations in between) but as Newbryford eludes to, they are older (original) motors so not sure they have the special address commands as this makes no difference what so ever.

 

(On a side note, I also can't seem to change, or issue a different address numbers once I assign/set up a motor. Once It's been assigned a number (e.g. 7) it won't accept a new number, no matter how much I try...this is for ALL of my motors.

Does anyone have a really simple step-by-step 'Idiots guide' on how to change or amend a new address number for Cobalt points...as clearly I'm an Idiot! lol)

 

I've contacted DCC Concepts and they are looking into it...but I will certainly try turning off RailCom in the mean time and see what happens. I can do without this as I have no plans to use it.

[Jamie Smith]

Quick update...looks like RailCom was the culprit behind the issue of registering new address for the points. Turned it off and all was good.

 

Still waiting for a fix on the zig-zag issue however!

 

And for anyone with this issue in the future... DCC Concepts gave me the following reply (Big thank you to Mick at DCC);

 

Hi Jamie,

Thanks for the reply.

 

If they are original Digital, then they do not have the 197-199 special commands for autocentre and reverse operation.

 

To repeat the addressing procedure:

 

Connect motor to normal DCC with system in run mode.

Flick switch to SET.

Send a "point change" command from the system [*]

(Repeat a couple of times)

The motor will not move (although the very first batch of Digital will give a slight shuffle - similar to loco decoders when writing CVs. The first batch will also give a tiny shuffle at power up that lasts less than a second)

Flick switch to RUN.

 

And that should be it.

 

[*] When using screen based systems, the point will have to be created and given an address in the "track build" mode. Then select normal track operation to carry out the procedure as above.

 

Turn off Railcom for addressing, as the Railcom pulse can sometimes affect the procedure.

 

Can you try them in "manual" mode?

Connect DCC power and also a pushbutton on terminals 4/5. You can use a couple of short pieces of wire and "dab" them together.

As you press the button, the motor should move one way, press it again, it will move back.

 

Best Regards,

Mick