7mm Well, here's a funny (DCC) thing

oldravendale

Western Thunderer
I've now been lucky enough to spend two or three afternoons in my new workshop - time spent so far in repairing models which have become slightly damaged during use at club. Not a problem at all, as I enjoy seeing my builds in use, and other seem to gain as much pleasure as I do from seeing them hauling trains.

However, today was a time for something new, and I had a DCC sound decoder to fit to my A3 - an exercise I've carried out numerous times previously. This time it went somewhat awry.

The A3 had been run in on conventional DC control over a few weeks at club, and was running well. I removed the chassis and fitted the new decoder entirely conventionally. Once wired up it was checked using a Lenz Compact on a programming track. It read correctly as loco 3 which I renamed as loco 64 to match the running number and on setting it up to run the chassis operated as expected. I then fitted the body and tender (with pick ups) and connected the speaker. I rechecked on the programming track and it read as loco 64 without any default. I then set it up to run - which it didn't! I exchanged the Lenz controller for a Multimaus and it still failed to run. I replaced the A3 with a new Dapol Terrier on address 3 which ran perfectly. I set the A3 up again on the programming track and tried to reset to the ID 3, but it failed to do so.

On removing the tender and the chassis from the body I rechecked on the programming track where it read as loco 64 but still failed to operate. I remade the connections between motor and decoder and set up on the programming track again. The loco read as 64. I reset it to ID 3 which it accepted this time. I tried to run the chassis alone again but it failed to do so. I reconnected the Multimaus and the chassis still failed to work. I put the Terrier back on the track without removing the A3 chassis. Both worked!!

The current situation is that I've now refitted the body without bogie or tender and checked on the programming track. It reads as loco 3 and when tested runs as loco 3. I'll fit the bogie and tender in the morning and hope that the loco continues to operate before renaming it for a second time.

My question is - why did it fail first time around??

Additionally, when it starts up on DCC it's a "jump start" rather than being smooth. It also makes a "jump stop". What's the solution?

Brian
 

Steph Dale

Western Thunderer
My question is - why did it fail first time around??
Did you remember to do a reset on the decoder after it was installed? I've had similar problems and the simplest solution is to reset all decoders to factory settings; then you know what you're dealing with.

Additionally, when it starts up on DCC it's a "jump start" rather than being smooth. It also makes a "jump stop". What's the solution?
Dunno at the mo, what make of decoder is it? If it's ESU like you normally used then you need to be brave and have a reasonable length of run for it.

Steph
 

oldravendale

Western Thunderer
No - I didn't do a reset. I'll try one tomorrow - I think it's CV 8 is it not? I'll look it up.......

Yep. ESU decoder. Perhaps the reset will sort the problem.

B
 

Yorkshire Dave

Western Thunderer
when it starts up on DCC it's a "jump start" rather than being smooth. It also makes a "jump stop". What's the solution?

This could be the starting voltage, speed curve or motor control parameters. Or a combination of all three. What motor/gearbox combination is in the loco?

I concur with Steph and perform a decoder reset first.
 

TheSnapper

Western Thunderer
Hi Brian

For what it's worth I had a similar problem recently witha Loksound XL v.4.
I normally set the address on the main (POM), but unusually this time for some reason, I set the address on the Programming Track.
As you experienced with your A3, it didn't respond when I tried to run it normally.
Re-setting sorted it out.
I don't have an explanation, but will always set the address on the main from now on.

Tim
 

oldravendale

Western Thunderer
Helpful comments all, there. Thanks.

Motor/gearbox is Escap, David, of which I still have a few.

I'll do a reset initially and see whether that sets things back to normal. That's an interesting comment about your experience too, Tim. It seems to mirror my situation.

More playing this afternoon and I'll report back.

Brian
 

Steph Dale

Western Thunderer
Aah, the default settings in the decoder won't be right for the Escap and will tend to over drive it in response to the feedback.

You'll need to alter the motor drive parameters, which is where being brave comes in: there's an auto calibration on the decoder (CV51? Can't remember) which involves the loco setting off like a rocket. You may remember the last time I did it to one of your locos.

As an alternative, there are CV settings which can be tweaked manually and there's a little routine for how to go about it in the manual.

All the above assuming the decoder is an ESU Loksound v4.

Steph
 

TheSnapper

Western Thunderer
Brian - I think Steph is referring to this procedure:


Place the loco on the track with plenty of room in front.

Ensure direction is set correctly


Set CV54 to zero

Press F1


The loco will shoot off at high speed and then stop.

Following this, the motor should run smoothly.
Tim
 

JimG

Western Thunderer
Place the loco on the track with plenty of room in front.

I just got a Loksound Select the other day for my SW1 switcher and when reading the manual, I noted this auto calibration function. What does "plenty of room" mean? :) I've got twelve feet of run at best and I have visions of the locomotive launching itself into orbit off the end of the track. :)

Jim.
 

Steph Dale

Western Thunderer
Jim,
That might just be enough. I'm not convinced the direction is all that reliable or consistent. Of course with a high ratio gearbox it shouldn't go so far.

You can use a rolling road to get you in the ball park, a spin through the routine in the manual is good to fine tune.

Tim,
That's the one, thanks!

Steph
 

richard carr

Western Thunderer
Personally I wouldn't rely too much on the auto set up function, my experience is that it doesn't work that well.

If you already have an escap motor set up and running well, then just copy those settings to the new loco, its a 5 minute job with a Lok programmer or a Sprogg.

Richard
 

JimG

Western Thunderer
That might just be enough. I'm not convinced the direction is all that reliable or consistent. Of course with a high ratio gearbox it shouldn't go so far.

You can use a rolling road to get you in the ball park, a spin through the routine in the manual is good to fine tune.

I don't have a rolling road that will take four axle diesels so I'll just content myself with doodling about on my test track with Decoder Pro. :)

Jim.
 

oldravendale

Western Thunderer
Thanks for the additional thoughts.

As I have only 2 metres of track perhaps the auto set up is not for me, although I could give it a go on the rolling road.

Brian
 

InvernessTMD

Western Thunderer
My 60 had the same issue, would short the layout when it stopped, cv54 to zero and off it went (on a rolling road so no chance of going off the end), although I had to use a beefier power supply as the multimaus kept tripping out, has worked perfectly since.
 

SimonT

Western Thunderer
The strangeness of this hobby. I have been utterly disappointed by this procedure. On pressing F1 the locos have run about four inches and stopped. Perfect low speed control thereafter on every one. Mashima 1833 and Branchlines 40 or 50 to 1 gearboxes before you ask.
 

oldravendale

Western Thunderer
The continuing saga.

The decoder is an ESU Loksound 4.

I've tried the CV 54 trick all afternoon but am an abject failure. I'm certain it's finger trouble - I can't even change the loco address. I've spent the afternoon reading and re-reading the instructions but am non the wiser. I even looked up the process on line and saw a very nice video about programming using the Multimaus, but still failed. Now going back to the drawing board and quizzing Steph.....

The good news is that the loco is running well on address 3 with very good sound, however, it still has the "kick" both forward and reverse when coming to a stand.

I will, of course, be dreadfully embarrassed when the reason for my incompetence is revealed, but in a spirit of hoping to help other poor technophobes out there in la la land I will report on the process which eventually gets to grips with this.

It's been about 18 months since I last fitted a decoder to a loco and that seemed to go OK.......

Brian
 

Rob Pulham

Western Thunderer
It's been about 18 months since I last fitted a decoder to a loco and that seemed to go OK.......

I am right there with you Brian, it's been about five years or more since I last fitted a decoder to a 4mm loco. So when I finally get my stuff out of the box I may be in the same situation.
 
Top