N Gauge Forum

General Category => N Gauge Discussion => Topic started by: mojo on October 14, 2021, 03:06:40 PM

Title: DCC to DC Advice
Post by: mojo on October 14, 2021, 03:06:40 PM
I have just received a Dapol A3, used but looks to be excellent, however it is DCC fitted and when placed on track there is no sign of life.
What do I need to do to have it run on DC only?
Maurice C.
Title: Re: DCC to DC Advice
Post by: Chris Morris on October 14, 2021, 03:12:14 PM
The best thing is to replace the chip with a blank. If you know anyone who does DCC offer them a chip in return for a blank. DCC locos can run on DC but they are usually slow and sometimes have inertia switched on. If a DCC loco doesn't run at all on dc it is  usually because the chip has been programmed not to accept dc.

Title: Re: DCC to DC Advice
Post by: Dr Al on October 14, 2021, 03:35:54 PM
Chris above is all spot on.

The one thing I'd add, is that if you want to retain the chip (say it's a DCC fitted model from new and you want to keep pristine), find a friend to alter CV29 (usually by adding 1 to its existing value) to turn on DC running. Often DCC users turn this feature off, so the loco appears dead on DC.

Assuming a Dapol factory fitted DCC unit, it'll have a Gaugemaster DCC23 chip, which run absolutely fine on DC.

Cheers,
Alan
Title: Re: DCC to DC Advice
Post by: mojo on October 14, 2021, 09:52:40 PM
Thanks Chris & Alan.
Does the CV become CV291 then or some other configuration?
Mauice C.
Title: Re: DCC to DC Advice
Post by: mojo on October 14, 2021, 09:54:22 PM
Is there a forum member residing in West Yorks who could do this for me?
Maurice C.
Title: Re: DCC to DC Advice
Post by: Dr Al on October 14, 2021, 09:59:08 PM
Quote from: mojo on October 14, 2021, 09:52:40 PM
Thanks Chris & Alan.
Does the CV become CV291 then or some other configuration?
Mauice C.

No. What you need to do is read back the value of CV29 firstly.

Above I made a mistake - for changing direction of the model it's change by 1; for turning on DC operation you need to enable it using the guide below:
http://www.2mm.org.uk/articles/cv29%20calculator.htm (http://www.2mm.org.uk/articles/cv29%20calculator.htm)

Basically, to give example, say you read back CV29 and it has a value 2, you need to change its value then to 6 to enable DC mode. If you play with the calculator above you'll see what I mean. Anyone who is able to program DCC near you should be able to do and understand this ok, as it's fairly basic DCC stuff.

Cheers,
Alan
Title: Re: DCC to DC Advice
Post by: Steven B on October 15, 2021, 09:23:35 AM
Quote from: mojo on October 14, 2021, 09:54:22 PM
Is there a forum member residing in West Yorks who could do this for me?
Maurice C.

Come along to the NGS Yorkshire Area Group meeting in York on the 30th October - someone should be able to help:
https://yagngs.wixsite.com/yorkshire-area-group (https://yagngs.wixsite.com/yorkshire-area-group)

(i.e. let me know you're coming and I'll bring re-programming gear with me!).

Have you checked the box for the DC blanking plug? The original owner may have put it with the detailing bits.

DCC Supplies have a Dapol blanking plug in stock (which will fit):
https://www.dccsupplies.com/shop/dapol-spares/n-gauge-spares/n-gauge-generic-spares/generic-n-blanking-plug-6-pin-nem-651/ (https://www.dccsupplies.com/shop/dapol-spares/n-gauge-spares/n-gauge-generic-spares/generic-n-blanking-plug-6-pin-nem-651/)

Bachmann/Farish sell a pack of five, part number: 379-428
https://www.petersspares.com/graham-farish-379-428-6-pin-decoder-blanking-plug-straight-pk5-n-gauge.ir (https://www.petersspares.com/graham-farish-379-428-6-pin-decoder-blanking-plug-straight-pk5-n-gauge.ir)

There's also the LaisDCC one which you can find on eBay for a couple of quid.

I wouldn't like to say if there's room for the Bachmann or Lais part in the Dapol model. There should be be but with Dapol you can never be quire sure!


Steven B.
(Yorkshire Area Group chair/secretary)
Title: Re: DCC to DC Advice
Post by: mojo on October 15, 2021, 10:18:44 AM
Thanks again for all the help.
Steven, I need to see that it is running on DCC quickly so that I know it is in working order, but thanks for your offer. If I can find someone with DCC locally to check this then that would be a start.
I will try a model shop Frizinghall probably if all else fails.

Incidentally, where is the chip/plug situated?
Maurice C
Title: Re: DCC to DC Advice
Post by: ntpntpntp on October 15, 2021, 07:56:34 PM
Quote from: mojo on October 15, 2021, 10:18:44 AM
Incidentally, where is the chip/plug situated?

In the tender, as I understand it most Dapol models end up with it sloping down to the rear.

Here's a Dapol Hall class photo of the original decoder board and DC blanking plate (by the look of it) before updating to sound

https://www.youchoos.co.uk/Index-Resource.php?L1=Guides&Item=DapolNHall (https://www.youchoos.co.uk/Index-Resource.php?L1=Guides&Item=DapolNHall)
(https://www.youchoos.co.uk/Resources/DapolHall/IMG_8079.JPG)

If it's an older model that's been hard-wired it'll still most likely be arranged in a similar way.


I would second the advice to remove the decoder and fit a DC blanking plate if you'll never want the DCC capabilities.  As it stands even if the decoder were to be enabled for DC the driving characteristics will be different to a plain DC loco (the decoder usually needs around 6V in the track before waking up and realising it's being fed with DC)
Title: Re: DCC to DC Advice
Post by: mojo on October 19, 2021, 12:59:06 PM
Thanks for all the helpful suggestions so far, (I have a further request).

I took the model to Frizinghall Model Railways on Saturday and a very obliging young man had the loco running within a few minutes after I explained the situation, also re-connected the driveshaft and all without charge. Excellent service.

As was suggested the model does require a much higher controller setting to start moving, so I now have a blank chip waiting to be fitted.

Where does the tender un-clip from it's chassis please?

Maurice C.
Title: Re: DCC to DC Advice
Post by: Dr Al on October 20, 2021, 10:53:03 PM
(https://www.youchoos.co.uk/Resources/DapolNA3-Zimo/IMG_7574.JPG)

[your PCB will look different as this one has a speaker fit, but the tender clips are as standard.]

Cheers,
Alan
Title: Re: DCC to DC Advice
Post by: mojo on October 21, 2021, 11:34:22 AM
Thanks for the photo Alan but unfortunately, as I am not familiar with Dapol products, I cannot make out where the clips are.
Front, back or sides?
Maurice C.
Title: Re: DCC to DC Advice
Post by: Dr Al on October 21, 2021, 11:38:58 AM
Sides - one just in front of the motor, one just above the 4th (rearmost) axlebox - same on both sides. They can be tight if never opened (though this will have been to fit DCC), but don't lever under the tender body as you'll damage the edges - just grab and pull the top, wiggling side to side, and eventually one clip will release (usually the rear ones release first) and the others will then follow.

Cheers,
Alan
Title: Re: DCC to DC Advice
Post by: mojo on October 21, 2021, 02:38:12 PM
Many thanks Alan, mission accomplished!
Maurice