Duchess of abercon

[kiltedscot]

Hi there, hope someone can help. I have changed a few locos from DC to DCC with no problems, After changing the Duchess of abercon to DCC.The loco now runs like a bag of nails locomotive just serviced and new brushes fitted and oiled.I.E. runs slow,jerky around the track sometimes needs a little push to start.

cheers Dave

[Fishmanoz]

Just to confirm - it was running well on DC?

What decoder have you fitted?

[kiltedscot]

Hi there loco ran fine on DC layout (still using same layout) decoder fitted is the R8249.hope this helps

Dave

[Fishmanoz]

So this is a tender drive Ringfield motor model and draws more current than modern motors, in fact often exceeds the 500mA an 8249 can deliver.

If I were to discount dirty/oily track/wheels and the pickups in good contact with the wheel backs, I would suspect the 8249 may be operating right at its current limit and maybe exceeding intermittently.

Do you have a higher current capability decoder you could swap in?

Also for peace of mind, I’d be doing a DC stall current test (see Brian Lambert site for how to do one).

[Going Spare]

The only tender-driven Duchess of Abercorn is the 1981 release which has an electrical path from the uninsulated loco driving wheels to the motor and out via the uninsulated tender wheels, relying purely upon metal-to-metal contact at the loco driving wheel axle/chassis block, chassis block/pivoting pony truck frame, drawbar contact/tender pin and tender motor block/axle interfaces. Any interference in that path through poor contact due to dirt will be more critical under DCC control than with DC.

[ColinB]

I did a lot of work on my tender driven Duchess locos when I converted them to DCC. I think your big issue is using a Hornby decoder. They are only rated at 500 mAmp a Ringfield can draw up to 600 mAmp. In fact I am surprised you haven't fried it, with mine it stalled on a point and it was no more. I use Zimo DCC decoders in my old Ringfield locos and I don't have any affiliation with the company, I just found that they worked the best. They are rated at 800 mAmp so more suited to the motor. I also found Hatton's and DCC Supplies ones also seemed to have issues with Ringfields although according to their specifications they shouldn't. There again that is just my experience.