Decoders and MDC Roundhouse steam locomotives.

[Anonymous]

Help!! I have installed a digitrax DH123 decoder in my brand new MDC ten wheeler. This is a newer version of MDC's products, but not the newest. It still has the brass tender wheels and tires on the drivers, but came with a Sagami Can motor. The motor has been isolated and I have improved electrical pick-up on the tender. The track is clean, the wheels are clean,
1). The loco runs o.k with straight DC power, and DC power through the decoder but is a little jerky.
2). The loco is very jerky and eventually will bog down and stop in DCC and runs a little better in reverse, but is still jerky.
3). I have done modifications to CVs, per Tech Help at Digitrax. We improved start voltage so the loco begins moving at lower throttle settings.
4). I have swapped decoders, using the original and two others, changing the new decoders CVs to copy setting suggested by Digitrax, no improvement!
5). I have replaced the can motor with an open frame motor and noticed no improvement.
6). I have asked MDC for their thoughts.
NOTES: When running DC, start voltage appears to be around 5 volts and top end volts are around 21!

Have any of you built MDC steamers and been successful in converting to DCC? I think MDC has again changed motors and provided flywheels. It's my understanding the wheels are nickle plated now also.

Any suggestions would be appreciated!

[Anonymous]

Hmm..just recieved 2 2-6-0's and 2 4-4-0's both have nickel-silver wheels on the tenders, and the drivers are not traction. as for converting them to DCC, it wa pretty straight forward, and yes they have new flywheel open body motors.

you might want to change your brass tender wheels to nickel-silver ones, and you can order the new driver wheels off the MDC roundhouse site to change out the traction ones.

but the most likely problem you're having is either a dirty drack, or dirty pickups. DCC is really finicky with dirty contacts, DC can be compensated by appying more power, so it doesn't show up. Suggest you clean the contacts on the engine and the pickup wheels as well as throughly cleaning the track.

Jay.

[Anonymous]

Track and wheels are not dirty, what is a traction wheel?

[Anonymous]

QUOTE: Originally posted by deschane

Track and wheels are not dirty, what is a traction wheel?

Traction is the rubber thing on the drivers, most older Loco's used it since the motors weren't that great and the traction gave better pulling power for them. if you've replaced the Motor with a newer one, i'd say replace the traction drivers with metal ones. this will have the added benifit of more surface contact for the power, thus probably elimiating any loss of power or signal to the loco.

Jay

[Anonymous]

Jay, MDC does not supply their locos with traction tires on the drivers. I thought that might be what you were alluding to. No, like I say, the wheels and track are clean. There is something else going on here. Thanks for the suggestions!

Mark

[Anonymous]

QUOTE: Originally posted by deschane

Jay, MDC does not supply their locos with traction tires on the drivers.

mark, you said you had tires on the drivers, which confused me to think you had traction drivers. I know MDC doesn't use traction now, but wasn't sure if they used it on older models.

Basic wiring of an MDC loco is primary pickup is through tender, grounding is through loco via the axels on the drivers. Try removing the lower plate, take the drivers out and sand and clean the contact area there. it sounds like you're having poor contact or dirty track issues. also file the tender underframe where the contact strips touch it (screw acess head)

Jay

[Anonymous]

NTDN, I think the proper name for the rim on the drivers of a steam loco is called a tire. This is a brand new loco which I built. When I started testing it out and began having problems, one of the first things I did, was disassembled and clean the all electrical contacts in both engine and tender, so I could rule them out as a source of the trouble.

[Anonymous]

QUOTE: Originally posted by deschane

When I started testing it out and began having problems, one of the first things I did, was disassembled and clean the all electrical contacts in both engine and tender, so I could rule them out as a source of the trouble.

well if you've ruled out the Motor, the pickups, and any electrical connections, then you shouldn't have any problems. So let's focus on the track.....

1) Are you getting a full 12 volts to the rial in all locations?
2) does it bog down only in certain spots? Turnouts, ect
3) have you run feeders about every 3 feet? don't rely on rail joiners for power, they're not good for it.

Jay

[Anonymous]

I don't know that I can say I have ruled out the motor. I feel my track is fine, because the other 8 locos I have either converted to DCC or came that way run very well. I will however, check voltage around the layout and get back to you.

[Anonymous]

I am finding I have a consistant 15+ volts AC around the entire layout. Voltage runs about 15.08 to 15.14 volts.