Need help - DCC Engine Not Running Smoothly


D&J RailRoad said:
I still think it's an issue with the wiper contact with the wheels.
Do you have a means of measuring current draw? That would tell you if something is an intermittent short.
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My layout uses DCC++ and JMRI, so there is a window where I can watch current draw. However, it's not a real time display (it lags a little bit) so it's hard to see spikes. The only amp meter I have access to is a clamp style oscilloscope probe which lives at work and although it would be possible to take home, I would rather not bring home $25k worth of equipment if I don't need to.

Other than cleaning the wipers and wheels, what else could be done to improve that connection?
 
I believe Bmann charges $50-65 now for repairs..if it's worth it to you.. If they can't fix it they send you a different loco...If it's still under 1 yr warranty it could be free if you'd registered it... Just sayin'......
 
The wipers need a clean surface to rub against to conduct electricity. I couldn't tell from the pictures how many are on each wheel. Of other concern is shorting. If you can unplug the decoder you may be able to roll the motor to see if there is any shorting action.
 
bklynman01 said:
I laid some brand new track this weekend, and tested it using a little 0-6-0 Tank Forward switcher. This little engine that could... just couldn't.
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Ok, I've been reading this thread with some interest, as I have an MDC 2-8-0 that has similar issues. I think it's issue is that its axles are not making good contact with the frame. Looking at the explosion diagram for this loco, it is a way different configuration. In your case, I want to see the inside part of the bottom cover. I presume it is made of plastic?
want to see.jpg
 
Sorry for the delay, had to to take a day to make some trees and build a mountain. Now that I'm refreshed about this, here we go...

The wipers are here, and there's a picture of how they lay on the engine. I tried to get from all angles, but the little spotlight I use on my bench was causing some shadows. Let me know if there's a better image that may help.

1647644761965.png



I've cleaned the portion of the wiper that contacts the wheels. You can see the little bumps at the end of each piece where they touch. I also tried to give a slight bend so that the contacts are pressed up against the wheels nicely. The curvature of the wipers seems to fit the wheels, maybe it's just to make them less obvious when looking at the loco from the side? Either way, that shape does make it somewhat difficult to keep the contact point (the tip of the wiper) aligned with the outer rim of each wheel. From what I can tell, they're lined up pretty well.

The points where the chassis side contacts touch off on the wipers is pretty clean. They shouldn't be rubbing much, but I would imagine there would be some kind of mark where they touch, no? Anyway, I've cleaned that area a few times, and cleaned the other contacts as well.

Any ideas?

PowrCab said:
I believe Bmann charges $50-65 now for repairs..if it's worth it to you.. If they can't fix it they send you a different loco...If it's still under 1 yr warranty it could be free if you'd registered it... Just sayin'......
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I think I only paid about $75 for this at a show, but I'll look into this. If it's $50, maybe it's worth it...

thanks!
 
bklynman01 said:
The wipers are here, and there's a picture of how they lay on the engine. I tried to get from all angles,
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Each wiper (one on each side) is a solid piece of metal. No joints or connections.

Points of non-connected electrical transfer:
from track to wheel. and there are three of these on each side.
wheel to wiper. likewise three on each side
wiper to contact fingers. single connection on each side. no motion involved.

Seems like all of those have been cleaned and tested. My next idea was the board itself, but you said you ran power straight to the board and it worked well.
 
Have you checked the running gear to see if there is anything binding or rubbing? As the hesitation seems to be related to the rotation of the drivers, that might be an indication of same. Also, have you checked the gaging of the drivers? And how about quartering?
 
Remove the connecting rods then try again to see if there is any mechanical binding there. That would rule it out.
I'm also, reading through this, thinking electrical, but better to know for sure.

Also, check for any connection between the wheels on each Axle. There should be none. Then, fully assembled, check for connection between all wheels on each side.

My first thought was the motor itself - perhaps it as an old three pole motor (which all tend to run for crap with that same jerky motion on DCC), but then I saw that little DCC ON Board sticker, so most likely not the case.
 
No. Since you bought it second hand I believe it's going to be at least $65 for a Bmann fix..(+ postage one way ?)

Not sure: Have you put power to the black and red leads while it's not on the track ? I.E. If, while on its side it still baulks/stutters would eliminate wheel pickup as culprit ...leaving wipers and motor...and I'm thinking at this point it is going to turn out to be a motor problem...

KBO2 I don't think there are any DCC issues that have come with old 3 pole motors..If it did it'd likely have old horn hook couplers as well as pizza cutter flanges..No. This is most likely a 5 pole, skewed.....
 
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PowrCab said:
No. Since you bought it second hand I believe it's going to be at least $65 for a Bmann fix..(+ postage one way ?)

Not sure: Have you put power to the black and red leads while it's not on the track ? I.E. If, while on its side it still baulks/stutters would eliminate wheel pickup as culprit ...leaving wipers and motor...and I'm thinking at this point it is going to turn out to be a motor problem...

KBO2 I don't think there are any DCC issues that have come with old 3 pole motors..If it did it'd likely have old horn hook couplers as well as pizza cutter flanges..No. This is most likely a 5 pole, skewed.....
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Most of mine (nearly 40, OO scale) are 3 pole motors, they either work, need a push to start, (which is a broken winding) or you get zilch out of them, (I've fried the motor).Never had this Jerky movement on either the Steam or Diesel loco's.
The only other explanation I can think of is a motor bearing, but that's a rarity, and I'm really not sure that could cause the problem anyway.
 
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Everyone, thank you so much for the help! I've always thought my troubleshooting skills were decent, but this one has me wondering. Your input is really helpful, I appreciate all of it.

KB02 said:
Also, check for any connection between the wheels on each Axle. There should be none. Then, fully assembled, check for connection between all wheels on each side.
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I checked resistance between the wheels when fully assembled. There was the expected connections between wheels on the same side. AND there was about 200K Ohm from one side to the other. Removed the wipers/cover and checked again but had no connection between right/left. So something about the assembly was causing a high resistance short. I cut some small pieces of shrink wrap and laid them over the axels and assembled again, this solved the resistance problem. However, the loco won't run with those pieces in place. So I used the clear nail polish again to coat the portion of the wipers that is inside the assembly (the blue box in the image below). This resolved the connection between the wheels. Now, I read under 5 Ohms between wheels on the same side, but OPEN from any of the left/right combinations.
1647865478099.png

I had a lot of hope after this, really. The shorting between wheel sets seemed to be the type of issue that would cause intermittent shorting which results in jerky movement. But no. Operation is still the same.

PowrCab said:
Not sure: Have you put power to the black and red leads while it's not on the track ? I.E. If, while on its side it still baulks/stutters would eliminate wheel pickup as culprit ...leaving wipers and motor...and I'm thinking at this point it is going to turn out to be a motor problem...
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I have not done this, and now that you say it, I'm not sure why I haven't. Seems to be a logical first step, but haven't done this yet. I'm working from home today, maybe I can try this at lunch time...

KB02 said:
Remove the connecting rods then try again to see if there is any mechanical binding there. That would rule it out.
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This is what I want to do next. Everything looks electrical, but at this point, I have no clue.
To remove the wheels takes some effort on this loco. Will update when I get this next.
 
If you're getting a short between the frame and both wheels on one axel then one or several of the wheels must be reversed in the frame. One of the wheels should be insulated from the axel. If one wheel set is installed in the frame reversed from the others, you'll have a short. The insulated wheels should all be on one side of the loco.
 
PowrCab said:
Not sure: Have you put power to the black and red leads while it's not on the track ? I.E. If, while on its side it still baulks/stutters would eliminate wheel pickup as culprit ...leaving wipers and motor...and I'm thinking at this point it is going to turn out to be a motor problem...
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Well, the same problem existed. Here's what I noticed...

I used a pair of alligator clips, one side on the tracks and the other end I just pressed on the wheels. If I held the clips so that they also contacted the flanges (inboard side of the wheel), it ran fine. As soon as I slid the clip face off the flange and depended solely on the surface of the wheel, there was intermittent connection and jerky movement occurred. This was the same on all of the wheels - as soon as the clip detached from the flange and depended on the widest part of the wheel, the jerky movement happened.

SOOOO... there's something wrong with the face of these wheels. Let's go back for a second to an earlier post - do you think that pitting on the wheel face could be the culprit? At this point, I'm thinking yes.
 
bklynman01 said:
SOOOO... there's something wrong with the face of these wheels. Let's go back for a second to an earlier post - do you think that pitting on the wheel face could be the culprit? At this point, I'm thinking yes.
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With that as a prognosis, I just looked at that picture you posted of the wheels way back at the beginning of this. Just an observation, I see some pretty good wear bands on a few of the wheels, and others not much at all.

I might suggest you try "polishing" them with some electrically conductive cleaning fluid. Thinking of things like Rail Zip 2, "Conduct-a-Lube", LPS-1, or even Amzoil MP (metal protector).
 
If you're saying the problem IS the wheel treads/tires, then I think it's time to send loco to Bmann where they will either fix or replace it..
Everyone has given you all the scenarios except I believe, wheels being out of quarter/rods binding..But I don't think it's that, due to your latest test report..
Either moth ball, or have loco repaired/replaced by manufacturer..You won't save much, if anything, replacing wheels yourself If that IS the problem..
You can phone Bmann repair as well.
 
If you're sure it's the tread of the wheel, sounds like something was painted onto the wheel and you have some of the tread exposed. Not knowing what might have been painted onto the tread makes it difficult to determine what to clean em with. I don't think Bachman would replace it as a warranty if it was done by a user.
This would be the only time I would consider using acetone on wheels. Use a scrap piece of track to run the loco on using jumper wires, then lay an Acetone wetted paper towel across the track and run the loco in it till the wheels operate clean.
 
No. I meant I believe Bmann will fix or replace loco for what looks like $65.00..as it's a second hand item no longer under year warranty...
 
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If your sure it's the wheels, look around and see what the cost of a junker would be, might be cheaper (and quicker) than sending it to Bachmann.
 
Okay, I went through the store at Bachmann's site and there are no geared drive wheels available, but they do have non geared wheel sets. They're pretty cheap, so not a big deal if that's the direction.

Before buying any parts, I sent an email to their service team with a link to one of the YouTube videos of it running. I'll see what they say and go from there.
 
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