# LGB Engine hesitation, especially when moving forward



## jdejong (Nov 27, 2016)

I have some new (to me) engines that show very little wear but one of them has a very weird stutter and hesitation when moving forwards, and sometimes when moving in reverse.I test another train on the same track segment to rule out the track. I also oiled the train and gave it a general cleaning to make sure everything was good. Lights and other DCC functions work without issue and reverse seems to work much better so I am kinda at a loss. Any thoughts?

Here is a video 



 to give you a better idea of what I am seeing. The second train in the video is to show that the track is working fine.

Thanks in advance for any ideas 

-J


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## Greg Elmassian (Jan 3, 2008)

Sounds mechanical... how does it run on DC...

Greg


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## East Broad Top (Dec 29, 2007)

I'm wondering if it might be low-speed stuttering caused by the decoder's BEMF settings. I've seen locos stutter like that, but it goes away when BEMF is turned off or the PID parameters of the BEMF are adjusted. Whose decoder is in the loco?

Later,

K


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## Greg Elmassian (Jan 3, 2008)

If the BEMF parameters are wrong, they would be wrong in BOTH directions, right?

(answer: yes, there are no separate forwards and backwards settings)

While that jerkyness looks similar to bad BEMF parameters there is still a mechanical difference between forwards and reverse on that loco.

Greg

Greg


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## rayjturner (Feb 20, 2008)

I have an LGB Stainz (0-4-0 acting the same way. Only I'm using Aristo Revolution to drive the motor. I have tried two receivers - same results. I have tried running on pure DC - runs butter smooth at 5 seconds/revolution. I have used these Revolution controllers on several other engine types - work fine. I have also thought of BEMF. No way for me to turn it off though. Also, it running seems to be smoother after running for 5-10 minutes. Is something warming up? I have checked the driver quartering carefully and also tried moving it one cog either way - same results. Could it be something with these LGB motor blocks? 
Ray


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## Greg Elmassian (Jan 3, 2008)

there could also be something weird, like a swap between the pickup wire and the motor lead, that will evidence itself only in one direction.... eventually this will kill the decoder.... ask me how I know this...

Greg


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## Dan Pierce (Jan 2, 2008)

I have seen this before and my guess is an axle gear shifted and in one direction only the motor gear is on the edge to engage the axle gear. in the other direction the axle shifts to the other side and the gear partially engages. All LGB engines I have worked on do shift the axles side to side when changing direction.Note that this does explain why one direction is OK and the other is bad.

I have this engine and it came in the MTS starter set. Engine part number is a 20900.1 (.1 for digital in a set which came with 2 digital engines and the MTS system).


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## jdejong (Nov 27, 2016)

As Dan hit on this is an engine from the LGB MTS starter set. I have not opened it up the top of the engine but it should have the stock LGB decoder in it. 

I can try it on a DC track segment but my guess it this is something mechanical and not digital.

Assuming it is a partial engagement of the gear after the axel shifts, how does one go about fixing this? Is it just an alignment issue?

Thanks guys for all the thoughts!

-J


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## Greg Elmassian (Jan 3, 2008)

Posting pictures when open will help a lot.

Greg


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## Dan Pierce (Jan 2, 2008)

I use a wide blade screwdriver and center the axle gear on the axle. This can be done from the bottom, just remove the bottom plate. Be sure to align the wheels when done or the side rods will bind.


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## East Broad Top (Dec 29, 2007)

Greg Elmassian said:


> If the BEMF parameters are wrong, they would be wrong in BOTH directions, right?
> 
> (answer: yes, there are no separate forwards and backwards settings)


Agreed. The loco running in reverse did not strike me as being terribly smooth, either, especially at around :40 into the video where it really lurches backwards. Since BEMF is easily turned on and off on some decoders, I figured it worth mentioning as something that could quickly be checked if the decoder allowed. You'd have an answer one way or the other simply by reprogramming a CV.

Later,

K


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## jdejong (Nov 27, 2016)

So I took the bottom of the engine apart again and removed the wheels and put them back in making sure they were centered and the same issue is still occurring. I also ran it on a DC track here are some video's of the train on the DC track. You can also hear a very audible difference between forward and backward. Backward can stutter a little but forward is really pretty bad.











If is is BEMF, can i make adjustments to that using the LGB 55015, or is something else required? Is there instructions somewhere?

Thanks!

-J


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## Greg Elmassian (Jan 3, 2008)

No BEMF adjustments in 55015, in fact I don't believe it has it at all.

Take the siderods off and try, the loco looks out of quarter.

Greg


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## East Broad Top (Dec 29, 2007)

Try bypassing the decoder, feeding DC directly to the motor itself. You'll have to take the loco apart to do that, but you're going to have to do that to fix it if it's a mechanical issue anyway. If it stutters like that directly with DC to it. then it's definitely something mechanical--either something in the gears or the motor itself. If it runs smoothly, then there's something wonky in the decoder.

Later,

K


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## kormsen (Oct 27, 2009)

i agree with Greg.
on the starting pic of the video, whose number ends on "32" it can be seen, that the rod is lower on the front end.
that loco might be "centerd", but it definitly is not "quartered".


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## kormsen (Oct 27, 2009)

take a look!
i would think, the aixles are one tooth off.


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## Greg Elmassian (Jan 3, 2008)

I agree, still looks off to me, and would explain a lot.

Greg


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## wolfetrac (Dec 24, 2010)

I have the same Loco and it had the same problem. It was the motor itself. I swapped motors with a spare motor block I had laying around and the problem was cured. The motor that came out of this loco is different looking then what I used to see inside other LGB motor blocks. It is all silver looking and looks like it has fixed brushes. The loco only had about 1 hour run time on it. I noticed it ran bad since new but I figured it would improve with some run time but it never got any better.


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## Greg Elmassian (Jan 3, 2008)

Since we have not heard from him in almost 3 months, and no result of removing the siderods (which would eliminate the question of siderod binding), we can only speculate. The way it cogs when running is suspicious.

We may never know the real situation.

Did your loco "cog" the same way?

Greg - 124


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## HotGens (Jan 8, 2018)

Here to check out some comment... Not my kinda thing


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