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Bachmann 2-8-0 smoothness (or lack thereof)

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  • Member since
    May, 2018
  • 3 posts
Bachmann 2-8-0 smoothness (or lack thereof)
Posted by oliver37 on Friday, May 04, 2018 12:34 PM

Hi all,

I'll give you a little background for perspective, but if you want to jump to the actual issue, you can skip to the bold text below.

I started my first layout late last year and have learned a lot since then (chronicaled here).  It is DCC and all of my locos have Loksound decoders, except for one BLI set.  I have programmed a variety of CVs over the last few months and I am comfortable with doing so.

Recently I wanted to add an era-appropriate steam loco to my Northern California layout, and decided that a Western Pacific 2-8-0 was close enough.  Having researched the Bachmann version of this model for a few months (much of which was done on this forum), I pulled the trigger on a DCC version from Trainwold, which was on special.

I never intended to keep the OEM decoder, as a) it doesn't have sound and b) my expectations of its performance was low.  So I already purchased a TCW WOW decoder kit to try out in it.  That being said, the slow speed performance is really bad...

The Actual Issue

Here's a video that sums it up best.  As you can see there is a lot of lurching and the loco doesn't seem capable of maintaining a cosistent speed at the lower speed steps.  What those speed steps actually are is anyone's guess because the speed curve seems massively non-linnear and I use Digitrax, but that doesn't really matter as much as the lurching, since I plan to replace the decoder anyway.

This is the second copy of this loco and the first one performed basically the same, which is why I returned it.  I will take a moment to say that Trainworld gladly exchanged the first unit and has been very easy to deal with.

So my question is this:  do you experts believe that the mechanical condition of this unit is good enough to produce smooth low-speed operation with the superior TCS decoder?  I probably shouldn't take the loco apart and try it, as I may need to return it to Trainworld again.

Honestly, shipping things back and forth is kind of a pain, and I am open to fiddling with the mechanicals a little bit if you guys thingk it can easily be fixed.

https://youtu.be/yOWmQFgctv0

 

Thanks in advance for your help!

  • Member since
    February, 2002
  • From: Reading, PA
  • 24,870 posts
Posted by rrinker on Friday, May 04, 2018 3:18 PM

 Running it in for a while will probably help. At the points it seems to bind, check the side rods, it's possible the quarter is a little off and causing a bind in the rods.

But don't discount how poor the stock DCC decoder is - coupled with the capacitors across the motor. If you have a spare better quality motor decoder laying around, give that a try - clip off the capacitors, and see how it runs with a better decoder.

                                --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by BigDaddy on Friday, May 04, 2018 3:51 PM

The latest video on brasstrains.com claims that out of quarter problems show up at 9 and 3 o'clock.  If it happens at 10 and 2 it's not a quartering issue.  The video looks like a a 9 and 3 issue to me.  That's my entire knowledge about quartering. 

Not sure how easy it is to disconnecting from the motor and see if it free wheels or binds.

 There are a lot of happy steam Bachmann owners here, so it's surprising it happened in two locos.
 

Henry

COB Potomac & Northern

By the Chesapeake Bay

  • Member since
    December, 2004
  • From: Pa.
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Posted by DigitalGriffin on Friday, May 04, 2018 4:23 PM

stock DCC decoder is horrid. Trust me on this.

The Soundtraxx/Sound value one is much smoother.  I own 4.

 

Edit: After looking at the video the quarter does appear off.  Or possibly the crosshead is bent.  I've had that happen before.

send it to bachmann.  They will fix it up.

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    January, 2009
  • From: Maryland
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Posted by ATLANTIC CENTRAL on Friday, May 04, 2018 4:59 PM

There are noise suppression resistors and capacitors on the factory light board that are required in europe, but effect slow speed performance. This is true for DC or DCC operation.

A search of this form should provide more detail, previously posted by me or others on how to identify and remove them.

Once gone, even the junky stock decoder will have acceptable slow speed.

When you install the sound decoder, remove the factory light board completely, the performance will be greatly improved.

Sheldon

    

  • Member since
    January, 2017
  • From: Southern Florida Gulf Coast
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Posted by SeeYou190 on Friday, May 04, 2018 10:45 PM

oliver37
Hi all,

.

Just since no one else said it already...

.

Welcome to the Model Railroader forums.

.

Your first few posts are delayed by the moderatros, but that ends soon enough. I hope to see you around for a long while.

.

-Kevin

.

Happily modeling the STRATTON & GILLETTE RAILROAD located in a world of plausible nonsense set in August, 1954.

  • Member since
    August, 2003
  • From: Collinwood, Ohio, USA
  • 6,389 posts
Posted by gmpullman on Saturday, May 05, 2018 12:24 PM

Hi, and Welcome!

I remember when some of the early Spectrum locomotives were coming from Bachmann. Some of the fellows around the shop were talking about the "new" belt drive and its reliability. Belt drive? It was a whole new concept at the time.

I have since sold off many of my early Spectrum locos but reading about your "lurching" I wonder if it could be a belt problem, such as the belt taking a permanent "set" from being stored for a while.

Take a look at this skhetch and you will see the belt on the motor shaft.

http://www.bachmanntrains.com/home-usa/dwg/dwgs/H836-IS001.PDF

This is the part number for the belt:

http://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=66_68_86&products_id=925

Still, before getting into any major overhaul, I would follow randy's suggestion and run the locomotive in — at least an hour in each direction at various speeds — and see if that begins to make an improvement.

Hope that helps,

 

Good Luck, Ed

  • Member since
    May, 2018
  • 3 posts
Posted by oliver37 on Saturday, May 05, 2018 8:48 PM

Hi Everyone,

Thank you for the feedback and the warm welcome!  After reading your replies I decided to tear into the loco to figure out what was causing the issue.  I removed all of the wheels, inspecting them for 90-degree indexing of the side rods (I think this may be quartering?) and checking the wheels for guage while I was at it.  

I didn't see anything out of whack, except for some white paint on the wheels that I cleaned off.

Everything seems okay here...

Uh-oh

I don't know how I didn't notice sooner, but one of these little guide tracks coming out of the piston was bent...that would probably do it!

Everything is back together and the loco runs much more smoothly.  The motor control is, as you all have mentioned, still abysmally bad, but I'm optimistic that the new decoder will take care of that.

https://youtu.be/IUTpobZj1NE

Ready for the new decoder!

Glamor shot

 

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  • From: Western, MA
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Posted by richg1998 on Sunday, May 06, 2018 11:49 PM

ATLANTIC CENTRAL

There are noise suppression resistors and capacitors on the factory light board that are required in europe, but effect slow speed performance. This is true for DC or DCC operation.

A search of this form should provide more detail, previously posted by me or others on how to identify and remove them.

Once gone, even the junky stock decoder will have acceptable slow speed.

When you install the sound decoder, remove the factory light board completely, the performance will be greatly improved.

Sheldon

 

There are no noise suppression resistors. Those are inductors. Check the prefix. You will see a L not an R. They are 4.7 micro Henry inductors on my Bachmann locos. They form a tuned circuit with the capacitor/capacitors.

Remove the caps, the inductors are a moot point. They become a short piece of wire. Measure the resistance. Clueless believe they are resistors. I have seen this a number of times in forums. Check the color code. I have measured them with an inductance meter and checked the color code. You can find it on the Internet. Very easy.

Rich

N

  • Member since
    January, 2009
  • From: Maryland
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Posted by ATLANTIC CENTRAL on Monday, May 07, 2018 4:57 AM

richg1998

 

 
ATLANTIC CENTRAL

There are noise suppression resistors and capacitors on the factory light board that are required in europe, but effect slow speed performance. This is true for DC or DCC operation.

A search of this form should provide more detail, previously posted by me or others on how to identify and remove them.

Once gone, even the junky stock decoder will have acceptable slow speed.

When you install the sound decoder, remove the factory light board completely, the performance will be greatly improved.

Sheldon

 

 

 

There are no noise suppression resistors. Those are inductors. Check the prefix. You will see a L not an R. They are 4.7 micro Henry inductors on my Bachmann locos. They form a tuned circuit with the capacitor/capacitors.

Remove the caps, the inductors are a moot point. They become a short piece of wire. Measure the resistance. Clueless believe they are resistors. I have seen this a number of times in forums. Check the color code. I have measured them with an inductance meter and checked the color code. You can find it on the Internet. Very easy.

Rich

 

True, they are inductors, and yes only the caps have to be removed to void the circuit.

But again, this is a big factor in the slow speed performance of these locos, DC or DCC.

Sheldon 

    

  • Member since
    December, 2004
  • From: Pa.
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Posted by DigitalGriffin on Monday, May 07, 2018 11:45 AM
I had a feeling the cross head guides were bent!

Don - Specializing in layout DC->DCC conversions

Modeling C&O transition era and steel industries There's Nothing Like Big Steam!

  • Member since
    May, 2018
  • 3 posts
Posted by oliver37 on Wednesday, May 09, 2018 10:14 AM

To close the loop on the decoder swap project...I swaped the decoder for the TCS Wow kit that I mentioned yesterday.  The kit includes a motherboard, decoder, and speaker.  Though I do own a soldering iron, I would not consider myself a solderer, nor had I installed a DCC system in a loco before, so I began the install assuming that I would get at least something wrong.

Here's the OEM Bachmann motherboard.

The installation guide on the TCS website appears to use an older Bachmann 2-8-0 that was not already configured for DCC.  My loco is newer and obviously DCC already, and the wire colors in the tender *did* match the TCS wiring diagram, with the exception of white, which was actually yellow (I understand that older Bachmann locos did not match at all).

The tender was pre-drilled for a speaker, and the TCS speaker dropped right in.  I secured it with a few globs of hot glue.  I did not use the included speaker enclosure, as I was already pressed for space under the motherboard.

The biggest challenge was mounting the motherboard, as the tender's screw posts were a) too short with the speaker installed and b) not lined up with the holes in the motherboard.  So, as you can see in the picture, I glued some cork on top of the old screw posts on one end, and on top of one of the weights on the other end.

Yes, that is a string of hot glue running from the black wire to one of the weight screws.  I don't know how I did that.

I could not get any combination of pins/screws to firmly secure the motherboard to the cork, so I ended up placing a small drop of glue between them at each end, hoping it wouldn't eat away at the circuit board.

In this picture you can see the drops of solder already added to each pad.  I put those there...not sure if this is correct soldering protocol or not, but it seamed easier than fiddling with a wire, solder strand, motherboard, and the soldering iron all at the same time.

Here's the installed motherboard and decoder.

Okay...here's the amazing part:  the loco worked first time out!!  I can barely solder one wire to another reliably, so I was shocked.  Now we can get to the whole point of this thread - smooth operation.  I know you all said (and I believed) that the Bachmann decoder was lousy and that there would be a big difference with, well, anything else.  But, holy moly, I did not expect THIS big of a difference.

This thing will creep along at one tie every 2-3 seconds, which is so slow it's hard to tell it's moving sometimes.  It is also commendably quiet.  This decoder has taken a loco that operated like a garbage disposal full of rocks and turned it into one of the smoothest locos I have, and that's in a roster of Loksound locos.

The sound quality is also a cut above.  I didn't have too many complaints with my Loksound sound, but this is clearly better, with less static, more depth, and more realism.

The auto-chuff volume (depending on grade and load) works really well, the rod clank sounds great when coasting, and the braking sounds are awesome.  I actually found myself waiting for steam to start billowing out of the cylinders when setting off from a start.

Here are some videos.  The first is a nice, slow start from a stop and then deceleration back down to a stop.

https://youtu.be/KflJku1WIt0

The second video is another start, though I believe I jumped straight to speed step 2 in this one, instead of speed step 1 in the first video.  It's still cool.

https://youtu.be/k0G_cVlQn5c

The last video is a high speed braking application to a stop.

https://youtu.be/y0cMAkb_Vdc

Thanks again everyone for your help.  I hope that this thread can be used by others down the road who are considering the same, or similar, modifications.

 

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Posted by Redvdub1 on Thursday, May 10, 2018 7:47 AM

Your problem is familiar to me..One of my 2-8-0s is smooth throughout the entire speed range...the other NOT.  My problem is that the "unsmooth" one has too much slop in the chassis opening that holds the motor.  As a result the motor literally wobbles in place ...ergo lurching.  I intend to try epoxying the motor in firmly before I buy a new chassis...I've heard that this can work. 

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