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Installing decoder in 4-4-0 American, Bachmann

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  • Member since
    December 2007
  • From: Gateway City
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Installing decoder in 4-4-0 American, Bachmann
Posted by yankee flyer on Monday, November 1, 2010 1:11 PM

 

Hey Guys

I'm totally confused on this Bachmann 4-4-0. It has motor drive in the tender with only one wire from tender to the boiler and only one wire from the front truck going to the head light. If I isolate the motor from the pick up can I leave the boiler as is, with the head light on all the time. Then control the motor only with the decoder? I bought a Digitrax DZ125 that should be small enough to go in the tender. I am assuming that the boiler acts as one wire for the head light, but if they are using the front trucks, drivers, and the tender trucks to spread the pickup across a longer wheel base, why would there not be a second wire going  between the boiler and tender?Sigh

Thanks I hope someone can give me a little insight.

Lee

  • Member since
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  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Monday, November 1, 2010 2:52 PM

You have one that is not DCC ready, it is a very cheap toy train that was never meant to have a decoder installed into it.

I have two of them and have never attempted to put decoders in because they don't run well enough to justify the cost and effort.

 

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  • From: Colorado
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Posted by fwright on Monday, November 1, 2010 3:45 PM

Lee

A couple of weeks ago, Harold Minkwitz published a thread in the General Discussion forum linking to his reposted web site article on improving electrical pickup in the Bachmann 4-4-0.  Here's the link:  http://www.pacificcoastairlinerr.com/1879/bachmann_4-4-0/wipers/

Hope this helps

Fred W

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  • From: Gateway City
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Posted by yankee flyer on Monday, November 1, 2010 4:24 PM

Thanks Guys

My loco is a new Bachmann item # 51101, it is very well detailed in my opinion and looks to be well made.
I am trying to  understand the wiring concept so that I might install a decoder without smoking it. After using an ohm meter I found there is continuity on the right side from the pilot truck back to the rear tender truck,  but the left side does not carry through. I do have wipers on both sides of the tender trucks. In order to cross insulated turn outs I believe there should be continuity from the pilot to the tender.
Oh by the way I can't get the boiler-driver assembly apart. It's probably painted together.
IMG_0278.jpg picture by Yankeeflyer

If anyone else has installed a decoder or can help I will be most appreciative.

Lee

  • Member since
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  • From: Western, MA
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Posted by richg1998 on Monday, November 1, 2010 4:49 PM

This is a standard DC loco that picks up on the right side loco drivers and left side tender wheels.

Isolate the two motor leads. Connect the decoder using the NMRA wiring instructions for DCC.

Install pickups on the the other tender wheels. Install pickups on the two loco drivers that are insulated.

You should have all wheels with pickups but some locos have rubber tirers. Don't expect them to pull much.

Nothing to it if you know what you are doing. I have done three tender drive locos like that. Two Bachmann, one Mantua General and one IHC. I used a Lenz N scale decoder.

Get yourself a cheap digital multimeter off of ebay or get one from Harbor Freight. They are usually less than ten dollars. I have had three of these meters for some years and are very close to what my expensive meter reads.

A photo of three of my loco installs. Nothing special. The bird shot is for more weight in the tender.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
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  • From: Gateway City
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Posted by yankee flyer on Monday, November 1, 2010 6:44 PM

Rich, Hey

I do have all wheel pickup on the tender. Ifthe boiler casting is the right side pickup then the pickup wire on the pilot is left rail and I should be able to run a wire from there to the tender left side and get electric pickup spread across the entire wheel base pilot to tender?  Smile  I'll let the head light stay on all the time.
I did put a decoder in my 2-6-0 but but it was more normal I just had to carve out a channel to put the four extra wires.  Am I on the right path?

Thanks

Lee

 

  • Member since
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  • From: Reading, PA
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Posted by rrinker on Monday, November 1, 2010 7:26 PM

 You only have 1 wire between the tender and loco because the drawbar acts as the other 'wire'. Quite common on steam locos that pick up from both sides of the tender. Back in the day htere's be one wire, or no wires,a nd it would only pick up on one side of the engine and one side of the tender. If you can isolate the motor from the chassis you can add a few extra wires, you'll also have to add wipers for the side of the loco that currently does not pick up. These wipers have to be insualted fromt he frame. You will have a total of 4 wires - two from the loco pickups back to the same side of the tender pickups, and two from the decoder to the motor.

                                    --Randy


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
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Posted by fwright on Monday, November 1, 2010 8:53 PM

yankee flyer

Rich, Hey

....I'll let the head light stay on all the time....

Lee

Leaving the original headlight wired to the track after switching to DCC is more problematic than folks realize.  The headlight is equipped with a 12V bulb, and rarely sees a full 12V on the rails when on DC (we don't operate at those speeds).  It works pretty well - less than full brightness and heat most of the time.

Switching to DCC changes the situation.  You now have 14.5 volts (or thereabouts, sometimes 16v) on the rails 100% of the time.  The bulb is operating above its rating, and generating lots of extra plastic-melting heat.  Most decoders have a 12V output for lights, some have 1.5V.  If you are not wiring the headlight to the decoder, you should replace the bulb with a 16V bulb - one with the smallest current rating you can find to keep the heat down.  Or wire in an LED in place of the headlight bulb.  Use at least a 1K resistor (1.5K may work better) in series with the LED.

my thoughts, your choices

Fred W

  • Member since
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  • From: Western, MA
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Posted by richg1998 on Monday, November 1, 2010 10:05 PM

My locos do not have LED's or light bulbs so I was not concerned about lighting. My tender drive locos are a few years older.

Normally the right side drivers send power via the loco frame. A wire connects from the loco frame to one motor contact.

Some send power to the motor contact via a pin on the loco and a spring loaded tender tender draw bar. My IHC does that.

The wire in the tender from the tender wheels connects to the other motor lead.

I disconnected the wires at the motor and connect the decoder orange and gray decoder wires there.

The decoder red wire was connected to the right side tender wheels and the power from the right side loco drivers.

The black wire was connected to the left side tender wheels. I installed driver pickups on the loco left side and those contacts went to the black decoder wire.

For a loco light, I would try a 22 ohm ½ watt resistor in series with one light bulb lead. I am guessing at the resistor wattage as I do not know what the light bulb requires for current.

If you can replace the light bulb with a Miniatronics 1.2mm, 1.5 volt bulb, a 470 ohm ¼ watt resistor will work just fine. I am doing that with a couple light bulb installations.

Make sure you insulate the ends of unused decoder wires before testing. Some have been impatient and and a wire touched one rail and smoked the decoder.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
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  • From: Gateway City
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Posted by yankee flyer on Tuesday, November 2, 2010 7:41 AM

Very valid points that I hadn't thought of. Thanks
Every manufacture seems to use a different method to accomplish the same thing. I'm still trying to see how to get the boiler off the frame. I'm also considering putting  the decoder in the first passenger car with sound.
Hmmmm  
Things to do. 
Reduce the head light heat! 
Get a wire from the front truck back to the tender!  To increase pickup wheel base.
Get er done.   Laugh

Thanks  

Lee

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