Thomas

Home | News | Products | Services | Reference | Notes | Calendar | Prototype | Stories | Account | Links | Revisions | About Us

Up

Thomas the Tank Engine (with moving eyes) by Bachmann

My incentive for modifying the “toys” that are being produced for the younger set is to present them at train shows.  In a hobby dominated almost exclusively by 55-year-old men, I love the interaction with children that are still interested in the hobby.  I feel strongly that we have to be able to transition them from “Thomas” to modeling.  This means selling them (and their mom’s) on the seriousness and broad appeal of the World’s Greatest Hobby.  It does a lot to see Thomas running alongside or helping a UP SD90 drag 100 cars around a huge, well-detailed modular layout.  This is where the connection is made.  Kind of like the “Roger Rabbit” or new “Looney Tunes” movies where fantasy and reality come together.  This age is from four to about eight depending on the child.  I’ve found that this is also the time for girls to make the transition as they start to get interested in the hobby also.  So, with these concepts in mind, and understanding that our modular layout and our business layout is DCC, any engine I get has to be “decoded”.  It took awhile to get just an engine.  I waited about five months.  It was worth it.  I first started looking for Thomas and Thomas friends engines about two years ago.  The only ones on the market at the time were Hornby.  I looked at every show and every web site and finally was able to get a Hornby James and a Duck (his real name is Montague).  My first task was to modify them.  I started with the James since it had more kid-appeal.  The challenge was to find space.  And then there was the massive 3 pole motor.  My little DN121 was no match and quickly burnt out after about a month of running.  When I heard about Bachmann’s reprise of the Thomas group I quickly ordered several sets and several individual engines.  The Bachmann Thomas is the one that I will be describing in this article and will do a Bachmann James (which I decoded with sound) in a later article.

Space

In preparation I always completely disassemble the engine to determine space limitations.  I also search the Internet looking to see if anyone else has done this engine and how they did it.  In this case, since it is brand new, there were no references.  In the disassembly I use the instructions if available and of course they were.  Interestingly, Bachmann has decided for this model to provide a removable cab.  Not that they had to, since a one piece body, I would have thought, would be appropriate given the lack of any detail.  With the cab removed it becomes obvious that there is scads of room to put in a decoder and maybe some weight since the little choo choo only weighs in at 3.0 ounces and with decoder and harness 3.2.  My plan is to put in an inexpensive decoder (DH123D) rather than much pricier units like DZ123 or DN123.  While these may gain some space for added weight, usually the problem is current.  In this case the current draw will be minimal as the engine is not a standard can motor with flywheel but a miniature open frame.  All the more reason to put in a heftier decoder.  I put in the older DH121, since I had a spare lying around.

 

Electrical

Europeans!  What are they thinking?  Well obviously they were not planning on me putting this on a DCC layout.  When I decoded the Hornby James and Duck they were immediate shorts.  In defense, Hornby's three-pole motor needs a little help.  So, they added a capacitor in parallel with the motor.  This is great when your track is running DC and does a fantastic job of smoothing out the rough edges but on a DCC layout with AC present on the track the capacitor acts as a dead short.  I immediately clipped these little darlings out on the Hornby's, as I had no further use for them.  On the Bachmann Thomas they had also used a capacitor in parallel with the motor but was not as harmful.  The designers had placed some resistance on the trackside leads to prevent a direct short from appearing and tripping the booster.  Nevertheless, it may be prudent to remove this nasty circuit and let the new decoder circuits handle the mess rather than try to fix it with analog components.

To splice or not to splice, that is the question

With the cab off there is plenty of wire.  You could really just clip and splice.  A few minutes and… wha-la ...the job would be over.  But…I decided that I really needed to do my normal engine service that includes:

  1. Remove all packing grease and re-lube. This, by the way, improved performance significantly.
  2. Check all wheels for gauge.  The Hornby models were all out of American HO gauge and had to be adjusted.  I really didn’t think the Bachmann model would be any different but was pleasantly surprised when all wheels were dead on gauge.

This meant removing all the parts.  While I was at it then, I decided to solder the joints at their origin rather than splice.

I started by cutting (or unsoldering) the red and black wires from the motor circuit board.  These will be orange and gray respectively from the decoder.  I elected to try it with the capacitor/resistor circuit still in.  In the commercial version we remove the circuit altogether. If you elect to try it without the circuit be very careful soldering directly to the motor as you may melt the plastic surrounding it.  Nothing bigger than a 15 watt iron and around 6 and no more than 10 seconds applying heat.  Kind of like spray painting, better to do it in two short bursts with it cooling off in between rather than one long one.  Also, tinning your wires for small stuff helps a lot.

Then, disassembling the undercarriage, I clipped (not de-soldered) the leads to the copper pickup strips.  This was fear of overheating these strips.  Any amount of heat will destroy this part.  Better, if you are not adept or faint of heart, to do the splice thing and not apply heat in this area.  Notice that you must thread the black and red wires through several parts including the wheel sets. (look at the picture...the first time I messed up!  Compare this with the first picture of the engine and you will see that there is supposed to be another part, the running boards and base that I forgot.  Had to unsolder, re-string the wire through the missing piece and solder again...(oh well). Another option is to put in a connector here.  I didn’t.

Test

Ok, that’s about it.  What about the lights?  What lights?  This thing doesn’t have any lights…yet.  I put it together without the cab to do a quick motor test.  I wanted to see if the circuit board and the capacitors were going to be a problem.

Well, no problem.  And without putting lights in it, I decided to button it up and test for now.

Since there has been some confusion about the circuit board wiring we have elected to remove it.  It will not hurt the engine or its performance.

One more step…set the address.  As is customary, using the reporting marks on the engine, assign it the number…1.

If you want to buy a New! "Ready to run" Thomas with DCC and lights already installed just click "add to cart" below.

Item Name: Thomas with DH123 decoder and lights
Item Number: TB-1605874112
Price: $77.12

Please e-mail for other options/pricing.


Contact us at 919-562-4378 or e-mail:info@trainbuddy.com

(c) Copyright 2002-2007, K.A Parker & Associates, Inc.  All rights reserved

This page was last updated: 2007-10-12