Bachmann 44 tonner - making it better

[chicken45]

I would be interested in one for sure!

[u18b]

Both hoods slope slightly towards the ends, so there is less clearance the farther you go away from the center. While designing the board I mounted a blank board on the chassis and then I pushed a decoder in under the hood until it jammed.  Then I backed it out slightly (to leave a tiny bit of clearance.  I already filed down the PC board mounting posts on the chassis to mount the PC board as close to the chassis as possible.  I will revisit this while making the 2nd batch of these boards, but I suspect that unless I use thinner decoder, I won't be able to fully move it under the hood.

Excellent thinking.

[PiperguyUMD]

Next was the decoder conversion. I like clean installs, so I designed and etched a printed circuit board to replace the factory installed decoder.  It will hold the DZ125, new warm-white LEDs, the over-current protector for the motor, and the current limiting resistors for the LEDs.  I originally thought of eliminating the over-current protector (the yellow disc), but if Bachmann bothered to use it to protect the small motor, I didn't want to take any chances either. 





This is the new DCC board next to the original Bachmann decoder. It is amazing how many components there are on the very basic Bachmann decoder, and how large it is compared to the DZ125 (which has much more advanced capabilities).

Here is the new decoder attached (by the original screws) the the frame.  I had to file down the screw posts on the frame slightly to give me enough clearance for the decoder and the LEDs.

I'm an electrical novice, but I want to try to etch my own board for my 44 tonner, and for my S4.  From what I read so far, I can draw out the board and print it on a transparency using a laser printer.  I can then use an iron to transfer the ink over to the new board.

Where do I find the current limiting resistors, and how do I determine which ones I need?  I wouldn't mind picking up a few of those LEDs too!

Thanks!

[lv4142003]

jmlaboda and Reinhardt, what will you do to your shells to make 65 ton GE's?

[peteski]

I'm an electrical novice, but I want to try to etch my own board for my 44 tonner, and for my S4.  From what I read so far, I can draw out the board and print it on a transparency using a laser printer.  I can then use an iron to transfer the ink over to the new board.

Where do I find the current limiting resistors, and how do I determine which ones I need?  I wouldn't mind picking up a few of those LEDs too!

Thanks!

Piperguy:
The PC board shown in this writeup was hand-drawn directly on the copper-clad PC board using a technical pen and Testors enamel.  But you are correct, there are iron-on methods for producing etch masks on PC boards.  I have never used that method.  If you do some online searches you will find several makers of such etching systems.  I recommended http://www.pcbfx.com/ to one of the members here and he told me that the system worked great.

This reminds me that one of these days I have to get back to this project as I have few TRW members waiting for some of those PC boards from me. 

[mmagliaro]

I've use PnpBlue from this place:  http://www.techniks.com/

Worked really well and could handle traces fine enough to do a standard 0.1" pin spacing IC.

[PiperguyUMD]

Piperguy:
The PC board shown in this writeup was hand-drawn directly on the copper-clad PC board using a technical pen and Testors enamel.  But you are correct, there are iron-on methods for producing etch masks on PC boards.  I have never used that method.  If you do some online searches you will find several makers of such etching systems.  I recommended http://www.pcbfx.com/ to one of the members here and he told me that the system worked great.

This reminds me that one of these days I have to get back to this project as I have few TRW members waiting for some of those PC boards from me. 

That's a really cool system!  I'll look into it. What about the resistors?  Which ones did you use for the 44 tonnor?  How would I determine which resistors to use for the Bachman S4?  Thanks for your help!

[peteski]

That's a really cool system!  I'll look into it. What about the resistors?  Which ones did you use for the 44 tonnor?  How would I determine which resistors to use for the Bachman S4?  Thanks for your help!

Oops - forgot that one. I used 1000 ohm (1K ohm) 1206 SMD (Surface Mount Device) size resistors. The "102" imprinted on the resistor shown in those photos indicates its resistance. That is a "standard" value used with white LEDs in DCC installs (or even DC installs).  It limits the LED current to around 10mA (which is plenty bright for most white LEDs).  It is not critical and chosen to suit your taste in headlight brightness. Anything from around 560 ohms and up to several kilo-ohms will work.

The LEDs themselves were purchased as an electronic surplus  item and are long gone at the place I bought them from (Electronic Goldmine).  But there are many sources of warm-white SMD LEDs out there: both model railroad suppliers (like Ngineering) and electronic suppliers (like Digikey or Mouser Electronics).  The ones I used in this install are 1206 SMD size, mounted on their side.

[alhoop]

For those of us without a supply of 30 cent Testors ( ), I wonder if nail polish would work?

I've been using red enamel nail polish as resist for years.
All-Electronics and many others carry the powdered etchant.
Use a glass container to mix it in as it gets very warm
PS - I like Peteski's idea on using an inkewell drafting pen .
Al

[u18b]

I then carefully assembled the coupler and the spring in the coupler box. This was a bit of a pain, but I finally managed.

Man, you weren't kidding.

I changed out mine tonight.

Thanks for the ideas.

BTW- I used 2004 couplers.

[reinhardtjh]

jmlaboda and Reinhardt, what will you do to your shells to make 65 ton GE's?

Mostly just painting it the right number.  If you compare dimensions between the 44 and 65 ton models you will find they are within inches of each other in some places and the same in others.  The most noticeable difference other than the doors and vents is that the 65-ton has a thicker decking.  I think the weight difference is nearly all in ballast comprising a the thicker deck.

65-ton:


44-ton:

[Chris333]

Top photo is a 44T, bottom photo is a longer loco.
But a 45T is shorter than a 44T.

[sirenwerks]

Mostly just painting it the right number.  If you compare dimensions between the 44 and 65 ton models you will find they are within inches of each other in some places and the same in others.  The most noticeable difference other than the doors and vents is that the 65-ton has a thicker decking.  I think the weight difference is nearly all in ballast comprising a the thicker deck.

65-ton:


44-ton:

I agree, the Bachmann model presents as more of a 65 tonner than a 44 tonner. The window treatment aside, the deck and skirt are definitely more like a 65T. You could even get away with adding more skirting to hide the gap between truck and frame.

[Chris333]

44 tonner


The GE 65 ton model was introduced in 1940, filling the gap between the 45 and 80ton models. It's design was very similar to that of the GE 44ton (introduced the same year), but was slightly longer (having narrow end walkways, which the 44ton lacked). and more powerful.

The 65ton in your photo is a II-A1 phase. II-A2 had 2 ladders on each side centered on the trucks. II-A3 had end ladders.

[Ed Kapuscinski]

Yep. It's the ladders and walkway that I use as a spotting feature between the two types.

It's amazing how many "44 tonners" turn out to actually be 65ers.