Greg

The Bachmann PNP adapter board that has wires for all the pins in the socket while not included with the K27, it has been included in the box of all Bachmann locomotive with the socket since that time.

Reciently their parts department has also caried this part.

Hope this helps.

Stan

Don Sweet of RCS of New England routinely instals RailPro in a wide variety of Bachmann locomotives that have the interface without any issue. I believe he uses the adapter that has the wires plugged into the socket

So the question is what do you have in the socket, which wires are connected to the railpro unit, how are the switches in the locomotive set and how is your battery connected?

Stan

Quote from: Fred2179 on August 13, 2025, 04:15:17 PM

Quote from: StanAmes on August 10, 2025, 06:26:20 PMmake sure there is DC voltage on the Bachmann's B+ and ground connections

It actually has a battery squashed behind the motherboard, connected to the battery input, and the loco and chuff work fine - except the chuff isn't synchronized.
I will try grounding the chuff trigger, but I think the trigger wire from the Revo is connected to the Chuff Sensor pad and nothing changed.  See my photo on post #14.

Please follow all 4 steps I posted providing the answers for each step.  You need to check the voltage at the B+ and Ground  Battery input 1 is connected to J1-1 and J1-12 only when you have the battery switch on.  It is not connected to B+ and ground.  I believe the revolution provides this voltage but best to confirm.

In step 2 you need to disconnect the solid conection to the Chuff sensor and simply "flicking the chuf wire to the locomotive ground" as Greg suggests.  Each time you flick the chuff wire to groud you should get a single chuff. If the revolution is in auto chuff mode then you might get a whistle of bell sound.

You need to disconnect the chuff wire to the sensor when you do this, If there is no voltage on B+ to ground you will get no chuff and if the Revolution  is not configured for sensor chuff you also will get no chuff.

Your photo shows how you connected wires to the Bachmann board.  I believe this is a revolution issue and not a bachmenn locomotive issue. 

Stan

Greg

The K27 board has chuffs that go positive when a chuff is made. (Note we now have a replacement chuff board that goes negative)

All the Bachmann Locomotives since the K27 that have a chuff circuit that goes to ground when the chuff is trigerred.

I suggested 4 steps for Pete to take

1) ensure the revolution chuff is configured correctly by taking the revolution chuff trigger input and touching it to ground.  You should get a chuff each time you make a connection to ground and no autochuff.

2) As you suggested make sure there is DC voltage on the Bachmann's B+ and ground connections.

3) if 1 and 2 are successful try bending the revolution pin J1-5 so that it does not make a connection to the Bachmann main board.  This may not be required but I have no idea if JK makes any connection to this pin

4) Connect the revolution chuff input pin to the Bachmann Chuff Sensor on the main board ensuring that the connection does not overlap to any other solder pad.

Hope this helps

Stan

Quote from: Greg Elmassian on June 30, 2025, 02:45:05 PMStan, it seems that you are telling the poster to check that the Revolution has the speaker connected to J2-1 and J2-3....

I do not think that is the case. Where did you find documentation that this is true?

Greg

I believe you are correct that the Revo does not connect its speaker output to pins J2-1 and J2-3.  I can not positevely confirnm this as I do not have a Revo board to test.

Peter (Fred2179) believes that his Bachmann board is lacking a trace between these two pins and the speaker socket.  Unless there is a defect on his board (unlikely) I sent him a specific set of tests to confirm that the reason he had to make his own connection to enable the speaker is simply because the Revo board does not support this feature.

Stan

Stan

Peter

Sometimes I can make a mistake so I went out and double checked my D&RG 2-6-0 with both an ohm meter and with two different plug and play decoders and I can positively confirm that the speaker in the Bachmann 2-gen 2-6-0 is correctly connected to J2-1 and J2-3.

While it is possible that you have a defective board, I believe it is much more likely that you have measured incorrectly.  Remember once you soldered the Revo speaker outputs to the Bachmann board the Revo J2-1 and J2-3 are connected to the REVO speaker outputs when the Revo is pluged into the socket.

The best way for you to double check on your end is

1) use an Ohm meter (not a voltmeter measuring voltage))

2) remove the Revo board from the socket.

3) check the Bachmann board by using the ohm meter to check the connections from both the speaker output pins and the solder pads that you connected to the Revo speaker output.  You should find that pins J2-1 and J2-3 are connected to both of these two places.

Next with the Revo board out of the socket use an ohm meter to check the speaker output pins you connected the speaker to are connected to the Revo J2-1 and J2-3 pins.  If there is 0 ohms between these two connections the Revo should properly connect to the Bachman speaker.  If there is no connection, you must manually connect the speaker between these two products.

Please remember that while Bachmann publishes its connections to its non-proprietary plug and play socket, that by no means ensures that everyone who has products that plug into the socket follow that documentation.

Hope this helps

Stan

On the SJR&P many of our C-19 locomotives have battery packs in the tender for the purpose of DCC backup power. One side effect of this is that the tenders are heavier than stock tenders.

Yesterday the tender of one of our C-19 locomotives kept derailing, a condition we have not seen before.

On close inspection I found that the rear truck side frames were hitting the tender frame interfering with the trucks ability to rotate through curves. While the truck side frames are intended to have some play, the play on this truck was excessive.

On disassembly I found that the single spring that is inside each side frame had collapsed. I replaced these springs with springs Bachmann uses on its 1:20 freight trucks. After replacement the tender truck now operates like new.

This particular C-19 was one of the first to receive a battery pack. Inspection of other C-19s with battery packs showed several that were beginning to have excessive sideframe play but not the extent the problem one had. Each will have its springs replaced as well as a preventive measure.

Below is a photo of the collapsed spring next to a new one.

Stan

The Bachmann 2-6-6-2 comes with a manual. In the manual there is a pinout of the socket.

12   Rail +   12   Solid Key
11   Rail +   11   Not used
10   Motor +   10   Firebox Flicker
9   Rear Locomotive Headlight   9   Not Used
8   Smoke Unit   8   Cab Light
7   Locomotive Ground   7   Not used
6   Locomotive Positive   6   Not used
5   Chuff Trigger 1   5   Train Bus -
4   Front Locomotive Headlight   4   Train Bus +
3   Motor -   3   Speaker -
2   Rail -   2   Chuff Trigger 2
1   Rail -   1   Speaker +
Solid Key

As with all Bachmann locomotives with a socket J1 has 12 pins while J2 has 11 pins. J2 also has a solid pin in positions 0 and 12 to help prevent plugging in the socket packwards,

Because the 2-6-6-2 is an articluated locomotive each engine has its own unique chuff input. In the prototyps the engineer would put steam to both engines during starting for maximum power and then as the locomotive gained speed would switch to reusing the steam from the front engine to power the rear engine. the J2-2 pins allows you to produce the same result if you have a sound device that alllows for two chuff inputs or you use a seperate sound device for this pin.

Hope that helps.

Stan

Greg  the first loco with the socket was the K27.  None of the Shays ever had the socket.

It is my understanding that the function pins for all Bachmann locomotives that have ever had the socket are low current pins.  Thats part of the design.

The + and - connections are not low current.  These pins power the elecronics, the functions, the smoke unit, and the fans.

Stan

All the function pins on the socket used by bachmann (including the smoke pin) are low current control function pins and have all the protection circuits inside the locomotive.

Using the smoke unit as an example, the smoke function pin is low current while the power to actualy produce smoke is consumed through the + and - pins.

In your wiring diagram you have neglected to connect the + and - connections to the locomotive.  Without these connections there is no power being provided to the locomotive to operate the functions. The total current of all the functions and the smoke unit draw goes through this connnection so do ensure that your product can support the load.

Please also note that your locomotive had an excellent chuff unit.  I do not believe that the product you are using can take adadvantage of this feature.

Hope that Helps

Stan

Bachmann is a sponsor of this show and will be the show this weekend with there latest Large Scale items

Northeast Large Scale Train Show

April 28 & 29, 2023

Friday - 9:00 am to 5:00 pm

Saturday - 9:00 am to 5:00 pm

Eastern States Exposition - Young Building, West Springfield, MA

West Springfield, Massachusetts

nelsts.org





Who's At The Show

The Northeast Large Scale Train Show features 45 exhibitors: operating layouts, manufacturers, and retailers.



For a complete list of of Who's Who at the show, click here.

Live Steam-Up

The New Hampshire Garden Railroad Society is hosting a "Live Steam-up" at the show, and providing a 44' x 22' Gauge-1 (45mm) track space for steam-powered trains. They are also providing space to store and service steam locomotives during the show.



The society is also inviting anyone with an operating Gauge-1 steam locomotive to bring it to the show and run it on their tracks. Please note however that only propane and butane fueled locomotives will be allowed to run. Open flame or coal fired locomotives can be displayed, but cannot be fired indoors.




Drag & Brag

The Drag & Brag table is one of the most popular events at large scale train shows. It's an opportunity for large scale modelers to bring in projects and show them to an admiring audience. Show visitors, in turn, get to see some really creative modeling and ask questions about how the work was done.



Show visitors are eligible to bring large scale modeling projects for display.


Clinics

The Large Scale Show will offer four clinics, lead by some of the hobby's most experienced modelers. Access to all clinics is included with show admission.



Battery controlled locomotives - Don Sweet
Large scale operations - Stan Ames
Pruning garden railroad miniature plants - Nancy Norris
Garden railroad access - Nancy Norris


Clinic details



White Elephant Section

The White Elephant Table is one of the most popular sections at large scale shows. If you have any S-scale, O-scale, G-scale, F-scale, 7.25 gauge, 7.5 gauge and larger model railroad gear, you are welcome to bring the items to show and sell them at the White Elephant Table.



For more information, click here.



Raffle

The Steam Locomotive Operation Group is sponsoring a raffle at the Northeast Large Scale Train Show. $2400 worth of large scale gear has been donated.



The full list of donated items and raffle details can be found here.

Train Show Banquet

On Friday evening, April 28, the Large Scale Train Show banquet will be held at the Storrowton Tavern on the grounds of Eastern States Exposition

.

The event starts at 6:00 pm and is sponsored by Only Trains.



Seating is limited to 60 guests. For reservations, contact the Show Office at: [email protected].

Hope to see you there

Stan Ames

You may be out of luck depending on which Acccucraft tender you have,

The problem is the coupler pocket.  The Bachmann locomotive couplers use a pocket that normally is not a seperate part.  I believe that the only Bachmann option is to use a drop down freight car coupler which uses the same box as the Kadee  #830 or #906.  This coupler box is longer then the Accucraft coupler box and will not fit on many of the Accucraft tenders.  If this voupler box does not fit the ony other option is to either have someone 3D print one for you or use a transition car with a coupler at the body height at one end and a truck height at the other end.

Hope this helps

Stan

Quote from: yellow_cad on April 15, 2023, 12:39:05 PMI want to couple a tender with body couplers to a car with truck couplers so I need it to offset to a lower height.  Jim

We would like to assist you but to do so we need the exact tender you are wishing to install the ofset down coupler on.


The reason is that there are several options depending of the exact coupler pocket the tender has.

Bachmann produced a drop down coupler for freight cars or tenders that use the standard coupler box, the same larger box that kadee uses.

Bachmann also produced a varietf of other drop down couplers for its 2 gen 2-6-0, latest 4-6-0, C-19 K27, forney, climax and 2-6-6-2.

If you let us know the exact tender you wish to install the drop down coupler or better yet a photo of the existing coupler pocket as well as an identification of the tender, then we can identify what your best option is.

Without this information it is impossible to provide you accurate information.

Hope that helps

Stan

Bachmann produced several options for this.  Which tender will you be putting the couple on?

Stan

While the socket used in the Dash 9 is identical to the one used by bachmann in its steam locomotives since 2007, it's new for the 1:29 diesel folks, especially to the Revolution Train engineer folks.

To assist this population I thought it useful to go over the functions.

The Dash 9 has 8 functions each of which can be controlled separately.  To activate a function you simply connect the function pin to ground.

On J1 there are three functions

Front Headlight J1-4  1.9 mA
Rear Headlight J1-9  1.9  mA

Most users will connect these terminals to a function output on the device they put in the socket which switches the pin to ground to turn them on.  Doing it this way allows directional or independent control and also headlight dimming. through the device installed in the socket.

There is one identified compatibility that has been identified. Revolution has two sets of products.  One provides linear motor control and one provides PWC motor control.  Unfortunately the PWC frequency and approach used by Revolution is not compatible with the Dash 9 headlight lighting circuits. The revolution engineers are aware of this and hopefully will have a solution with their plug in board adaptor shortly.

The third function on J1 is the Smoke activation function.

J1-8 Smoke Activation 11.2mA  The smoke unit itself draws up to around  0.6A. but this current is funneled through the + and - connections and not through the function pin.

This function pin can be connected to any available function output or you can manually install a wire between the J1-8 solder pad and the J1-7 ground solder pad.  When this is done the switch on the top of the locomotive can be used to turn on and off the smoke.

J2 functions,  Plug in devices specifically designed for Aristocraft locomotives normally do not support connections to J2.  The total current draw is well under 50mAs so all the functions can be connected to the revolution functions if so desired.

J2-10 Front Number board lights 5.5 mA (2 leds)
J2-9 Cab Light 2.8 mA
J2-8 Safety Lights 20.1 mA (8 leds)
J2-7 Right Ditch Light  2.8 mA
J2-6 Left Ditch Light  2.8 mA

Note a feature not documented in the manual is that the front ditchlights will not turn on if the front headlight is also not on. 

One issue with the revolution is that although you can hook up 6 functions, 3 of these functions also share sound functions.

Some suggested mapping for the Revolution folks. The safety lights can either be connected to ground or connected to the function number that turns on the sound.
The left and right ditch lights can be connected to a seperate blinking circuit which is connected to the horn function or to one of the three separate functions.  You can also connect both ditchlight solder pads to the -(gnd) solder pads.  In this case the ditchlights will always go on when the front headlight is also on.

I hope this helps explain how the functions work on the Dash 9.  The upcoming GP40 will likely have similar function mappings.
Stan Ames