Converting Bachmann 2 x K-27 & Climax to battery power with Sierra sound

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,973
565
Bucks/Oxon/Northants area
Ok, rather than dredging up the old thread, where I made my initial enquiries, I have started a new one here to cover the actual installation of a suite of components bought from RCS. A swift and reliable supplier and a damn decent one to deal with. There are a couple of non orthodox elements - the use of old Sierra Soundtraxx sound cards and the use of the onboard chuff sensors supplied with these locos. In the case of the Sierras an RCS SSI-9 device has been included to get round the PWM issue and a neat little fix has been supplied to get round the "chuff inversion" issue with the K-27 chuff sensors. Now here is my problem - while I am confident of being able to wire it up as per the supplied diagram, attached, I am a little confused as to instructions I have been given as to where the voltage/battery inputs should go in to the locos themselves. It seems logical that the output from the ESC should go in at the points marked +MOTOR- on the top left of the PCB. It should then follow, to my mind, that fly leads from the battery should input into the screw terminal block, right of the legend PICK UP marked +BATT-. However my instructions say that only the ESC output should be connected to this last mentioned terminal labeled for battery input and nothing else. I include images of the PCB with/without dummy DC PCB in place so all the legends are visible. I also have included Bachmann's own schematics and RCS's installation sheet for further clarity. What is the right way to do this ? The supplier is presently unavailable to answer my queries. Note that there are no ground wires used in the Sierra trigger circuits.

Loco PCB without dummy DC PCB
20210215_191050.jpg
Loco PCB with dummy in place
20210215_190751.jpg
RCS full installation sheet, specific to installs using the Sierra card and SSI-9. I am using the supplied Cobra ESC
20210215_130459.jpg
Bachmann PCB schematic
20210210_192930.jpg

Just a little P.S.The component set supplied also includes one of their neat battery PnP's, to replace the dummy DC PCB's. It apparently allows the full functionality of the PCB to be employed. One problem RCS have not updated their Install instructions to demonstrate its incorporation in one involving a Sierra card and SSI-9. I do not intend to use it unless there is a very good reason to. Here is an image of how it would look if installed. I get the motor + & - inputs and I can understand the wires intended for connecting front and rear lights to marked outputs on the ESC for directional operation. It's the 2 middle ones, black and blue that go into the ground and decoder pins that have me mystified.

20210215_194657.jpg

Sorry if this is all a bit dense, in both meanings but I do not have the confidence to install with the apparent conflicts and omissions I am presented with. Self inflicted in all probability. Max
 

Greg Elmassian

Registered
8 Mar 2014
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698
San Diego
www.elmassian.com
Can you present the instructions that say:
However my instructions say that only the ESC output should be connected to this last mentioned terminal labeled for battery input and nothing else.

That information is not shown. (and it is wrong, probably for some other loco or situation)

Normally when you feed the ESC output into the power input, it's to avoid re-wiring lights or other items. For example, my quick and dirty method to DCC USA Trains diesels connect the motor outputs directly to the entire main board, thus lighting the lights but they will not be constant voltage.

Greg
 

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
27,713
2,864
Tamworth, Staffs.
First point :
If being done as a 'simple' install, you are just replacing track DC in, with the output of the ESC, so should only connect the output from the ESC Once.

Regarding the little break-out board:
This is just a convenient way to get into the loco wiring..
The board could also be used for a DCC installation. In this case, the 'decoder +' would be the common connection for the lighting, and the 'decoder -' would give a negative reference, possibly for the original chuff sensors?

So I do not believe you need to connect these two wires.

I would urge a little caution, and suggest you wait for clarification / confirmation from Tony.

PhilP.

<edit> Greg and I typing at same time..
 

Tony Walsham

Manufacturer of RCS Radio Control.
25 Oct 2009
2,219
50
Casino, NSW
Hello Max
Do not make use of any Stock Bachmann K27 or other items show
Use only the instructions supplied with the #RCS-Battery-PnP kit.

The battery supply is then fed into the BIK-u3a kit NOT the Bachmann socket pcb. All other wiring is taken into account with the supplied instructions.
The only addition required is the chuff signal inverter as shown with the instructions previous;y sent.
Bachmann chuff signal inverter.
Do not make use of any Stock Bachmann K27 or other items shown, such as the old design adaptor plate shown.
I should be home this coming weekend when I can arrange verbal communication.
 
Last edited:

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,973
565
Bucks/Oxon/Northants area
Thanks for all your inputs. Glad to see you are back in circulation Tony, I was getting worried there.

"Use only the instructions supplied with the #RCS-Battery-PnP kit."

The problem here Tony is the instructions supplied to me with the Battery-PNP kits, and those available via the link, stop short of showing this part incorporated in an installation with a Sierra & SSI-9. The RX & ESC variations I can figure out. The last sheet, stapled in, with this part's documentation as supplied is just the regular SSI-9 install sheet, which has no reference to the Battery-PNP kit incorporation in it. Also the 2 "centre" wires are variously described black and blue or black and red. As shown their pins go into holes marked GND & Decoder on the Bachmann PCB, not the self evident function pairings of the the other 4 assigned pins - motor & lights.

Where the Battery-PNP kit's attendant leads go I am having to guess - the red & black ones with the JCT attached on the end - the ESC ? The white & yellow ones emanating from the Light R and Light F pins I assume go to the ESC's dedicated terminals for F&R directional lights (as a point of note my K-27's like others do not have a rear light fitted. I assume that is a redundant generic thing) The centre pair, either, Black & Blue or Red & Black - direct to battery or redundant ? These last two leads assignation seem to change dependent on the type of installation. With no actual schematic showing the Battery PNP kit with the Sieara and SSI-9 incorporated I am left in limbo here.

Your statement Tony - "Do not make use of any Stock Bachmann K27 or other items show" - Which stock items are you referring to, the DC dummy PCB or more ?

You can perhaps see the various sources of my confusion now.

The real issue is that my relationship with electronic stuff is very much like a dyslexic to words. Yes, I can follow a schematic, at least where the wires go and so long as there are no fancy symbols. But it has to be explicit, with no room for conjecture. That is the situation I have now - I do not have a schematic that is explicitly for an installation using the battery-PNP kit in conjunction with a Sierra Soundtraxx card and the attendant SSI-9 to sort out the PWM issue. I need a "join it by numbers" guide, no ifs or buts. I have an reluctance for these reasons, and resultant inability, to improvise where electronics is concerned.

I shall await further instructions. Max
 

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,973
565
Bucks/Oxon/Northants area
The penny has finally dropped on the RCS Battery-PNP kit. It's a very neat simple solution to adding battery and rc to a Bachmann loco fitted with the PNP PCB. Max.
 

Tony Walsham

Manufacturer of RCS Radio Control.
25 Oct 2009
2,219
50
Casino, NSW
Hello Max.
I am far from recovered. I have Lyphoma that is apparently quite aggressive.
It will be some weeks before I can function properly
 

PhilP

G Scale, 7/8th's, Electronics
5 Jun 2013
27,713
2,864
Tamworth, Staffs.
Tony sent me a PM, asking if I would help Max with this..
I have been sent the schematics and instructions, and will review them with Max..

Once Max is sorted, he will update the thread.

This should allow Tony to concentrate on getting fit again.

PhilP.
 

maxi-model

UK/US/ROW steam narrow gauge railways 1:1
27 Oct 2009
4,973
565
Bucks/Oxon/Northants area
I have to offer my sincearest thanks to Tony, despite his situation, in directing PhilP to come to my aid and at such short notice.. All the best to you Tony and stay strong. Looking forward to seeing you up and about and back at the helm soon..You can't beat this forum for the help and depth of support that is here. Max