I have recently finished installing an RCS PnP-3BK + Phoenix in one of the new Bachmann 2-6-6-2T locos for a very good customer.

For now I have used the stock Bachmann "Super" socket just to see how it could be achieved.
I say achieved, as Bachmann opted to not use their own socket clearance standards that they proposed and had used with the K-27.
This has made the installation in the 2-6-6-2T a lot more difficult than it should have been.
However, in an obvious attempt to solve an installation problem of their own making Bachmann, did make the socket movable forwards a little by making an adaptor plate to which the socket is mounted.  What a pity one set of leads is not long enough to reach the receptacle on the socket pcb, when the socket is moved forwards.
This has movability has enabled the heatsink on the RCS PnP-3BK to fit under the steam dome.  More on that later.

Before starting work on any new loco I like to run it for a bit on track power to find out what the ideal battery voltage should be.  This I duly did and discovered 14.4 volts will provide an adequately high top speed.  So 14.4 volts it would be.
Whilst running the 2-6-6-2T backwards and forwards on my test track I noticed that it was not as smooth as I have seen reported elsewhere.  I though I had better go over it and see why.  First of all I noticed all the drive rod screws were loose on the rear truck. So I tightened them up and tried again.  The loco now would barely run at all.  The bind was so bad it could barely turn over.
Then I noticed the reason why.

As there was no packaging damage I guess the loco must have been assembled like that and the screws left deliberately loose so that it would run at all.
What to do??
This was going to be a demo loco to be shown at the recently concluded Brisbane Model Train Show, so it had to run well.
I immediately contacted Bachmann and they agreed to send me a replacement driver which they duly did.  Only problem was it did not get here in time for me to get it fitted.  I had already left for the trip to Brisbane.
In the meantime Gordon Watson, from Argyle Locomotive Works, made a special mandrel that snugly fitted the crank pin.  With a deep breath Gordon gently bent the boss back to square without breaking the casting.  That has lasted for the duration of the show butl the driver will be changed before I deliver the loco to my customer.

Anyway.  Back to the installation.

Fortunately the 2-6-6-2T is a well thought out design and is quite easy to disassemble.

The first job is to take off the side tanks and boiler moulding.
Read up on the exploded diagrams to find the 4 x screws that hold the assembly to the frame, and the two (very tiny) screws that fit down through the headlight mounting bracket. Remove the two screws located under the headlight. Then sit the loco upside down in the packaging and remove the 4 x screws holding the water tanks to the frame.

 

Next I removed the rear engine assembly from the chassis.  Really easy with just two screws.  One in front of the motor and one behind the motor.

Then I removed the cab roof so that I could get at the screws inside that hold the airtanks onto the frame underneath the cab.
Once they are removed you can then access the 4 x screws that actually hold the cab to the floor.  These are coloured white in the pic.
Then remove the 2 x screws that hold the bunker to the floor.  These are shown as blue in the pic.
Lastly remove the 6 x screws that hold the cab floor to the frame.  These are yellow in the pic.

 
With the bunker assembly removed from the frame then separate the bunker from the rear wall of the cab.

 
The RCS metal cased receiver was glued with silicone to the bunker side of the cab rear wall just low enough to clear the lugs of the oil tank top when that is later put in place.
The AZARR antenna was connected to the receiver and the thicker loaded part (shown here in white) was mounted vertically.  A small hole was drilled just below the ridge that supports the cover and the antenna wire was threaded through to the inside.

 

The antenna wire was tack glued with dabs of silicone up the inside of the cab wall, along the top and then left free standing facing forwards.  This will not be seen when the loco cab is reassembled.



When the bunker is removed you will see a bundle of wires running underneath the cab floor. I believe they are intended for connecting a DCC decoder in the bunker and are useless for our purpose.  They run in a channel in the frame casting. 



Once the rest of the cab and floor are removed you can see the channel.  I removed the Bachmann wires and used the channel to fit the 3 x charge jack wires and 3 x receiver signal wires in.

 

Once the required wires are in the channel I recommend sticking a small piece of tape over the channel to hold the wires in place during re-assembly.
Instead of the regular RCS servo lead connector wires that run from the PnP-3 to the receiver I opted for a short servo extension lead feeding into a double adaptor lead so that I could get the signal to the PLUS-3 decoder for the extra sound triggers.
That completes the receiver installation.
Very carefully reassemble the cab parts in the reverse order you took them apart.  Don't forget to mount the air tanks under the floor before you put the roof back on.

Next I turned my attention to the tanks and boiler moulding.
If you intend to use the PnP-3BK you will have to cut away a bit of plastic here and there to get it to get the PnP-3BK to fit.
It is possible to fit the PnP-3AC (intended for AristoCraft locos) without any cutting needed.  Unfortunately Bachmann locos are wired backwards to AC locos so if you choose the PnP-3AC you will only be able to use the sequential direction change operating program instead of the Centre off two button system.  Many  RCS operators prefer the sequential direction change method anyway.
Here is what plastic had to be removed.

Next I fabricated a small styrene mounting plate for the ON-OFF switch, Phoenix programming jack and volume control.

 

There is not much space for batteries so I had to use AA size ENELOOP hybrid cells made up in two 6 x cedll twin stick packs.  These are adequate for light running but will not last very long if required to do any of the serious hauling this locomotive is capable of.  My customer is quite happy to have the main traction batteries right behind the loco in a trail car and have them run the loco out on the mainline.
The wiring is the same as I recommend with my very basic # U-BIK kit.  There is not room for the regular # BIK-U3 installtion kit.
Although not shown here, the Phoenix P5 + P5t easily fits along the LH side of the tanks.  As the socket pcb is not equal either side of the center line, there is no room on the RH side.

Bachmann have got the chuff signal the normal way round for this loco and no special electronics are required to interface with the P5.  I simply connected one of the Bachmann chuff triggers to one of the chuff input wires on the P5.
I connected the other Bachmann chuff trigger to the other chuff wire on the P5 via small reed relay.  The coil of which is controlled by the (not normally used but) latchable 4th function of the # PLUS-3.  This gives me at will manual control of switching from "simple" to "compound" on the run.  The system latches on to "simple" when first turned on.

I programmed the sound to the Phoenix UINTAH.

Her she is all buttoned up and raring to go.
Note that I have shown with a yellow arrow, where the extra bit of plastic lip needs to be removed to more easily clear the RCS PnP-3BK receiver plug on the pcb.


 
So what do I think of the 2-6-6-2T?
The engineering design is excellent. 
Except for the not to specifications socket clearances.  Plus the 2 x small screws under the headlamp holding the boiler shell to the smoke box door are wimpy to say the least.  Really small and very easily lost.
It runs superbly.  I mean really superbly.
Range with either PNP-3 is well over 100' feet when testing on a layout that is part on the ground and part up in the air.
This was achieved without adding motor noise suppression. The motors each have a suppression pcb mounted on them.  I chose tp leave that pcb in place.
However, I am concerned about adequate cooling of the RCS heatsink with such a potential current hog.  It is hidden up underneath the steam dome which, in my opinion, does not allow adequate air circulation.  It may be necessary to drill some holes in the top of the steam dome to allow hot air out.  Even so, I doubt the 3 amp capability of the PnP-3 will be adequate either.

For the next installation I propose to strip the socket pcb out, use a very low profile speaker and fit sub C batteries and a 5 amp # BASIC-5.