Battery conversion of an LGB Mikado

[DGE-Railroad]

Another thread that was created in the DCC forum, since it involved upgrading a non-decodered Mikado to a modern decoder, but is also an RC and Battery conversion, so should probably be cross posted here!

The next candidate for a Revo DCC/ESU battery RC conversion is on the slab and this time I'm positively spoilt for choice when it comes to space!
The ESU decoder is an XL5 which will mount forwards of the speaker, above that large lead weight where you can just see me trialling a piece of styrene to be used as the mounting board, for thickness.


Just forward of the lead weight is an ESU smoke unit for plenty of smoke, and then there's the headlight. If the smoke goes well, I'm thinking to upgrade to the new ESU dual unit, giving separate cylinder 'steam'


The Revo receiver will sit in the tender, away from the magnetic interference of the speaker and along with the battery - that's an 18v 5ah tool batttery rattling around in the tender. It makes a change not to be searching for something that will fit in the space!
Realistically I'm expecting to install something slightly smaller - that ah rating is going to be overkill. I'll stick with the 18v as smoke output tends to be suceptible to lower voltages from what I've read.

The tender already has a small 4-line power distribution which is really handy: 2x power from the receiver to the decoder and 2x tail light back from the decoder. I want to keep things as stock as I can, so retaining the stock loco/tender connection is a plus.




I felt the track skates spoilt the overall look a bit, so decided to remove them.

The Revo bind switch is under the water cover. The power switch will be joining it once it arrives.
The head, tail and cab light have all been changed to warm LEDs with built-in resistors, so they can plug straight in to the decoder harness



I'm now waiting on the decoder and some more connectors to turn up...

 

[DGE-Railroad]

The other bits have arrived so there's no excuse not to make some progress!

Mounting the decoder and receiver required a solution that'd work for everything. I was after something self adhesive and removable but both boards have 3mm holes which are annoyingly too small to work with most PCB standoffs.

The ESU XL has a completely bare strip between the two end mounts so I use double-sided tape here to stick it to styrene box section which is in turn stuck to the loco


The Revo receiver comes with some tiny standoffs but they're meant for screws. My solution has been to cut the tops of some PCB adhesive feet and glue the Revo standoffs to these. It works like a charm (PCB foot in back of pic, modified versions at front)


The receiver and decoder are trial-fitted and a power-on test done in the bench



I've added the main power switch under the water hatch in the tender. There isn't much height to play with, so I've adopted the tried and tested 'screw the switch into a nut and JB-weld that to the mounting point' approach.

 

[DGE-Railroad]

The end is in sight, and it's nearly ready for a run on on the track.

Here's a video of the bench test, checking current draw, sound, movement and smoke functions.

Mikado Revo DCC ESU with smoke

 

[DGE-Railroad]

Tool battery power socket arrived from China. A 2Ah battery fits well. The 5Ah is about 5mm too tall

 

[DGE-Railroad]

Cylinder steam pipework is proving a challenge. The tank output for this is essentially directly below the chimney.

On the LGB there's the 'steam pipes' in the way and the bottom of the smokebox (which now has a channel cut out of it!)

Directly below that is the top of the steam chest, which is also going to need a bit of opening up, to allow a 9mm tube through it:


The steam chest is relatively hollow but does have the front mounting point' for the gearbox (that central screw in the picture) and directly beneath that, the pilot truck:

 

[DGE-Railroad]

Well there's no going back now!

I really didn't want to cut anything but it was unavoidable if I wanted the cylinder steam so I have kept it to the bare minimum.

I have opened out the front mounting support to allow the pipework to sit flush and far enough back.
On the plus side this allows it all to fit inside the Mikado steam chest.



Admittedly that doesn't look too flush, but it can, honest!

 

[DGE-Railroad]

Now completed! It's been a long journey and I've learnt a huge amount along the way, but I'm pleased with the results.
Mikado maiden run

Next up, a K27!

 

[Greg Elmassian]

Nice. Were you unable to synchronize the cylinder cock noise with the steam out there? Also, any way to synchronize it with the piston in the cylinder?

Greg

 

[DGE-Railroad]

Nice. Were you unable to synchronize the cylinder cock noise with the steam out there? Also, any way to synchronize it with the piston in the cylinder?

Gregthe

Thanks Greg.
So i suspect it would be possible to synchronise the smoke to the cylinder clock noise, I'd just need to find and understand the noise sequence.

If you have the time and inclination, I'd recommend downloading the programmer software and one of the factory sound files from the ESU site - no hardware is needed to run the software and its interesting to play with. Its incredibly powerful.

Smoke operations are integrated with sound slots. Each sound slot is a flowchart of states and conditions. The first 'prime mover' type sound slot outlines noise and smoke for various movement states.

I chose the pre created blowdown sound sequence slot for the cylinder steam, however I think there is a separate cylinder cock noise slot. I think it would be a case of connecting or merging these two..

As regards piston position, I think that be more difficult. The decoder has no appreciation of cylinder position so I think you'd need a mechanical or optical switch to determine that, then use the logic condition to add some finesse to the blowdown sequence. At the moment its quite a coarse one in any case; function button pressed causes the sound sequence to start and then to loop until the button is toggled off to exit the sequence. Changing the loop from infinite to timed is on my list of improvements to make.

It may also be worth adding a speed condition to the blowdown sequence too; at the moment it can be triggered at any speed!

 

[Greg Elmassian]

Yes two things, have the smoke start and run only during clearing of the cylinders, but that is not necessarily called blowdown, at least here in the US.

clearing the cylinders of condensed moisture, to increase efficiency, and also avoid hydraulic lock is accomplished by opening valves at the bottom of the cylinders that allow some of the steam to escape, and thus take out condensed moisture.

Blowdown is a valve on the bottom of the boiler, to purge sludge and impurities that have settled to the bottom of the boiler, and exhausts from a different place, certainly not the cylinders.

Also to be completely realistic, the clearing of the cylinders normally has 2 vents per cylinder, and the steam exits from them alternately.