Saturday, June 07, 2008

How I Installed a Decoder in my Stainz loco

As indicated in Progress Report 13 - Digital Developments, I have invested in MTS Digital Command Control which means I have had to install decoder chips in my locos. As always, I do not profess to be an expert, I tend to muddle my way through things, but I'm hoping that my efforts will help someone else who may be going through the same process as myself.

Chipping a Stainz 0-4-0
Like most new to G gauge, I started with a starter set which I bought from Garden Railway Specialists (GRS) and brought home to Cheshire on the train, much to the interest of passing small boys and several not so small boys. I hadn't realised it at the time, but the starter set Stainz loco was equipped for the installation of a DCC decoder - as evident from the sticker on the underside of the body:

The first job is to prise off the whistle from the cab roof. This is very susceptible to damage when the loco is turned upside down as I've learned from bitter experience, as you can see from its battered appearance.
This is a push-fit and just needs gentle pressure from a flat bladed screw driver.

Next, I removed the air pump from the side of the boiler. A small Phillips headed self tapper holds it in place.


You can do this later, but it does need to be removed at some point as it straddles the split in the boiler in which the main circuit board is located.

Now to serious business, remove both couplings. These are each held in place with a single screw.


The next job is to remove the four screws holding the sub chassis to the main body. Once the couplings have been removed, these can be found beneath them, two each end.

Before the sub chassis can be separated, the bracket holding the valve gear needs to be removed (I nearly snapped this delicate mechanism because I failed to spot this). A single small Phillips headed screw holds each one in place, either side of the loco.

The brackets can be eased out from behind the tanks:

Notice the two short lugs which position it on the footplate.

Now the sub-chassis can be eased out of the main chassis.

and the cable linking the sub-chassis to the rest of the loco can be unplugged:

The next job is to separate the red main chassis from the cab and the boiler. Firstly, the four screws holding the cab in place are removed:


Then, you'll need to unplug the yellow and brown leads to the smoke unit. You might want to make a note of which way round they are connected - I don't think it matters, but just in case.

These pull out:

At this point, I also unplugged the two ribbon cables as well:

Then, the nut holding the chimney in place is undone:


and the chimney lifts out. Be careful not to damage the bulb in the process, it should drop out of the headlamp.....

Next, the steam pipe thingy (?) just in front of the tank on the left hand side is prised out:


and the two parts should now separate quite easily (if they haven't already fallen apart).

A good idea to remove the lead weights from the tanks as this point, in case they drop out and smash something delicate.

Before separating the the boiler from the cab, the pipe just in front of the cab needs to be removed - another push-fit.
Separating the cab and the boiler foxed me for a while, but as can be seen from this photo, by a combination of twitching, cursing and throtching, the boiler will ease out past the lugs in the cab which hold it in place - it's a lot easier clicking it back together ......

To split the boiler, the two lugs either side need to be pushed in whilst at the same time easing the two halves apart. An octopus would come in handy here, but, with a bit of fettling and footling, eventually the two halves will separate ......

Lastly, the lead weight needs to be unscrewed to reveal the circuit board beneath:



Before attaching the LGB MTS Decoder II chip, click all the dip switches on the loco board to the off position:

Then snip off the four trailing wires from the decoder - yes really! The simply line up the pins underneath the board with the sockets on the circuit board and press home. Note: not all the pins have sockets - just the ones which are needed.

Be gentle! And that's it .... one chipped Stainz.

The next job is, of course, to reassemble the loco.

Just a few pointers. You will no doubt be far more careful or observant than me, but when reassembling a few things to remember which, in my enthusiasm, I forgot or found out............
  • Don't forget to screw the weight back down (it was only when it startled rattling around I realised)
  • Don't forget to put the two lead weights back into the tank ..... doh!
  • Don't forget to put the black plastic top to the cylinders in place (with the pipes inserted) before attaching the nut to the base of the chimney
  • It doesn't seem to matter which way round the smoke unit leads are connected (I didn't make a note of which way round they went, so I may just be lucky) .....
  • Make sure the ribbon cables don't get trapped when you join the chassis to the body

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