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

Monday, June 02, 2008

Progress Report 13 - Digital developments

When the railway was first constructed, I relied initially on the 1 amp power supply that came with the original starter set. This proved more than adequate for controlling the line's only loco. After I'd constructed the control panel, I bought another 1/2 amp power supply in case I ever needed to run two locos independently. This set-up proved adequate in the early stages of the line.
After a while, the tedium of having to dash in and out of the outhouse every time I wanted to adjust speed or to stop a train became too much to bear and so I invested in an Aristocraft Train Engineer remote control device and handset. Although I was using only a 1 amp transformer, I went for the 10 amp version as I intended (and still do when I can find the funds) to buy a track cleaning loco.

This clever little unit has done sterling service for nearly two years. Acceleration deceleration is programmable so that locos slow down and speed up realistically. Even the emergency stop and reverse buttons include smooth deceleration. What's impressive is that packed into this little unit is a wealth of expansion potential. For example, you can run up to ten transmitters through the one receiver (not that I have ten rail-keen friends or relatives). Also, it is possible to put receivers in each loco and have them independently controlled. However, all I wanted was the most straightforward and simple control - a remote radio-controlled replacement to the standard controller. All I had to do was attach two wires, insert the batteries into the handset and away I went!
Eventually, I invested in a 10 amp transformer / power supply which was quite expensive (c £60.00) but well worth the investment as it meant I'd have plenty of expansion potential for that day when the track cleaning loco or even the double Fairlie arrived!

I was also considering buying the additional switch controller, which would have enabled me to switch between various sections of track and hence run more than one train at the same time. However, some unexpected back-pay was ploughed into buying a secondhand parallel MTS Central Station, transformer and handset at a very reasonable price from Garden Railway Centres. I'm not convinced the price of these products is realistic, the prices do seem overly inflated given the cost of consumer electronics these days, but it does provide me with a lot more flexibility in terms of expanding the system. Although fiddly, I found the fitting of of the decoders (£50-60 each!) quite straightforward (see How I fitted the loco decoders). In addition, I purchased a reverse loop module which detects the short-circuit created when a loco runs into or out of a loop and automatically reverses the current. Again, this was extremely straightforward to add into the wiring as I had already run the wiring from the loop back into the outhouse to the a DPDT reversing switch in the control box. Although now no longer necessary, I am keeping the control box and the electrical sections as I will still want to run unchipped locos from time to time. For example, I have a gandy dancer which I'm not going to bother to chip for those occasions when my young nephew visits.

I was quite impressed with the system - for a while! Despite adding an extension cable to the Loco Remote (the Hornby Trains DCC cable uses the same connectors), the inconvenience of once again being tied by the cable length to the outhouse became too frustrating, particularly when I added the extension to the line. So, although I had severely overspent this year's budget, I splashed out on a wireless transmitter and receiver (which was not far short of the cost of the entire Aristo Train Engineer!).

Although I am still a novice when it comes to DCC, I am already finding the benefits to be tremendous. Being able to independently control my four locos without having to substantially reorganise the wiring or change the pointwork opens all sorts of possibilities for operation.

However, were it not for the back-pay, I would have been more than happy to have continued with the Train Engineer, which to my mind is a far more cost effective way of getting wireless control and - had I gone down further down the route, would have provided me with almost as much flexibility.