How I fitted my own DCC power buffers

The things I enjoy most about my railway are slow running and shunting operations. However, as most of my locos are short wheelbase 0-4-0s I often get very frustrated when they stall or stumble on minute patches of dirt on the rail or when they encounter the plastic frogs of pointwork. As shunting requires a lot of slow running over pointwork, there are occasions when I have to bite my lip, mutter and count rapidly to 10.

About a year ago I fitted a Massoth Power Buffer to one of my locos (see Progress Report 37) and have been very pleased with the results. Although the power buffers are less than £25, having now retired, I felt the outlay to equip the rest of my loco fleet was something I would have to postpone until funds improved. All that changed when I came across an article in a copy of Voie Libre explaining (in French) how someone had added his own power buffer. A quick trawl through the internet unearthed an entry on the Massoth Users' forum by one of their technical staff explaining how a simple DIY buffer could be added to one of their decoders. As Massoth manufacture decoders for LGB, the same process can be carried out on their LGB's 'own brand' decoders.

Once the equipment has been purchased, the process is actually quite straightforward and took me only an hour (though on some locos, it took a little longer to create the space needed to accommodate the additional circuitry).

Before fitting the buffer, the decoder's CV29 has to be reprogrammed to disable analogue control. Without this, the power buffer would confuse the decoder into believing it was under analogue control and hence would ignore DCC commands.

The programming module was inserted LGB (55015) Universal Remote:

This was then wired up - the yellow and green wires into the transformer and the brown and white leads to the decoder via a piece of rail which I reserve for programming purposes.

CV 29 was then programmed by following these steps:

• 1 - The loco was placed on the track and the transformer was powered up
• 2 - The letter C appeared on the LED display on the handset
• 3 - 29 was then entered on the remote's keyboard
• 3 - 0 was then entered into the keyboard (this tells CV29 to accept 14 steps in digital only)
• 4 - The right arrow was pressed on the remote
• 5 - Provided everything is OK, the letter C should appear on the display

For each buffer, I bought three electronic items from my local Maplin store:

• a 150 ohm resistor (product code M150R) - £0.32
• a 35v 2200 uF electrolytic capacitor (product code VH55K) - £1.49
• a 1N5400 diode (product code QL81C) - £0.52
• Total cost =  £2.33

The diode and the resistor were soldered together in parallel.

These were then soldered to the positive lead of the capacitor and a plain (red) wire was soldered to the the other end of the two components. Another (grey) wire was soldered to the negative lead of the capacitor. The whole assembly was then shrouded in insulating tape to help avoid accidental short circuits.

Connectors were soldered to the other ends of the wires and these were then pushed on to the D+ and D- tags on the Massoth L decoder (this is identical to the LGB 55021 decoder).

The decoder and buffer were then inserted back into the loco and the loco re-assembled.

Yes, it really was that simple, but the proof of the pudding ..............

For me the advantages of this system far outweigh the disadvantages. The loco won't run on an analogue powered railway and the the CVs (including the loco channel number) cannot be programmed unless the power buffer is disconnected. However, as it is connected to the decoder's power feed tags it's a fairly easy process to remove the buffer should the decoder need to be reprogrammed. Alternatively, a switch could be wired into the feed to the buffer should I want to more easily disable the buffer.

Progress Report 37

It's been a while since the last report but there was a lull because the other part of my life took over. However, a combination of low level tick-over on various projects together with a flurry of recent activity has given a few developments to report on.

Running sessions

Some decent weather recently has provided an opportunity to have a few running sessions. I try to run a realistic timetable with regular passenger trains, a daily pick-up goods and an afternoon mixed train, interspersed with full and empty ore trains to and from the copper mine. (See A typical operating session)

 The pickup goods arrives at Bickerton

 The down passenger ready to depart Beeston Market with a full ore train about to reverse into the exchange siding.

I also spent a happy day or two producing a couple of videos showing train movements to which I added relevant sound effects:

• Loco No. 3 on passenger duties
• Loco No.1 takes the pickup goods

 Engine shed

It took a while but eventually I completed the double-road engine shed for Beeston Market.

It was constructed from a plywood shell covered in weatherboarding made from coffee stirrers. It was inspired by the shed at Southwold, though this was only single track. For more information in its construction see How I constructed the engine shed

Four more open wagons join the stock roster

Three more wagons have been constructed using the resin moulded sides as previously (see How I constructed the third batch of open wagons).

It is becoming increasingly difficult to find Hartland wagon chassis in the UK but Steve Warrington at Back2Bay6 managed to track down six more which will enable me to eventually bring the total to twenty, which will be sufficient for the railway as a whole. One open wagon has been constructed from a GRS conversion kit.

 Two LGB wagon chassis are cut and shut together to produce a short wheelbase open wagon and a long wheelbase van. I am still in the process of constructing the van and will make a posting describing the process once completed. (See How I constructed an open wagon and a van from a GRS LGB conversion kit). See also Stock List.

Two more cattle wagons join the line

These were constructed from IP Engineering wooden kits, though slightly modified (see How I constructed two cattle wagons from IP Engineering kits).

I also bought an open livestock wagon kit and intend to construct this once time permits. I will then either buy a few more kits or construct something similar myself from scratch. See also Stock List.

The BP tank wagon is anglicised

The secondhand tank wagon had been bashed into something more UK looking along the same lines as the GRS tanker wagon converter kit.

As I didn't have any 10mm square section plasticard to hand for the timber baulks, I created my own from some 8mm square tubing with two layers of 2mm thick plasticard. The open ends were plugged with filler.

I now have two tanker wagons which is sufficient for the railway. For more information on the conversion (see How I anglicised an LGB tanker wagon). See also Stock List.

Detailing the workman's coach

The four wheeled workman's coach which was bought some time ago as part of a job lot from eBay has at last been improved and detailed. Footboards were added (from lolly sticks), brass door handles and grab rails were added to the exterior and a compartment divider and some basic seating were added to the interior.

A re-spray of undercoat and a final coat of chocolate brown Plasticote spray finished off the re-fit.

Goods stock is liveried and weathered

All the goods stock which had not previously been painted in PLR livery and/or weathered has now been duly treated using Halfords grey primer and my time-honoured method of daubing with mucky brown/black acrylics and wiping off with a paper towel while still wet. Once this dried the wagons were given a light dusting of matt 'sand' and 'dark earth' spray from Humbrol rattle cans.

The stake wagons were also given removable timber loads (chains yet to be added) 

The bolster wagons will be having a papier mache tree trunk load (under construction)

Two Schleich cattle have been added to each of the two existing cattle wagons, together with straw represented by strands of hessian recovered from an old skipping rope.

 See also Stock List.

Power Buffer added to Loco No. 2 (Bickerton)

A Massoth Power Buffer has been added to loco 2 (Bickerton). One of the irritating things about running 0-4-0 track-powered locos over pointwork with dead frogs is the tendency for them to stutter or grind to a halt. I decided to experiment with adding a power buffer to one of the locos to see what difference it made. A great difficulty is, of course, that the buffer uses a large electrolytic capacitor to maintain electrical continuity over dead-spots in the trackwork - which takes up a fair amount of space. It's frustrating that the smaller the loco, the greater the need for a power buffer, but the less space there is within the loco to house one. Finding a location for the buffer more or less required a complete dismantling of the loco and a re-jigging of the lead weights. However, with some re-fitting sufficient space was found within the firebox to locate the power buffer.

I had hoped to be able to re-program the CV values to enable the buffer to be automatically switched off when the decoder is re-programmed. However, this proved impossible with my Universal remote and I therefore added a hard-wired switch into the circuit to isolate the buffer when the decoder needs programming.

There has been considerable improvement in the smooth running of this loco since the buffer was added and so I am considering adding power buffers to the rest of my locos which are largely 0-4-0 motor block powered.