#WarrenYard_Locos #DecoderFitting #DCC #DCC_Conversion DCC Loco Conversions - 1 - DCC and Me DCC a Marmite Technology The "Realising My Dream" series of posts summarises the development of my personal railway, warts and all, but what about this new fangled tech called "DCC", fad, gimmick or maybe useful? 50 years on from my first childhood with most real world hassles out of the way I had dived back into model railways with relish, but how things had changed since I last enjoyed my trains back in the early 70s at the company railway club. I still had all my locomotives and rolling stock from the 1970s that I intended to run, some of those were over 10 years old even then, some nearly as old as me. The company railway club was long established and working to 4mm scale, OO gauge with all the track work hand built with code 100 rail on copper clad fibreglass sleepers. There was certainly some talent demonstrated crafting all the point work. Stock was owned by the members and was mainly Hornby Dublo with some British Trix so Dublo/Trix couplings were the de-facto standard. At the time the Triang Mk3 hook and bar was current but was not liked for two reasons, one the size, and two the off centreline hooks would cause the front wagons in a long train of wagons (5-6ft) to crab significantly and aid derailments. So all the stock I bought (including Wrenn, Airfix GMR, Palitoy Mainline and Hornby) I retrofitted to those couplings. Second hand Dublo and Trix was available from a local model shop which like many others faded away by the early noughties. Along with my 2nd childhood a devil came onto the scene to extract cash from my wallet, eekBay and my modest collection of 'vintage' exploded with even more Dublo and British Trix, oh dear. Now this was before I was able to build a layout anywhere, not for at least another 5 years, so they piled up in stackable Stollen cake trays from Lidl, thanks Lidl, great long term stock boxes! DCC or not DCC? Building the railway baseboards and supporting framework was very much independent of whether I continued with DC or migrated to DCC, it was only when committing to track laying and wiring a decision is required. Having been a professional engineer I cast a critical eye over this "Only two wires" system. This was probably the biggest dubious quality sales pitch statement since someone coined the phrase "The greatest thing since sliced bread". I hate pre-sliced bread, always too thin and goes stale quickly due to all the exposed surfaces, no problem, throw it away and buy more! The only two wires earache has since been superseded by those selling expensive cars, "Self Drive", "Auto .. blah" etc. "oh but you still need to sit in the driver’s seat and stay fully alert with nothing to do but stare at the road and fall asleep". Ok, back from my "One foot in the grave" semi-rant, (loved that show, I appreciate it even more as I become a Victor), off I go again, two wires eh? Let's face it, if the non-techie public was told the truth it would be total gobbledegook, and besides for introductory layouts it only needed a few "Two wires", or in 'tech' speak "pairs of wires" and sales would not have been forthcoming. So I suppose they knew what they were doing. Technically, system wise, yes, it is only two wires, basic operation is that all power and control is passed in an outgoing signal to the decoder and returns back to the source, hence the two wires. Implementation however needs multiple pairs because in the real world we have joints in our rails and nickel silver has higher resistance than copper, giving the user the potential for intermittent connections and voltage drops on a well loaded system. If you do run everything possible it will require a sound power distribution system to satisfy demand over the entire layout. This wasn't required so much in my DC days, it was a mix of controlled 12vDC for trains, 16vAC for points and uncontrolled 12vDC for other items such as lighting and signals. The weakness of DCC is also its greatest strength, digital circuitry that responds quickly to demands but also to an interruption in the power supply which causes it to reboot when power is re-applied. A momentary interruption of DC is not noticed as the motor continues as a flywheel keeps the loco rolling and carries on immediately power is restored. Unfortunately the DCC components will shut down quickly, reboot and ramp up speed again based on your CV settings, if the interruption occurs again, it repeats the cycle. The “only two wires” started the Marmite scenario over DCC and has been the cause of many heated debates, sorry, arguments with battle lines drawn, and casualties, those chucked off of groups or left in disgust. Having worked on the large cab-control wired company club layout supporting up to 13 drivers the thought of even wiring a large layout with DC for even say, 4 driver cab-control with large inflexible control panels was daunting. A railway cannot evolve if that optimised control panel needs changing or all the section breaks are in the wrong place. Track sections too short for a long loco or too long for a short one is also irritating. Concluding So DCC is good for me because :- 1) I can drive and park any given loco anywhere, 2) I can really drive a double header, 3) I can really drive a banker, 4) My railway can evolve easily and readily. My series of posts is not about whether you like Marmite, sorry, DCC or not, they are about the 'fun' I have had with locomotive decoding fitting over the last 9 years, and hope I can convey what you may be up against with models from different manufacturers over the last 50 years. By all means tell me where I have gone wrong, could have done it better or different, or for me to explain in more detail, have a chuckle at what may seem masochistic, or any questions whatsoever, but please don't try and convince me that DC is better than DCC, Rule 1 applies. Decoder fittings I will cover is for driving locos only, I do not use DCC for sound or accessories. However I will include many pre-DCC, those so called "DCC Ready" horrors and on through to those which need small machine tools to modify e.g. Hornby Dublo integrated motors which I have yet to tackle. Next: Before I get on with the conversions I'll outline my general approach, techniques and tools, useful and not so useful. Jim Image: Hornby Dublo Stanier 8F

Posted by Jim Franklin at 2021-05-22 18:41:31 UTC