{"id":4588,"date":"2022-12-16T20:06:58","date_gmt":"2022-12-16T20:06:58","guid":{"rendered":"https:\/\/ngtrains.com\/blog\/?p=4588"},"modified":"2022-12-20T19:28:20","modified_gmt":"2022-12-20T19:28:20","slug":"brymston-rr-24-bendy-engine-progress","status":"publish","type":"post","link":"https:\/\/ngtrains.com\/blog\/brymston-rr-24-bendy-engine-progress\/","title":{"rendered":"Brymston RR\u2013 #24\u2013Bendy Engine Progress"},"content":{"rendered":"

\"\"<\/a>I<\/strong><\/span>n odd moments I have been progressing the sorting out of one of the bendy engines. In the first episode about this bendy engine I dismantled the front truck and reduced it to it component parts. \u201cOff Camera\u201d as it were, the parts have been cleaned and sprayed with an etching primer ready for reassembly.<\/p>\n

F<\/strong><\/span>irst move was to establish some polarities to be sure I put the wheels in the right way round. Tradition on American brass models is to have wheelsets insulated on one side only so the other side conducts to the frame. Then, on a tender engine, the tender is live to one rail and the loco to the other. You can see the problem here \u2013 no tender.<\/p>\n

O<\/strong><\/span>n this loco, being a Mallet there is a fixed power unit and an articulated one. The fixed unit has one side live to the frame and wiper pickups to the insulated side and then on the articulated truck just one side live to the rail. So its got 3 wheel pickup to one rail and six wheel pickup to the other rail. I intend to add wipers to the articulated end but for now I just need to make sure the wheels live to the frame on both are on the same side.\"\"<\/a><\/p>\n

T<\/strong><\/span>his was done with a multi-meter on its continuity (beep) setting. PANIC<\/strong>.<\/span> It beeped to both sides!<\/span> For now I went with the wipers as a clue and resolved to sort the potential issue out when it was the rear bits turn for overhaul.<\/p>\n

U<\/span><\/strong>sing the beep test the live wheel was identified with red marker pen and then assembled into the frame. I WISH IT HAD BEEN THAT EASY!\u00a0 The driving \"\"<\/a>wheels are sprung and, unusually for American brass they actually work. Usually you\u2019ll see a coil spring above each axle box that is so strong it does nothing other than press the wheel hard against the keep. This has wire longitudinal springs that hook behind two pins on each side and then bear against the axle bearings. Neat when together but I used up a lot of fitters language getting them in.<\/p>\n

\"\"<\/a>N<\/strong><\/span>ext to add would have been the cylinders but here I found a problem. This first picture is how they should look with the guide bar above the slidebar and with the rear end keeping the crosshead captive.<\/p>\n

T<\/strong><\/span>he clue that something was amiss was the crosshead falling out of the other side. Looks like tomorrow mornings task involves whittling some nickel silver fret offcuts to shape.<\/p>\n

\"\"<\/a>F<\/strong><\/span>inally for this small work session I decided to have a look at the fixed power unit and disconnected the motor. A retest of the wheel insulation revealed there to be no problem. The beep to both sides was because the fancy Canon motor is such low resistance that there was a path through the motor from the insulated wheels.\u00a0 Some power to the motor wires had it all running. It has a small squeak once per revolution and its seems tight. There\u2019s some dubious looking oil oozing out of the spur gear box but that will all get cleaned out when this bit get overhauled<\/p>\n