mikesndbs Posted December 3, 2022 Share Posted December 3, 2022 (edited) Hi Guys I am just restoring this loco and have come across some weirdness I need advice on place. Done the motor and she now runs ok but the chassis has tight spots and I note on one side the coupling rods are very tight. Also see some odd bushes behind the rods on the crank pins on one side, don't think I have ever noticed that before. Here's some photos. Be most grateful for any assistance. Once it uploads about 15:50 here is a video of her Edited December 3, 2022 by mikesndbs added video link Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted December 3, 2022 RMweb Premium Share Posted December 3, 2022 3 minutes ago, mikesndbs said: Hi Guys I am just restoring this loco and have come across some weirdness I need advice on place. Done the motor and she now runs ok but the chassis has tight spots and I note on one side the coupling rods are very tight. Also see some odd bushes behind the rods on the crank pins on one side, don't think I have ever noticed that before. Here's some photos. Be most grateful for any assistance. There's a bent / twisted RH connecting rod for a start, which won't help. Other bits of the motion would benefit from the application of smooth-jawed narrow pliers. I can see plastic insulating bushes in the insulated side wheels - as there should be on a two-rail loco. CJI. 1 Link to post Share on other sites More sharing options...
mikesndbs Posted December 3, 2022 Author Share Posted December 3, 2022 14 minutes ago, cctransuk said: There's a bent / twisted RH connecting rod for a start, which won't help. Other bits of the motion would benefit from the application of smooth-jawed narrow pliers. I can see plastic insulating bushes in the insulated side wheels - as there should be on a two-rail loco. CJI. Thanks, what would you do with the pliers? Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted December 3, 2022 RMweb Premium Share Posted December 3, 2022 1 minute ago, mikesndbs said: Thanks, what would you do with the pliers? Press out the bends and twists in the motion that are very evident in your photos taken from below. CJI. 1 Link to post Share on other sites More sharing options...
mikesndbs Posted December 3, 2022 Author Share Posted December 3, 2022 54 minutes ago, cctransuk said: Press out the bends and twists in the motion that are very evident in your photos taken from below. CJI. Hi again, so four of the bends are done to avoid the crank pins. Straightening them means the pins hit the vale rods. I did tweak the drop link on one side which made things better, however there is still a really tight spot on the main rods one side only causing the engine to slow each revolution. Normally Wrenn stuff is great, but thjis old girl needs more help. Link to post Share on other sites More sharing options...
Il Grifone Posted December 3, 2022 Share Posted December 3, 2022 (edited) Dublo/Wrenn 2 rail locomotives have metal cylinders live to chassis, so require the valve gear insulated from the wheels by nylon bushes - much more reliable than Tri-ang's plastic cylinders and fragile motion brackets. Here I would remove the pick up assembly and motor and then check everything runs smoothly. It should be possible to turn the motion from any/all of the wheels. Any stiff points are due to bent rods or wheels out of quarter. Unfortunately the crank pins are rivetted over behind the wheels which makes dismantling tricky. Removal of the wheels should only be undertaken with extreme care and as a last resort. Apart from the crank in the connecting rods to clear the leading crank pinks, all the rods in the valvegear should be straight, It does rather look like a quartering problem however. Edited December 3, 2022 by Il Grifone Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted December 3, 2022 RMweb Premium Share Posted December 3, 2022 3 hours ago, mikesndbs said: Hi again, so four of the bends are done to avoid the crank pins. Straightening them means the pins hit the vale rods. I did tweak the drop link on one side which made things better, however there is still a really tight spot on the main rods one side only causing the engine to slow each revolution. Normally Wrenn stuff is great, but thjis old girl needs more help. Agreed, the four bends are intended to avoid hitting the crankpins. Have you taken out the twists and bends in the connecting rod behind the RH crosshead? CJI. Link to post Share on other sites More sharing options...
mikesndbs Posted December 3, 2022 Author Share Posted December 3, 2022 Hi all, many thanks for the thoughts and suggestions. I've just started working on the loco again now. Its rods and radius arm get stiff on one side near the top of the stroke. I can't see why. The first photo shows the affected side and I've shaded the stiff parts. Link to post Share on other sites More sharing options...
mikesndbs Posted December 3, 2022 Author Share Posted December 3, 2022 AHA! Drop link was twisted ever so slightly, reshaped it and now runs much better, still a small stiff spot but I think a bit of running will help. Only disaster is I reversed the motor magnet lol Link to post Share on other sites More sharing options...
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