Chuckles51 Posted August 11, 2020 Share Posted August 11, 2020 Hi all I have a Bachmann WD 2-8-0 which keeps derailing on curves especially the front pony truck - any suggestions? Neil Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted August 11, 2020 Share Posted August 11, 2020 Assuming this is the OO specimen rather than the GF N. Several things to check on the loco. Is the flat spring on the pony truck properly seated? It can get dislodged to one side and then the truck wheelset comes off the rail like a mad thing, and will help the rest of the loco off. If the spring is correctly positioned does it positively maintain the wheelset in contact with the rail as you lift the front of the loco a millimetre. If not adjust the spring pressure. (Above applies to all Bach pony trucks of this design.) Coupled wheelsets. Are they all free to move independently from side to side, no bent coupling rods or fouling from the moulded brake gear? Do the sprung 2nd and 4th axles move freely up and down (small movement)? The sprung saddles on these axles can get stuck in old gluey grease at the top of their travel, leaving the wheelset less constrained than it should be. Is the loco to tender coupling free moving? The track. Does derailment occur only at certain locations, or is it random? Can you see what is happening What is the minimum radius you are sending the loco around? (specified for 2nd radius - 438mm - minimum.) I know what this mechanism doesn't like, old 'system six' points that are well used. Had to take the pony truck off to make it work on these on a friend's ancient layout, shortly after this model was first released twenty years ago (and where did that time go?) Link to post Share on other sites More sharing options...
Chuckles51 Posted August 11, 2020 Author Share Posted August 11, 2020 12 minutes ago, 34theletterbetweenB&D said: Assuming this is the OO specimen rather than the GF N. Several things to check on the loco. Is the flat spring on the pony truck properly seated? It can get dislodged to one side and then the truck wheelset comes off the rail like a mad thing, and will help the rest of the loco off. If the spring is correctly positioned does it positively maintain the wheelset in contact with the rail as you lift the front of the loco a millimetre. If not adjust the spring pressure. (Above applies to all Bach pony trucks of this design.) Coupled wheelsets. Are they all free to move independently from side to side, no bent coupling rods or fouling from the moulded brake gear? Do the sprung 2nd and 4th axles move freely up and down (small movement)? The sprung saddles on these axles can get stuck in old gluey grease at the top of their travel, leaving the wheelset less constrained than it should be. Is the loco to tender coupling free moving? The track. Does derailment occur only at certain locations, or is it random? Can you see what is happening What is the minimum radius you are sending the loco around? (specified for 2nd radius - 438mm - minimum.) I know what this mechanism doesn't like, old 'system six' points that are well used. Had to take the pony truck off to make it work on these on a friend's ancient layout, shortly after this model was first released twenty years ago (and where did that time go?) It is the OO specimen. thank you for your reply lot's for me to look into and I will reply once I have tried your suggestions. Neil Link to post Share on other sites More sharing options...
Fogbomb Posted August 17, 2020 Share Posted August 17, 2020 Hi This thread might help me to remove the front pony on my Gresley V2 2-6-2 as I’ve purchased a new one from Bachmann and after removing the screw from the pony, I find that the suspension spring center shaft is preventing it from removing it off the chassis. Do I need to remove the chassis itself to get at the spring shaft to remove it? Any guidance would be appreciated as this is all a new world to me....thanks! Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted August 17, 2020 Share Posted August 17, 2020 20 minutes ago, Fogbomb said: Hi This thread might help me to remove the front pony on my Gresley V2 2-6-2 as I’ve purchased a new one from Bachmann and after removing the screw from the pony, I find that the suspension spring center shaft is preventing it from removing it off the chassis... Is that a coil spring on the front pony truck? If so you have a split chassis V2, now well out of production. The catalogue number on the box will enable 'someone' to confirm this if you post it here. Link to post Share on other sites More sharing options...
Chuckles51 Posted August 17, 2020 Author Share Posted August 17, 2020 Hi all went away and had a look at my WD. What's happening is that when the pony truck reaches the curve it lifts up and hits the bottom of the chassis and jams and comes back down and derails when the last driving wheel reaches the start of the curve (the Curves are second radius ). the driving wheels move freely, the loco to tender coupling moves freely. regarding this "If the spring is correctly positioned does it positively maintain the wheelset in contact with the rail as you lift the front of the loco a millimetre.". I tried this and the loco stayed on no problem. Hope this helps Neil Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted August 17, 2020 Share Posted August 17, 2020 32 minutes ago, Chuckles51 said: ...What's happening is that when the pony truck reaches the curve it lifts up and hits the bottom of the chassis and jams and comes back down and derails when the last driving wheel reaches the start of the curve... That sounds like the pony truck screw (or something else) is holding the pony truck in the straight ahead position. First thing to try, slacken off the pony truck pivot screw half a turn at a time, until the pony truck pivots freely, then test run the loco. Link to post Share on other sites More sharing options...
Fogbomb Posted August 19, 2020 Share Posted August 19, 2020 Thanks for the prompt reply, and yes it is a split chassis Bachmann V2 model (31-552). I’m tempted to take a photo or two to support my query, so I’m not wasting members time. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted August 20, 2020 Share Posted August 20, 2020 9 hours ago, Fogbomb said: ...it is a split chassis Bachmann V2 model (31-552). OK. To remove the front pony truck you have to detach the keeper plate from the underside. Two screws on the centreline to remove, and then carefully unclip one of the ends from the lugs cast into the chassis - the rear end is usually easiest to release but this has to be done carefully to avoid breaking the pick up wires from the trailing truck to the chassis halves. Do this with the mechanism inverted, otherwise all the driving wheels will be left dangling. The pony truck spring can then be detached by unclipping the plastic guide it is arranged around. When reassembling it takes some patience to reseat the keeper plate, and do not over tighten the securing screws. On 17/08/2020 at 16:50, Fogbomb said: ... Gresley V2 2-6-2 as I’ve purchased a new one from Bachmann... When you write of this as a new purchase from Bachmann, is that simply new to you, or was it sold to you as new? This release probably dates to the late 1990s, and the mechanism construction is long discontinued. Link to post Share on other sites More sharing options...
Chuckles51 Posted August 23, 2020 Author Share Posted August 23, 2020 On 17/08/2020 at 19:25, 34theletterbetweenB&D said: That sounds like the pony truck screw (or something else) is holding the pony truck in the straight ahead position. First thing to try, slacken off the pony truck pivot screw half a turn at a time, until the pony truck pivots freely, then test run the loco. Tried This Somewhat worked having had a look at the bottom of the loco again I think the front steps is causing the problem I have attached an Image to see if this helps. On 20/08/2020 at 13:40, 313201 said: Hi Everyone, I am not sure if this has already been suggested so I will offer my apologies now if it has. I have a Bachmann WD 2-8-0 and I found that gluing a relevant sized piece of lead to the plastic pony truck has minimised the number of times it derails so I will add another piece to it subject to this being possible given the available space. This does require the spring to be removed as it is fiddly to refit it but also, removing that spring does allow space between the pony truck and the chassis but its not much so any lead fitted in this space will need to be flattened enough so that it does not foul on the chassis. Hope this helps. Thanks for the Suggestion Neil Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted August 23, 2020 Share Posted August 23, 2020 That completely answers the question. The steps are 'user optional' fitments that have to be tested against the minimum radius the loco will operate on. There's no way they can fitted for set track operation. (Something like 30"/750mm minimum radius definitely works.) 2 Link to post Share on other sites More sharing options...
Fogbomb Posted August 24, 2020 Share Posted August 24, 2020 Thank you 34theletterbetween B&D for the guidance and sincere apologies for the late response. The loco is circa 1990’s and the replacement part was posted out to me form Bachmann as a complete pony. I’ll take onboard your guidance and see how I get on.......your efforts are much appreciated by this novice/ newbie to the hobby. Link to post Share on other sites More sharing options...
Chuckles51 Posted August 31, 2020 Author Share Posted August 31, 2020 Hi all Removed the step's and it has solved the problem and goes round the layout fine, thank you all for your help and suggestions. Neil Cafferky 1 Link to post Share on other sites More sharing options...
Sam Moss Posted September 2, 2020 Share Posted September 2, 2020 We've recently bought a new old stock LNER example for the club. Suitably relivered into an Annesley based example it went into service this Saturday and kept intermittently stalling and the front pony truck jumping off. Turns out the guard irons on the front pont were just catching point work. A quick crop with a pair of side cutters has cured it. Link to post Share on other sites More sharing options...
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