GEM80_Pom Posted January 21 Share Posted January 21 (edited) Firstly, this is not about split gears... it seems Bachmann have found a new way to make their models "fail to proceed" 🙄. I have a new-ish Class 66 (371-379) where the motor spins but the loco doesn't move (makes for a great sound-effect in a double-header  😂 ).  I unclipped the bogies and both have the same problem: the intermediate idler gears that transfer power to the wheel axles were out-of-mesh with their neighbouring gears. The axles for these idler gears are smooth and consequently the gears are free to slide sideways. Also, the width of the bogie's inner channel, where the gears are, is just wide enough to allow adjacent gears to sit on opposite sides of the channel and consequently they don't touch each other. Even if I slide the gears back into a meshed state, the gears soon slide into an unmeshed state again after a few seconds of running the loco.  My questions are: Has anyone else experienced this? ... what model(s) of loco? Has anyone taken this up with Bachmann? ... and what was their response? Is there a way to fix this problem? ...I can only think of looking for miniature washers, or fashioning bushes out of wire insulation, to keep the gears positioned in the middle of the axle.   In the photos below, power comes from gear '1', then to gear '2', then on to gear '3'. However, gear '2' is always unmeshed on the opposite side from gear '1'. Edited January 21 by GEM80_Pom Labels used on photos Link to post Share on other sites More sharing options...
RMweb Gold D9020 Nimbus Posted January 21 RMweb Gold Share Posted January 21 All the more recent Farish models have white (nylon) gears which are much less likely to be troublesome than the earlier black plastic kind — so your model is perhaps not as recent as you think — the white gears have been used since a year or two before COVID at least. 1 Link to post Share on other sites More sharing options...
scruff Posted January 31 Share Posted January 31 (edited) Did you buy the loco new? is there a chance that one or more of the gears are fitted the wrong way round? Have you tried a small spot of epoxy resin on the shaft to keep the gears in place? Â Cheers Mark Edited January 31 by scruff Link to post Share on other sites More sharing options...
GEM80_Pom Posted February 2 Author Share Posted February 2 (edited) To clarify, I bought the loco as a 2nd hand item, so I don't know its age. I am glad to hear that Bachmann will be using white nylon in future: I remember buying a Poole Class 25 back in 1987, when white nylon first replaced brass gears, and it has been my quietest and most reliable loco so far.  I have compared the sizes & positions of the idler gears with a similar loco... and they match. The idler gears in the functioning loco are also free to slide from side-to-side but they never quite lose contact/mesh with each other. However, the lack of alignment in the functioning loco makes me think the forces are being concentrated on an unnecessarily thin width of the gears' teeth 😧  To explain why one loco works and the other doesn't: the widths of the bogies' inner channels are ever-so-slightly wider in the non-functioning loco (i.e. the sides bow slightly outwards), consequently allowing the gears to decouple. If the bogies are made of a thermoplastic then I will try heating them in hot water and then squeezing the bogies to a narrower dimension (after stripping all removable items first of course 😉).  Edited February 2 by GEM80_Pom Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted February 2 Share Posted February 2 This problem lurks in OO product too, whether it is over wide channels or narrow gears, or a bit of both. (And for completeness,the opposite problem of tight channel, wide gear or wide gear boss.) Â My preference has been to push out the gear shafts and add washers to keep the gears as well positioned as possible for optimal meshing. It's somewhat fiddle-de-dee work, this gear can be positioned with very little slack, but that one needs to be left 'looser than I would have thought optimum' if there's not to be gear noise. 1 Link to post Share on other sites More sharing options...
RMweb Gold 2mmMark Posted February 3 RMweb Gold Share Posted February 3 An easy way to make spacer washers is to cut a slice of empty biro tube to the appropriate thickness, cut it to make a split washer, then slip it over the axle, leaving everything else undisturbed. 2 Link to post Share on other sites More sharing options...
Dr Al Posted February 22 Share Posted February 22 The top bogie gear is worn down - very clear in the picture - a common issue on Farish 66s. You need to replace these - the rest of the gearing is all fine. Â This will just allow the worms to bump across that gear rather than mesh with it. Â Cheers, Alan 1 Link to post Share on other sites More sharing options...
carderrail Posted February 23 Share Posted February 23 The Class 66 - 371-379 was produced in 2006. Â Just for info. Â Regards Tony 1 Link to post Share on other sites More sharing options...
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