90rob Posted August 22, 2018 Share Posted August 22, 2018 Now that is the crux of the matter. With some, the models appearing to be excellent performers whilst others seem to run like dogs no matter how they are tweaked. The manufacturers should maybe try doing more to identify the inconsistencies and the reasons behind them. It does seem odd. I seem to recall that the 14xxs were received in two or three batches. I suppose the poor performers were not all from the same batch? Link to post Share on other sites More sharing options...
RMweb Gold Brinkly Posted August 22, 2018 RMweb Gold Share Posted August 22, 2018 Didn't PMP actually do that? I want to say he did, but with little improvement running wise. Was it on his blog? Regards, Nick. Link to post Share on other sites More sharing options...
RMweb Gold Captain Kernow Posted August 22, 2018 RMweb Gold Share Posted August 22, 2018 Now that is the crux of the matter. With some, the models appearing to be excellent performers whilst others seem to run like dogs no matter how they are tweaked. The manufacturers should maybe try doing more to identify the inconsistencies and the reasons behind them. This was the problem with a Bachmann 82XXX I had a few years ago. No matter what I did, I couldn't get it to run smoothly. In the end, I modified a Comet 76XXX chassis and put that under the Bachmann body. Link to post Share on other sites More sharing options...
coachmann Posted August 22, 2018 Share Posted August 22, 2018 Hi Coach Do you think it would be possible to assemble the gears in the 48XX so that only one axle is driven and use the coupling rods (possible bushed) to drive the other as they should? Not that I am contemplating it, but it might be useful for others that want a better performing loco without ditching the chassis. Cheers Keith If cogs are removed and the drive is to taken to just one axle of a DJM 14XX, I rather suspect the very floppily fitted coupling rods would fail to do the job of acting as coupling rods due to the large amount of slack. Still, one never knows until it is tried. I was fortunate in having one decent runner, but the biggie for me now is, do i want to spend quite a lot of money on having DCC sound professionally fitted knowing that the speaker will be very small. I am fond of 14XX's, but I may have to go for a Bachmann 64XX instead.........A loco I know I can completely gut and fit in a cab-filling Flame 10 speaker. Link to post Share on other sites More sharing options...
Paul_sterling Posted August 23, 2018 Share Posted August 23, 2018 I want to say he did, but with little improvement running wise. Was it on his blog? Regards, Nick. I think someone on this thread did the work as well, and did see an improvement. I think you would have to really go to town on the mechanism though, and remove everything that isn't required, not to mention lap the remaining gear-train in as much as possible. I've often wondered if it is in fact the quartering of the gears that are causing the problem on this model, leading to incompatibility with coupling rods. Paul. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted August 23, 2018 RMweb Premium Share Posted August 23, 2018 It could be almost anything really, but my thoughts are directed towards the chassis where the two halves might not always fit together in perfect alignment. Unlike the new Farish N gauge split-axle chassis design for their steam locos which have separate drop-in bearings, which it would seem thus make allowance for any slight mis-alignment, with the design used - which seems to mirror that used in the Dapol N gauge GWR pannier as well as other recent 4mm offerings - the bearings are pressed into the chassis halves and therefore it would appear the individual wheels have to be assembled into the chassis/onto the gear muffs rather than the wheelsets/bearings/muffs being built and then just dropped into place. With less than optimum alignment this could lead to excess friction in the wheel bearings area causing, when coupled with the backlash in the spur gear train, on/off loading on the little motor and the resultant, hesitant/jittery/less than smooth performance that some are experiencing. This is all speculation of course, but based on many decades of struggling with building locos in a variety of scales. Often something which works quite well in one scale or particulation situation doesn't always work in another, and I think that this design concept might just be one such. The thing is nothing is sure or certain until it is proved one way or another, and doubly difficult when it concerns items produced in quantity rather than just single builds. That many work quite okay only adds to the puzzlement........ Izzy Link to post Share on other sites More sharing options...
coachmann Posted August 23, 2018 Share Posted August 23, 2018 (edited) Even with everything removed so that the driving wheels are unencumbered with gearing, the chassis is not as free running as I would have expected. With regard to driving one axle, I am now confident that the sloppy coupling rods would do the job that coupling rods are expected to do. Edited August 23, 2018 by coachmann Link to post Share on other sites More sharing options...
RMweb Gold Captain Kernow Posted August 23, 2018 RMweb Gold Share Posted August 23, 2018 I think you would have to really go to town on the mechanism though, and remove everything that isn't required, not to mention lap the remaining gear-train in as much as possible. This is the thing, though. Some folk seem to have spent a lot of time on these mechanisms, trying to get them to run better. I've got to the stage now, where I'd rather spend that time building something that's (hopefully) going to actually work properly. 3 Link to post Share on other sites More sharing options...
RMweb Gold 57xx Posted August 23, 2018 RMweb Gold Share Posted August 23, 2018 But Larry, nobody on this thread has suggested that they do. Having said that Dapol managed simple springing on centre axle of their Austerity/J94 way back in the early nineties, Bachmann did the same with their Class 08 Shunter and Hornby made provision for springing the centre axle on their 08 shunter when that was introduced. Strangely Hornby have only started fitting the coil springs on their latest 08 releases. There's also the Bachmann pannier with it's centre sprung axle as another example of a non-exaggerated RTR solution. Link to post Share on other sites More sharing options...
Porcy Mane Posted August 23, 2018 Share Posted August 23, 2018 (edited) It does seem odd. I seem to recall that the 14xxs were received in two or three batches. I suppose the poor performers were not all from the same batch? Unless Kernow/DJM mark their boxes in a similar manner to Hornby there may be no way of telling for the humble punter. I don't own a 14xx, my only experience being with the similar drivetrain from the DJM J94. My own feeling based on the experience of the three J94's I've had through my hands is the problem is not down to batch differences but the combined running tolerances in the drive train. One of the J94's running qualities was improved immeasurably just by cleaning all of the factory lube out of the loco then re-applying a tiny amount of PTFE grease. The improvement was down to a measured decrease in electrical continuity of the pick up method. I never tried the incline test on this loco. Conversely one of the things I suggested to PMP was to stuff the geartain full of grease to see if the extra rotational and rolling resistance might go some way to dampen the gear train backlash on inclines. This of course, would not be practical for a working loco. Dunno if PMP ever tried this. As for the small coreless motors, I love them and think they have many uses in model railways. The but is, they have to be paired with a complementary gear/train/box. P Edit. Thinking about this; wasn't it the Kernow/DJM Well Tank that was originally supplied with a conventional motor but with subsequent batches the design was changed to incorporate the small coreless? My mind is probably tricking me (yet again). Edited August 23, 2018 by Porcy Mane Link to post Share on other sites More sharing options...
Paul_sterling Posted August 23, 2018 Share Posted August 23, 2018 Even with everything removed so that the driving wheels are unencumbered with gearing, the chassis is not as free running as I would have expected. With regard to driving one axle, I am now confident that the sloppy coupling rods would do the job that coupling rods are expected to do. I would presume it better to fit replacement rods with tighter tolerances if they were to substitute for the gearing as drive between the two axles, too much slogger might allow the wheels to get out of line when crank pin, wheel bosses and rods all align. If that was done, and drive still tight, it could only be alignment, tightness in the remaining gears, or quartering that could be at fault. Cheers, Paul. Link to post Share on other sites More sharing options...
JSpencer Posted August 23, 2018 Share Posted August 23, 2018 Edit. Thinking about this; wasn't it the Kernow/DJM Well Tank that was originally supplied with a conventional motor but with subsequent batches the design was changed to incorporate the small coreless? My mind is probably tricking me (yet again). Yep. The ones done under Dapol had a big open frame motor. The DJM ones coreless (the same fitted in the J94). Gear train, pickups etc are the same on both batches which was bearing pick ups on the drivers and wipers on the 'sprung' front axle. Needless to say, the Dapol has more grunt, but is also more noisy. I do not know it the O2 used the same motor as the Well tank and J94 since I've never needed to open one up but it does have bearing pickups on the drivers and wiper pickups on the trailing pony, quite a successful loco out performing the bigger heavier Hornby H class (which sadly has the centre of gravity behind the drivers) . The split geared drive on these first appeared in modelrails Sentinel which used Dapols N gauge super creep motor. The Well tanks, O2, J94, 14XX and 1361s being an evolution, albeit loosing wipers and becoming more rigid from the J94 onwards. Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted August 23, 2018 RMweb Premium Share Posted August 23, 2018 There's also the Bachmann pannier with it's centre sprung axle as another example of a non-exaggerated RTR solution. And the 2251 class. All seem to have a dual cog to give some extra reduction from the motor/worm, an idler to reach the axle gear and the gear on the axle itself and they work! Keith Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted August 25, 2018 RMweb Gold Share Posted August 25, 2018 I don't like the sound of dismantling the gear connection to the leading drivers and letting the coupling rods do the work. They'll do the work all right, but at the cost of increased wear in the bushes as there is too much play between the bush and the crankpin for this to work for any great length of time; the chassis isn't designed to be used like this and such use will shorten the working life of the coupling rods. Of course if you are happy to replace these every so often, then it'll work fine; wear can be limited by gentle driving, smooth starts and acceleration, and light loads. You don't want to be banging around at high speed with a 14xx anyway! Link to post Share on other sites More sharing options...
Paul_sterling Posted August 25, 2018 Share Posted August 25, 2018 I don't like the sound of dismantling the gear connection to the leading drivers and letting the coupling rods do the work. They'll do the work all right, but at the cost of increased wear in the bushes as there is too much play between the bush and the crankpin for this to work for any great length of time; the chassis isn't designed to be used like this and such use will shorten the working life of the coupling rods. Of course if you are happy to replace these every so often, then it'll work fine; wear can be limited by gentle driving, smooth starts and acceleration, and light loads. You don't want to be banging around at high speed with a 14xx anyway! I think its safe to say if the gear train to the front axle was removed, the rods would be getting changed to a better fitting type. Paul. Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted August 25, 2018 RMweb Premium Share Posted August 25, 2018 I think its safe to say if the gear train to the front axle was removed, the rods would be getting changed to a better fitting type. Paul. Hence my comment in post #2304 about "possibly bushed" to get a more reasonable fit. Keith 1 Link to post Share on other sites More sharing options...
RMweb Gold NHY 581 Posted August 25, 2018 RMweb Gold Share Posted August 25, 2018 All of these issues should have been sorted before the model went on sale. It should not be left to the customer to develop/modify the model to the point where it runs reliably and without fault. Rob Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted August 25, 2018 RMweb Premium Share Posted August 25, 2018 All of these issues should have been sorted before the model went on sale. Rob It probably was, but manufacturing tolerances and poor quality control had done their worst. Keith Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted August 26, 2018 RMweb Gold Share Posted August 26, 2018 That sounds right. The problems probably were sorted out at the pre-production stage, but the different manufacturing facilities in China have not, in this case, managed to maintain consistency of quality control and the issue has not been picked up at the assembly/packing stage. The models arrive and are distributed to the retailers, and are sold mail order without being test run; the customer has to sort it out. This, of course, shouldn't happen, but in the real world it does and unless each individual model is thoroughly test run, the cost of which would be passed on to the customer, it will continue to. Link to post Share on other sites More sharing options...
coachmann Posted August 26, 2018 Share Posted August 26, 2018 P That sounds right. The problems probably were sorted out at the pre-production stage, but the different manufacturing facilities in China have not, in this case, managed to maintain consistency of quality control and the issue has not been picked up at the assembly/packing stage. The models arrive and are distributed to the retailers, and are sold mail order without being test run; the customer has to sort it out. This, of course, shouldn't happen, but in the real world it does and unless each individual model is thoroughly test run, the cost of which would be passed on to the customer, it will continue to. Personally I dont see as that at all. It wouldn't matter if the gears were made by a watchmaker, it was still a idea that rendered connecting rods superfluous and led to them having super-size holes because they were in fact cosmetic. DJM has 'form' when it comes to design. Link to post Share on other sites More sharing options...
JSpencer Posted August 27, 2018 Share Posted August 27, 2018 P Personally I dont see as that at all. It wouldn't matter if the gears were made by a watchmaker, it was still a ###### idea that rendered connecting rods superfluous and led to them having super-size holes because they were in fact cosmetic. DJM has 'form' when it comes to design. The idea worked well on earlier smaller designs but I maintain the relatively small motor and rigid chassis employed from the austerity onward lead to ad-hoc or mediocre performance (the 71 is no exception, it is by far the most rigid set up in a Diesel or Electric I have with very little down play on the bogies). The bigger King class carried the idea further still. I was looking forwards to that, the CAD detail was exceptional but the motor in those early CADs was 1/4 of the size that Hornby used. Doubtless EPs would have shown this to be hopelessly under powered and Hattons would have upped the spec. History is full of examples of ideas that work exceptionally well at small scales but fail badly when scaled up. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted August 27, 2018 RMweb Premium Share Posted August 27, 2018 Totally agree with the motor being probably the main issue. As I have remarked on another thread it would be interesting to try using another larger, more powerful one, to see what might result. Whether it would be able to ‘power through’ any off/on resistance caused by the slack gear train etc. Fitting another might be a challenge though given the solid nature of the chassis - getting a worm/the original worm to mate at a usable angle. Izzy Link to post Share on other sites More sharing options...
RMweb Gold Brinkly Posted September 17, 2018 RMweb Gold Share Posted September 17, 2018 I fitted cast plates on my 14xx loco and removed the emblem. Couple of other jobs too, but you definitely don't need to remove the original number plate, as the etched replacement fits very nicely on top. If anyone is interested, I've detailed the work in greater depth here. Kind regards, Nick. 11 Link to post Share on other sites More sharing options...
Dad-1 Posted September 22, 2018 Share Posted September 22, 2018 MMMmmmm Just got this one ? Simply not good enough, I hope Hatton's have some 'good runners' Apart from waddling and wallowing along both my Hornby & earlier Dapol versions run well enough on DCC Dad-1 Link to post Share on other sites More sharing options...
RMweb Gold Brinkly Posted September 22, 2018 RMweb Gold Share Posted September 22, 2018 MMMmmmm Just got this one ? Simply not good enough, I hope Hatton's have some 'good runners' Apart from waddling and wallowing along both my Hornby & earlier Dapol versions run well enough on DCC Dad-1 That is shocking, send it back! It won't improve at all. I've had two replacements, the third seems to be alright. The chassis and mechanism on these models is very poorly designed. 1 Link to post Share on other sites More sharing options...
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