mike knowles Posted November 4, 2010 Share Posted November 4, 2010 A friend at the club recently acquired two of the Heljan 4mm scale Class 14 locos. Initial running on DC showed them both to be good, smooth runners. As requested, I fitted Hornby 8249 decoders to them (the ones with the NMRA label, which I believe is what Hattons suggest to use). However running them on DCC shows all the problems usaully associated not with just dirty, but absolutely filthy track, wheels and pickups. The locos would only run a few inches before stalling (and the lights going off), requiring a push to get them going again. I would point out that the track wheels and pickups are clean. It was also noticed that when pushing the locos the lights would often initially come back on momentarily in the reverse direction, before changing to the correct direction and the loco moving off again. In frustration, the decoders have been removed and the blanking plugs re-installed. Running on DC is again back to normal. Any ideas anyone? Anybody out there who has chipped their's, what decoder have you used? Link to post Share on other sites More sharing options...
RMweb Gold RedgateModels Posted November 4, 2010 RMweb Gold Share Posted November 4, 2010 check the pickups are running corrctly on the wheelbacks. QA on assembly is not all it should have been. DCC is more sensitive to current interuption, so fitting a chip might expose such a weakness in assembly. I have managed to get mine to run with a Loksound Micro, so they can work well with DCC chips. Link to post Share on other sites More sharing options...
SRman Posted November 4, 2010 Share Posted November 4, 2010 Just a suggestion: are there any capacitors? If there are, they may be interfering with the decoder operation so cut them off and seal any bare wires with some heat-shrink or tape. It also sounds like the decoder may be shorting out on something if the lights are also going off when it stops. DCC decoders are far more sensitive to any minor, momentary shorts than when running on DC. Check the pickups and wiring for any possible areas where metal can touch metal. Link to post Share on other sites More sharing options...
corax67 Posted November 6, 2010 Share Posted November 6, 2010 If the loco's ran well under DC but are poor under DCC then look at the decoder rather than the loco. Try a different decoder in them for a start - I will not use install Hornby decoders ever because I have seen far too many problems with them over the years (even though they now bear the NMRA logo). I have fitted Class 14's with Lenz, TCS and Zimo decoders for customers - my own one runs on a Lenz Gold -and all run beautifully smoothly with superb slow speed control. Link to post Share on other sites More sharing options...
locoworks Posted November 7, 2010 Share Posted November 7, 2010 the decoder may be the issue? but i received a 14 from hattons and i sent it back, it was fine on DC, but fitting a chip gave me nothing. i removed the chip and metered out the socket and there was a full short between the red and orange wire locations on the socket. ok for DC, NO use for DCC. they replaced the loco and the next one worked fine. it may be your socket rather than the decoder is at fault, or perhaps the decoder is of the usaul Hornby standard in this area?? maybe a BEMF issue if the decoder has it?? Link to post Share on other sites More sharing options...
Pete Piszczek Posted November 7, 2010 Share Posted November 7, 2010 There's an issue with the plug grounding out on the chassis though the tape. All those sharp prongs under the plug can easily puncture the tape as you push a chip down into the plug... http://www.rmweb.co....dpost__p__85808 Link to post Share on other sites More sharing options...
rouse2037 Posted May 2, 2011 Share Posted May 2, 2011 I purchased a Heljan 14 recently and it ran fine from the box on dc. I then plugged in a Bachmann 36-552 decoder and . Awful. The thing now buzzes and barely moves until I crank up to speed step 3 (on the 14 step setting) on my Gaugemaster. I have checked the chip, pcb and chassis etc for any metal touching but all is fine as far as i can tell. Any other suggestions to improve the running and get rid of the buzzing sound? I have not experienced this before on Heljan or Bachmann loco's and have always used Bachmann decoders. Cheers Roger Link to post Share on other sites More sharing options...
Lady_Ava_Hay Posted May 2, 2011 Share Posted May 2, 2011 I purchased a Heljan 14 recently and it ran fine from the box on dc. I then plugged in a Bachmann 36-552 decoder and . Awful. The thing now buzzes and barely moves until I crank up to speed step 3 (on the 14 step setting) on my Gaugemaster. I have checked the chip, pcb and chassis etc for any metal touching but all is fine as far as i can tell. Any other suggestions to improve the running and get rid of the buzzing sound? I have not experienced this before on Heljan or Bachmann loco's and have always used Bachmann decoders. Cheers Roger 14 step setting is not really supported by most current chips. Change it to 28/128 and then check the running. If it is still a bit suspect, remove the capacitors. remember that Heljan locos are power hungry and less than 1 amp rating will give problems. Link to post Share on other sites More sharing options...
rouse2037 Posted May 3, 2011 Share Posted May 3, 2011 14 step setting is not really supported by most current chips. Change it to 28/128 and then check the running. If it is still a bit suspect, remove the capacitors. remember that Heljan locos are power hungry and less than 1 amp rating will give problems. Thanks for the idea but it runs worse - or rather wont move at all on 28/128 speed step setting until I turn the speed up higher - ie pretty much the same as on 14 step setting. I have adjusted the CV settings for start voltage/acceleration/deceleration/top voltage etc but again with little improvement... however, i'll give the settings another go and get the amps up higher maybe? Where are the capacitors? Cheers Roger Link to post Share on other sites More sharing options...
James90012 Posted May 3, 2011 Share Posted May 3, 2011 My advice from experience, is uber clean track for DCC and wheel pickups. That along side using a decoder such as a Lenz Silver will help reduce this issue in particular. A loco DC is a completely different one to when it is DCC'ed. A different model with different running characteristics. Link to post Share on other sites More sharing options...
k9-70 Posted May 3, 2011 Share Posted May 3, 2011 I purchased a Heljan 14 recently and it ran fine from the box on dc. I then plugged in a Bachmann 36-552 decoder and . Awful. The thing now buzzes and barely moves until I crank up to speed step 3 (on the 14 step setting) on my Gaugemaster. I have checked the chip, pcb and chassis etc for any metal touching but all is fine as far as i can tell. Any other suggestions to improve the running and get rid of the buzzing sound? I have not experienced this before on Heljan or Bachmann loco's and have always used Bachmann decoders. Cheers Roger It's the Bachmann 36-552 2function decoder that's causing all your problems. Change it to either the Bachmann 36-553 3function or the Lenz Silver Plus decoder for much better locomotive control. Also set your controller to either 28/128 speed step for much better locomotive control. K9-70 Link to post Share on other sites More sharing options...
rouse2037 Posted May 3, 2011 Share Posted May 3, 2011 My advice from experience, is uber clean track for DCC and wheel pickups. That along side using a decoder such as a Lenz Silver will help reduce this issue in particular. A loco DC is a completely different one to when it is DCC'ed. A different model with different running characteristics. True. I guess i have been very lucky over the years with loco's. Every one I have bought have run very well both on DC and when chipped so the 14 is a challenge! As for clean track, I would normally agree apart from the fact that my 22 (on a 20 chassis, with decoder fitted without any running in on dc first) runs superb on Neptune Rd - on track which is very far from clean - right down to a crawl taking over several minutes to cover 4 ft.. and so does my Heljan Hymek.. and three Bachmann 24's ! Cheers Roger Link to post Share on other sites More sharing options...
rouse2037 Posted May 3, 2011 Share Posted May 3, 2011 It's the Bachmann 36-552 2function decoder that's causing all your problems. Change it to either the Bachmann 36-553 3function or the Lenz Silver Plus decoder for much better locomotive control. Also set your controller to either 28/128 speed step for much better locomotive control. K9-70 Thanks - I was wondering if the 36-553 would be better - I'll try and get hold of one Roger Link to post Share on other sites More sharing options...
Gordon H Posted May 3, 2011 Share Posted May 3, 2011 14 step setting is not really supported by most current chips. It certainly ought to be, because 14 step mode is part of the original Baseline Standard as set out in S9.2 Section B: "It is the intention of this Standard that, in order to conform: a Command Station must encode operator control input in conformance with the Baseline Packet semantics; and a Digital Decoder must recognize and provide suitable locomotive control electrical output in conformance with the Baseline Packet semantics." Link to post Share on other sites More sharing options...
Adrian Wintle Posted May 4, 2011 Share Posted May 4, 2011 It certainly ought to be, because 14 step mode is part of the original Baseline Standard as set out in S9.2 Section B: "It is the intention of this Standard that, in order to conform: a Command Station must encode operator control input in conformance with the Baseline Packet semantics; and a Digital Decoder must recognize and provide suitable locomotive control electrical output in conformance with the Baseline Packet semantics." 14-step mode, while supported, is an historical irrelevance. I would suggest that if support for it were dropped very few people would notice and a bunch of regular 'why is my loco doing this?' questions would disappear. In response to the OP, it is possible that the Class 14 draws too much current for the Hornby chip and the erratic operation seen may a result of the chip getting overloaded. Adrian Link to post Share on other sites More sharing options...
RMweb Gold RedgateModels Posted May 4, 2011 RMweb Gold Share Posted May 4, 2011 Hattons tested the class 14 using a Hornby chip and even recommended it for fitting over other brands. Mainly on size I suspect as the space available is small. I'd use a TCS-M1 meself, don't think a Bachmann 3 function would fit without modifying the chassis, but am hapy to be proved wrong Link to post Share on other sites More sharing options...
Tim Hale Posted May 4, 2011 Share Posted May 4, 2011 The Heljan motor is notorious for a high starting load, therefore I find the suggestion to use a R8249 to be somewhat optimistic. A big 36-553 maybe the answer but the problem could be the physical size (hence the suggested R8249) therefore look at the better US decoders or the excellent DCC Concepts decoder. DesA Link to post Share on other sites More sharing options...
RMweb Gold roundhouse Posted May 4, 2011 RMweb Gold Share Posted May 4, 2011 Hattons tested the class 14 using a Hornby chip and even recommended it for fitting over other brands. Mainly on size I suspect as the space available is small. I'd use a TCS-M1 meself, don't think a Bachmann 3 function would fit without modifying the chassis, but am hapy to be proved wrong I have used many different makes of decoders in both British and American models in various scales and the Hornby decoders with the NMRA Mark have performed well in all locos I have fitted them except in a Farish class 66. Hattons tested the class 14 using a Hornby chip and even recommended it for fitting over other brands. Mainly on size I suspect as the space available is small. I'd use a TCS-M1 meself, don't think a Bachmann 3 function would fit without modifying the chassis, but am hapy to be proved wrong I have used many different makes of decoders in both British and American models in various scales and the Hornby decoders with the NMRA Mark have performed well in all locos I have fitted them except in a Farish class 66. Link to post Share on other sites More sharing options...
Gordon H Posted May 7, 2011 Share Posted May 7, 2011 14-step mode, while supported, is an historical irrelevance. I would suggest that if support for it were dropped very few people would notice and a bunch of regular 'why is my loco doing this?' questions would disappear. While the Standards are there they should be followed - to the letter - that is what they are for. Doesn't matter how few people would notice or how inconvenient it might be to keep answering questions that crop up. Even more so in this case because we are referring to a mandatory Standard (S9.2), not a Recommended Practice (RP 9.x.x). Link to post Share on other sites More sharing options...
lapford34102 Posted May 7, 2011 Share Posted May 7, 2011 Just an observation as I had similar problems with mine. It worked passably well on DC straight out the box but was a disaster on DCC . After a rather protracted investigation it came down to the wheels and required heavy cleaning of the the backs of tyres to remove whatever was contaminating them. This seems to have cured the running problems though I'll feel happier with a few more hour running experience. Cheers Stu Link to post Share on other sites More sharing options...
Lady_Ava_Hay Posted May 7, 2011 Share Posted May 7, 2011 While the Standards are there they should be followed - to the letter - that is what they are for. Doesn't matter how few people would notice or how inconvenient it might be to keep answering questions that crop up. Even more so in this case because we are referring to a mandatory Standard (S9.2), not a Recommended Practice (RP 9.x.x). Mandatory is only relevant if you want NMRA standard approval to use the NMRA mark on your products. Early Hornby kit didn't. There are a fair number of products on the market that don't conform to NMRA standards. Link to post Share on other sites More sharing options...
dave flint Posted May 9, 2011 Share Posted May 9, 2011 I initially put a Hornby 8249 in my 14, but just found I'd put a tcs m1 in a loco I'm selling. I've now put that m1 in the 14 (it seems ideal for this application) and it STILL runs poorly, with intermittent pickup, as witness by flickering lights. And it was the same on dc only. I reckon that there is too much slop in the wheels - try it, there is a lot of play side to side. I think the pickups can't cope with that movement. I ended up giving it a good sideways wiggle which improved matters, but I'm going to have a play with the pickups when I have more time. Link to post Share on other sites More sharing options...
dave flint Posted May 9, 2011 Share Posted May 9, 2011 The Heljan motor is notorious for a high starting load, therefore I find the suggestion to use a R8249 to be somewhat optimistic. A big 36-553 maybe the answer but the problem could be the physical size (hence the suggested R8249) therefore look at the better US decoders or the excellent DCC Concepts decoder. DesA I agree with the sentiment, but think that only applies to the big can motors on their 47s, lion, falcon etc. This 14 is a different, and much smaller beast. Link to post Share on other sites More sharing options...
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