RMweb Gold JCL Posted August 21, 2013 RMweb Gold Share Posted August 21, 2013 Hi there I've a Bachmann Deltic bought with a pre-fitted Loksound v4 decoder and I'm running a Digitrax Zephyr (the original one). My other locos run ok, but the Deltic seems to speed up and slow down "in waves" - almost like it's hitting batches of treacle on the tracks. It's been suggested to me that sometimes the Digitrax system has problems with Loksound decoders. Has anyone else found this? I can upload a video if it helps. cheers Jason Link to post Share on other sites More sharing options...
RMweb Gold Oldddudders Posted August 21, 2013 RMweb Gold Share Posted August 21, 2013 In the last few days, Nigel Cliffe of this parish has helped me with a Lokpilot V4 which wanted to start at about 15smph (scale miles-per-hour) despite CV2 being at 1. It seems the latest ESU products have a sophisticated method of motor control which initially requires a sort of automated set-up. You may have the same issue, although I am also a Digitrax user. I quote his suggestion: "put loco on track with a decent run of clear line ahead of it, OpsMode, set CV54=0. Then press F1 and stand back. The loco will shoot off at great speed and automatically set various motor parameters." I found the loco stopped after a few feet, and thereafter has been very controllable. Not worth not trying. Do not reset CV54 afterwards. . Link to post Share on other sites More sharing options...
marc smith Posted August 21, 2013 Share Posted August 21, 2013 This maybe a daft suggestionBut could it be that an interference suppression capacitor is fitted to the circuit board?Ages back, when first dabbling with DCC I fitted a decoder into a loco,only to find it often just launched itself forward at breakneck speedand for no apparent reason..... I was told to remove any TVI capacitors, and have done so ever since, before fitting a decoderMarc Link to post Share on other sites More sharing options...
Nigelcliffe Posted August 21, 2013 Share Posted August 21, 2013 Hi there I've a Bachmann Deltic bought with a pre-fitted Loksound v4 decoder and I'm running a Digitrax Zephyr (the original one). My other locos run ok, but the Deltic seems to speed up and slow down "in waves" - almost like it's hitting batches of treacle on the tracks. It's been suggested to me that sometimes the Digitrax system has problems with Loksound decoders. Has anyone else found this? I can upload a video if it helps. cheers Jason Check the following: 1 - on the Zephyr, DC address zero is either disabled in an Op-Switch, or definitely at "stop". 2 - on the Zephyr, check the status edit of the decoder - see the Zephyr manual for status editing (If you find that the status edit for a loco seems to be changing randomly after you've turned off the Zephyr, then you have a faulty Zephyr; there are a handful with this fairly rare bug, and it needs a trip back to the makers to solve it ). 3 - consider removing any suppression capacitors inside the loco. 4 - do the auto-calibration run which Ian describes above. I've never heard of a running problem between ESU decoders and Digitrax hardware. There is a limitation on programming; many older Digitrax devices can only access CV's below 255 on their keypads, which makes some setup of recent ESU decoders more awkward ( the process for systems which can't access high CV numbers is in the ESU manual). If you own a computer interface, eg. PR3 or LocoBuffer, or a recent throttle, eg. DT402, then those CV limitations don't apply. - Nigel Link to post Share on other sites More sharing options...
RMweb Gold JCL Posted August 21, 2013 Author RMweb Gold Share Posted August 21, 2013 Hi everyone, I have to pop over the border, but will go through each suggestion to see if I can get it running better. I've also just got a Bachmann 21pin decoder from the UK, so I will try that too. I'll report back to let you know how I get on. The person who fitted the sound decoder messed up slightly anyway, so they could have missed some stuff. Nigel - you'll probably be putting two and two together for one of the reasons for my post on the eLink Link to post Share on other sites More sharing options...
RMweb Gold JCL Posted August 22, 2013 Author RMweb Gold Share Posted August 22, 2013 After checking no capacitor, I've had a chance to try Nigel's and OldDudder's suggestion and it's working a lot better than it was! It's only slightly hesitant in places now, so I'll check the track in those places, give it an oil and run it in properly (the latter I couldn't do before as it was painful watching it!) Thanks everyone for your help. Link to post Share on other sites More sharing options...
RMweb Gold JCL Posted August 22, 2013 Author RMweb Gold Share Posted August 22, 2013 Just got back in and tested the loco again. Unfortunately it's "stuttering" again - surely it doesn't need warming up? I put in a standard Bachmann 21 pin and it ran ok, so the mechanism is right. The interesting thing is that I have other Loksound v4 locos which run OK out of the box, so it's not Loksound decoders as a whole. I'll try Nigel's other pointers tomorrow and let you know how I get on. cheers Jason Link to post Share on other sites More sharing options...
RMweb Gold JCL Posted August 23, 2013 Author RMweb Gold Share Posted August 23, 2013 Hi everyone, I hadn't checked the motor. I must have been on drugs as I checked the circuit board for capacitors instead of the motor - honestly, I know better than to do that. Anyway, after gaining access to the motor (not easy because of the hardwired speaker in the fuel tank), I snipped off the three capacitors. On putting it back together and crossing my fingers I've tested it and the loco rolls smoothly now, with no hint of a hesitation. Thanks so much for everyone's help! You've removed source of frustration that's been in the back of my mind for the last few months. I'm so pleased I found this forum. cheers Jason Link to post Share on other sites More sharing options...
daveymills Posted August 24, 2013 Share Posted August 24, 2013 hello all By chance I have a similar problem. I have fitted a new v4 loksound chip (Olivia's sound) to a Heljan Class 27. I am using a Digitrax Zephyr purchased 12 months ago. As soon as I turn the dial to start the loco, even on speed step 1, the loco shoots forward immediately to a fairly high speed and will not stop until I return the dial to 0. Turning the dial to higher speed steps, does not increase the speed that the loco immediately jumps to - it seems to reach the same speed, but this does prolong the slowing down time when i return the dial to 0. The sound functions seem to run fine. I have tried to tinker with CV2, CV3 (both set to zero), and CV29 is set not to run to a user-defined speed table and is set to 128 speed steps. I tried to perform the test above (setting CV54=0 and letting it tune itself) but this had no effect. Any ideas ? thanks Dave Link to post Share on other sites More sharing options...
RMweb Gold JCL Posted August 25, 2013 Author RMweb Gold Share Posted August 25, 2013 Hi Dave, It might be worth starting a new topic with your question. I don't think too many people will come back to this one because it's resolved. One final note on this one for posterity, I also turned off Back EMF for good measure. With the running in and the changes made the loco now runs like a charm. cheers Jason Link to post Share on other sites More sharing options...
daveymills Posted August 26, 2013 Share Posted August 26, 2013 Thanks Jason for the advice - will do Link to post Share on other sites More sharing options...
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