RMweb Gold Nickey Line Posted April 6, 2012 RMweb Gold Share Posted April 6, 2012 Sometime later...! After further experimentation I've found that the jerkyness can be cured by turning off the DC bit in CV29... i.e. subtract 4 from the value in CV29 for those as don't know... jerkyness now completely cured. Strikes me as rather odd that this should make so much difference! adding this in part as a 'bump', as a mere edit doesn't do the job... Link to post Share on other sites More sharing options...
Suzie Posted April 6, 2012 Share Posted April 6, 2012 This makes a difference because you are not getting a good DCC signal to the decoder, and the Bachmann 36-553 does require a very good signal, much better than the minimum specified by the NMRA. The proper cure (short of getting a good decoder!) will be to do a bit of work on cleaning the wheels and pickups (and possibly the track too). You should notice an improvement in responsiveness to the controller when this is done. The CV29 fix works because you are preventing the decoder from switching to DC mode when it has given up trying to decode the data packets, so it tries again at decoding rather than trying to guess the DC voltage on the track, and if you are lucky it will actually decode one before the stop timeout (which is much longer than the DC timeout for reasons of practicality). Link to post Share on other sites More sharing options...
RMweb Gold Nickey Line Posted April 6, 2012 RMweb Gold Share Posted April 6, 2012 Hmmm interesting; perhaps this 'feature' doesn't work as it's supposed to, as I found exactly the same results when wheels and track are spotless (I use IPA for track/wheel cleaning by the way). Link to post Share on other sites More sharing options...
Suzie Posted April 6, 2012 Share Posted April 6, 2012 It might be that your command station is outputing a DCC waveform that is not compatible with the decoder, they do not work with Bachmann's own E-Z Command system! Link to post Share on other sites More sharing options...
RMweb Gold Nickey Line Posted April 6, 2012 RMweb Gold Share Posted April 6, 2012 Nope, I'm using a Lenz system. Can't speak for the original poster though of course! But as I don't intend to run my locos on a DC system anyway, it's not a problem. Link to post Share on other sites More sharing options...
Alex Thompson Posted June 22, 2012 Share Posted June 22, 2012 I have Just brought a G2A with a Bachmann 21 pin chip. What values for 54/55 do you all think is best for smooth running for this loco? Link to post Share on other sites More sharing options...
RMweb Gold RFS Posted June 22, 2012 RMweb Gold Share Posted June 22, 2012 This is documented here on the Bachmann web-site - http://www.Bachmann.co.uk/pdfs/decoder_settings.pdf Link to post Share on other sites More sharing options...
PACman Posted March 19, 2013 Share Posted March 19, 2013 Hi guys, just picking up on this thread again... I have just fitted a Bachmann 36-554 3 function decoder to a new Hornby B1 and made the adjustments noted previously to CV 54, 55 and 29 and it has made a big difference to its slow speed performance, however it is still a little rough at a crawling pace, despite the B1 having one of Hornby's 5-Pole motors fitted. Is there any other adjustments I can make to slow speed running other than CVs 54 and 55? More challenging is the use of the new 36-557 4 function 21 pin decoders; I have fitted one to each of a Bachmann G2A and SDJR 7F. On either loco I am unable to read back CV values for CV 54 or 55, each just reporting back a value of 255. Also worryingly, the G2A when placed on the Main Bus will creep forward without any command to move having been issued; might this be anything to do with me having removed all the capacitors and resistors and having now attached the decoder wires direct to the motor? Are there different CV values that should be used for the new 36-557 decoders? I have been successful in setting the loco address for each, but I don't seem to be able to read CV 54 and 55, so cant tell what values they are being set to (indeed if they are receiving the programming at all!). Any help gratefully received. Paul. BTW I use the Hornby Elite running v1.41 firmware. Link to post Share on other sites More sharing options...
Suzie Posted March 19, 2013 Share Posted March 19, 2013 The 36-557 is a different decoder from a different manufacturer to the 36-554, so you will need to get the manual for it to see which CVs it supports and how to configure them. Link to post Share on other sites More sharing options...
PACman Posted March 19, 2013 Share Posted March 19, 2013 Thanks Suzie, you are right. However, there does not seem to be anything equivalent to the CV 54,55 to control the back EMF effect; instead there seems to be a wealth of "Advanced Motor Controls" which I think I need a PhD to understand. Has anyone any experience of using these new 36-557 21 pin decoders? They are a very different beast from the 36-554 decoders they are supposed to be replacing, and programming them seems very alien to working with previous Bachmann and Hornby decoders. Paul. Link to post Share on other sites More sharing options...
johnd Posted March 19, 2013 Share Posted March 19, 2013 (edited) Thanks Suzie, you are right. However, there does not seem to be anything equivalent to the CV 54,55 to control the back EMF effect; instead there seems to be a wealth of "Advanced Motor Controls" which I think I need a PhD to understand. Has anyone any experience of using these new 36-557 21 pin decoders? They are a very different beast from the 36-554 decoders they are supposed to be replacing, and programming them seems very alien to working with previous Bachmann and Hornby decoders. Paul. Glad I am not the only one having problems with this decoder. I also use an Elite with the latest firmware. At the moment I am in daily e-mails with Bachmann concerning the 36-557 decoder, there latest reply is the are going to contact Soundtraxx and see who is making the decoder for them. All I can do with the 36-557 fitted to a Heljan 128 is control the loco (address 3) and turn the lights on an off using function keys 0,1,2. Attemps to change any CV's do not work. Have fitted the decoder to other loco's and get the same situation. I am waiting to see what Bachmann come up with as to the solution but as it is the decoder is next to useless. Edited March 19, 2013 by johnd Link to post Share on other sites More sharing options...
PACman Posted March 20, 2013 Share Posted March 20, 2013 Well I have been on the Bachmann website and their documentation for the 36-557 is daunting to say the least... a 37 page User Guide and a 57 page Technical Guide for a decoder may be comprehensive, but doesn't help the novice in knowing what can/should be changed!! Strangely, the guides are named as 36-558 and not 36-557, so I am not sure if I am looking at the right thing at all. What is desperately required is a single page reference sheet on basic CV settings to make a loco work (e.g. CV settings for Small Steam, Large Steam, Shunting Loco, Diesel Loco etc.). If people wish to fine tune them afterwards then they can, but at least the majority of users can get their locos working then. Perhaps Soundtraxx and/or Bachmann can provide here? Paul. Link to post Share on other sites More sharing options...
johnd Posted March 20, 2013 Share Posted March 20, 2013 Well I have been on the Bachmann website and their documentation for the 36-557 is daunting to say the least... a 37 page User Guide and a 57 page Technical Guide for a decoder may be comprehensive, but doesn't help the novice in knowing what can/should be changed!! Strangely, the guides are named as 36-558 and not 36-557, so I am not sure if I am looking at the right thing at all. What is desperately required is a single page reference sheet on basic CV settings to make a loco work (e.g. CV settings for Small Steam, Large Steam, Shunting Loco, Diesel Loco etc.). If people wish to fine tune them afterwards then they can, but at least the majority of users can get their locos working then. Perhaps Soundtraxx and/or Bachmann can provide here? Paul. A very basic sheet comes with the decoder, that is alright if you amend the CV's my decodes won't let me let's any. On the verge of taking them back to the retailer. !!!!! Link to post Share on other sites More sharing options...
RMweb Gold Oldddudders Posted March 20, 2013 RMweb Gold Share Posted March 20, 2013 I have put a 36-557 in my Bachmann C Class without drama. So far I have not done much with CVs apart from setting CV29 to my usual 34, thus avoiding runaways if there is a short, and altering the address to 1256. Starts moving very slowly at about step 3 on my Digitrax DT400, and runs commendably quietly and steadily. I have done all the programming on the layout - Operations Mode Programming strikes me as the only way to tune a loco, as you can see the result of each CV change at once. This is even more true for sound locos. In the same parcel as the 36-557 was a 36-558, 6-pin decoder for my latest Bachmann N. Less impressed by the performance of the loco, but that may improve with tweaks. Point is, the 36-558 comes with a data-sheet twice the size of that of the 36-557, packed with CV settings and factory values, e.g. 11 different CVs quoted for Back-EMF settings. Much more useful for those at sea with set-up. Link to post Share on other sites More sharing options...
Johnny Rock Posted February 11, 2021 Share Posted February 11, 2021 I've had similar running problems with Bachmann locos not fitted with flywheel motors. Apparently some budget decoders were intended for flywheel motors. I took advice from Coastal DCC and have changed the CV 54 values from 50 down to 10. Now running so smoothly and a very realistic crawl when needed. didn't even need to disconnect capacitors. Result!!! 1 Link to post Share on other sites More sharing options...
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