I have a Model Power F7A with Amtrak Design. Train worked before decoder was installed on a all DC track. Now, after I installed a HO123 Digitrax Decoder, and trying to run it on a DCC track, the train needs to be push started to start running. When I give the train throttle, I can see the driveshaft try to turn, then just stops. If I push the train, and the driveshaft starts turning, the train will take off, slowly reaching desired speed. The decoder is installed correctly, I rechecked it a number of times. Im thinking that the motor is not designed for DCC and maybe there is not enough voltage to get the train started. Any comments or suggestions from anyone? thanks Matthew
I can think of 3 likely problems.
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You say the engine starts after a push and slowly reaches speed? You may have set your momentum pretty high. Let the engine sit for a few seconds before pushing it and see if it starts on its own. Also reset your decoder. If that doesnt work it might be something mechanical.
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Most likely the wheels or track are dirty. if you have a light in the loco then watch it. If the light goes out when the engine stops or the light flickers when you are running than this is the case. Once the engine gets moving its momentum will carry it over dirty spots on the wheels and track. Also if this is one of the cheap model power locos with only 4 wheel pickup they wont pick up very well no matter what you do, but adding weight will help.
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It could also be a bind in the gear train somewhere. If the motor is still buzzing when the engine stalls this is likely the problem.
thanks for the detailed reply. I am new to this DCC stuff so please bare with me and thanks for your help. the train and the track is brand new, so that rules out part of number 2. It is a cheap one, but like I said in the first post it ran on DC. It is light, so I will try adding weight. The motor does buzz, its more of a vibration when the throttle is at 1 or more. When the throttle is at zero, no buzzing. The light is very bright, whether the train is sitting there at 0 throttle or running at 99 after the push start and everywhere in between. I dont know much about the momentum setting, but I will read up and see how to change it and how to reset the decoder. I have a Super Cheif Starter Set. Thanks again for your help. Matthew
Your CV#2 may be set lower than the minimum value for your mechanics. CV2 is the V-start, and represents the minimum voltage at which the drive can get the locomotive underway. Typically, the value is somewhere between 38-42, depending on the loco.
If the motor is buzzing and the light is shining then the loco has power. So we know that the problem is that the motor doesnt have the torque to make the engine move at that low power setting. Now the only question is whether you have the momentum set way too high or the motor just isnt getting enough power. Generally the cheaper motors need more power, and your DH123 should be able to handle the load, but you might want to adjust your speed steps so the loco runs like you want.
The first thing to do is do a full reset on the decoder. This will get rid of any momentum setting that you accidentally made or were accidentally programmed to the decoder before you got it. You do this by programming CV 8 to value of 8. Then reprogram your address and try again. If it still has issues you might have to adjust your speed steps. I think start voltage is CV2 but im not sure off the top of my head. Just keep raising the value of CV2(?) until the engine starts like you want it to.
Good luck
Check to insure that the decoder or wires are not touching or binding on the drive shaft. Having to push the engine to get it started indicates that something is rubbing on the motor shaft, preventing it from turning.
Fist off, I would like to thank everyone who replied. They were fast replys with detailed information. I like this community for that reason. I hope to be able to offer advise to others when I learn more about this hobby. Must have been a momentum issue, I reset to factory and everything works fine. I found my book too, that is why I didnt know how to reset the decoder, I lost my book, but found it. The motor runs extreemly well, fast start up and it almost flys off the track around the turns. It almost seems like it is going too fast. I will read up the manual to see if I can place speed restrictions on the engine. thanks again for all the great help. Matthew
Matthew,
You sure can put a speed restriction into place, by using CV’s 5 (Max) and 6 (Mid). See sections 6.6 and 6.7 in that manual. Oh, and if it gets misplaced again you can download any/all of the Digitrax manuals here: http://www.digitrax.com/pdfdocs.php
HTH,
Steve
Glad it works!
Like steve said you can set the top voltage on your speed tables. I also suggest you get a computer interface (digitrax or locobuffer) for your digitrax system. Then you can download a free program called decoderpro and program your engines on a computer. This is a lifesaver for programming speed tables if you want to change how a loco runs or match it up to the characteristics of another loco for consisting. Plus if you have another problem with the decdoder you can reprogram your saved file for it and get it back just the way it was.
Thanks for the info, I looked throught the digitrax site before I found my book and only found the manual for the Super Cheif, and not the one about programing. I will go to the link and look better. JPM335, where do you suggest I get a computer cable from? The cheapest, and what brand do you recommend the most? Is there a site on the internet that sells this cable or should I contact my local Digitrax Dealer? I think that I would like to be able to program trains from the computer, it sounds like the options that it provides are very useful. Thanks again, Matthew
It is a good practice to perform a decoder reset any time you install a decoder. There’s no telling WHAT values are set in some decoders when they come from the factory. I’ve seen this to one degree or another in decoders from all manufacturers I use (Digitrax, NCE and TCS), but the DH123s have been the biggest offenders and are the ones which convinced me to make this a hard and fast rule when installing any decoder.
If in the future you install decoders from other manufacturers, be aware that the different manufacturers have different ways of resetting their decoders to their default values, and that many older decoders (and some current ones from a couple of manufacturers) have no easy way of resetting the decoder to its default value. This isn’t anything that’s been addressed by the NMRA RPs for DCC, so each manufacturer is within its right to handle it any way it pleases.
Here are the most common reset CVs/values used to reset decoders to their (intended) factory default values:
- Digitrax Series 3 decoders: Set CV08 to 8.
- Current Lenz Decoders: Set CV08 to either 8 or 33.
- Current NCE decoders: Set CV30 to 2.
- TCS decoders: Set CV08 OR CV30 to 2.
By resetting to factory defaults, you could just as well have reset CV2, the one for V-Start.
No problem. Here’s he direct link to the decoder manual I was referring to: http://www.digitrax.com/ftp/decodermanual.pdf
I didn’t see this answered so I hope I’m not stepping on JPM335’s toes by jumping in here. Anyway, what you actually need is more than just a cable. At the least, it’s a level shifter such as the Digitrax MS100, and at the top end it’s a fully-buffered intelligent interface like the LocoBuffer USB. You should be able to get either at any hobby shop that is well-stocked with LocoNet-compatable accessories.
Again, if I may be so bold as to suggest, if it were my money I’d buy the LocoBuffer USB. More info and a list of dealers is available here: http://www.rr-cirkits.com/
You’ll also need computer software to go with it. Probably the best, especially for programming decoders but also for much, much more is the free JMRI suite. It’s available here: http://jmri.sourceforge.net/index.html
Thre is also a very active Yahoo group where JMRI is discussed, with many of the developers answering questions and providing fixes: http://groups.yahoo.com/group/jmriusers/
[quote user=“mrvegas”]
I think that I would like to be able to pr
[quote user=“Stevert”]
No problem. Here’s he direct link to the decoder manual I was referring to: http://www.digitrax.com/ftp/decodermanual.pdf
I didn’t see this answered so I hope I’m not stepping on JPM335’s toes by jumping in here. Anyway, what you actually need is more than just a cable. At the least, it’s a level shifter such as the Digitrax MS100, and at the top end it’s a fully-buffered intelligent interface like the LocoBuffer USB. You should be able to get either at any hobby shop that is well-stocked with LocoNet-compatable accessories.
Again, if I may be so bold as to suggest, if it were my money I’d buy the LocoBuffer USB. More info and a list of dealers is available here: http://www.rr-cirkits.com/
You’ll also need computer software to go with it. Probably the best, especially for programming decoders but also for much, much more is the free JMRI suite. It’s available here: http://jmri.sourceforge.net/index.html
Thre is also a very active Yahoo group where JMRI is discussed, with many of the developers answering questions and providing fixes: http://groups.yahoo.com/group/jmriusers/
[quote user=“mrvegas”]
I think that I would
Matthew, Being pretty new to DCC myself, I have started a file folder with all of my decoder manuals along with a 3x5 card that has the critical data for the CV’s for Adjusted values. This way, if I have a glitch that takes things out, I can quickly re-program to known values for each engine. it also makes easy reference when I get a new engine from the same manufacture to have some baselines to go by. Case in point a new Atlas Silver Series GP-40 that I have. After break-in, it was a tick or two different than a previous GP-40. After a little adjustment, these two run like they were made for each other. Chris
Chris,
Do you have a DCC system that has a computer interface? If so, among lots of other things, JMRI allows you to keep, reload, and and print the CV settings for each loco on your roster. You can also copy the settings from one loco to another, and do those “little adjustments” in the process. Like I said earlier, JMRI is the greatest thing ever for programming decoders.
Steve