I know most of the posts here are DCC related but I thought I would try here first. I run DC, using a Troller Autopulse Momentum 2.5. To date it has operated fine; rarely, if ever do I use the momentum feature, normally just using the throttle.
Tonight I came across various posts through a few other forums regarding these controllers burning out some earlier can motors. I've also read they were great controllers. I've run open frame Mantuas, Athearn Genesis Challenger, IHC and Rivarossi locos with no issue that I know of... except this reminded me of a RR Pacific I posted about many months ago with what I thought was a bad motor.
I got the Pacific used and it ran GREAT at first, but then after running a few times for 10-30 minutes, it got way slow, jerky and the motor got so hot it began to melt its mounting tabs in the shell. I now wonder if this might have been related to the controller and be what I was reading about?
Those of you who've come before, what say ye please? I've considered temporarily wiring one of my other controllers up and trying the Pacific again?
Thanks in advance!
Duane
Duane,
What brand is the Pacific? How old is it?
There is always some risk that any kind of pulse power throttle may run some motors a little hot, but in general most motors used in model trains in the last 30-40 years should work just fine on that throttle.
The one thing I will say, is that running a loco very slow, for a long period of time, is likely the worst case. It works like this, at slow speeds there is a lot of "pulse", the pluse gently goes away as the speed increases. That is a bit of an over simplification, but it gets to the point that long periods of very slow speeds could run a motor pretty hot on a throttle of that type.
Sheldon
Sheldon, I abbreviated it in the post as RR but the Pacific is a Rivarossi. I typically run at some type of scale mainline speed so I don't think I'm operating in extended slow speed. I run my "long" freights a bit slower but this was used for passenger service. No issues with any of my other locos including two other Rivarossi 0-8-0's, which typically get lashed up as helpers on the freights.
Maybe the Pacific's motor was just, shot but I couldn't help but wonder after reading some of the motor burning threads regarding these controllers.
Thank you for your experience!
The RR motor is not the type that would easily burn up from pulse power. The only kind of motor I'd worry about would be a coreless type, they really don't like anything other than smooth DC, or high frequency PWM. 60 Hz pulse power and low frequency PWM heat them up very quickly.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
You could try tunning up the motor some, could have dry motor shaft bushings (bearings) use a light oil on each end of the motor shaft, also check brushes being too tight, or worn. Those two alone will make a motor run hot. You say it is used, so that may not have ever been done before.
Frank
Thanks Frank. I remember I did oil the bushings- I didn't try getting the motor apart. it looked like I would have to pry the case open IIRC, thinking I would probably destry it in the process. I may dig it out again and look at it. I didn't think it would be susceptable as my other two Rivarossi's have been fine and their motors look identical other than different shafts for different drives, and I did read some about the coreless burning up.
Thank you all!
As was pointed out, the more likely cause of the overheat is excess friction or binding in the drive train. A visual inspection could tell you whether or not you had congealed grease in the gears or totally dry bearings. If it was running well for a while, and then over-heated chances, and there was no drops or hard derailments to bend valve gear or rods, it's probably a lubrication issue.
One of the best performance tools you can have is an ammeter or a multimeter set up to measure current draw by the locomotive. Current that changes as the drivers rotate (slowly) would say a mechanical bind. Current above 0.5 amps (just the engine) indicates high friction, or weak magnets.
Based on your first post, the excess heat may well have weakened the magnets, or melted the insulation on the armature windings. This would lead towards a motor replacement if it continued to overheat and/or drew high current.
Just a place to start....
Fred W
singletrack100it ran GREAT at first, but then after running a few times for 10-30 minutes, it got way slow, jerky and the motor got so hot it began to melt its mounting tabs in the shell. I now wonder if this might have been related to the controller and be what I was reading about?
It sounds like you have shorted pole windings in the motor. The symptoms are slower than normal speed, hot running and a jerky condition which gets worse after the motor heats up.
Since it ran great at first, whatever happened was not present or took a while to cause a concern.
Thick lubricant would be even thicker at the beginning of the run. A bind would also be present at first unless something shifted and that is a possibility. Dry bearings are very possible because at first it would not be apparent.
Excessive pulse scheduling can also cause a motor to run hot but mainly at slow speeds. After the 30% mark, the pulses are not as aggressive. So I doubt that the Troller damaged your motor.
If motor replacement is required, definitely find the root cause or you will burn out another motor. If no bind is present and the bearing were lubricated, the motor may have just failed. It does happen.
Jim
Thank you all so far... I am feeling more relieved from all this that the controller is fine. Like mentioned, I've used it then, since and currently still do, with no issues with any other loco's. Just a concern I had after coming across some of those other posts. I don't remember the specifics back then, but I did post about the loco and was directed by you all how to test amp draw, which I did with loco assembled and on the track... I remember an astonomical something like 5 amps! I think we determined then it was solely the motor.
I stored it away then but may pull it out and inspect it further. It did not drop or any of that, and didn't jerk around or show signs of bind then, and I don't remember any old grease or any of that being in there. I'll look more but I think it wasn't the controller, just the motors time to go. I can't vouch for how much prior use it had or to the maintenance or lack of. I haven't looked for a motor for a while but may start to again. Thanks a bunch guys, my mind is a bit more at ease!