Hi all,
I’ve just finished doing up a used brass locomotive, and while I’ve got it running smoothly, it requires a little push to get moving most of the time - but once it’s moving, it has no trouble with slow speed creep. I think this may be a result of the old grease that’s on the mechanism - would this be the most likely cause of this behaviour? And if so, what’s a good way to get rid of the grease?
Thanks in advance,
tbdanny
Danny, is it Steam or Diesel? One of the things I would look at is slop in the worm gear. I have one switcher that will sit there till I am to 15% power, then jumps forward. After it is moving it will creep at 3% power.
It could be dirty wheels and or track a course, but I am pretty sure you have checked that.
Cuda Ken
Either you have a “open” circuit, aka bad connection, or you have a faulty motor, one of the segments is shot.
Again, a good set of amp and volt guages are a must for diagnosing connection problems, otherwise it’s the old “pin the tail on the donkey” time. Take a wild guess…
Mark
I’m guessing it’s an older brass model, open frame motor, running on DC? I’ve had some issues with the grease being burnt onto the motor shaft inside the motor bushings. This required a teardown of the motor and mounting it in the drillpress and hitting it with some 1000 grit paper. Cleaning up the brushes and contacts is also easy at this point , so while it is in the drill, hit the contacts with some paper too, then make sure and burnish it. One thing to be careful with is the thrust washers on the shafts. sometimes they stay on the shaft, sometimes they stick to the bearings, just don’t loose them.
Using a ammeter would be a good thing to use if you have one. The before and after results are useful, the start, running, and stall amperage is useful as well. Some of those old motors have had the magnets go weak. You could probably get them remagnetized, but it would be reccomended to replace the motor with a newer can motor, since they are much more efficient with power and run smoother.
Weak magnets in the motor from it’s long-term storage or just a faulty motor. Many old motors of the open frame type required a very high starting voltage. Replacing the motor with a newer can motor should solve the problem if you can find one that will fit.
The locomotive has already been re-motored, with a brand-new Mashima. The motor worked fine when I tested it on DCC, then showed the same behaviour when put into the mechanism.
Have you tried increasing the Starting Voltage on your decoder?
All,
I’ve got it fixed. There was no motor mount in the loco when I got it, so I had to build one out of styrene. It wasn’t quite in line. 1 hour of poking around later, it’s running like a dream.
Thanks for all the advice.
Cheers,
Tbdanny
If you had indicated in your original question that the locomotive has a replacement motor, you could have saved us all a lot of guessing.
Good to see you figured it out.
Since it’s a brass loco did you verify that after removing the motor mount that you still have isolation from the track voltage?. If the frame is electrically touching one side of the track you might run into problems if not isolated. Sometimes the paint on a motor can temporarily isolate it but over time normal vibration will get the frame through the paint and burn the decoder.
[:^)]
But, if he’d done that, the rest of us that have read this thread out of interest wouldn’t have gained the benefit of seeing all the answers.
I’m all in favour of “imperfect” questions. They achieve lots more information than perfect ones… Think about it, if the OP had known/thought to put in the crucial detail he probably wouldn’t have asked the question… then the 3rd party readers wouldn’t have got to read the variety of answers. Those answers might solve a problem for me/them one day.
[8D]
With the above in mind, here is another problem we have seen on some of our 2 axle B-B diesels at Boothbay. Some defect occurred in the truck wiring on one truck so it was not picking up any power. The loco would stall or not start on places like switch frogs. At higher speeds the flywheel would carry it over, adding to the confusion. A little poking around with a continuity meter found the problem. It was hidden from a visual inspection by the gear tower and sideframes
In my first reply to this thread, I indicated that the locomotive had been re-motored. It was when I was reading that reply after posting it, combined with cudaken’s comment about slop in the worm gear, that provided illiumination. And if that hadn’t been the cause, it could have been any of the solutions mentioned in this thread.