I've got a HO scale Manuta 2-6-6-2T that I'm hoping to use as the basis for an On30 conversion. However, it has a rather unusual problem. When I put the plastic chassis on it, the locomotive runs smoothly. But as soon as I put any weight on it (such as the body), it starts to perform poorly. It'll limp along the track, and the motor will even stall at some points.
I would like to build an On30 loco out of this engine. Mechanical troubleshooting isn't my strong point, and I'm not sure where to start with this. Could anyone point me towards what could be the issue?
The Location: Forests of the Pacific Northwest, OregonThe Year: 1948The Scale: On30The Blog: http://bvlcorr.tumblr.com
Is this one of the older ones with an open frame motor? It's possible that the magnets in the motor have gotten weak over time, so the motor can't output much power anymore. The solution to this is to either replace the magnets with new neodymium magnets or replace the motor outright. If the motor gets fairly hot during use, weak magnets are probably the culprit.
-Peter. Mantua collector, 3D printing enthusiast, Korail modeler.
After reading your post I stuck a 1 pound weight on my Mantua 2-6-6-2 (not a 2-6-6-2T) and it ran OK on my 48” bench test track. I think I bought mine about 10 years ago. When I placed my order it was pre-release and didn’t arrive for almost a year.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Mine does have a slight wobble when it runs. It's not major in my case, so I just see it as a logging loco going on rough track. I did look into it, and it seemed to be a combination of problems, including a rubber tire that has a funny lump on it. One wheel also seems to be a bit crooked. Like I said, it's not major in my case, and I tend to run this engine very slowly, but I might have to fix these at some point if the wobbling gets worse.
Simon
Mine came with a can motor, which has since been replaced with a can motor from NWSL.
I should also mention that this behaviour is being seen with just two large fishing sinkers on the chassis, without any shell attached.
My 2-6-6-2 has been a very nice runner, no problems and it has the original can motor. It is a bit noisy, side rod noise when running over about 40% throttle.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Too much end play in the gearbox of motor armature? Does the same thing happen if you make it pull something, or with just the drive, tilkt the test track and see if it does it on a grade even without the shell or weights.
Poossibly drivers out of quarter on one engine or the other - noot a lot, or it would bind with no load, but if just a little off, the normal slop in the mechanism might handle it with no load, but as soon as a load is placed on it and it really has to turn the other drivers through the rods, it binds up.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Is your motor connected to a rubber tubing drive? I had to replace mine. These can start spinning under load if the tube is too old.
The immediate advice I would have is to measure the 'periodicity' of the limping observed. There is one rate for any 'cogging' in the motor, others for gears in the reduction train, or in the thrust arrangements on a worm; others for side rod binding -- and then there are potentially 'amplified' effects of any of these when a cocked or bad bearing or other thing that binds or compromises smooth rolling requires "moar power" to overcome it. Note also that you can, and perhaps do, have complex binding 'limps' when more than one of the effects are present together, so look for more periodicity than just speed-related limp-limp-limp.
To clarify slightly: the chief problems with driver quarter on electrically-driven models do NOT involve accurate close-to-90% accuracy, only consistent precision that is consistent for all the driver pairs in a given engine. Here is where a good quartering jig, even if homemade and not square to a couple of minutes or seconds of arc, is an invaluable tuning tool, as are the tools and methods to press on or rotate drivers without damage or distortion to get them all correct. (Then slop in the rods... or even in the longitudinal bearing clearances or equivalent of 'wedges' ... can be accommodated in rod drive much as it appears in the prototypes...)
This is porbably a long-shot. My Mantua 2-6-6-2 had a rotting/cracked leading truck bracket that made it run really bad. I removed the lead and trailing trucks, and it ran great.
Try removing these and see if the problem is resolved.
My plan is to (eventually) build new lead and trailing truck frames from brass. For now, I have a funny looking 0-6-6-0 that runs well.
-Kevin
Living the dream.
The testing mentioned actually occured without the lead or trailing trucks in place. I suspect it's something within the mechanism, possibly to do with the quartering.
Before you tear into things to check quartering, go for the easy stuff if you're not mechanically inclined. It can be a very deep and frustrating subject.
Mike Lehman
Urbana, IL
mlehman Before you tear into things to check quartering, go for the easy stuff if you're not mechanically inclined. It can be a very deep and frustrating subject. his sounds more like a cracked gear problem, similar to many issues found commonly in some diesels. The plastic gear is cast onto a metal shaft, but over time the plastic cracks, cqausing issues that sound very similar to your articulated. Somene haqs already noted thetr are belts in the drive, so may be worth checking them for any damage, stretching, or hardening, as well as any gears that are involved.
Lastspikemike... I found [this] article interesting: https://model-railroad-hobbyist.com/sites/model-railroad-hobbyist.com/files/users/fernpointfiles/Mallet