HELP me please!!!...getting frustrated!!!

[Nick100]

The other thing that can happen is a screw that is longer than it should be. Because you installed it in the wrong location or the previous owner installed a longer screw. insulating bushing in the wrong location or missing. I hope you find the short.

[Wolfangel]

Thanks everyone for the help.  To all the ones that mentioned the wheelset being wrong...and needed to be flipped...that was correct.  I did that and the train runs perfect and very strong.  Thank you all very much.  I have been trying to figure this out for a week...i didnt know about the isolated wheels...i mean its all metal...how could it be a bad ground....and it was.  And im not new to electrical stuff....i build custom r/c cars...slot cars...pretty much anything that has an electric motor.  But this just flat out stumped me real bad.  Like i said...im a newbie to all the train stuff....but im learning all the time.  Thanks guys for your help.

[hon30critter]

Hi Wolfangel!

Welcome to the forums!!   

It sounds to me that when you put the locomotive back together one of the trucks or axles is backwards. 

Your locomotive only picks up power from one wheel on each axle and the other wheel is insulated. Some of the pick up wheels are supposed to run on one track and the others on the opposite track. What you may have done is put a wheel set in so that the pick up wheel is on the wrong track. That means that power is going from one wheel, through the chassis or body and then directly to the opposite track. Dead short.

Look at each wheel set. You will see that one wheel is mounted directly on the metal axle (what I will call the 'pick up' wheel for lack of a better term) and the other wheel has a small plastic bushing between the wheel and the axle. Next, have a look at which side the pick up wheels are on. They should all be on one side on the tender and on the opposite side on the locomotive.

Hopefully, all that is required is that one axle or truck needs to rotated 180 degrees.

Now, to throw a curve ball at you, even if you get the short circuit figured out, the locomotive will still not have good power pick up because only half of the wheels are actually conducting power. If you have trouble with the engine stopping periodically after the short is cured, the best solution is to add power pick up wipers to the insulated wheels. Here is a picture of a similar locomotve with power pick ups added to the wheels in the top of the picture. The pick ups are soldered to small pieces of circuit board (painted black so they are a bit hard to see) and the boards are epoxied to the chassis with wires connected appropriately. In this case, the locomotive pick up wipers were made out of brass strip but .015" phosphor bronze wire works much better:

The tender trucks are done a little differently. This engine has DCC and sound, hence all the wiring and plugs. Here you can see the phosphor bronze pick ups. Note that this method is best suited to plastic trucks:

There! Now you have your next model railroading challenge already lined up for you! If you have more questions don't hesitate to ask.

Dave

[Soo Line fan]

You have a wheel set or driver crossed. Place paper under the wheels and remove one at a time to find the short.

[tstage]

This is just a suggestion.  A more concise subject title will help steer the right folks to your thread.  Something like "Motor runs fine...but NOT when hooked up to chassis", or something to that effect.

Again, just a suggestion...

Tom

[Old Fat Robert]

Wof: As Rick pointed out,  it appars that you have shor tcircuit issue. The first the thing to do is to breathe: take a minute (or more)to just think about the problem. A hor means a crossing of polarities and you find where that is happening. After your deep breath exercise,turn the engine/tender assembly upside down and just take a really good long look at it. Is everything where it should be? Are the insulated wheels all on the proper side and the non insulated ones all on the other side? Did some insulation from a wire break off allowing a metal to metal contact. Don't get frustrated, just slowly and carefully examine the unit. Don't rush it. The anwer is there.

[ricktrains4824]

First, .

Now, the "front wheels", are they the front of the locomotive itself, or on the tender? 

I ask as, symptoms you are describing are of a dead short. Wherever the Sparks are coming from, and that when you lift off the rails makes the locomotive work, is where that dead short is occurring. 

It may be something as simple as a wheelset installed backwards/reversed of the normal way, to something a little more complicated. 

Either way, it is fixable. 

Is it possible for a picture of the offending area? This would help us in answering what, and how, to fix.

[Wolfangel]

Ok...I am new to all the train stuff....but I am learning...and having a great time doing it. I am in the process of building a 5 x 16 foot layout. I have all the track down....and everything the way I want it. But...now to the point. I recently got ALOT of train stuff from a friend for a VERY good price. In the box full of cars and train engines I found a Mantua 4-6-2 engine...all metal...the chassis...the wheels....the body....everything. It never really did run right. So i decided to open it up and do a thorough cleaning....it needed it. This is the engine that has the tender that hooks to the positive wire for power.....and has brass wheels on one side for the electrical pickup. After I put it all back together...it wont run...UNLESS you take out the motor by itself...then it works fine. You put the motor back on the chassis...it wont run...UNLESS you push down on the back of it and lift the front wheels (NOT the four) off the track...then it runs....put the wheels back down...motor stops and the transformer/controller goes into overload protection. It sparks big time from the front wheels. ANY help somebody could give me would be greatly appreciated it. Thank you very much.