MTH Premier Bi Polar problem

Does someone have an MTH parts diagram for these engines?

Jeff, FWIW: I've taken the MTH bipolars apart a couple of years ago and my memory is scant at best. There're screws that attach each section to the frame, and you also need to up-plug the connecting harnesses. Other than taking the sections off and examining for fitting, I don't know what to suggest. I don't recall any springs, however. A parts diagram might help, and don't know where to find one.

Thanks. Yes a parts diagram, as MTH use to do, would be of great help. I went on their site, but there is no indication that I could see that showed there was one available on the MTH website.

Have you tried contacting MTH? I know they're operating to some extent under new organizational management, and the latest BiPolars were last released just as the company was re-organizing. Let me know how you make out.

don't know which model you have there exactly?

\\Mkt\disk4\_Library 1 - Inst.PDF (mthtrains.com)

the MTH parts site seems to be struggling right now when I choose the parts diagrams

@Paul Kallus posted:

Jeff, FWIW: I've taken the MTH bipolars apart a couple of years ago and my memory is scant at best. There're screws that attach each section to the frame, and you also need to up-plug the connecting harnesses. Other than taking the sections off and examining for fitting, I don't know what to suggest. I don't recall any springs, however. A parts diagram might help, and don't know where to find one.

OK thanks for your note.

@Engineer-Joe posted:

don't know which model you have there exactly?

\\Mkt\disk4\_Library 1 - Inst.PDF (mthtrains.com)

the MTH parts site seems to be struggling right now when I choose the parts diagrams

I haven't contacted them since they are as you say struggling.

I gotta be honest, I tried researching this earlier today, and the bi-polar is one of the few, very few engines I don't have and sadly have not worked on one locally.

So I ran across the same PDF manual already linked in the topic- and while it's not a parts diagram, there are plenty of pictures of the sub assemblies.

@Jeff B. Haertlein posted:

I have a Milw. Rd. Bi Polar, and one side of the shell returns to center, while the other end shell does not want to return to exact center, thus it slightly over hangs the frame. Is there a spring somewhere to adjust/replace? We have already been working with the springs mid way down that apparently work the trucks. Thanks.

The point I'm getting at is, there is no centering spring or mechanism I can see in any shape or form for the truck or the cab. Bottom line that my take away tells me- the cab is connected to the driven portion of the truck, and this is how it tracks and points. The front truck slides and pivots like just about every other form of articulated truck I have ever seen.

So, I think this is either an expectations issue, a track issue, because call me crazy, but the wheels in the driven portion have no room to go "out of gauge", so within some tolerance, the truck wheels and flanges then determine where that nose of the cab points.

Again, clearly in this photo below from the manual- and yeah, sure it's the 5V PS2 version, point being, the front articulating non-driven truck just pivots. The screw, spring, ands washer just provide downward pressure to the truck- nothing more, nothing less.

Again, my questions would be:

#1 are you sure all wheels are on the track and not derailed?

#2 The front or rear could within some tracking tolerance wander left or right and since the nose sticks out long far in front of the actual flanged wheelset might not always 100% track straight.

#3 Ensure all the driven wheels that have traction tire grooves- have installed traction tires. Say if one side had thrown a traction tire, then the truck under load might track more left or right because all the traction was on one side.

There are tons and tons of topics in this forum of engines of all types not tracking or wandering. Some of this is just how rails work, some of this is defects like missing traction tires, some of this is just limitations of the model scale vs the real thing.

@Vernon Barry posted:

I gotta be honest, I tried researching this earlier today, and the bi-polar is one of the few, very few engines I don't have and sadly have not worked on one locally.

So I ran across the same PDF manual already linked in the topic- and while it's not a parts diagram, there are plenty of pictures of the sub assemblies.

The point I'm getting at is, there is no centering spring or mechanism I can see in any shape or form for the truck or the cab. Bottom line that my take away tells me- the cab is connected to the driven portion of the truck, and this is how it tracks and points. The front truck slides and pivots like just about every other form of articulated truck I have ever seen.

So, I think this is either an expectations issue, a track issue, because call me crazy, but the wheels in the driven portion have no room to go "out of gauge", so within some tolerance, the truck wheels and flanges then determine where that nose of the cab points.

Again, clearly in this photo below from the manual- and yeah, sure it's the 5V PS2 version, point being, the front articulating non-driven truck just pivots. The screw, spring, ands washer just provide downward pressure to the truck- nothing more, nothing less.

Again, my questions would be:

#1 are you sure all wheels are on the track and not derailed?

#2 The front or rear could within some tracking tolerance wander left or right and since the nose sticks out long far in front of the actual flanged wheelset might not always 100% track straight.

#3 Ensure all the driven wheels that have traction tire grooves- have installed traction tires. Say if one side had thrown a traction tire, then the truck under load might track more left or right because all the traction was on one side.

There are tons and tons of topics in this forum of engines of all types not tracking or wandering. Some of this is just how rails work, some of this is defects like missing traction tires, some of this is just limitations of the model scale vs the real thing.

Thanks for your comments. I can add that yes all my wheels are on the track. And the one side of the shell is more stiff and tracks back like it should. The other side is more loose and does not track all the way so it is in line.

@Jeff B. Haertlein posted:

I have a Milw. Rd. Bi Polar, and one side of the shell returns to center, while the other end shell does not want to return to exact center, thus it slightly over hangs the frame. Is there a spring somewhere to adjust/replace? We have already been working with the springs mid way down that apparently work the trucks. Thanks.

Jeff

Jeff ,Do you have really close up photos of each side showing the difference in the overhang ?

@Dallas Joseph posted:

Jeff ,Do you have really close up photos of each side showing the difference in the overhang ?

I will be able to shoot a few pictures later today.

Is the wire harness between the hood and cab getting in the way?

Note also that each end has a pivot joint that fits in each side of the frame; these things have to be secured in place with just a little bit of force.

@Dallas Joseph posted:

Jeff ,Do you have really close up photos of each side showing the difference in the overhang ?

Here's a picture of the slight overhang on the Bi-Polar. Once again, the left end shell seems pretty tight and returns to center on the frame. The right side is quite loose and does not return to center. As I recall, when I got this used item, it appeared to be in rough shape in some areas. This should conclude my post on the subject. When I get a chance I will open up both ends and inspect for any abnormalities. Picture below.