Large Scale Central

B'mann 4-6-0 Pilot Repair

Problem Solving
#1

Hi Everyone,

The shaft running up from the pilot wheels into the chassis of North Star, our Bachmann 4-6-0, split. I’ve no idea where the screw went. The B’mann parts page lists a new pilot as “sold out.” Has anyone:

  1. Fit the new draw-bar style pilot to an older chassis?
  2. Repaired one of these older style pilots? I was thinking of filing that post off, replacing it with a piece of tube, and running a bolt straight through it.

I am also curious of B’mann parts are just subject to plastic fatigue after 2-3 years. I ask, because part of the chassis actually snapped during reassembly following some internal wiring repairs. I did not witness the break, I theorize it cracked along an existing fault after I screwed everything back together. The Triple O is not all that level and has tight curves. Would that stress the frame as well as this post on the pilot before its time?

I’d prefer not to buy a whole new chassis if I can avoid it. North Star remains a family favorite, but, with the crew getting older, I am reaching a point I can retire it to Advent and Christmas specials. I’d thus rather get North Star running as economically as possible.

Thanks in advance,

Eric

#2

I think that any of the Bachmann chassis would fit the North Star engine. If I am correct that one has the simple slide valve gear with metal side rods. If you want to replace the chassis, let me know am sure I have one laying around I can send you, just for the cost of postage. You can just swap the parts from the current chassis to the replacement.

Dan Stuettgen

C&RGS

http://www.danstrains.net

#3

Simple easy Fix. And save money.

Jason

#4

Dan,

Thanks. When we replaced the chassis, I got a more complex one with valve gear, so, yes, it was pretty “parts agnostic.” You can see the original on the left (now part of Mik challenge) and the new one installed on the right:

Boy, hard to believe that was almost four years ago! Time flies…

Moving on, the part that broke is in the photo below:

That little bit of plastic is the top of the hollow post that fits the screw holding the whole contraption together. The screw itself is one with the ether…

I’ll PM you in a moment with the address. Thanks for helping me save a bit of ca$h!

Aloha,

Eric

#5

Fit the new draw-bar style pilot to an older chassis?

I found the thread that had been nagging me - even has a photo of George’s drawbar conversion on an old chassis.

http://www.largescalecentral.com/forums/topic/27214/bachmann-repair-warranty-service/view/post_id/344868

Here’s the official photo of the spare part. Earlier versions didn’t have any pickups and thus no wires.

The screw itself is one with the ether…

Looks to me as if your screw is still inside the loco. Unscrew the screw in front that goes in to the smokebox and it will probably fall out!

One fix, if Dan’s parts don’t work out, would be to drill out the hole in the top tube that broke and use a longer screw with a washer, plus some spacers to make it sit on the track. However, I’m sure there are lots of spare pilot trucks in peoples junk boxes. (Sorry - I sold my 4-6-0 junk box when we moved and I lost my garage storage.)

#6

Pete,

Dan’s chassis is on the way. The plan is to use his pilot to put North Star back on the track. After that, I’ll try to effect a repair per your suggestion using the remainder of Dan’s chassis. After that, who knows, a 4-6-0T with a canopy cab?

Eric

#7

Update:

Dan’s parts (enough for the next 4-5 failures!) are on hand. Family obligations will likely keep us from swapping out the pilot this weekend, but North Star will be back on the rails before too long!

As an aside, I joked about what to do with some of those parts…I didn’t think 4-6-OT existed. Stupid internet…

It is an appropriate wheel configuration for sugar cane lines, like this one in Australia:

…or, if I am hard over for a canopy top, South Africa offers the following in 3’6" gauge, which would be a neat prime mover in 1:24-ish PLAYMOBIL scale!

A canopy top? Really?

I have to clear the work bench of a few other projects first, luckily!

Eric

#8

Eric Mueller said:

Boy, hard to believe that was almost four years ago! Time flies…

Ha! You ain’t seen NOTHING yet. My daughter just got a plaque acknowledging 20 years of teaching!

#9

@Bruce: Thanks for the warning!

Update:

North Star was among a host of projects today. I took one of Dan’s donor chassis, removed its bottom plate, then turned to on the patient. Only my 1:24 crew joined this time.

This is the 4th or 5th time I’ve had to take this old loco apart for some sort of repair. Each time, I find something else has broken. The plastic post holding the bottom chassis plate to the smokebox, for instance, had snapped:

The crewchief to the left is pointing to the plastic post that used to connect to the smokebox. Maybe I overtorqued it when I reassembled North Star after fixing the broken solder joint?

More distressingly, the post that holds the screw for the brass bar that picks up electricity from the wheels broke:

I never touched this screw. I guess this plastic is just getting brittle with age. I am beginning to strongly suspect these models were never designed with repairs in mind…

Since Dan’s chassis had the pilot truck nicely wired in place, I decided I’d just swap out bottom plates, pilot and all. It turns out, however, that the older bottom plate lacks a slot for detail part that holds what I presume are drain lines. Yo can see the slot just above the crew chief. The team above him holds the part that fits in the slot, and the fellow in green is resting his arm on the drain lines:

I briefly considered modifying Dan’s chassis part to accommodate these parts, but I got cold feet. No one will miss them.

Reassembly went pretty smoothly, with the exception of the brake that decided to fall off…

…and the crew took time to pose with their new scrap parts as the JB Weld set:

After running an errand, I put power to the rails, placed North Star on the tracks, and…nothing. I replaced a fuse in my controller, tried again, and the old boy lurched forward…about an inch. I took “him” off the track, popped Kid-zilla’s Mack on the track, and Mack happily started circling the railroad. I took North Star back to the lanai, leaving Mack to happily circle (lucky Mack), and tried to put power to the wheels to see what would happen. Same thing. I got either nothing or lurch. It was then that I noticed that the donor bottom plate doesn’t quite align fore-and-aft with the original chassis, preventing it from closing properly. I suspect that this may be leaving something to rattle around and cause a short or simply keep the axels from sitting where the need to be when the motor applies torque to the drive gear. At that point, I had to break down the worksite and prepare for guests, which was probably for the best. It also started to rain, so Mack had to come in, too. Poor guy.

Eric

#10

Update:

I repaired the old bottom plate with JB Weld. This stuff is amazing! Thanks to John Leister (sp?) for the tip at some point that this stuff exists. d Kid-zilla joined be to move the pilot to the repaired bottom plate and to reassemble North Star. The test came up the same…a few turn then nothing. I placed my voltmeter across the track and, sure enough, every time I placed North Star on the rails, it dropped from ~24V to 0V. Somewhere in this marvel of Chinese quality control there is a short…My suspicion is that a loose screw or exposed piece of wire in the boiler shell is causing this. On the upshot

  1. I am getting pretty good at field stripping B’mann ten-wheelers, and
  2. most of the cheap plastic tabs for the screws that hold boiler to chassis have long since snapped off, so disassembly is getting easier.

The beach calls…North Star will have to wait with Charlie the Railtruck (B’mann) and Christmas Thomas (LGB m2075(battery) almost repowered with a Smallbrook Studios motor block) on the list of “Projects of Perpetual Puttering.” North Star, with parts on hand and known fault will at least have the honor of sitting atop that list!

Eric

P.S. Adding insult to injury, the sewing machine I fixed yesterday broke in a different spot today. Maybe my bad luck is transferring to CINCHOUSE’s hobbies?

#11

Eric,

It sounds like you may have the pilot truck turned 180º and it causes a short when on the track and voltage present. Check it out. (https://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#12

@Joe:

Thanks. Unfortunately, turning the pilot 180 blew the fuse in our controllers, which, of course, is why we have fuses! If it matters in terms of troubleshooting, after I put the pilot back in its original orientation, I touched North Star to the tracks one wheel pair at a time. Each time, regardless of wheel pair, voltage across the tracks went to 0V.

I only have on 5A fuse left in my ready spares, and I need the trains to deliver beverages to my grill station tomorrow. North Star will have to stay on test tracks using one of my LGB throttlepacks for the foreseeable future!

Eric

#13

Although it didn’t help, that test did give some valuable information. Since it does not blow the fuse when oriented properly, but voltage drops to zero, that tells me that it is not shorted, but is drawing more current than the pack can supply. Probably something jammed in a gear, or something keeping the wheels from turning. could be rods, axle alignment or any number of things. Time for another tear down when you get the time.

#14

Eric Mueller said:

@Joe:

Thanks. Unfortunately, turning the pilot 180 blew the fuse in our controllers, which, of course, is why we have fuses! If it matters in terms of troubleshooting, after I put the pilot back in its original orientation, I touched North Star to the tracks one wheel pair at a time. Each time, regardless of wheel pair, voltage across the tracks went to 0V.

I only have on 5A fuse left in my ready spares, and I need the trains to deliver beverages to my grill station tomorrow. North Star will have to stay on test tracks using one of my LGB throttlepacks for the foreseeable future!

Eric

When I said “check it out” I meant with an ohm meter to determine if the port and starboard side of the pilot truck were orientated the same as the drive wheels. Sorry you blew your fuse.

#15

@Joe:

Fuses are cheap, and “destructive testing” is a time honored Triple O tradition! Thanks for the guidance on the way forward!

Eric

#16

Update:

I found myself with this thing called “time” this morning, so I decided to follow Joe’s advice and investigate North Star for physical obstructions to operation. First, I found a bit of what I thing was tinsel wrapped around the starboard after drive wheel:

Some work with a dental pick and tweezers removed the tinsel but did not put the old fellow back on the tracks. Next, I removed the bottom plate again for a visual inspection. I didn’t see anything, but putting power to leads sure as heck showed that something was binding somewhere…

…it’s just too bad I never saw where that jam was! After I untangled this mechanical knot by removing a connecting rod, I got North Star back together and again applied power, first to the pilot then to each pair of drivers. After reversing the direction of the pilot (Thanks, Joe!), all was well, I put the bottom plate back on, and took North Star out to the track…only to find one of the leads connecting the brass bus bars to the motor and lights was getting jammed in the center drivers! Once more, the old loco went to the lanai. Once more, the bottom plate came off, once more power was carefully applied, and once more, North Star went out to the mainline…

Video: North Star on the Mainline

Success! The 1:24 crew spent the rest of the day joyriding in the gondola of their work caboose. Kid-zilla even insisted that North Star pull the exulted “Festzug” and deliver beverage to the grill master to celebrate North Star’s return to service. While I am in my limited experience dubious of B’mann mechanical quality, I tip my hat to the physical beauty of their products. It was a real joy to see this model running trouble free for the whole afternoon and most of the evening. Kid-zilla announced again that “North Star is one of my favorites!” making the loco’s continued (and too frequent) maintenance worth the trouble.

Next step before closing this thread will be to find a way to mount the broken pilot to Dan’s donor chassis as insurance against the next break. I’ll get to that when I get to that. In the meantime, I have those buildings to rehab and Christmas Thomas and Charlie to bring back to life and off the list of Projects of Perpetual Puttering!

Thanks for all the help in getting family favorite back out on the rails!

Eric