Large Scale Central

A little B-mann K27 help please

Modeling Rolling stock
#1

My K has been a pain in the ass since I got it. I’ve done the recommended upgrades (I think) but it still has issues.

The first problem are aristo wide switches, this I assume is a switch problem, I’m slowly fixing and soon replacing them. But the K hates them. And yes I realize they are at it’s minimum radius.

The biggest problem is the front truck it will not stay on the track to save it’s life. I’ve checked it’s gauge, I’ve added a stronger spring it still hops off at will.

Next is the first set of drive wheels. Any time the loco is under load it gets light in the front end and hops off sometimes in straights, sometimes in turns. Then it catches a switch and all hell breaks loose. It too is in gauge.

It’s not the trackwork, I’ve checked it, gauged it and checked level. Plus it doesn’t do it in the same place all the time. Also the connie has no issues with it at all as don’t any of my other locos.

Anyone know of fixes for either one?

For the record it’s battery powered with Rodney’s drive. It has the upgraded wheel weights and the 2 drive wheels are locked. Sorry, don’t remember which two at the moment.

Thanks for any help
Terry

#2

I’m not a K-27 expert and I’m sure you’ll get info far better than any I can offer. However one thing stands out from what you’ve said that is applicable to almost any loco in any scale…

That is the fact that you put a stronger spring on the lead truck. This could very well be what’s causing the front drivers to raise just enough to allow the flanges to clear the rails at certain times which if true means there’s no problem with the driver tracking at all.

Try adding weight instead of a stronger spring to the pilot truck would be my inclination.

#3

I agree with Boomer, it does need a lot of room. It’s almost to big for my layout. I had several curves I had to re-do, mostly for clearance purposes, but also to ease the curves a bit. If it’s an older version it probably has only one set of weights in it, at the back of the boiler. Mine was a new version and had weights front and back. A heavier spring on the front truck helped mine a lot. (actually I just added another spring to the existing one, from a KD coupler set)

#4

Prolly doesn’t help you, but mine has the Rodney s gearbox. I run on 15’ minimum dia with LGB 1700 switches. And my track is far from level or perfect. Other than the gearbox, nothing else has been done to the loco. Go figure…

#5

Terry Burr said:

My K has been a pain in the ass since I got it. I’ve done the recommended upgrades (I think) but it still has issues.

The first problem are aristo wide switches, this I assume is a switch problem, I’m slowly fixing and soon replacing them. But the K hates them. And yes I realize they are at it’s minimum radius.

The biggest problem is the front truck it will not stay on the track to save it’s life. I’ve checked it’s gauge, I’ve added a stronger spring it still hops off at will.

Next is the first set of drive wheels. Any time the loco is under load it gets light in the front end and hops off sometimes in straights, sometimes in turns. Then it catches a switch and all hell breaks loose. It too is in gauge.

It’s not the trackwork, I’ve checked it, gauged it and checked level. Plus it doesn’t do it in the same place all the time. Also the connie has no issues with it at all as don’t any of my other locos.

Anyone know of fixes for either one?

For the record it’s battery powered with Rodney’s drive. It has the upgraded wheel weights and the 2 drive wheels are locked. Sorry, don’t remember which two at the moment.

Thanks for any help
Terry

You cannot lock 2 and 3, even though some clueless moron says that’s what you lock. It A) kills your radius, and B) causes lead truck derailment.
You will also spend considerable time searching for cylinder covers.

Lock 1 and 4, and confirm.

That said, I have one tight curve (the Tree) of oh, four foot radius, and it goes around it just fine.

If the gearbox is jamming in the slide, the rear of the engine is low. Nose is high.
Folks who designed this pig need to go back to school.
Pull the smokebox front off, load stick-on lead weights inside until you get the nose to quit bouncing.
If you can find much stiffer springs, add them to the rear two driver axle journals.

I have three K’s. This pig is used for demonstration. The Magnus is actually used. The other pig is in pieces, and has been for some time, with no plans to reassemble at this time. Someday…but why.

With weight in the nose, 1 and 4 locked, nose stays down better, and the distance between locked driver and lead truck is far less than with 2 and 3 locked, so the angle of the pilot flanges to the rail on a curve is MUCH less, and they don’t “pick” at the cylinder covers.
One more thing…put a little grease on the drawbar peg on the tender to keep the drawbar from hanging up…and…pick up the tender (loco still on track) and do a “swing” test, looking for jammed wires in those stupidly huge wire bundles.
You may have to loosen the plate that holds the wires to the loco chassis (remove boiler and cab, usually) to pull them out.

All sorts of things you have to watch out for.

BTW, my 35+ year old Magnus K-27 has…1 and 4 locked. Factory. That’s why I knew it worked. Sometimes experience helps, right?

TOC

#6

I appreciate opinions from everyone, we all have some sort of knowledge to share.

Richard, I should have been more clear, the front drive wheel hop was there before the stronger spring, although I’m sure it doesn’t help.

Boomer, I couldn’t agree more about radius and diameter. Most of my layout is 20’ diameter or bigger. Those friggin aristo wide switches are crap though. Yes they can be fixed but that is a different thread. I have checked the mechanicals of it and all seems sound. Trackwork is on ladder roadbed as well so that’s out too.

Dave, I’ll check on the axle lock probly won’t be for awhile though, getting married tomorrow then honeymoon for a week.

One thing that crossed my mind while typing. Rodney’s motor block conversion moves the motor back somewhere in the area of 1.25". would this effect the motor slide and jam the gearbox? Also could it be enough to throw the loco’s center of balance off causing it to hop? I did take care of the fan/harness issue around the motor so I know it’s not that.

I don’t know if I said this but the lead driver only does this when the loco is under load. The pony truck always falls off.

Thanks again for the help and tips
Terry

#7

Terry, something else that prolly is of no help. I ordered my block from Rodney with the new motor option.
The only thing that was displaced was the wire cable. Since I hard wire my own, that was removed.

Congrats on your wedding and I wish you both well.

#8

I sent my motor to Rodney for him to install the gearbox on it.

Terry

#9

Terry Burr said:

I appreciate opinions from everyone, we all have some sort of knowledge to share.

Richard, I should have been more clear, the front drive wheel hop was there before the stronger spring, although I’m sure it doesn’t help.

Boomer, I couldn’t agree more about radius and diameter. Most of my layout is 20’ diameter or bigger. Those friggin aristo wide switches are crap though. Yes they can be fixed but that is a different thread. I have checked the mechanicals of it and all seems sound. Trackwork is on ladder roadbed as well so that’s out too.

Dave, I’ll check on the axle lock probly won’t be for awhile though, getting married tomorrow then honeymoon for a week.

One thing that crossed my mind while typing. Rodney’s motor block conversion moves the motor back somewhere in the area of 1.25". would this effect the motor slide and jam the gearbox? Also could it be enough to throw the loco’s center of balance off causing it to hop? I did take care of the fan/harness issue around the motor so I know it’s not that.

I don’t know if I said this but the lead driver only does this when the loco is under load. The pony truck always falls off.

Thanks again for the help and tips
Terry

First, congratulation on your upcoming nuptials!

Second, I had this same problem with a B-mann 10 wheeler. I even put a BBT pilot truck on it and it still derailed on certain switches and I found the front drivers were always the cause. I found, after much experimentation , that the balance was off. The rear of the loco was heavier than the front. Since I don’t do smoke, I quit 10 years ago…hehehe, I put 8 ozs. of lead in place of the smoke unit. Problem seems to be solved! Best of luck on both points above.

#10

Joe Zullo said:

I found, after much experimentation , that the balance was off. The rear of the loco was heavier than the front. Since I don’t do smoke, I quit 10 years ago…hehehe, I put 8 ozs. of lead in place of the smoke unit. Problem seems to be solved! Best of luck on both points above.

Which is why I recommended lead in the smokebox. The other issue on these kluges is the strap on the motor. Longer motors, possibly jamming…and the additional moment arm weight of the longer motor can cause the gearbox to jam…which is why I mentioned that, also.

I have a new gearbox in my test unit. Solves the problems and keeps the motor in the same place. Add to that a complete rebuild of the way the gearbox is fited…selected slide shims…the strap is in the junkbox.

TOC

#11

OK what do yous guys mean by locking drivers 1 and 4? I do have a problem with the lead truck derailing for no apparent reason, and had thought to add some styrene to the point where the spring slides back and forth to add some downforce…

#12

Remove the wimpy springs that center the drivers on axles 1 and 4. Add nylon washers until it holds the wheels from moving sideways.
Not too tight.

My first issue was they allow the loco to crab sideways (depending on loco, 5/8" to 3/4" side play at pilot beam) and due to the “innovative” lock slide inside the axle, under load, oh, say, 10 cars on a 4% grade of 13’ diameter) the nose is clear over to one side.
You come out of the curve at the top, the pilot beam is clean over…and that “innovative” locking slide coupled with wimpy springs…it won’t center.
Hit my bridge.

Plus, you keep the geometry from shifting putting an extreme angle on the pilot truck.
Stops the wheels from hitting the cylinder heads, all of that stuff,

There was this MORON who told folks (after I first recommended it) NOT to do 1 and 4, rather 2 and 3.
I said it wouldn’t work…and one day, I swapped the shims to 2 and 3…and the stupid thing wouldn’t stay on the track at all.

Put it back.

Even with 1 and 4 locked, it goes around my 4’ radius just fine.

The issue with weights is, the loco is now level…but low. It’s a crying shame the folks who built this decided to do all the testing “in house”.
It needs stiffer springs in the rear, better motor and gearbox support…among a big list of other things.

I have never been so disappointed in a loco…even more than the old TYCO Chattanooga Choo Choo.

One more thing…every one of these we’ve had here…they all are different. All track differently, operate differently.
No sense, no rhyme, no reason.

I remember one early on, lead truck issue…yet we could follow it with two more, no issues at all.

All I can suggest is what I have done to fix the stupidity. And what works on mine.
TOC

#13

Terry Burr said:

The first problem are aristo wide switches, this I assume is a switch problem, I’m slowly fixing and soon replacing them. But the K hates them. And yes I realize they are at it’s minimum radius.

Thanks for any help
Terry

Terry

Best to take the issues one at a time. We have 6 K27s on our layout and it has taken some time to fully understand the Aristo wide radius turnouts. They now work fine.

There are a lot of fixes out there that work. there are two problems. Picking the point on the diverging route and picking the frog. You need to look closely at your turnout and figure out where the derailment is occuring.

For the points on the turnouts causing problems I ground the stock rail at the point a little so that the point fits into the stock rail.

Many fix the frog picking by fixing the spacing on the guard rails (they are wide). A simple and easy alternative fix is to slightly grind back the point just a little bit so that it is impossible to pick the point. Works great.

Also ensure that the rails are smooth and nothing is sticking out. Often where the frog meets the rails it is not smooth. Just a little filing at that spot fixes a lot.

Lets get the turnout fixed first and then we can discuss some improvements to help pilot wheel tracking.

Hope this helps

Stan

#14

“Many fix the frog picking by fixing the spacing on the guard rails (they are wide). A simple and easy alternative fix is to slightly grind back the point just a little bit so that it is impossible to pick the point. Works great.”

That just makes the frog worse, so that the wheels can drop into the frog.

It’s NOT a flange-bearing frog.

To fix the frog, narrow the guard rail flangeways to NMRA specs, but you also have to have the loco gauge and back to back right.

Greg

#15

1.535" check gauge, wing to guard, G1MRA. Worked fine on Llagas for what, 20 years?

#16

Curmudgeon mcneely said:

Remove the wimpy springs that center the drivers on axles 1 and 4. Add nylon washers until it holds the wheels from moving sideways.
Not too tight.

My first issue was they allow the loco to crab sideways (depending on loco, 5/8" to 3/4" side play at pilot beam) and due to the “innovative” lock slide inside the axle, under load, oh, say, 10 cars on a 4% grade of 13’ diameter) the nose is clear over to one side.
You come out of the curve at the top, the pilot beam is clean over…and that “innovative” locking slide coupled with wimpy springs…it won’t center.
Hit my bridge.

Plus, you keep the geometry from shifting putting an extreme angle on the pilot truck.
Stops the wheels from hitting the cylinder heads, all of that stuff,

There was this MORON who told folks (after I first recommended it) NOT to do 1 and 4, rather 2 and 3.
I said it wouldn’t work…and one day, I swapped the shims to 2 and 3…and the stupid thing wouldn’t stay on the track at all.

Put it back.

Even with 1 and 4 locked, it goes around my 4’ radius just fine.

The issue with weights is, the loco is now level…but low. It’s a crying shame the folks who built this decided to do all the testing “in house”.
It needs stiffer springs in the rear, better motor and gearbox support…among a big list of other things.

I have never been so disappointed in a loco…even more than the old TYCO Chattanooga Choo Choo.

One more thing…every one of these we’ve had here…they all are different. All track differently, operate differently.
No sense, no rhyme, no reason.

I remember one early on, lead truck issue…yet we could follow it with two more, no issues at all.

All I can suggest is what I have done to fix the stupidity. And what works on mine.
TOC

That is exactly the symptoms 125 is showing. I have 12 foot curves on The Loop…and after 10-12 circuits of The Loop it is defianetly point off to the left after making consistant right turns. I’ll hav to fix this at the next Shopping…

#17

If folks knew how many times I begged the last “CEO” at Bachmann to send me a chassis…no boiler, no cab, no tender, just a complete chassis…so I could wring it out before full production started…but, no, they now had a new “technical advisor” who was going to solve all their problems…you know, things like inverted chuff, 14.5:1 gearing…pilot beam off in the weeds.
We’d have caught all of that stuff, and gotten it fixed…pre-production samples…you know, the ones they told me didn’t exist, and I think there were six in country.
The absolute blindness to do what they did…when they had the chance to hit the top…

I thought I put all those fixes out long ago, didn’t I, Bart?

The only real hard part of this fix is finding proper nylon washers.
I had the correct thickness, hole was too small…used a hole punch, nibbled around the inside until it was correct.

TOC

#18

Yeah…but I didn;t have 125 back then…or any plans for one…so I didn’t really pay any attention…heheheheheheh

#19

What thickness washer did you use? I thought the axles were locked but looked at it before I left and it’s not. Sorry, I didn’t have mine then either to remember sizes.
Terry

#20

I think I hit pay dirt.

I started tearing into the k’s drive train the other day and found a few problems, some major.

First thing I noticed is sitting on the level workbench the loco had some serious ass sag. I would guess that adding Rodney’s motor block doesn’t help this because it moves that monster motor back an inch or so. Just a guess but the rear springs were compressed about 3/4 while the front springs were fully extended.
I removed the shell and flipped it over. Next problem, the drive axle #3 is stuck fully compressed.
Problem numero three, the same axle is wedged in the drive housing and won’t slide side to side.

Off to work I go. I freed up the motor mount so it would slide up and down and lubed it. Next I loosened up the gear cover on the bottom. In order to get the axle to slide it has to be completely loosened. I really didn’t care for this so I added shims so it would be tight and I’ll make a permatex seal to keep dirt out.
Next I went about locking axles #1 & #4 per Dave’s suggestion. I found nylon spacers at Home Depot with the right inner diameter. I then cut them down to length and installed them.
While working on the loco upside down I noticed that the weight of the motor and drive axle fully compress the suspension. More work…

I removed the third axle, again, and bored out the mounting holes for the springs large enough to accept an accucraft coupler spring. I trimmed the springs until I could fully compress them into the mounting hole. I then put the stock spring inside the accucraft one and reinstalled the axle. Better but still not the same as the other axles.
More work. I got the brilliant idea (from my 11 y/o) to put a spring on top of the gearbox pushing down. Here’s a pic of what I did.

(http://i73.photobucket.com/albums/i231/paintjockey/IMG_20131017_124720_209_zpsc9297810.jpg)

The screw holds a piece of styrene tube in place with the spring around the tube. By doing this I added enough down force that axle #3 now has the same spring as the others.

I took the loco out and tested it. It tracks perfectly and the front truck doesn’t derail either. It mostly handles the aristo wide radius but this is the switches fault no the locos. Oh, and I put a stock spring back in the pony truck as well. I hooked up a long train to check and bummer, it still has the front hop when it starts really working. More work…

For my next trick. I tore down the trailing truck & removed the springs. I have a box of random springs laying about so I found a suitable one that is way stiffer than the stock. I trimmed them for length by compressing them in place and reinstalled everything.

I road tested it this morning and BINGO!! front end hop gone!! Still tracks perfectly as well!! The only drawback I have found is loosing a tad bit of tracktive effort. Instead of 14 cars up the 100’ 2% grade it can only do 10. But, it can do it without derailing. Three things on this. First I don’t believe a real K27 could do that anyways. Second, It was morning, the track was cold, wet and I’m sure I have oil and grease all over the wheels from working on it. Third, the shell is still off. So there’s a little bit of missing weight.

I am now a very happy K27 owner.

Terry