LGB Mikado Derailments

[pmindigo]

I'm a new member but a long time LGB train collector and operator.
The leading and trailing wheels on my 2-8-2 LGB Mikado's are derailing on a consistent basis when navigation points. The leading truck appears to bounce at the frog and jump the rail. The larger and more consistent problem is that when the engine is passing straight through a right hand switch the drive wheels and the trailing truck (wheels) appear to push the tongue open which either causes the tender to be diverted to the right line which derails it, or the tongue is left half open which will cause the next train that passes through to derail.

Has anyone else seen this problem? I have two Mikado's and they both cause this problem. I'm thinking about adding lead tape or a spring to apply more pressure to the trucks. Any additional thoughts on how to solve this problem would be appreciated. My steam engines are on the shelf for now.

The image below show the switch after the Mikado and Tender pass through.

 

[Paul M]

Welcome to the forum, hopefully someone will be able to help, but I would say check the point springs, they may be weakened and not holding the point blade in place sufficiently

 

[Greg Elmassian]

First check the gauge of the loco wheels, and then check the gauge of the switch.

Use the G1MRA standards. (for back to back or gauge) .... or you can read my page on how to apply the NMRA standards:
(but you need to read it through)

Track & Wheel Standards

Greg Elmassian web site on large scale trains and garden railroads, cigars, and computers

elmassian.com

If you don't have a set of vernier calipers, go to Harbor Freight and buy an inexpensive pair, do NOT use the Kadee gauge.

Having this problem straight through really sounds like a gauge problem.

Greg

 

[phils2um]

You say that you're thinking about adding a spring to the trucks. Are there not springs on them already? I don't have a LGB Mikado but all the LGB locos I have with leading or trailing trucks have springs to help keep the wheels on the rails.

 

[dunnyrail]

The point is wrong, that blade should be hard against the rail closest to the point motor leaving no gap. What is quite likely is that the point motor has been pulled apart and not put back together correct. Do you have another point motor or switch to temporarily replace it with to see that you get the perfect fit. Then test your loco to see if you still get derailments, I believe they will not occur. Just holding the blade across with a screwdriver with the motor off would prove things if you do not have a spare motor or wish to remove one from another point.

 

[Paul M]

The point is wrong, that blade should be hard against the rail closest to the point motor leaving no gap. What is quite likely is that the point motor has been pulled apart and not put back together correct. Do you have another point motor or switch to temporarily replace it with to see that you get the perfect fit. Then test your loco to see if you still get derailments, I believe they will not occur. Just holding the blade across with a screwdriver with the motor off would prove things if you do not have a spare motor or wish to remove one from another point.

Looking at more closely, is the point motor actually attached properly

 

[dunnyrail]

Looking at more closely, is the point motor actually attached properly

Not sure if that is the problem, I think the motor has been put together badly. If the arm is not fully across in the rack the gap and arm is not fully over one side as the result. The picture appears to show that.

 

[Ralphmp]

Guys, the photo shows the point after the loco has been through (see post #1).

I had a similar sounding issue with a Ballerina a while back so I swapped the trucks for brand new ones direct from Marklin and problem hasn’t, so far, recurred. When I removed the old trucks I noticed there wasn’t a spring in the mounting, just the one on the axle. The new trucks came with a spring - which I fitted - but I can’t conclusively state that this fixed the problem.

It was suggested to me by a knowledgeable friend that if the axle spring gets weak or stuck, this could make the truck less able to deal with undulations in the track. Might be worth checking the Mikado truck axles are moving freely against their springs.

 

[JimmyB]

Not sure if that is the problem, I think the motor has been put together badly. If the arm is not fully across in the rack the gap and arm is not fully over one side as the result. The picture appears to show that.

I have to agree it would look like a poorly re-assembled motor, having stripped down a few, my first attempts at re-assembly ended similarly, until I understood the the principle behind this motor drive.

 

[Gavin Sowry]

I'm thinking about adding lead tape or a spring to apply more pressure to the trucks.

Whoa! My advice, especially to new players, is to hold off on doing mechanical alterations until you are dead sure that your track is within proper tolerance (including cross level), and in this case, that the switch rails actually butt up to the stock rails, and are not half cocked, as in the photo. Then, and only then, consider the rolling stock. First key issue to check, is what is called the back to back gauge, that is the distance between the backs of the wheels. Do nothing else until you get this right. Next mechanical check, is to see if any axles are bent, or the wheels are wobbly (caused by the wheel tread/flange not being clipped firmly into the wheel centre. Harking back to the track, you have, of course, made sure that there is no rubbish fouling the flangeways, or stuck under the cover plate over the tie bar (it pops off).

I remember the very first Large Scale loco I bought, second hand. It was in a shop, and I asked to see it run.... it promptly derailed on the first curve, so I bought it. Later on, when I had the courage to dismantle it, I took the wheels out, and did a roll test on a sheet of glass. I srmised that one axle was bent, so I took the wheels off to straighten the axle, which turned out not to be bent. When reassembling the wheelset I happened to notice that one set of tyres/flanges was sitting at an angle. Quick squeeze with the pliers had that snap fit back in its proper place...... no more wobbly wheels!

 

[JimmyB]

Whoa! My advice, especially to new players, is to hold off on doing mechanical alterations until you are dead sure that your track is within proper tolerance (including cross level), and in this case, that the switch rails actually butt up to the stock rails, and are not half cocked, as in the photo. Then, and only then, consider the rolling stock. First key issue to check, is what is called the back to back gauge, that is the distance between the backs of the wheels. Do nothing else until you get this right. Next mechanical check, is to see if any axles are bent, or the wheels are wobbly (caused by the wheel tread/flange not being clipped firmly into the wheel centre. Harking back to the track, you have, of course, made sure that there is no rubbish fouling the flangeways, or stuck under the cover plate over the tie bar (it pops off).

I remember the very first Large Scale loco I bought, second hand. It was in a shop, and I asked to see it run.... it promptly derailed on the first curve, so I bought it. Later on, when I had the courage to dismantle it, I took the wheels out, and did a roll test on a sheet of glass. I srmised that one axle was bent, so I took the wheels off to straighten the axle, which turned out not to be bent. When reassembling the wheelset I happened to notice that one set of tyres/flanges was sitting at an angle. Quick squeeze with the pliers had that snap fit back in its proper place...... no more wobbly wheels!

Though I agree with all of this Gavin, the fact that the blades have stopped in the midway point when connected to an electric motor drive suggests a problem with the point (switch) assemble, i.e. point and motor.

 

[AlanL]

For information the LGB Mikado has a srung lead truck and gravity trailing truck.
I have regularly ran trains through facing points without any motor or spring switch to hold the point blades in position. The wheel profiles and flanges are very course and tolerant to errors. If you wanted to deliberately move the point blades with a model locomotive you would find it impossible. Even if the blades started to open, the big flanges and course wheels would try to push the blades back to the stock rail.

Could I suggest that the point blades are closing in on the locomotive wheels either due to flexing of the point as possible in full size but unlikely with our models, or the pile of the carpet below the point is pushing the throw bar.

The LGB Mikados are a fairly weighty beast and are pushing the track into the carpet causing the throw bar to move slightly. Try it with a piece of card below the point to isolate the carpet.

The leading truck jumping on the frog may be lack of spring, incorrect gauge or track flexing?

Alan

 

[Greg Elmassian]

Yes, something is fishy... having the leading/pilot truck derail on a steam loco is common when there are issues with weight/springing.

But the trailing truck? That is very unusual especially on the straight through path.

I did not look closely at the picture (since it was attached, not embedded) and I agree with Jimmy, get the switch situation understood first, that switch should NEVER look like that in my opinion.

Greg

 

[pmindigo]

Thanks for all of the tips and feedback. Iv'e isolated the issue to the 8 driving wheels and I believe what is happening is that the 3rd or 4th set split the tongue flange which is not seated tightly to the rail. These switches are older LGB R1 and R3 models with motor drives. They do not have internal springs. I did test again on a section without carpet and while I've seen this to cause cars to uncouple, it is not the root cause here. Greg, I'm planning on picking up a set of calipers this week and will make adjustments where needed. I discovered that I could easily adjust the front and rear truck wheel back to back dimension. While the front and rear trucks are bouncy (technical term), the main cause of the derailments is the drive wheels splitting the tongue flange and rail so no need to add a spring or lead tape at this time. The rear truck does have an internal weight, but the front truck is very light. Any tips on sharpening the tongue flange tip so they seat tighter to the rail?

Would be interested in hearing from others that may be running LGB Mikado's on LGB R3 and R1 switches.

Thanks again!
Phil

 

[Rhinochugger]

I seem to remember that one of the issues with the LGB Mikado is the pivoting drive chassis that has a tendency not to fully straighten out on the straights.

You need to talk with ebay Mike - he had more than one of these locos. I can remember seeing one of them perform faultlessly, hauling the LGB Happy Birthday car as part of its consist on my birthday the December before the pandemic.

 

[JimmyB]

If I recall correctly LGB points do not have internal springs like Piko, you have the manual control of motor to hold the blades in place.

 

[pmindigo]

For information the LGB Mikado has a srung lead truck and gravity trailing truck.
I have regularly ran trains through facing points without any motor or spring switch to hold the point blades in position. The wheel profiles and flanges are very course and tolerant to errors. If you wanted to deliberately move the point blades with a model locomotive you would find it impossible. Even if the blades started to open, the big flanges and course wheels would try to push the blades back to the stock rail.

Could I suggest that the point blades are closing in on the locomotive wheels either due to flexing of the point as possible in full size but unlikely with our models, or the pile of the carpet below the point is pushing the throw bar.

The LGB Mikados are a fairly weighty beast and are pushing the track into the carpet causing the throw bar to move slightly. Try it with a piece of card below the point to isolate the carpet.

The leading truck jumping on the frog may be lack of spring, incorrect gauge or track flexing?

Alan

My Mikado's do not have springs on the front truck. Can you send me a photo so I can figure out how to add them? All equipment is LGB.

 

[ebay mike]

I seem to remember that one of the issues with the LGB Mikado is the pivoting drive chassis that has a tendency not to fully straighten out on the straights.

You need to talk with ebay Mike - he had more than one of these locos. I can remember seeing one of them perform faultlessly, hauling the LGB Happy Birthday car as part of its consist on my birthday the December before the pandemic.

I is here - having been notificated my username has been mentioned in dispatches. I still have three Mikados, albeit now back in their boxes since the railway has been lifted. Never had any running problems specifically through pointwork, but did experience a couple of derailments which were investigated and attributed to a distorted traction tyre which had managed to become slightly stretched and developed a small hump which protruded outside the limit of the wheel flange. As for your point (turnout) blade not remaining in position, I seem to remember there was a small shaped spring under the plastic ramp in the centre of the track which was supposed to give a degree of pressure to either left or right to hold the blade in place once it had been thrown. I initially actually used all my points (trailing and facing) without either motors or the manual switches to start with - relying solely on this spring to hold them in position. Changing direction was done by moving the blade with my fingers and it worked like that for at least a couple of years until I acquired a stock of the square manual switch levers.

 

[JimmyB]

As for your point (turnout) blade not remaining in position, I seem to remember there was a small shaped spring under the plastic ramp in the centre of the track which was supposed to give a degree of pressure to either left or right to hold the blade in place once it had been thrown. I initially actually used all my points (trailing and facing) without either motors or the manual switches to start with - relying solely on this spring to hold them in position. Changing direction was done by moving the blade with my fingers and it worked like that for at least a couple of years until I acquired a stock of the square manual switch levers.

Mike, I believe it is the Piko that has the spring, which should be removed (according to their instructions) is a motor is added. The LGB blades are held in place by the external manual control or motor.

 

[Rhinochugger]

Mike, I believe it is the Piko that has the spring, which should be removed (according to their instructions) is a motor is added. The LGB blades are held in place by the external manual control or motor.

I'm pretty sure that the LGB points in manual mode have the over centre spring that Mike mentions - I got rid of mine a good while back, but as they were the first G scale points I had, I do remember .................