BLI CAB FORWARD ISSUE

[Anonymous]

I have had a BLI cab forward for about three months now. It has about 10 hours of running time on it. Until yesterday, it ran perfectly. Yesterday, I hooked it up to a tain consisting of 19 40 ft. box cars, two forty foot flatcars and a caboose. All cars are weighted to NMRA standards, have metal wheelsets and Kadee couplers. When the cab forward started pulling this train it ran nicely, but the second set of driver wheels derails over EVERY turnout. When I run the locomotive by itself, it derails about 10 percent of time when going over a turnout. I use Peco code 100 medium and large turnouts. Has anyone experienced a similar problem? I have never had a similar problem with my Trix Big Boy even whe it pulls the identical train.

[Don Gibson]

1. Do you have a 'Tire' on one of the wheels in the 2nd set?
2. What does B.L.I. say?

The second set of drivers turn independantly from the first. - or is supposed to.
if you dont find the solution, You may have to change the turnout's.

[cacole]

Check the wheel gauge on the second set of drivers -- you may have one or more axles with the wheels out of gauge. Derailing on a Peco code 100 turnout is usually a result of out-of-gauge wheels catching on the tip of the frog.

[Anonymous]

Cacole--thanks for the tip, I didn't think to check the gauge of the wheels. The loco ran fine for quite a while and the problem manifests itself when pulling a long train. Perhaps there is an issue with the weight of the train pulling on the back end of the loco. I have very few derailments on turnouts with other locos, so I suspect that the problem is with the loco not the turnouts.

[Don Gibson]

THERE IS NO TURNOUT MADE ...
that some piece of equipment won't like.

Edit:
Yes, check the gauge of the wheels - and while your at it, the gauge of the points. Pre-fab turnouts do NOT come out all the same.

[Anonymous]

You raise a good point Don. About 20% of my Peco turnouts need some sort of minor modification. Usually it's just a little filing here or there.

[Don Gibson]

...There is no turnout made that some piece of equipment wont like" ...

QUOTE: "When the cab forward started pulling this train it ran nicely, but the second set of driver wheels derails over EVERY turnout. Has anyone experienced a similar problem?

YES - and there is no easy answer. I just aquired a brass limited edition 2-6-6-4 collectors piece, and it won't make through my #6's. Choice: I can replace with #8's or a different brand #6's. Most layouts have limited space, so I prefer to upgrade turnouts first, and go to a larger # second.Since the only curved part of most turnouts are the point rails, and different manufacturer's have different length points (and therefor radii) this is where most problems occur. Secondly, point rails are only secured by the ends. they often dont hold their memorized 'curve'.

After checking for the obvious (wheels gauge, truck bind or restriction) I now upgrade to a more expensive turnout. I find the the more expensive turnouts have NMRA ( tighter) specs, wheras most popular turnouts have been designed to accomodate a wider variety of products. if you were a shop owner would you want newbies returning engines because they derail on tight-spec turnouts?

In order to run on the 'popular' 22" radii (and smaller) manufacturer's have to build in certain amount of 'Slop' in their drives The more expensive engines are built with more realistic specs. and therefor require superior turnouts and wider radii curveture. Either that, or park it in a showcase.

[Don Gibson]

...There is no turnout made that some piece of equipment wont like" ...

QUOTE: "When the cab forward started pulling this train it ran nicely, but the second set of driver wheels derails over EVERY turnout. Has anyone experienced a similar problem?

YES - and there is no easy answer. I just aquired a brass limited edition 2-6-6-4 collectors piece, and it won't make through my #6's. Choice: I can replace with #8's or a different brand #6's. Most layouts have limited space, so I prefer to upgrade turnouts first, and go to a larger # second.Since the only curved part of most turnouts are the point rails, and different manufacturer's have different length points (and therefor radii) this is where most problems occur. Secondly, point rails are only secured by the ends. they often dont hold their memorized 'curve'.

After checking for the obvious (wheels gauge, truck bind or restriction) I now upgrade to a more expensive turnout. I find the the more expensive turnouts have NMRA ( tighter) specs, wheras most popular turnouts have been designed to accomodate a wider variety of products. if you were a shop owner would you want newbies returning engines because they derail on tight-spec turnouts?

In order to run on the 'popular' 22" radii (and smaller) manufacturer's have to build in certain amount of 'Slop' in their drives The more expensive engines are built with more realistic specs. and therefor require superior turnouts and wider radii curveture. Either that, or park it in a showcase.

[Anonymous]

I read this topic since it starts.

I´m sure that the turnouts are not the problem!

FACT IS: The AC ran perfectly for a good time and then starts to derail over EVERY turnout with a train and over many turnouts when running alone.

This is a problem of the engine. Have you tried to see what will happen when the engine derails, the eyes as near as possible beside the turnout and at track level, okay the track must be at the side of the layout. This is often helpful.

When you check the engine also check the tender and the wires between engine and tender, possible one of the wires hang down or was streched to much. Or the bolster couldn´t swing enough because of wires or so.

[ndbprr]

here is an opinion since I don't own the engine. IF (note the IF) the traction tire is on the set of drivers that is derailing it could be possible that the force of moving a train is causing the traction tire to skew the drivers to one side allowing them to pick the switch.