turnout derailments

[ArnS]

I have all HO E-Z track and DCC turnouts. All work find and switch on demand.  Problem is one left turnout tends to derail cars when in the thrown position. The engine runs through just find but cars derail easily, even at slow speeds. The cars are weighted properly and run through just fine if I push them by hand. I checked the gage of the track and the cars and all are on spec. I video taped it and ran it back in slow motion. When the derailment occurs the front truck causes the points to momentarily go to the closed position and the wheel runs to the outside of the point. The rear truck follows the turn OK because the points have sprung back to the thrown position where it should be. This can happen to any car from the first behind the engine or one farther back. It doesn't happen all the time but more often than not. Any help would be greatly appreciated.
Arn

[Jim Banner]

You have already checked everything I would normally suggest and gone a large step beyond.  I really like your idea of video taping the process and watching it in slow motion.  All too often, things that go wrong at normal speed do not occur when you run the train at slow speed.  But at normal speed, they  happen too quickly to see what is happening.  Thanks for a great addition to the list of diagnostic tools.

I will suggest one more test on your turnout.  Set it to the closed position and gently move the points to the thrown position using just your finger.  Then set it to the thrown position and gently move the points to the closed position.  The required force should be the same both ways.  If it is not, there is probably a problem with the spring inside the switch machine or possibly the machine is not throwing the points far enough in the thrown position, that is, they throw enough to touch the stock rail but not enough that the spring keeps them firmly there.

If you bought your recalcitrant DCC turnout from a Bachmann dealer, consider sending it back to Bachmann for repair/replacement.  Alternately, open it up and try adjusting the spring.  I don't know if they use a metal or a plastic spring but my own experience adjusting plastic springs has generally not been a happy one.

Jim

[ArnS]

Thanks for the reply. I tested the spring tension in both directions and it seems to be about the same. I did find though that when I manually press the point against the outside rail after toggling the switch, the cars make the turn much more consistently. They always run fine in the closed position. I tried bending the point a little and it seems to help some. I will continue experimenting with that point. Thanks again for your help and I will post again if I get it fixed. I would hate to tear that switch up to replace it because it's all landscaped and ballast put down.
Arn

[captain1313]

arns

I've solved 90% of my Bachmann trunout problems by using  a Dremel tool with a pointed diamond bit to cut off the lower portion of the rail were the points meet main rail.  It seems , at least to me that there is too much up and down play on the points and they seem to hit that lower portion of the rail and than stop rather than climbing up over it.  Moving the points by hand has more force then the switch machine.  I even sometimes cut a little of the inside of the rail to male a small pocket just like the Atlas turnouts.   

Kevin

[ArnS]

Thanks Kevin for the tip. I did take the lower lip off the main rail where the point meets it and that seems to have solved the problem. The train follows the point much more smoothly, even at higher speeds. Hopefully the problem will not resurface. I may go back and dress up the other turnouts later. Thanks again, you guys are great.
Arn

[ArnS]

Just a follow up. I dressed up some of my other switches and it makes for much smother running. Fortunately I have a Dremel tool and a small enough bit to work with. Be very careful though that bit can take off a lot of material in a hurry. I hope this helps others with the same problems.
Arn