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Discussion Starter #1
Greetings Everyone,
I probably already know the answer to this question/problem but I wanted to get your opinions before I do any drastic remodeling.
My problem is that my engine's (Bachmann Connie) front trucks tends to jump the track at the switch pictured below. It doesn't always happen but I always tend to get nervous when the train aproaches this section. Is this due to the fact that the train is coming into the switch from a gradual curve. I don't run the train really fast usually so I don't think speed is the issue.
Please take a look at the pictures and give me your thoughts.

BTW I run the engine from left to right.

Thanks,
Richard

 

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Here's the trick to figuring it out.

Lay on the ground with your remote in hand and very slowly run the engine back and forth over the switch. You'll likely see a wheel lifting up or something.

Short of that, check the gauge of the wheels.

Yea, somebody will tell you to throw away that Aristo turnout. The solution won't be that drastic.
 

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Richard, any more info on where it derails? And is it when the switch is set to go left or straight, etc.? Your track work looks pretty good, I assume it is pretty level side--to-side? Is it only just the front pilot wheels? The other wheels will go through okay? The curve looks gradual enough, but what diameter is it coming into the switch?
 

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First thing I'd do is to file a very slight taper on the tips of the points. That solves 90% of all derailments that happen at the tips of the points. What happens is that the flange comes in and catches on a slight edge, causing it to ride up and over. By filing a slight taper onto the tip, you eliminate the edge that the flange would want to climb up on.

Two resources for you to check:
Anatomy of a Switch

Troubleshooting a Switch

This second link has a drawing showing what I'm talking about. It's also got other things to look for that may be causing your problems.

Later,

K
 

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Discussion Starter #6
Thanks for the quick replies jimtyp and k...

After running a short test I have found the following. The front pilot wheels jump up at the point indicated by the arrow in my exploded view below. What I've also discovered is that all the wheels, including the tender car lift slightly when the come in contact with the point. My initial reaction is to try Kevin's suggestion of tapering the entry point to eliminate the desire for the wheels to ride up.

Also thanks for the links Kevin. I will take a peak at them.




Richard
 

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Discussion Starter #7
Well I guess I should have looked at Kevin's links first before replying. It is not the point that is the problem, but rather the entry point at the flange indicated by the arrow in the picture below. Should I still try to taper the flange? Since it is a plastic part will I encounter anyother issues?



Thanks,
Richard
 

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Throw away the Aristo switch/DesktopModules/NTForums/themes/mls/emoticons/hehe.gif

First, I'd rather there was a straight section to the left of the switch. One at least as long as your longest loco (without tender).

Second, I'd drop a truck off of some convenient car.
Compare the width between the wheels with the lead wheels of the loco. Should be the same.
Compare the size of the wheel flanges. Should be the same.

Gently roll the truck through the turnout. Does it bump?
Put pressure straight down and do it again. Does it bump?
Force the truck against the outside of the curve. Does it bump?
Force it against the inside of the curve. Does it bump?

If it Bumps, clicks, or in any way does not roll through silently and smoothly, then you have a problem.

Most likely problem will require you to use a ******* file to make the flange-ways deeper. But there may be other fixes needed depending on where (exactly) the bump or click happens.

If the truck goes through silently and smoothly without finding the problem. Remove the front wheels of the loco and use them to repeat the test.



B:cool:B
 

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Ignore the man above !. The frog on the wide radius switch should be ground down a bit. Some like to use a thin edge of a file. I use carbide cutter on a dremel tool like below -



I use a spare wheelset as a depth gauge.

I have 13 wide radius switches and except for the above modification they work fine with small steamers to big dismals pulling long smoothside coaches.

-Brian
 

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It wouldn't hurt to round that off a bit. A few things could be happening. First, the back-to-back spacing of the wheels could be tight, forcing the wheels to rub against both sets of guard rails. With the tolerances on Aristo's switches, I think the BTB spacing would have to be REAL tight for that, but it's worth a check. (Common practice puts the "optimum" back-to-back spacing of wheels at 1.575".) If that's fine, it may be the wheel is catching on the inside edge of the guard rail, causing it to bump and ride off the track. Filing the inside edge a bit smoother should mitigate that.

The next thing I'd look at is the entry going into the frog. If the flange is bottoming out on that, it could push the wheel up and over. Grinding the flangeways down as others have suggested should keep that from being a concern.

Later,

K
 

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The first thing I'd do is check the back to back gage on the front truck. Next I'd do a little filing on the switch points. Most Aristo turnouts will have to much clearance at the guard rail as you noted where derailing. Also check your cross level ahead of the switch and through the switch. This is also critical. Later RJD
 

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Discussion Starter #12
Greetings all,

I have been spending some time testing my Connie through the switch that seems to be a problem. One thing I discovered was that the front pilot wheels measured 1 7/16" from inside flange to inside flange. This created a lot of play between rails, enough to still be in the curve as it approached the flange of the turnout. I know Kevin mentioned that the distance should be 1.575 inches but I'm not sure how to measure that exactly.

Well I tried widening the distance of the wheel flanges just a bit and I was successful in stopping the engine from derailing at the point of the turnout flange. My problem now is that the engine completely locks up and stops as if it hit a brick wall. It is now on my snack bar to be tested and played with. I will check all the screws on the wheels where the gears are to see if they are tight.

If any of you have any suggestions I would certainly appreciate it.

Thanks,
Richard
 

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1 7/16 is definitely too narrow, so that's probably where your problem lied. 1.575" is a smidge over 1 9/16", so your front truck was at least 1/8" too narrow.

As for your next problem, I'd first look at the screws that hold the counterweights on. If they get loose, the counterweights flop a bit and jam up against the valve gear. With the 2-8-0, periodically tightening the counterweights with a small phillips-head screwdriver is going to be routine maintenance.

Later,

K
 

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Discussion Starter #14
Hey Kevin,

You were absolutely right about the counter weights. I brought the engine in to check it out and the front left weight completely came off. Several other weights were loose as well. I tightened each one up and the engine ran perfectly. No derailments, no sluggish up and down motions...just really smooth. I now know to keep an eye on this and to double check everything every couple of runs.

Thanks for all of your help and thanks to the other guys that were generous with their suggestions and expertise.

MLS is a great site and it's good to be back.

Richard
 

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Please read my page on the WR switch.

First, I suspect your wheel gauge is too narrow, you need to pick a standard and gauge the wheels.

The entry to the guard rail is ok, but the flangeway width is too wide on the WR switch. Shim it, try 0.106"

.... you can use the Aristo gauge to set your wheel gauge.

The frog is too high, and trimming it flush with the rails will make the frog flangeway depth WAY too shallow, deepen it to standards, again the Aristo gauge is good for this.

Here's a direct link to my page: (with all this info) http://www.elmassian.com/index.php?option=com_content&view=article&id=86&Itemid=96


Regards, Greg
 

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Discussion Starter #17
Greg,

Thanks for the additional input. You are correct, the wheel guage was too narrow on the pilot wheels of my Connie. Changing the guage helped a lot. I was able to run the engine flawlessly for about an hour without any derailment.

I do think the Aristo turnout is still a problem though and I've been reading with interest your link regarding modifying them so they work better. I think some of your suggestions are just what I need to make it work smoother.

Thanks,
Richard
 

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You are welcome Richard. I have never found anyone who has really looked into these turnouts that disagrees with the mods I suggested. Most of them were on the forums already, although I came up with the idea to use the router on the frog, it's really easy.

If you shim the guardrails only, it will stop wheels from "picking the frog". If you do the other mods, the "bump" when going through the switch will be eliminated, and they will be really smooth.

Of course checking the points and point fit to the stock rails is needed, but I rarely have to mod this part.

Regards, Greg
 

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I've read, with interest, the turnout problems etc....And now, I've got a question:
If optimum wheel spacing is 1.575", does someone, like the NMRA, make a Large scale wheel gauge?
Don't have turnouts yet. Will need them eventually, for passing/storage sidings.
And maybe a few industrial sidings.
 

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Aristocraft does.

I use my handy calliper
 
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