2 'weird' issues with a new layout


Z

Zombie13

New Member
So, I'm just starting but using really old track (like 30 years old) and rolling stock and loco. I have 2 loops that can be run either one unique loop (a flat oval) or like a folded infinity sign with one 'loop' feeding into the other. There are no reverses or anything, but there are 2 turnouts.

Issue 1: Sometimes, on the folded infinity, the loco partially derails at random points. It looks like the front wheel on the front truck skips off. It doesn't derail enough to stop moving, just enough that you can hear it if you know what to listen for and when it hits a turnout it really messes up. Not sure exactly how to deal with it, given that it seems to be intermittent. Any suggestions would help.

Issue 2: This one is stupid, but all my rolling stock currently has the stupid cheap horn couplers. Almost all the time when the loco follows a right curve, it drops the leading car (and thus all the others...). Other than changing out couplers to the Mag-Matic ones (Kadee or whatever they are), is there anything I can do?

Z.
 
What radius curves, what engine?

Hork hook may have lost it's built in spring. Without it it can easily uncouple. Are they all at the same height above the rail?
 
Not having ever used the horn/hook, or the different brand designs of them, take this as thoughts rather than advice. I note that what I assume is the horn, indicated with the red arrow in this pic
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sticks out a fair way in front of the coupler (ignore the blue and green for the purposes of this). Could it be that because of the tightness (small radius) of the turns, that is contacting the loco's rear and/or the trailing car's front edge and decoupling them. I only use the KD magnetic couplers where they have the hanging curved trip pin, but when I have 2 or more locos 'in consist', where the rear loco is in a reversed position and has a plow, the trip pin on the attached following car pushes against the plow and holds the coupler open when either going downgrade or coming to a stop and once that pressing together of the rolling stock, that opens the couplers, is removed on moving off, they stay uncoupled long enough to come apart.
Taking a small amount off the end of the horn as indicated may stop that, but experiment. A little at a time.
 
Many things can cause those problems.
Lets start with the track. It probably isn't derailing at random points, there probably are a few problems and you don't notice exactly where. It would be helpful to watch the engine go around and see exactly where the engine derails. Track has line, surface and gauge.

Line is whether the track is in a straight line or smooth curve. I will assume you are using sectional rack (pieces about 9" long). Look at the joints. Do the rail ends line up between the sections? Does the track form a smooth curve or if you sight down a rail is there a noticeable kink in the rails? Are the rails actually in the rail joiners? Are the rail joiners tight?

Surface is how smooth the track is. Are the pieces of track bent vertically? If you put a ruler over the joints is there a gap between the top of the rail and ruler? What is the track resting on? If you have a small level check across the tracks to see if the track is twisted and out of crosslevel.

Gauge is how far apart the rails are. If they are too close or two far apart the wheels will derail. That's not usually a problem, you will need an "NMRA track guage" to check that.

There can also be problems with the engines. The gauge my be off on the wheels (the wheels to far apart or too close together on the axle). Or the there may be something that prevents the trucks from turning enough to negotiate the curves. Some curves are too sharp for some engines. Knowing the engine and the curve radius might provide a clue. Sometimes a wire or connection or part of the drive train chain hit the frame or shell because its out of place.

It can also be a combination. If you are running an engine with an 18" minimum radius on 18" radius track and there is a small kink someplace, that can be enough to derail it.

We haven't talked about switches, they are a different issue, but no point into going into that unless you can identify that the switches are where the engine is derailing.
 
Thanks for the awesome responses. I'll answer what I can:

Engine: Athearn SDP-45 (like, 30 yrs old)
Curve Radii: I _think_ 18" but I really have no idea. I have both 'standard' track and flex track. The standard track curves all are the same radius I think, but I don't know what it is. I'll look on the box later, but its Tyco track so it might not say. The Flex track is curved to match (as close as I could) the standard track. I know some of it is tighter, but from what I can tell, thats not where its derailing.
Line: All the ones I've looked at so far line up. I did end up with some gaps, but nothing over 1/16" I think.
Joiners: Yes, and some are not snug, some are. A lot were left on the track, so I left them there.
Horn springs: They all spring as far as I can tell.
Hitting car/loco: I don't think this is the case, but I'll play with shortening the horn and see what happens. I think its only the first car after the loco.
Kinks: I don't have any kinks that I know of.
Gauge: I'll see what I can do to compare that. I know on the flex track its likely to be a problem (and I didn't even think about that).

I'm trying to get more track and some magmatic couplers, so all the issues I'm having might just evaporate (leaving a whole new set of them, I'm sure), but that won't happen until after Christmas at least.

Thanks for the info.
Z.
 
Ok, track radius is not specified on package.

Horn connection is not hitting loco or car, it just springs away on a right-hand curve. It's almost like the car isn't heavy enough or adding enough friction to hold the horn connection (if that makes sense).

Z.
 
Zombie13 said:
Ok, track radius is not specified on package.

Horn connection is not hitting loco or car, it just springs away on a right-hand curve. It's almost like the car isn't heavy enough or adding enough friction to hold the horn connection (if that makes sense).

Z.
Click to expand...
Are you dealing with a truck mount vs. a body mount coupler situation?
 
Zombie13 said:
So, I'm just starting but using really old track (like 30 years old) and rolling stock and loco. I have 2 loops that can be run either one unique loop (a flat oval) or like a folded infinity sign with one 'loop' feeding into the other. There are no reverses or anything, but there are 2 turnouts.

Issue 1: Sometimes, on the folded infinity, the loco partially derails at random points. It looks like the front wheel on the front truck skips off. It doesn't derail enough to stop moving, just enough that you can hear it if you know what to listen for and when it hits a turnout it really messes up. Not sure exactly how to deal with it, given that it seems to be intermittent. Any suggestions would help.

Issue 2: This one is stupid, but all my rolling stock currently has the stupid cheap horn couplers. Almost all the time when the loco follows a right curve, it drops the leading car (and thus all the others...). Other than changing out couplers to the Mag-Matic ones (Kadee or whatever they are), is there anything I can do?

Z.
Click to expand...
Issue 1: The locomotive is a six-axle, with a fairly long wheelbase (spacing from the front axle to the rear axle of each truck. First check the gaging of the wheels with an NMRA gage. If in-gage, turn the engine around and see if you have the same problem with the front wheels of the truck that is now leading. If so, then chances are it is the track radius of curvature. That locomotive should run on 18" radius track, but that may just be a bit tight. If the sectional track is, say 15", you won't be able to run it without derailing. (Possibly assemble a complete circle of the section curved track and measure the diameter of the circle from the center of the track. Eighteen-inch radius track is a bare minimum for six-axle diesels. Depending on whether the trucks have the axles extending to bearings in the sideframes, or the ends of the axles being even with the sides of the wheels, it would be possible to remove the wheels from the center axles, leaving just the gears in place. But that, of course would require some expertise in that modification.
Issue 2: The BEST solution would be to replace the hook-horn couplers with Kaydees. I know that can be a bit expensive, but if you are going to run very much at all, it is the best solution. Virtually all new models will have the knuckle type couplers, so if you are planning to add any rolling stock, you will have to make the change anyway (other than possibly converting one end on each of two cars, so the knuckle couplers will match up.
 
I say its a problem with uneven and poorly layed track. My tiny little 2-8-0 HOn3 engines kept derailing and I soon discovered the track laying I did stunk. I went back to tracing radius with yard stick with holes drilled into it to correctly get those curves layed out. Easements and leveled track finally fixed the problem.
 
I'm leaning towards pulling it all up and relaying it out. It'll just have to wait a few weeks due to life....

Thanks for all the suggestions and help.

Z.
 
Derailing trucks can have multiple causes. Undulating tracks, especially along curves, is problematic. On steamers, those undulations lift and tilt the frame, causing the front and back of the frame to lift flanges in the trucks clear of the rail heads.

Rails not close to level transversely, especially along curves, is bad. Rails not super-elevated correctly is bad. Often adjusting ballast under the ties can help a lot, but it takes analysis and patience.

Also, there can be flashing under the frame of the locomotive, or on the bolster, or parts get so worn pivoting all the time that there's no practical cure except to replace something.

Missing springs that hold the truck frame down, or improper weighting of the truck can be a problem.

Curves tighter than the azimuthal swing permitted by the design or mistakes in assembly can also cause trucks to derail.

Incorrectly spaced guard rails and fillers in frogs can cause the truck to derail.

I agree with the philosophical approach of JazzDad above. You learn nothing by destroying something that doesn't satisfy you. You'll never understand why it doesn't satisfy you.
 
18" radius is a MINIMUM radius. That is the point below which things start to go wrong. It is better to increase the radius up to 20-22". If you are 18" radius and accidently get a bit tighter curve, down to 17" radius, you could have problems. If you are at 22" radius and get it too tight you are at 21" radius and are still well in the OK range. Plus if you go 18" minimum, many newer engines have larger minimum radii, so going larger means you won't have problems with newer equipment.

Get a yard stick and drill some holes in it to use as a trammel to mark off curves. Another option is to take a piece of Masonite or even poster board and use the trammel to mark off arcs every 2" (18", 20", 22", 24", etc. and 19", 21", 23", etc) and cut along the lines to form 2" wide arcs that can be used as templates for drawing curves. I made mine of Masonite and use them all the time when laying out tracks.
 
I was checking last night and I think my curves are less than 18". Is the curve measured to the inside rail or the outside rail (won't make much difference, but it could be why I was small)?

Z.
 
A really good book is John Armstrongs book "Track Planning for realistic Operation". Thats why I've used 24" and larger radius' and #6 and longer turnouts. I run N&W 1930's steam (USRA 2-8-8-2's etc).
 
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