Don Gibson wrote: kbaker329 wrote: I was looking for responses from people with ideas or who had tried something that actually worked for my situation. If there aren't any, then fine. But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance. - Keith Baker ADVICE: I don't think getting 'snippy' with 'Midnight Railroader' or anyone else, is helpful;YOU have the problem. YOU chose your equipment. YOU choose to NOT change your radius, (too much work?) - not he. Now, go do the right thing.
kbaker329 wrote: I was looking for responses from people with ideas or who had tried something that actually worked for my situation. If there aren't any, then fine. But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance. - Keith Baker
I was looking for responses from people with ideas or who had tried something that actually worked for my situation. If there aren't any, then fine. But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance. - Keith Baker
ADVICE: I don't think getting 'snippy' with 'Midnight Railroader' or anyone else, is helpful;
YOU have the problem. YOU chose your equipment. YOU choose to NOT change your radius, (too much work?) - not he.
Now, go do the right thing.
I have a question concerning 6 axle diesels and curves under 22" radius. Most of my Atlas engines and a few of my Athearns handle 18" with no problems. However, a few others like my new Athearn N&W SD45 and my Southern SD40-2, don't. Has anybody modified a 6 axle diesel to work better on tight curves, i.e. modifying the trucks to allow more slop, allowing the truck to swing more, etc. I'm looking for ideas to try. And please, before the bandwagon starts rolling, I know 6 axle diesels look and run better on curves greater than 22-26 inches of radius, but my layout isn't going to be changed anytime soon, so that's what I've got. I can live with the overhang but not with the derailments! Thanks for any info.
YOU have the problem. YOU chose your equipment. YOU choose to NOT change your radius, - not he. YOU asked for options.
(YOU got them). Now, go do the right thing.
Keith,
You're getting (mostly ) good suggestions here.
While gauging and checking for interference, another thing to check is that the trucks are level. You can set the loco on a pane of glass and inspect the wheels to make sure that all 12 are in contact with the glass at the same time. It is possible for a truck to be slightly warped, or a burr or other manufacturing defect to cause a wheel or wheelset to ride higher or lower than the rest so that the truck will rock a bit. It sounds like the front wheels on the front truck are derailing, if I read you correctly. If the middle axle is lower than it should be, or the front axle higher, then the front wheels will tend to derail on curves.
Good luck, and let us know what you find.
Nelson
Ex-Southern 385 Being Hoisted
4x8 are fun too!!! RussellRail
I think GMTracing has a point here. The transition between level track and the grade that he's talking about is called the vertical curve. Especially when a sharp transition to the grade is combined with sharp horizontal curves, you can run into the intermittent derailment issues you seem to have.
It's as much about long wheelbase on both the chassis and the the three-axle trucks as anything. This will be much harder to cure than going around small radius horizontal curves. If you can get some more front to back rocking in the the connection at the king pin on each truck, that may help.That will help some with long wheelbase trucks. It's awful hard to change the wheelbase between truck king pins on a model, though.
Mike Lehman
Urbana, IL
I ran into a problem once apon a time ago with a couple of Athearn Locos I had. I tried checking the guage and it was fine, I still derailed. What I found was the side frames on the trucks were not allowing enough side play on the wheels. After moving the truck sideframes out a little the problem went away and my Sd40-2s and an SD60 could negotiate an 18"R curve with no problems. I did find a problem with the Genisis SD70MAC, the loco itself would make the 18s just fine but the couplers would not deflect enough and it would throw the first car behind it off the tracks. I didnt fix this issue but I figured if I shaved some of the plastic out of the sides of the coupler box (part outside the loco's body, if you own one you will know where I am talking). I sold the Genisis in favor of the same loco made by Kato.
I have never had an issue with my Atlas 6 axle locos on tight curves. I cant help you with those, I know that good trackwork will prevail over any modification you do to your locos. If you find that ALL of your 6 axle locos derail in the same exact spot then that is more likely a track issue over a loco issue.
Hope this helps you.
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Thanks again to all for the advice and information. It looks like I have some work to do as far as checking trackwork and my engines. If I can make it work, I'll definitely post the results. I just can't give up on seeing high nosed N&W SD45's running long nose forward pulling a coal train!
Thanks again, Keith Baker
Midnight Railroader wrote:Always interesting when someone says, "I need help, but I don't want to hear the real solution.
johncolley wrote:Keith, unfortunately this phenomenon is not limited to narrow radius curves. I have a Free-mo module which is a 45 degree curve of 72" radius with easements and suprelevation. Almost all locomotives go through it with no problems in either direction...except one make of SD40-2! Usually only in one direction, but occasionally in the other, enough to be annoying, especially at a meet or show! A lot of analysis with lights and mirrors finally showed the cause! The track had gotten just the tiniest bit of underguage tightness where the superelevation tapered off to "0". Repeated use of a jeweler's file along the inside surface of the outer rail in that area to gradually increase the guage, checking frequently, finally eliminated the problem. jc5729 John Colley, Port Townsend, WA
John, I had the same problem with one of the 1980's-era Atlas N-Scale RS3s; I would frequently come to griefs at one particular switch on a club layout; no matter which way this locomotive was pointing or where it was located in a consist one truck derailed. I regauged that sonofagun I don't know how many times; I used an NMRA gauge to check that particular switch I don't know how many times; I never could isolate any problem although I was told later that I may have had some axle slop on this particular truck--I never did check for that. Anyway, that particular switch had to be changed out and the problem went away.
Don't ever tell me that gremlins do not reside on model railroad layouts!
From the far, far reaches of the wild, wild west I am: rtpoteet
Being in N-Scale I can't address your particular locomotives but I do know that over the years this problem has been addressed frequently. One of the problems encountered with three axle trucks on sharp--read: 18" radius in HO-Scale; 9.8" radius in N-Scale--curves is that the swing of the truck causes it to contact the front steps on hood units causing a derailment of the leading axle on that particular unit. Three axle trucks SHOULD be operated on at least 37.5º curves--21" radius in HO-Scale; 11.5" radius in N-Scale. This renders not only better appearance but more reliable operation.
It should be noted that the Onion Specific designed their 4-8-8-4 steam locomotives to negotiated 20º curves; that's a 39.5" radius curve in HO-Scale; 21.5" radius in N-Scale.
I had the same problem with my SD45. I found that the front truck was hitting the coupler box and causing a bind. I just got the Dremel out a put a radius on the back of the box. That took care of the problem and increased the turning angle of the truck
Joe
Midnight Railroader wrote: kbaker329 wrote: I was looking for responses from people with ideas or who had tried something that actually worked for my situation. If there aren't any, then fine. But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance.Didn't work, though, did it?
kbaker329 wrote: I was looking for responses from people with ideas or who had tried something that actually worked for my situation. If there aren't any, then fine. But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance.
I was looking for responses from people with ideas or who had tried something that actually worked for my situation. If there aren't any, then fine. But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance.
Didn't work, though, did it?
There was a real suggestion before he complained. Patience, please. It's not like trying to call Berks county businesses that you need to use the services of and actually have to call say a thousand times or so before they call you back. The person, I've lost track, that insulted the initial question as not wanting an answer, well, he missed the question. The OP wanted OTHER solutions than the obvious. One was in fact given, lets discuss the merits of it. Another was given for gradient changes as well. So it did work, it just got a mud pie tossed into the thread for fun.
Hi Keith,
I also have fairly sharp curves and I can run my F45 around them. I use Peco flex track so a few things here.
1. Instead of going from a straight to a curve, use even a short piece of flex track and make a transition lead into the curve. 6 Axle trucks are notorious in picking edges and the graduation from straight to curve will help.
2. Double check the gauge of the Athearn wheelsets. It is possible for an axle to be slightly out and they are easy to adjust, using an NMRA gauge. You can check if it is the individual axle by swapping the wheelsets around, with the truck undone.
3. If you are using flex track, check that the track around the curve is actually in gauge also. Use model spikes to pin the track back to the right gauge.
4. Older Athearn diesels may have an insufficient clearance in the frame for the truck to swing. It may only require deburring an edge of the cast frame or a very slight widening... you do not need much.
5. Check the metal tab on the truck that the frame sits on. Is it also in need of deburring? Use a larger drill size and twist it with your hand to remove any roughness.
Feel free to contact off list should you need to clarify any of these points xdford47@yahoo.com.au
Regards
Trevor www.xdford.digitalzones.com FYI
GMTRacing wrote: Keith, If the grades end abruptly it is most likely the lead truck is wheelying off the track. if the top of the grade also has a curve the problem will be worse. If possible run up each grade slowly and watch what the truck does as it goes over the top. If the front axel lofts (leaves the track) the only real solution will be to make a more gradual transition at the top of the grade. I had just the same troubles with my first attempt at a layout and it was one of the major reasons I finally scrapped it. If you can fix the grades it will help. Good luck. J.R.
If the grades end abruptly it is most likely the lead truck is wheelying off the track. if the top of the grade also has a curve the problem will be worse. If possible run up each grade slowly and watch what the truck does as it goes over the top. If the front axel lofts (leaves the track) the only real solution will be to make a more gradual transition at the top of the grade. I had just the same troubles with my first attempt at a layout and it was one of the major reasons I finally scrapped it. If you can fix the grades it will help. Good luck. J.R.
Thanks for the advice, I'll take a look at my grades. And thanks to all who gave advice. I do appreciate it.
Keith
kbaker329 wrote: But if there are, I didn't want them buried underneath simplistic responses like, say, yours, for instance. Keith Baker
Keith Baker
Good for you Keith.
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
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Kenfolk wrote: Off topic but funny--... a bill in the Senate and call it the HO scale curvatures and easements crisis and ask for a billion dollars so all of us can have 100'x100' full basements to build in.But then what do we n-scalers get?
Off topic but funny--
... a bill in the Senate and call it the HO scale curvatures and easements crisis and ask for a billion dollars so all of us can have 100'x100' full basements to build in.
But then what do we n-scalers get?
51'X51' basement because you're not exactly half HO scale. The House will add the ammendment. Then the O, Z, and narrow guage guys get riders on other bills to be aded in as well. Before ya know it, our 3 sentence suggestion is a full 450 pages. Yippie!
Ok, now back on subject. Modify the loco to run on tight curves. I'm still struggling with my track plan to keep all the curves more than 24" but we can't always get what we want.(unless we call it a crisis and have access to ....oops. No more political humor, sorry.
Johnnny_reb wrote: ndbprr wrote:If it doesn;t bother you try removing the middle axle on each truck. I had an Atearn U30C years ago that just would not track at all and in furstration I didt hat even though Ihad 30" and larger curves. It cured the problem. belive it or not very few if any people will notice it. I'm just thinking out loud here. If removing the middle axle on each truck as you say cured the tracking problem then maybe removing the flanges from the middle set of wheels would do the same thing. Kinda like on a steamer like say a 2-10-0 when the middle sets of drivers have no flanges and are allowed to ride side to side over the rails but not to fall off.
ndbprr wrote:If it doesn;t bother you try removing the middle axle on each truck. I had an Atearn U30C years ago that just would not track at all and in furstration I didt hat even though Ihad 30" and larger curves. It cured the problem. belive it or not very few if any people will notice it.
I'm just thinking out loud here. If removing the middle axle on each truck as you say cured the tracking problem then maybe removing the flanges from the middle set of wheels would do the same thing. Kinda like on a steamer like say a 2-10-0 when the middle sets of drivers have no flanges and are allowed to ride side to side over the rails but not to fall off.
kbaker329 wrote: And please, before the bandwagon starts rolling, I know 6 axle diesels look and run better on curves greater than 22-26 inches of radius, but my layout isn't going to be changed anytime soon, so that's what I've got.
And please, before the bandwagon starts rolling, I know 6 axle diesels look and run better on curves greater than 22-26 inches of radius, but my layout isn't going to be changed anytime soon, so that's what I've got.
Always interesting when someone says, "I need help, but I don't want to hear the real solution."
You need wider curves or 4-axle motive power.
Johnnny_reb Once a word is spoken it can not be unspoken!
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Well, one thing you could try before you get into removing axles and/or making blind flanges would be to go out and get yourself a 9 inch section of 18 inch radius snap track. Turn the engine upside down and support it in a cradle or other softener protected stand so that you don't damage any of the roof detail.
Try to put the curved track into engagement with the wheel flanges and see if the trucks will swivel enough to allow this. If they don't, see what might be preventing it. Sometimes you'll find that something on the truck frame will hit the coupler box and inhibit the motion. Sometimes a detail on the truck, brake cylinder air line perhaps, will hit the side of the body or frame.
Another thing to look at is what is actually happening when the engine is moving. Is it derailing when operated by itself, or with another engine or car attached. I had a derailment problem that I couldn't figure out, until I saw that the kadee coupler "airhose" from one engine was riding up on the plow of the other engine. As the engine went into the curve, the "airhose" rode up higher and higher until it locked itself into position, derailing one engine or the other.
I think someone also mentioned this, but make sure you check the wheel gauge. I have one of the new Athearn SD40-2s that wanted to derail. I found the wheel gauge too tight on a wheel set or two on that engine.