KATO Wye turnout..Problem

[Alemino]

Dear All

 

To expand my layout i decided to buy a Kato "wye" turnout

 

 

Sadly i noticed that when trains pass it, i have way too much  derailments.

 

Firstly i was thinking that is a problem with my "european" made train.(maybe different wheels/sizes?)

 

But even with Kato/tomix/Tomytec trains i have the same, and i drive them slowly over there.

 

Is something that happens only to me? i got a monday turnout? 

or did somebody else experience similar problems?

 

Thank you for Feedback's

 

Alessio

 

P.S.edited for errors

Edited August 27, 2015 by Alemino

[inobu]

Typically we create the problem when we construct out layout. It is called "off camber". A lot of race tracks incorporate this into their race course. As the vehicle enters into the turn the road goes in one direction but the inertia pushed the vehicle in the other.  

 

The odds of this occurring doubles with the "Wye" because of the two turnouts and the switch wiring lifting the base of the "Wye". 

 

If the track leans to one side by 1 mm that is 160mm as far as the N scale train is concerned.

 

Trying taping both sides of the "wye" down and you should see the problem go away.

 

Inobu

[kvp]

There is a similar derailment problem with the Tomix R280 Y. Actually both are single turnouts, just with double diverging tracks. (this is not a 3 way turnout) The problem and the solution is very similar to the other Kato small turnouts, which it shares its radius and some of its parts. The main problem is that the trains tend to pick the blades because there is not much of a pocket for them. The turnout itself is R481, so it's slightly better for the trains than a the Tomix R280. If you fix the blades, then all it needs is a slow speed over the blades to be reliable. (actually it's as reliable as the other two Kato R481 turnouts)

 

ps: i think there is a topic about fixing the derailment problems of the Kato short turnouts somewhere on the forum...

[inobu]

The wheels pick the blades because the camber of the track in either direction causes the wheel flange to shift into the blade.

This is an example of how the camber will effect the wheel set.

 

 

Like the example. 1mm = to 160mm or 6.3 inches. just imagine if one side of the track were 160mm higher than the other. The wheelset will no longer ride on the cone and the flange will ride along the rail. 

 

I dont have problems with my either of my turnouts #4 or #6 and I run kato's Gunderson Maxi IV on #4 .

 

Inobu

[kvp]

The wheelset will no longer ride on the cone and the flange will ride along the rail.

This is the main cause of wheelsqueek on curves and a really common problem. However a proper turnout should handle this and even if all flanges ride on the inside of the rails (common for large axle distance two axle cars) the turnouts should work. One of the solutions employed by Tomix on some of its turnouts is to have guard rails just before the blades, so the flanges are pulled away from the blades, but this is not prototypical. Also, some of the older rolling stock (like most Piko cars) have completly flat (non conical) metal wheels that are always flange steered, sometimes even with spring loaded single axle trucks.

 

The positive side of having reliable turnouts is that they will work regardless of tilt, even if the whole layout is not completly level, which is a very common case.

 

ps: someone here, who had trouble with small (#4) Kato turnouts could surely help

[inobu]

kvp,

 

I think you are going off on a "wye". The point is to take into consideration that the camber of the track has its effect which causes the wheelset to shift which increases the probability of derailments. It is easier to insure the wye is level than to

file and slot the blade into the rail. 

 

I dont think you understood my point about the #4 turnouts. I have no problems with #4 as they do not cause issues even with Maxi IV which have long wheel bases

 

 

 

Inobu

[railsquid]

For the record, I've never had any problems with the Kato Y-points. The #4 points have proved problematic when there's a curve immediately before the point, but otherwise not. This is with a wide range of stock from different countries and production eras.

Edited August 27, 2015 by railsquid

[kvp]

 

 have no problems with #4 as they do not cause issues even with Maxi IV which have long wheel bases

Try it with long wheelbase 2 axle cars, not with short wheelbase bogies or anything which has flat wheels like most older plastic and aluminium wheels. You just happen to use good rolling stock and probably avoid curves right next to the blade tips.

 

It is easier to insure the wye is level than to file and slot the blade into the rail.

Except when you have rolling stock that is designed with constant flange contact in mind, in which case you'll just decrease the possibility but not eliminate it. Then one day the whole layout gets a bit tilted because the floor boards, someone leaning on it or something else and then the turnout is completly level to the board but otherwise badly tilted and the problem misteriously returns. Imho the best way to avoid a problem is to fix the turnout in a way that makes it work even when you are pushing the flanges to the rails by hand.

[Welshbloke]

I've been having the same problem with the #4 turnouts, mostly with B Train shorties which seem to try to follow both routes at once and end up stuck on the point rails.

 

One thing which wasn't mentioned in the thread about fixing these - has anyone tried bending the very tip of the point rail so it makes firmer contact with the stock rail, thereby nudging the wheel flange away rather than allowing it to get between the two?

[Mudkip Orange]

One thing which wasn't mentioned in the thread about fixing these - has anyone tried bending the very tip of the point rail so it makes firmer contact with the stock rail, thereby nudging the wheel flange away rather than allowing it to get between the two?

 

It's generally considered that you have to file down the standard Kato #4 to get reliable operation, as the from-the-factory point is too thick. To my eye the wye points are of similar thickness. I usually operate at low speed and have no trouble.

[katoftw]

I only had one train that had issues with the #4s.  The old style Kato D51 with loose style front leading wheel, (the newer D51 wheel isn't as loose).  Only that wheel would jump.  The stuggle was the frog area.

 

A Kato 500 Shinkansen could go through them (S-bend parallel siding) at full speed.  MircoAce Kihas not a problem.  And Kato/Tomix BO-BO-BO engines + kokis no issues either.

Edited August 27, 2015 by katoftw

[inobu]

Unitrack is more so a temporary tracking system. This type of system is susceptible to movement. This movement opens the door for the turnout to pitch in an off camber direction increasing the possibility of derailment. The problem is further exasperated by the weight of the proceeding train and cars. As the train moves forward across the turnout and further down the track its weight can further disrupt the track. This can cause a rolling motion that eventually drive the car to derailment. Understand that this movement is minimal to our eyes (1mm) but in the N Scale world 1mm = 160mm or 6.25 inches prototypical. That is a large shift. 

 

Answer

If you level the turnout and secure so it does not pitch or roll off camber to can minimize the shifting of the wheelset flange into the pick. Reducing the derailment potential.

Try leveling the turnout and taping the roadbed on both side

 

 

How does one navigate an off camber track? slow down and creep through it.

 

More than one posters has stated that they remedy the problem by slowing down. 

 

Inobu

 

In order to solve the problem you first must understand it.

[Kb4iuj]

Have you noticed how some Japanese use Arnold trackage. Which is rather crude looking but probably works great for trains being ran a prototype speeds. Super slow.

 

Something to think about is... Would a real railroad be able to handle such tight curves, while pulling a long train. Hence, with N scale derailments do occur with tight hairpin like turns.

 

Wonder if Kato or Micro-Ace if they'll ever sell a passenger car that will denote the G-Forces in a turn and where the weight distribution is at.. In real Long American trains in hilly areas, depending on where the loads are at be it steel coil cars at the end of the train. Well, if the engine is has crested a hill and the weight is at the back and the momentum is such. Just the torque of the weight of pushing and pulling can pull trains off the track, when the coil cars are headed down the hill and the locomotive starts going up another grade or down another hill. I believe it's called slugging). It'll like cold cock ya. Hence, is probably why most Japanese freight trains are quite small in length.

 

Anybody here using the "Fast Track Jigs"? You can make your own switches and super wide curves if you've got the space.

Edited August 28, 2015 by Kb4iuj

[Alemino]

dear All

 

Thank you for the valuable inputs, specially Inobu that explain why it happens the problem.

 

In my layout i did change few things, like adding a straight before the "ons-side" wye and making sure that the turnout is  perfectly flat.

Same i will get used to reduce even more speed. Results on the weekends :)

 

thank you, and have a nice weekend

Alessio

[inobu]

You must make sure that it does not move.

 

Inobu

[Welshbloke]

The really strange part is that I get more derailments if the train is running slowly. Give it some welly and it clatters through with no problem, slow down to a more sensible-looking speed and it tries to climb onto the point rails!

 

I have noticed some warped Unitrack, particularly 124mm straight sections but the #4 turnouts don't look quite flat either. They're sitting on a perfectly smooth table so the problem is definitely with the track.

[cteno4]

The metal plate bottoms of the points at time can be a little warped or not seated flatly into the top piece. Over the years we have had a few issues here and there with the #4 points on the club layouts, but mostly worked well. I tuned the blades a but but never did the full notch into the rail tuning. Fiddling with a #4 would get it working usually, but usually never 100% sure what you did to get it working right and since we use to tear the layout up each time there was no assurance things would be perfect next time.

 

Most folks reporting on them on the kato unitrak yahoo group say they workmwellmformthm with some fiddling and avoiding curves right before the blades if possible.

 

Cheers

 

Jeff

[kvp]

One of the tricks to get it to work at all speeds is to file small notches into the stock rails, so the tips of the blades can fit into them. Another problem is that the blades are not curved enough, so there is a track gauge difference through them, which can squeeze wider wheelsets up. The thrid problem is the angle of the frog and the position of the guard rails, which makes it suspectible for some thinner wheels to take the wrong turn. Longer axle distance cars and bogies and lightter cars are more suspectible to riding up on the blades, while heavier ones tend to cut them. What can be fixed is the blade cutting, but the other problems could remain, since the blade tips are not made from proper filed down solid rails, but instead use sheet metal, which can get out of shape easier.

 

ps: One think to look for in case of wheels riding up is out of gauge wheels, since the narrower gauge part around the middle of the blades can cause this.

[cteno4]

Forgot to mention a good wheel gauge is a must to check wheels if you have any issues like this as many times its just a wheel set out of gauge and can be dealt with quickly and not tear up something that aint broke (ie the point!).

 

some threads on tuning unitrak points with good links to the tuning

 

http://www.jnsforum.com/community/topic/9918-sharpening-kato-turnout-blades/

 

http://www.jnsforum.com/community/topic/1182-kato-point-derail-advice/

 

jeff

[railsquid]

Forgot to mention a good wheel gauge is a must to check wheels if you have any issues like this as many times its just a wheel set out of gauge and can be dealt with quickly and not tear up something that aint broke (ie the point!).

 

Good point, I have two (British) locos which should be identical, one always jumps all the points and I came to the conclusion after careful observation that it must be the wheel gauge.

 

Any idea where I can get a wheel gauge in Japan?

[kvp]

Any idea where I can get a wheel gauge in Japan?

 

The Kato unijoiner remover has one on its bottom. The whole tool itself is for loading gauge. The two small slots are for the rails, so make sure the wheel flanges are between the slots.

(otherwise a tomytec wheelset with the two metal halfs fully pushed into the middle plastic tube also works)

[cteno4]

A nice steel nmra gauge is really nice.

 

Jeff

[katoftw]

In another post I talked about #4 points.  I recently was using canter curves straight into opposing direction #4 points and failed to have an issue with them.  Tomix 800-1000 shinkasen and Kato D51-498 loco.  Speeds where on the end of the red section on a Kato throttle.  So going stupidly fast.

 

As early stated in this thread my old D51 (older style with motor seen in footplate area) used to derail the front leading wheel.  To reference the gauge width suggestion.  I think this is a good bet/avenue to chase.

 

The old D51 had the 2 wheels with the axle and a bracket that was about 8.5mm wide.  So the wheels ad about 0.5mm of lateral play.  The newer D51 version, the bracket is wider and the lateral play is minimal.  So the version which keeps its wheel at 9mm width failed to have issues, while the older version had wondering wheels and derailed on the #4 points.

[Welshbloke]

Having had a good look at my #4 points I suspect the shape of the tip of the point rails isn't helping. They're absolutely square with almost no curve between the leading edge and the running surface. Most manufacturers (and the real thing!) have a slight slope, so the point rail gradually rises to meet a wheel running from the toe end. It also means that the point rail will tend to catch the flange lower down, where there's more of a gap between it and the rail (assuming decent wheelsets with coned treads and tapered flanges). That way by the time the wheel leaves the stock rail for the point rail it'll have been gently steered onto it, rather than smacking into it head-on and pulling it away from the stock rail. I may try filing a slight slope into the top of the point rail, it'll do no harm and might solve the problem.

 

Compared to the #6 points (which cause no trouble with anything I've run through them), the older design has the point rails and tiebar as one solid piece, so there's less potential for wobbling about. Meanwhile the #4s have the point rails and tiebar as three separate pieces, with inevitable play (they wouldn't be able to move reliably if the tolerances were tighter). To follow the "swiss cheese" model of accident causes, the wobble in the point rails could well be the final hole lining up to cause trouble.

Edited September 3, 2015 by Welshbloke

[brill27mcb]

Actually, my understanding from posts on other forums by Charlie Vlk (a U.S. model rail consultant who once worked at Kato USA) is that the so-called #4 turnout is the earlier and higher quality offering from Kato. The #6 came later, and the construction of the points/frog and the internal circuitry were "cost engineered" to a lower price point, to be attractive to U.S. modelers. If you compare a #4 and a #6 side-by-side, top and bottom, you will see the differences, such as the 2 moving points on the #6 being a single stamping.

 

I use #4's almost exclusively and have little problem with them, but I generally take a modeler's file and slightly feather the end of the moving points on the flange-side, as well as the top and flange-side of the end of the rails on all track sections. You can feel a slight lip on the railheads at the ends of the sections, from the way the rail pieces are "chopped" to length during the manufacturing process. I also don't glue down ballast on the Unitrack, which I believe can increase the likelihood of contact and point-throwing issues. It's also possible that the rail tops on two joined track sections are not level -- it is possible to have some vertical "slop" in the Unijoiner. Feel across the joints on the top of the rails with your finger, and experiment with gently trying to raise one section compared to the other one, or pushing the Unijoiner all the way down. By watching carefully, I have observed that the train wheels sometimes bump around and get unstable at the rail joint just ahead of the moving points, and their motion can remain jostled as they hit the point tips just a few cm away, and then they derail. You want to smooth the whole path of the wheels.

 

Rich K.