Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

locomotive shorts on walthers switch

4215 views
22 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2011
  • 9 posts
locomotive shorts on walthers switch
Posted by Tedd on Saturday, June 25, 2011 9:15 PM

I have two identical Atthern Genesis locomotives.  They are six axle diesels.  I installed a Tsunami sound decoder in one and the other has the original board with a decoder plugged into the board. 

Both units ran fine before the Tsunami conversion.  Now the Tsunami locomotive shorts when crossing Walthers DCC friendly switches.  It doesn't do it all the time, if you run it slow enough it works fine.  All the other locomotives run fine and have no issues with these switches. 

I have checked to ensure the frogs are insulated and there appears to be nothing wrong with them.  The locomotive doesn't appear to have any issues. 

Has anyone experienced a one of kind situation like this?  If so, what fixed the problem?  The frogs are not powered.

 

thanks

 

 

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Sunday, June 26, 2011 8:38 AM

Welcome to the forums Welcome

Take one of the loco's causing the problem and push it through the turnout.  Each time try something different like using your hand to torque the front truck to the left then the right.

Also run the loco through the turnout and watch what's happening. Sometimes you can see where it's happening.  More times than not the problem happens at the frog when a flange hits both sides.

One way to check this is to disconnect one rail of the frog from it's track so nothing feeds it.  The short should disappear.

The cause can be the turnout or the locomotive. It's possible that while handling the loco during the decoder change tha something got out of line, or even the wheel gauge may be off.

 

Springfield PA

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Sunday, June 26, 2011 8:45 AM

Here's the point where the short will usually occur.

Springfield PA

  • Member since
    January 2008
  • From: Central Georgia
  • 921 posts
Posted by Johnnny_reb on Sunday, June 26, 2011 9:18 PM

Tedd

I have two identical Atthern Genesis locomotives.  They are six axle diesels.  I installed a Tsunami sound decoder in one and the other has the original board with a decoder plugged into the board. 

If both Locos are the same as you have stated, then the Tsunami install should be the suspect. Other then that look at the driver wheel gauge. Also check the turnout in question. It may be a combination of things. A Loco wheel set out of gauge, trash in the frog, the frog out of gauge, the Loco frame dropping down at the frog shorting across the track.

Johnnny_reb Once a word is spoken it can not be unspoken!

My Train Page   My Photobucket Page   My YouTube Channel

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Sunday, June 26, 2011 9:31 PM

We seem to forget that the frog on a Walther's DCC friendly turnouts is a dead frog. Therefore no short can occur at the frog on this type of turnouts. I suspect poor electrical contact between the rails and the loco, unless of course these are not the DCC friendly type..

Jack W.

  • Member since
    January 2008
  • From: Central Georgia
  • 921 posts
Posted by Johnnny_reb on Sunday, June 26, 2011 10:07 PM

I believe the spot pointed to is just before the frog. And may be getting power from both of the mainline rails causing a short of types at the point where the two rails are closest, being bridged by the drive wheel for just a moment before entering the frog.

Johnnny_reb Once a word is spoken it can not be unspoken!

My Train Page   My Photobucket Page   My YouTube Channel

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Monday, June 27, 2011 10:37 AM

Johnnny_reb

I believe the spot pointed to is just before the frog. And may be getting power from both of the mainline rails causing a short of types at the point where the two rails are closest, being bridged by the drive wheel for just a moment before entering the frog.

You do have a valid point, however on a Walthers DCC friendly turnouts this type of short is impossible to happen. Unless the wheels gauge is way off, I mean so off that the wheel set will not be able to ride the rails.

I will try to post a picture of a Walthers DCC friendly turnouts later on.

Jack W.

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Monday, June 27, 2011 11:03 AM

This is a #4 Walthers DCC friendly turnouts. The part marked is the dead frog.

The next picture show a place where a short is likely to occur, the spacing between both rails is too wide for wheels in gauge to bridge both rails.

Jack W.

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Monday, June 27, 2011 2:28 PM

It's actually just to the left of the small drawn circle where the rails are closest together.  I've had to fix a few in that area. Sometimes just a screwdriver blade tweak and sometimes a filing with my dremel.

Also it doesn't have to be the same wheel shorting. You can have the front wheel hit one rail and the second wheel hit the other

Springfield PA

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Monday, June 27, 2011 2:37 PM

Hamltnblue,

To the left of the small circle there is a dead spot no current is flowing.

You may be right or I might be wrong but to me it is impossible to short these switches with wheels in gage. To short by bridging both rails the wheel set has to be so off gage that it will be unable to ride the rails.

This picture shows the insulating gap that is isolating the frog next to the left of the small circle in the picture above..

 .

To me the OP problem is within the loco, wheels may be lifting from the rail for a very brief period of time as the problem shows only at speed.

Jack W.

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Monday, June 27, 2011 3:53 PM

So they added an additional gap before the Y.  Looking at that pic I can't see where the short could occur at the usual spot. The OP should verify that he has gaps at the same spots.  I've had a couple peco's with electrofrogs in insulfrog boxes. 

Here's a link to turnout wiring.

http://www.wiringfordcc.com/switches.htm

Springfield PA

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Monday, June 27, 2011 4:33 PM

These Walthers DCC friendly turnouts are on the marketplace for 2 years or more, they are 100% foolproof with DCC, no special wiring attention is required with them.

The frog is completely insulated with gaps before the frog and after the frog. I have 4 of them 3 are installed and in use, no problem so far.

The following picture shows where the gaps are.

 

 

Jack W.

  • Member since
    February 2011
  • 9 posts
Posted by Tedd on Tuesday, June 28, 2011 5:29 PM

Ok, I took the screw driver and spread the rails at the location and it fixed one switch completely, the other it appears that I am going to have to bond the point rails as the locomotive stalls when one truck is completely on them.  Thanks for the assist.

  • Member since
    January 2011
  • 137 posts
Posted by engineAL on Tuesday, June 28, 2011 7:51 PM

jalajoie

Hamltnblue,

To the left of the small circle there is a dead spot no current is flowing.

You may be right or I might be wrong but to me it is impossible to short these switches with wheels in gage. To short by bridging both rails the wheel set has to be so off gage that it will be unable to ride the rails.

This picture shows the insulating gap that is isolating the frog next to the left of the small circle in the picture above..

 http://i220.photobucket.com/albums/dd297/jalajoie/Code83C.gif.

To me the OP problem is within the loco, wheels may be lifting from the rail for a very brief period of time as the problem shows only at speed.

My theory is, since this is a six-axle diesel, one set of wheels could be before the gap on the powered points, and one after the gap, therefore electrifying the insulated part of the frog. When the wheel passes through the problem spot, the same thing will happen as if the turnout had a powered frog. If I am wrong, correct me, but it seems right.

Modeling the Maine Central in N scale.

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Tuesday, June 28, 2011 8:42 PM

WWtrain, at first glance your theory does make sense and I think you are on to something.

What puzzle me is the frog will be energized with the proper polarity therefore no short can occur.

Your theory is worth investigating further and I will make some test.

Jack W.

  • Member since
    April 2002
  • 921 posts
Posted by dante on Wednesday, June 29, 2011 10:33 PM

WWtrain

 

 jalajoie:

 

Hamltnblue,

To the left of the small circle there is a dead spot no current is flowing.

You may be right or I might be wrong but to me it is impossible to short these switches with wheels in gage. To short by bridging both rails the wheel set has to be so off gage that it will be unable to ride the rails.

This picture shows the insulating gap that is isolating the frog next to the left of the small circle in the picture above..

 http://i220.photobucket.com/albums/dd297/jalajoie/Code83C.gif.

To me the OP problem is within the loco, wheels may be lifting from the rail for a very brief period of time as the problem shows only at speed.

 

 

My theory is, since this is a six-axle diesel, one set of wheels could be before the gap on the powered points, and one after the gap, therefore electrifying the insulated part of the frog. When the wheel passes through the problem spot, the same thing will happen as if the turnout had a powered frog. If I am wrong, correct me, but it seems right.

I ran a 6-axle diesel through my Walthers #4 DCC-friendly with no problem/no short.

Dante

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Thursday, June 30, 2011 8:33 AM

I know I've had some Proto E-units that had wheelsets that were significantly out of gauge - too narrow. I think manufacturers do this to allow the engines to squeeze around 18"R curves. When I widened out the wheelsets, the problem went away.

Stix
  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Thursday, June 30, 2011 2:42 PM

I would take an offending loco and place it on the turnout.  Use your hand and torque a truck side to side while pushing it through to see  if a short can be created.  Many loco's have wheels that will slide side to side so that they can work on tighter curves. It's possible for one wheel to slide to the right while another is to the left.

Springfield PA

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Sunday, July 3, 2011 9:06 AM

Just a thought.   Idea

Have you checked the gap between the opposing rails just to the left of the circle to see if the gap is wide enough?
I have had to take fine a saw and widen the gap to keep some of my turnouts from shorting. On a three axle truck the center axle will shift, and the wide tread on some locos will short the two together.

Good luck.

Lee

Edit: Sorry about duplicating other's advice.

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Sunday, July 3, 2011 11:41 AM

That's what we were talking about earlier in the thread. This particular turnout has an insulator next to the frog thta makes the gap wider than say an atlas.

Springfield PA

  • Member since
    December 2007
  • From: Gateway City
  • 1,593 posts
Posted by yankee flyer on Sunday, July 3, 2011 11:54 AM

There is another problem I have had with the Atlas turnouts which may not apply to these turnouts.
By checking with a steel ruler I found that the frog sat high on some and caused the drivers to lift off the track, as some one else mentioned. I put a track nail beside the frog to draw it down.It worked in my case.

Good luck.

Lee

 

  • Member since
    February 2011
  • 9 posts
Posted by Tedd on Monday, July 4, 2011 7:53 PM

I would like to thank everyone for your thoughts on this. 

I checked the track gauge, rail gaps  and such, when I got to the locomotive I found the culprit.

The six axle locomotives center axles move a little better than a sixteenth of an inch.  The identical locomotive that I have does not do this.  So back to the manufacturer for repair. 

I did spread the rails in front of the frog with a small screw driver which did allow the locomotive to go through the switch a couple of times without an issue. 

Being that none of my other locos have any issues with this trackwork I rest assured that the problem was the center axle on that locomotive trucks.

Thanks.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, July 5, 2011 11:40 AM

 That's probably not a defect in the loco - in order for it to make typical sharp model railroad curves there needs to be some play in that center axle, otherwise it wouldn't run on anything less than 30" radius curves.

 In making a turnout 'dcc friendly' is removes the chance for the short to occur in the places indicated - which is useful for both DC and DCC operation.

                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!