I am nearly done the additions to the Red Baron railroad. I was testing out running and my SD70 kept having the front (or back) most wheels jump the track on a #6 USA Trains switch.

The configuration of the problem area is 10 foot diameter curves going into a right #6 USA Trains switch. See photo. After debugging it for a while, I realized the wheel on the outside was jumping up and thus the guard rail was not effective. This only happens when the engine goes in reverse, and only seems to be happening on this particular switch. All my other switches the engine runs fine on. This is the only one that is fed by a curve, and a graded curve at that.

Here is what I tried

• Leveling out the #6 switch. It was on a grade.
• Leveling out the curves feeding into the switch.
• Moving the track to my patio which is level and testing it there. Never seemed to jump here.
• Different #6 switch.
• Adding some straight track between the 10 foot curves and #6 switch. This seemed to work if i added almost a foot of track there.
• Floppy wheel spacing (back to back) on both front and back is at 1.570.

Nicolas,

The Aristo #6 turnout plastic bedding is such that the distance between rails is too tight (below NMRA spec.) To mitigate this the stock rails where the points make contact can be ground straight up and down. Also, the guard rails are too distant from the stock rails (again out of spec.) This can be correct.

See vignette (article) “Aristo-Craft #6 Turnout Issues” hosted for me by Greg E. on his Web site.

-Ted

Nicolas, before you do anything, (other than the reading Ted suggests), please set your back to back on the SD70… luckily this is pretty easy to do, although you will have to open the gearboxes.

Pay SPECIAL attention to how the bushings on the axles align in the gearboxes, I have all this on my site, and if you have trouble CONTACT ME before running… reassembly wrong will tear up gears, etc.

DO NOT ignore this advice, the number of people who have gotten this wrong is huge and you chew up gears almost immediately. Also, my site is correct, don’t go elsewhere, 50% of the sites are in error.

If you don’t have the back to back right (and these locos are NEVER shipped gauged correctly) you will never get good running, because the guard rails will be ineffective…

Also, you should follow my tip about lubing the plate that guides the floppy axle, that’s also a source of derailments.

Greg

Are you sure it’s not the wheel spacing on the loco?

Editing because it was just suggested(not quick enough…hehe) also note that this is a USA switch not an Aristo

Rooster is correct about the #6 turnout. My apology. But you can get ideas about what to look for on the turnout. The USAT #6 is likely more forgiving than the Aristo one, and I can operate two SD70s with an SD40-2 spliced between them pulling a long train over modified Aristo #6 turnouts without derailments.

-Ted

Greg Elmassian said:

Nicolas, before you do anything, (other than the reading Ted suggests), please set your back to back on the SD70… luckily this is pretty easy to do, although you will have to open the gearboxes.

Pay SPECIAL attention to how the bushings on the axles align in the gearboxes, I have all this on my site, and if you have trouble CONTACT ME before running… reassembly wrong will tear up gears, etc.

DO NOT ignore this advice, the number of people who have gotten this wrong is huge and you chew up gears almost immediately. Also, my site is correct, don’t go elsewhere, 50% of the sites are in error.

If you don’t have the back to back right (and these locos are NEVER shipped gauged correctly) you will never get good running, because the guard rails will be ineffective…

Also, you should follow my tip about lubing the plate that guides the floppy axle, that’s also a source of derailments.

Greg

Emailed you directly. I am having issues finding specifics on what you mean by “set your back to back”. I have looked through all the info on your site but unable to find this information. I am aware of the bushings on the gearboxes having taken them apart to remove the pick ups as I am battery powered. More info on the “back to back” procedure will be helpful.

I emailed you several links on the motor block and the SD70 specifically from my site Nicolas… also you will want to go to the standards page, I recommend the “track and wheel standards” page, that references all the applicable standards:

https://elmassian.com/index.php?option=com_content&view=article&id=85&Itemid=110

But to cut to the chase, please set the back to back at 1.575" (get a vernier caliper, even a cheapie Harbor Freight)…

Greg

Greg Elmassian said:

I emailed you several links on the motor block and the SD70 specifically from my site Nicolas… also you will want to go to the standards page, I recommend the “track and wheel standards” page, that references all the applicable standards:

https://elmassian.com/index.php?option=com_content&view=article&id=85&Itemid=110

But to cut to the chase, please set the back to back at 1.575" (get a vernier caliper, even a cheapie Harbor Freight)…

Greg

If by back to back you are referring to the back of the left and right wheels on the floppy part (the part that jumps up). Its at 1.570. Photos show both front and back. Front doesn’t derail, but back does.

Finally looked at the video.

Is that an aristo switch, looks like a Piko but cannot really tell.

Yes the wheel walked out of the frog, indeed you can see that the wheel “split the frog”… so if your back to back is right, then either the flangeway is too wide on the stock rail on the diverging route or gauge is tight there.

(That is given that you have eliminated excessive friction in the sliding mechanism for the “floppy axle”)

In the picture below, you can see the metal plate and the curved path of the guide pin for the floppy axle. This one not only needs lubrication, it has the poorer surface that I have encountered, some of mine are really nice smooth plated metal, and some look like this, very rough… any friction here and the loco will often derail on curves, especially switches.

Greg

Going to try lubricating that part. Also will check to see if its a rough surface or not.

Its a USA Trains #6 switch.

Here it is before lubrication.

That extra axle is jumping the first chance it gets. I kept stopping the video and it appears that it’s climbing the frog as soon as it can? Almost like it’s stuck in a curved position and would jump anything for any reason?

I have oiled my USA trains slide mounts for those axles as regular maintenance. When they are brand new they work fine. After some time, they get stiff and have little areas that bind. Just about any light oil or grease works.

Nicolas,

Your floppy axle wheel back to back spacing is good.

I am going to focus on the turnout.
I operate several locos with reduced flange depth of about 0.080 inch and learned to “tune” all my turnouts so they will operate without derailments.
I learned that the turnout spacing of the guard rail to stock rail should be close to NMRA spec (about 0.106 inch). The guard rails should have a gradual transition ramp which I think is OK for the USAT #6 turnout. Important, also, I discovered that raising the guard rail up above its adjacent stock rail by about 0.030 inch tended to stop wheels from climbing over it. I noticed some prototype turnouts have their guard rails higher than the stock rails, too - so real 1 to 1 railroads have a reason to do this - maybe for high speed assurance.

-Ted

Thanks Ted. I am still going to try greasing the sliding piece of the floppy wheels. Everywhere else on my railroad the train seems to work fine. It is only on this part that I am experiencing issues. Thinking about it more, it tends to jump the guard rail in the direction of the curve it was riding on. Adding a straight section long enough seems to fix the issue, which leads me to believe that it might just be sometimes getting stuck going around the curve.

That said, do you have much experience with #6 switches? I am not even sure how I would go about removing the guard rail, let alone making it taller. I can check the distance between it and the track.

Also note, I tried at least 2 different #6 switches with the same result. I could potentially try a third, but I felt that after it failed on 2, that it was something else and not likely the switch. Of course if the design of all of them is flawed, then that could be the problem.

Nicolas,

I have much experience with “tweeking” Aristo Wide Radius and #6 switches (both brass and stainless steel) but not the USAT brand. However, principles are the same. To get ideas for tweaking the USAT #6 switch, look at what I did to to Aristo’s #6.

To raise the guard rail, remove it, relocate as needed for proper spacing, and put washers under it when reinstalling it.

-Ted

Greased the slide mounts. Put the track back the way it was and all seems good. Ran the engine over it several times at high speed and it seemed fine. I noticed before greasing that it tended to bounce more, and it did pop up once today going through 2 #6 switches setup to move between parallel tracks. Looks like I could have left the road bed as it was.

I suppose having the switch at level grade is probably for the best anyways, though the grade on the curve is now steeper. If I ever need to, I can always prop it all back up to where it was.

Here’s what the trucks look like when greased.

I have also attached a photo showing a measurement of the gap between the guard rail and the main rail.

Nicolas,

Good to hear you got things working by greasing the floppy slide. One thing I learn over the years of experience is optimizing all items (track work, locos, rolling stock) all contribute to the most reliable operation.

-Ted

Ted Doskaris said:

Nicolas,

I have much experience with “tweeking” Aristo Wide Radius and #6 switches (both brass and stainless steel) but not the USAT brand. However, principles are the same. To get ideas for tweaking the USAT #6 switch, look at what I did to to Aristo’s #6.

To raise the guard rail, remove it, relocate as needed for proper spacing, and put washers under it when reinstalling it.

-Ted

I looked at the turnout. The guardrail is screwed down but there is also plastic tabs in the ties. I would have to cut those plastic clips off to raise it up leaving only the screws to keep it in place. I suppose that might be sufficient. However, since greasing the slide mount on the engine solved the issue, I will leave the turnouts a lone.

Nicolas,

That’s OK; You solved the problem.

-Ted