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Weird Problem with Athearn Trainmaster Diesel

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Weird Problem with Athearn Trainmaster Diesel
Posted by SeeYou190 on Thursday, August 24, 2017 9:31 AM

peahrens
- Diesel loco wheelsets just a tad out of gauge. The flanges should be centered in the NMRA gauge slots, not just sorta fitting into the slots.

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That is from another thread about derailment causes. I decided to post a new thread with my question so not to go off topic.

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I have an OLD Athearn Trainmaster that ran great for years.

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One day I checked it with my handy NMRA gauge, and found the center axle in each truck was a tad bit tight, so I properly reguaged them. Then the locomotive started derailing on Kato #6 turnouts. I put them back a little tight, and it worked OK again.

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Now it is causing intermittent shorts on the point rails of Shinohara (NON-DCC) #6 turnouts.

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Any ideas?

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-Kevin

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Posted by tstage on Thursday, August 24, 2017 9:58 AM

Hmmmmm...One of those "If it ain't broke, don't fix it" moments that comes back to bite you. Sad

Tom

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Posted by wjstix on Thursday, August 24, 2017 10:07 AM

The problem may be relating to the width of the rail rather than the gauge. Kato Unitrack in HO uses very narrow code 83 rail, getting close to scale width. Other maker's code 83 track is much wider. On a curve or turnout, there's less rail for the wheels to sit on when using Kato track. Widening the wheelsets' gauge a tad to compensate might make the wheels derail going through the wider non-Kato track.

You may have to fiddle with all the wheelsets a bit to find a Goldilocks "just right porridge" solution. It could involve some wheelsets being slightly wider or narrower than other wheelsets on the same truck.

Stix
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Posted by dknelson on Thursday, August 24, 2017 10:25 AM

Hard to judge without seeing the locomotive and where it derails but I can relate that some years back when I put a loco's wheels into correct gauge, using a NWSL wheel puller meant for just that purpose, it turned out I had not actually put it into correct guage all around the wheel.  That is, I had inadvertently created a tilt for the wheel versus axle.  So yeah, it was in gauge on one side, out on another.  Am I making myself clear?  What I should have done was test the gauge using the NMRA standards at multiple points around the wheel.

Dave Nelson

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Posted by BigDaddy on Thursday, August 24, 2017 10:49 AM

Wouldn't the center truck being tight be similar to a steam loco driver without a flange, an advantage for a tight radius?

Henry

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Posted by tankertoad70 on Thursday, August 24, 2017 11:16 AM

We have a similar issue with our older Shinohara turnouts down at the club after converting to DCC.  What we found was some of the older wheels are a bit "fatter" than newer offerings and those wheels contact both rails on the turnout when passing over them causing a short circuit.  The easiest solution for us was to replace the bar on the closure rails with a pcc tie that is cut in the middle so electricity will not pass between the two rails any more.Cowboy

Don in 'Orygun' City
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Posted by SeeYou190 on Thursday, August 24, 2017 12:40 PM

tstage
Hmmmmm...One of those "If it ain't broke, don't fix it" moments that comes back to bite you.

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You know... this is very true. I had this locomotive for at least ten years, and it was used when I bought it. It wasn't until I got a new shell for it and detailed it up that I checked wheel gauge. I should have left it alone.

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-Kevin

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Posted by 7j43k on Thursday, August 24, 2017 1:10 PM

wjstix

Kato Unitrack in HO uses very narrow code 83 rail, getting close to scale width. Other maker's code 83 track is much wider.

 

 

Width of some Code 83 rail heads:

 

Kato Unitrack:  .031"

Walthers/Shinohara:  .039"

Micro Engineering:  .032"

 

 

Ed

 

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Posted by rrinker on Thursday, August 24, 2017 1:35 PM

 Henry has it right, with the center axle a little narrow it allows movement so the lcoo can negotiate a tighter curve than it otherwise could. But you may have too much of a good thing - when you put it back you may have made it tighter than it was. In this case, it now allows the back of one of the wheels to brush the open point of the Shinohara turnout - and the open point rail of those is the same polarity as the closed point rail/stock rail. Thus a short. What you need is somewhere in the middle. At proper gauge, the truck can't negotiate the required radius curves, too tight and the wheel backs brush the point rail. 

                          --Randy

 


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Posted by xdford on Thursday, August 24, 2017 6:42 PM

tankertoad70

We have a similar issue with our older Shinohara turnouts down at the club after converting to DCC.  What we found was some of the older wheels are a bit "fatter" than newer offerings and those wheels contact both rails on the turnout when passing over them causing a short circuit.  The easiest solution for us was to replace the bar on the closure rails with a pcc tie that is cut in the middle so electricity will not pass between the two rails any more.Cowboy

 

I have a similar intermittent problem with older Athearn diesels over Peco on curves and a short crossing shorting... I have tried nail varnish and paint and have a reasonable success with a thin layer of ACC on the rail top.

Has anyone here tried turning down the sintered wheels to narrow the rail contact and avoid these locos bridging the insulated frog? Am I likely to create another problem doing  this?

TIA

Trevor

 

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Posted by rrinker on Thursday, August 24, 2017 8:17 PM

 I would not try to turn sintered iron wheels, you will likely return them to powdered metal. NWSL used to have replacement wheels even for the ooolder outside frame Athearn trucks like that Trainmaster (not even close to the same ones as the more modern Athearns with the inside metal frames.). However you may have different issues - if they are solid nickel silver, you're good to turn away, but if they are plated, you will quickly turn the plating right off before you've reduced the wheel enough. 

                                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

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Posted by xdford on Friday, August 25, 2017 6:41 AM

Thanks Randy,

I have some sets of the older NWSL wheels... I bought them on a budget at the time. For the most part I have got by on a "partial installation" for a long time but I have replaced some of the Peco turnouts. The problem seems to be very intermittent when traversing a set track curved turnout but a little more often with my Mantua locos usually with a longer load...

Thanks for the input,

Cheers from Australia

Trevor

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Posted by SeeYou190 on Friday, August 25, 2017 7:01 AM

rrinker
With the center axle a little narrow it allows movement so the lcoo can negotiate a tighter curve than it otherwise could. But you may have too much of a good thing

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The strange additional fact is that I have a pair of older Athearm PA/PB diesels (both powered), factory stock, not even painted. These all have perfectly gauged wheels, negotiate 21" radius Kato curves, and have no problems with any turnouts.

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I hope I can find a set of those NWSL wheels for the older axles/trucks. That could be my next try.

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-Kevin

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Posted by Lone Wolf and Santa Fe on Friday, August 25, 2017 10:44 AM

The center wheels on six axel diesels should have a certain amount of slop in them so they can move side to side to go around curves. In fact all of the wheels should have some slop. If there is no slop then they form a straight line instead.

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Posted by wjstix on Friday, August 25, 2017 4:47 PM

7j43k
 
wjstix

Kato Unitrack in HO uses very narrow code 83 rail, getting close to scale width. Other maker's code 83 track is much wider.

 

 

 

 

Width of some Code 83 rail heads:

 

Kato Unitrack:  .031"

Walthers/Shinohara:  .039"

Micro Engineering:  .032"

 

 

Ed

 

Be interesting to know what Atlas code 83 is, it seems to be considerably wider than Walthers / Shinohara.

Stix
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Posted by SeeYou190 on Saturday, August 26, 2017 8:28 AM

wjstix
Be interesting to know what Atlas code 83 is, it seems to be considerably wider than Walthers / Shinohara.

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This piece of Atlas sectional code 83 has a width of 0.040"

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-Kevin

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Living the dream.

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