Author Topic: Fixing Atlas Code 55 Points Hinges  (Read 607 times)

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C855B

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Fixing Atlas Code 55 Points Hinges
« on: November 11, 2016, 10:38:20 AM »
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I had a couple of older #10s fall apart while building a double crossover this past week. Annoying, for sure, and I was gritting my teeth at the money down the drain. We've discussed here "how to fix". The best practices seemed to be replacing the points rails all the way to the frog or replacing the hinges with rail joiners, also making new points since the factory points wouldn't work with the joiners. These techniques, to me, were very time consuming, not to mention my reservations about the long-term mechanical reliability of soldered joints with the (also newly-fabricated) throwbar.

There was another solution, using RTV silicone to keep the hinge retaining washer in place. I tried that, but the washer was still loose on the pin and as a result the affected point was floppy.

Fortunately, in both cases I was able to find the tiny retaining washer. And therein was the solution. On examination under my 20X magnifier, it turns out the core problem is the retaining washer. It has four internal teeth that, under spring pressure, grip the hinge pin. When pushed onto the pin at the factory, the washer slightly deforms into a cone shape, and it's this deformation that appears to have fatigued, loosening the washer. Solution? Re-flatten the washer (I used smooth-jaw duck-bill pliers), and press back onto the pin with a bit of tubing. The flattening restored the grip, and, frankly, I was surprised at how solid the renewed assembly was.

It was a very fast process - it took seconds... when I wasn't chasing the tiny washer around the workbench. :scared:  How long will this last? I don't know. The turnouts I was having the problem with were "pre-shortage", probably 10-12 years old. Similar performance after the fix is acceptable to me.

What happens when you can't find the washer? I posed this to Atlas, who responded they did not carry spare parts for turnouts. So I am contemplating reverse-engineering the washer and etching my own fret of replacements. If this problem becomes frequent as they age - no reports yet on the newest production, I take it - there needs to be spares for what amounts to a very simple fix.
...mike

http://www.gibboncozadandwestern.com

We don't make mistakes, we have happy accidents. We just don't tell anybody. -Bob Ross

davefoxx

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Re: Fixing Atlas Code 55 Points Hinges
« Reply #1 on: November 11, 2016, 10:49:16 AM »
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Yeah, @Chris333 was kind enough to mention that "dab o' silicone" trick after the vast majority of the turnouts on my layout were installed.  :P  That said, I haven't had this failure yet, but the previous discussions here on TRW have convinced me (if I ever do experience a failure) to pull the points and the closure rails and install solid switchpoints (no hinges).  Since I own a PointForm tool from Fasttracks, I already have the tools in my arsenal to make this repair, if ever necessary.

I'm happy that you've discovered a much easier fix for those who aren't so inclined to build or repair their own turnouts with handbuilt switchpoints.

DFF

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Member: ACL/SAL Historical Society
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C855B

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Re: Fixing Atlas Code 55 Points Hinges
« Reply #2 on: November 11, 2016, 11:10:50 AM »
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Well, if there's an advantage to the silicone trick, it's you're far less likely to lose the washer. From what I noticed in these repairs it's not going to prevent the fatigue issue, which will still loosen the points.

I think I have a turnout somewhere in the stash I ruined trying to fix a bad rail-to-rail contact. I ought to yank the washers off it and check the thickness. Maybe an increase of .001" could improve longevity... or  :(  require so much pressure as to break something in the press fit.

A fair amount of time wrenching on 1:1 cars provided an education on swaged assemblies like this. Press-on spring washers as fasteners are common, especially with interior bits. The key is knowing how (and when!) to fix, and when to toss it. With the switches, I found it interesting to see similar things done at the near-micro level.
...mike

http://www.gibboncozadandwestern.com

We don't make mistakes, we have happy accidents. We just don't tell anybody. -Bob Ross

towl1996

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Re: Fixing Atlas Code 55 Points Hinges
« Reply #3 on: November 11, 2016, 11:13:21 AM »
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What happens when you can't find the washer? I posed this to Atlas, who responded they did not carry spare parts for turnouts.

Congratulations, and thanks for finding the cause of the problem and providing a solution. What was Atlas's response, or did you ask, to the trouble possibly being with the assembly process? Are they aware of the situation?
Never argue with idiots; they'll drag you down to their level, then beat you with experience.

C855B

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Re: Fixing Atlas Code 55 Points Hinges
« Reply #4 on: November 11, 2016, 11:32:49 AM »
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I didn't ask. However, when checking the newest production run, on the ones I looked at it appeared that the washer was slightly eclipsed by the tie strip, as opposed to being out in the open in an access hole. This very small change in relative positioning could easily have been done to wedge the washer in place and at least keep it from dropping out. This may or may not be good - if the fatigue issue resurfaces and the hinge loosens, this will make it more difficult to re-form the washer, which has to be removed completely to adequately flatten. Banging on it still in the switch will result in much sadness (and was how I broke one).
...mike

http://www.gibboncozadandwestern.com

We don't make mistakes, we have happy accidents. We just don't tell anybody. -Bob Ross