Rainbows in the Lehigh Valley Gorge

[TMo]

Good question.... I'm hoping their tracking doesn't degrade, and maybe they will even run better.

Never had much of a problem with the tracks flat with either locos or rolling stock - maybe some issues with keeping trailers on 89' TOFC occasionally. Believe me, if I encounter more problems after the superelevation is finished, that M420 is going up for sale and I'll return the curves to flat and level. A beautiful locomotive model is not worth extreme pain and hardship.

[TMo]

Update on the superelevation project. One out of the 4 track sections has been glued in and working flawlessly (at least with the M420 at all speeds, orientations and directions). However, that is the only one of the 4 pieces that is a continuous superelevation. After I glued down piece number 1 adjacent, the loco derailed in a couple of places, especially in the transition between a 2mm superelevation and back to flat (unsuperelevated track) where the loco comes out of the curve. I determined I needed a more gradual transition and that meant lifting that piece out again. HOWEVER, when I'd glued it down I didn't have my standard silicone sealant handy and I resorted to Marine Goop. BAD IDEA! That stuff dries hard and is super-adherent. The track did not survive and I had to redo some of the roadbed and install a brand new piece of Code 83 flex track. The roadbed fix also created humps and bumps that needed to be sanded smooth and shims added in several areas, but I think I now (after 4 days of trial and ERROR) have that piece ready to be glued back down to the roadbed (not with Marine Goop!) since the loco now runs all the way through the transition and through the aforementioned good section of superelevated track. For those wondering, these are roughly 26"-radius curves - the tightest on my layout, but they are a far cry from the minimum radius that Rapido quotes - 18".

If after gluing this piece down and verifying continued good running of the loco, I'll then deal with the other half of the curve (the other two sections of flex track) which also contains a reverse curve before going into the tunnel, which means that I'll be doing 3 more transitions between flat and 2 mm superelevated track. Do I still love the deal I got on this locomotive? Sure, but there's a lot more buyer's remorse than when it first emerged from the box. Maybe I'm learning something beneficial if I ever build a new layout.

[jim currie]

I live by the rule measure twice cut once any track re aliment I do is not set solid till I'm happy with the set, but it looks like you set track directly on the foam I use a cork tape used for making radiator gaskets on large one's like trucks or equipment  a fifty foot roll is about 35 or 40 dollars or t use to be. Also for track glue I just use house paint sets up solid.
Jim

[TMo]

This is why I like this site. All kinds of great tips!

[TMo]

Superelevation update for today. I'm pleased to report that 3 of the 4 sections of superelevated track have been tested for use with the Rapido M420.... and all passed with (eventually) flying colors - some tweaking was necessary, especially around track joints. I just finished running the 3 continuous sections at sampled speed ranges from low to max speed, forward and reverse in both loco orientations without derailing. I'm feeling pretty good about the future, and the light at the end of the tunnel is within sight (if I squint).

I did send Rapido an email message late yesterday - text of it is below. Not sure it will engender much good will from Rapido, and I think there's only a small chance that my message results in a change in design or some future words in a manual, but I had to try:

"Recently procured one of your products. This unit (an M420W #33014 "HO Scale MLW M420 (MR-20b) Canadian National #3545 (Stripes Scheme)) had been derailing at a very annoying frequency in a set of winding 26"-radius curves with a continuous grade of about 2% since I acquired it in December. I would have liked to have bigger curves and less grade on my layout, but I'm short on available space and have made due since 2006.

I have about 16 other diesel locomotives (4 and 6 axle) from a variety of manufacturers (Athearn, Atlas, Stewart, Bachmann, etc.). Your model was my first Rapido. No derailment issues for any of my other locomotives. Aside from the derailment issue, I LOVE your M420 (I think the details, weight and power are fantastic) and I want to keep it, and I want to run it. Therefore, I did a deep dive into these curves and the differences between this Rapido model and my other locomotives. Here are my findings (in no particular order):

1) The primary source of derailment for the M420 is wheel lift on one of the four axles as the loco negotiates these graded turns. Flange on the outside wheel (this can be either the front or rear wheelset of either truck) climbs over the rail or the inside wheel falls off the rail while turning and climbing or turning and descending the grade.
2) The main difference between the Rapido trucks and anything else I have is the relative stiffness of the trucks in the roll and pitch axes. They are less nimble (more rigid) and allow less potential movement in roll and pitch axes than anything else I have. I do not see any method to adjust this stiffness from my end - it's built into your design.

The aforementioned section of track has a lot of scenery installed and the track had been ballasted. Nevertheless, since I am bound and determined to run this model on my layout, I explored superelevating the outside rail in this set of turns by 2mm. Having the weight of the locomotive push the inside flanges into the rail (in my case) was the secret sauce to success. However, transitioning back to the flat tracks beyond the curves was also troublesome as the front and rear trucks end up rolling over constantly changing track profiles. What I found was a gradual superelevation change (at least 2 locomotive lengths) can work. Believe me, this exploration has been rough and I've spent the better part of this month on a 12-ft section of track and my new locomotive.

So, why did I write this? 1) I love your manual, but your tough-and-cheek comment about "no problem negotiating 18-in curves", and avoiding modeling theme park operations is a bit too flippant. Based on a couple of forum entries, it appears that I am not the only one to encounter similar problems negotiating much wider curves that 18-inch radii. 2) Since it worked for me, suggesting superelevating track may be something that is suggested in the manual if there are derailment issues in curves, or maybe you could look into this issue and potential fixes to layouts that will allow operation without derailment. 3) I'd suggest that retooling future models or offering a retro kit to allow for more pitch and roll of the trucks should be undertaken by Rapido.

Again, I care enough about keeping your loco on my layout so important that I trashed a good bit of scenery and spent a lot of frustrating days figuring all of this stuff out. I'm floored by the level of detail and the great operation (at least on straight track). I hope you can keep producing unique models like this one and I applaud your attitude toward our hobby."

[TMo]

I didn't get a reply back from Rapido, but in the meantime, I joined the user's group where Charlie found the "M420 Derail" messages - canmodeltrains and started looking at all of the messages regarding the M420. There were two of those that perked my ears up - one in which someone had their retailer send his model back to Rapido and they made changes to his worm gear clips that both hold the worm gear in place and rest the trucks in the chassis. The clips were altered to allow more side to side movement of the trucks...

In the second, one of the respondents was describing how to do this yourself. Sent him a message and he sent me a guide from Rapido on how to alter the clips about an hour after I sent him a message. I will try making that change tomorrow night. Too bad I didn't find this a month ago. Se la vie, Eh?

[Charlie B]

I didn't get a reply back from Rapido, but in the meantime, I joined the user's group where Charlie found the "M420 Derail" messages - canmodeltrains and started looking at all of the messages regarding the M420.  There were two of those that perked my ears up - one in which someone had their retailer send his model back to Rapido and they made changes to his worm gear clips that both hold the worm gear in place and rest the trucks in the chassis.  The clips were altered to allow more side to side movement of the trucks...

In the second, one of the respondents was describing how to do this yourself.  Sent him a message and he sent me a guide from Rapido on how to alter the clips about an hour after I sent him a message.  I will try making that change tomorrow night.  Too bad I didn't find this a month ago.  Se la vie, Eh?

Todd, 
     I was trying to figure how you could get some more freeplay in those trucks but that is so simple it never crossed my mind. Those clips are common on many locomotives and it happens I have a couple that this could help with their performance. Now I have to remember which ones they are.  Thanks for the update.  I hope Rapido is making this modification to all that are in production.
Charlie