RP25 only suggests a wheel profile. It does not specify the flange depth, but only mentions a derived nominal number. For the flange spec you need to look at S-4.2 or S-4.3 for Hi-rail number. But that said, I recall measuring some Atlas C55 flex track a couple years ago and thought it passed muster even for the Hi-rail flange depth of .035". I don't have any track on hand to measure it again to verify my recollection. Maybe it was only correct for the S-4.2 standard. Anyone? In any case, a simple fix has been used by others to resolve this problem. We are only talking about a couple thousandths and a quick swipe with fine sandpaper bent over the edge of your NMRA track gauge is said to remove enough plastic from the spike heads to eliminate the flange buzz.
This would help a lot of people use locos on c55. Does anyone have a photo. I often have a hard time visualizing without a diagram or photo, and I am probably not the only one.
Micro Engineering Code 55 will not have any issues like Atlas Code 55 Micro Engineering Code 40 flex track will behave like Atlas Code 55. Even some new Atlas lo profile wheels hit the spikes on Code 40 flex, not to mention several recent release locomotives. Only the new low profile Kato wheels on the freight and the locomotives move without hitting spikes on the Code 40 flex. Now I did not try any of the IM stuff yet, but I am pretty sure it will be a bit of hit and miss. So on stuff I am working on, I followed that awesome San Diego (Balboa) layout rules - Hand laid code 40 rail. Made a test section using Fast Tracks ties and rail fixtures, and I have yet to have anything hit the tops of the ties. Even the over sized Micro Trains wheels.
I took and reduced the flanges on my locos that were hitting on the Atlas code 55 setting the flange depth to .017, about the same as the MT low profile wheels and had worries that the locos would not stay on the track but all worked OK. The atlas code 55 flex track that I measured, had a top of rail to top of spike head of .023, I do not know if Atlas has changed that dimension on any later produce track as the track I used was back in 2004-2005. And I am waiting delivery of my IM AC-12.
I dug through my track in in the garage and found a couple pieces of Atlas Code 55 flex track. Exact vintage is not known, but I can say for sure it is at least two years old. I started measuring clearance from the spike heads to the top of the rail and found quite a bit of variability over the length of a section of track with no discernable pattern. Most of the spikes had .036" to .039" clearance, but once in a while I would find some down to as little as .031". If I got a deviant number, I would measure each spike at least three times to confirm. I would say that less than one in ten spikes show the smaller clearance. I am not sure how to account for this variability. I have some bad track? Something in the molding process? My methodology? This track was never installed and not modified in any way. Both pieces of track showed this variability. This would explain the MTL high profile wheels hitting spike heads sometimes with their .036" flanges. By contrast MTL low profile wheels have .017" flanges and really old MTL high profile (ribbed back) wheels have flanges at .038". NMRA Standard S-4.2 specifies that flanges not be larger than .022" above the wheel tread. The Hi-Rail standard given in S-4.3 (for sharp curves and other adverse track conditions) is .035" maximum. The variability of spike heights found with the Atlas C55 flex track seems to indicate that it may not in fact be fully compliant with the NMRA Hi-Rail standard. But then the MTL high profile wheels are not compliant at all. I expect I will have my AC-12s within a couple weeks and I will measure the flanges when I get them.
Cab Forward #4292 Finally received word the two I ordered are on the way... this is a loco I grew up with living in Orland, Calif. (1942-1951). I don't model SP, but this one SP loco I had to have on my roster for nostalgic reasons. BTW... I notice #4292 seems to be particularly popular?!?:tb-err: Already it is 'Sold Out' with a couple of dealers. What, if any, significance does #4292 represent?
Maybe the number is easiest to change to #4294, the one at the museum in Sacramento? Or its is one of two numbers with tender lettering?
Well one of my two IMR AC-12s arrived this afternoon. But I was a bit taken back at the SIZE of the package!! And then I thought "Well maybe there are actually two loco's in this package." NOT!! So here are some photos to show what I am talking about... you too may be 'surprised' at why such a large package is needed.... Here's what arrived on my doorstep... What?? You thought you'd get my address THAT EASY??? Heheheee!! Okay... so there are two loco's in this box, right?? Guess again.... (and please don't mention the foot locker - it was just used as a photo platform...) And here is what actually inside this one box... (continued...)
WELL!! For a custom box THIS big, this had better worth the cost... sort of... And as soon as you lift the lid.... Oh Yeah! The Operators Manual... It gets better.... underneath the OM (Operators Manual) is a full size foam layer.... and underneath the full size foam layer is THIS.... Yeah.... there's actually a real (model) live IMR AC-12, slightly obscured by a 'sleeve' type package (ala Bachmann???) inside... Anyway, after all that and you finally get the loco extricated from its confinement, here's what is inside... Okay, so I'm slightly shaky with the photo... but it's really from all the 'excitement' of unearthing this wonderful steam loco BEAST.... (Yeah! There's more... but only a little!)
And after all the above it's about time to check this Baby out up close and personal, right?? Just before she hits the rails for testing, etc., etc., etc., of course.... Hokey Dokey... I've had my 'Fun' with this little gem... but truth be told IMR has a real winner on hand... :thumbs_up: Hope you enjoy yours as much I will enjoy mine!! OH YEAH - Almost forgot... included with this loco??? How about spare traction tires and couplers??? How is THAT for modeler considerations by a Manufacturer???
Good thing the NMRA specs are only "recommendations" and not "law". I dont believe we need any governing body "Telling" any of us how to enjoy a "Hobby"...JMHO .
But, if there were clear and concise guidelines everybody could seem to follow, we wouldn't be having these discussions. The problem is the variability of the manufacturing process. If they make the wheel tolerance right up to the limit, and the spike tolerance right up to the limit, when you get a wheel slightly oversize, and/or a spike slightly oversize, you have interference. There needs to be a little room for error in the spec.
Since you asked... how about 40 cars; 2 percent grade; no wheel slip. Consist: 20 Atlas 40 ft. stock cars; 18 Delaware Valley Airslide hoppers; 2 Deluxe Innovations woodchip cars. This critter can pull!!! :thumbs_up::tb-cool::thumbs_up:
That packaging looks a lot like Athearn's steamers. (From what I can see in the pictures... I still haven't got mine... )
Mine is at the LHS, soon to arrive on my doorstep. I've moved twice since I pre-ordered this thing. Does the loco include blowdown spreaders? I haven't noticed them in the pics.
Since I'm not sure what to look for... do these photos from Nscale Supply help?? http://www.nscalesupply.com/IMR/IMR-Locomotive-AC-12.html
Looking at the pics, it appears they don't have them. The Kato GS-4 has them, they are the small rectangular pieces that hang from piping near the trailing truck (sorry, no pics for example). Oh well, easy detail addition.