Thus, with proper back to back spacing set, if the wheel profile results in the wheel sitting on the fillet, then it's my contention that the standard wasn't tight enough.
No argument from me. When we started out evaluating the wheels to write the standards, few (if any) were even using fillets on their wheels. Since the NMRA's wheel standards don't specifically mandate a fillet of any variety, we made the recommendation of .020" - .030". I wish we could mandate it, but we can only recommend it. (Note that their "RP25" wheel profile is also just a "recommendation." It's just been around long enough for people to take them up on it. To be honest, given that few wheel manufacturers were even considering fillets, the thought that someone would jump to the opposite extreme didn't even enter our thought process. We thought it would be pulling hens' teeth just to get them to include them in the first place. Of course, since there's no evidence one way or the other that Aristo even looked at the standards, you can't use this one instance to judge the standards one way or the other. If they followed them--including the recommendations on the fillet--we wouldn't be having this discussion.
As I said earlier, I think we'd be much further ahead IF the NMRA only focused on a standard to use in the future. I see nothing to gain by grandfathering old designs. What we're trying to do is get a working standard that the manufacturers voluntarily accept.
In a Utopian world, that's the way to do business. And we could very easily have done that. Problem is, there's not a large scale manufacturer making trains who would even look at them if that were the case. They've got the market share, so if we want the standards to have even the slightest effect on the hobby, they've got to be made relevant to the manufacturers who are already making trains. You've got to get their attention if you want them to follow you. The standards can always be refined down the road. And feedback on forums like this is instrumental to making those refinements. Relying on upstarts to lead the way in that regard simply doesn't work. You've got to get the big forces behind you.
Fortunately, while the manufacturers don't necessarily listen to the NMRA, they do listen to their customers. Aristo-Craft is famous (notorious?) for changing wheel profiles in response to consumers--as was seen most recently with the PCC and with the wheels on the 2-8-0. They've re-profiled the wheel to have a smaller fillet. Again, I don't know if that new wheel has made it into production yet, but at one point I did see drawings of the refinements.
Kevin admits that the loco runs on the "fillet" and says everything is OK.
That's a fair assessment. The locomotive ran very well wherever I ran it, and continues to provide reliable service for its owner. I readily acknowledge others' experiences with this locomotive, and I use their experiences as a guide to help me look for particular areas of concern. Since the locomotive came out, I've heard both sides... people like Paul Burch who had to re-work the locomotive to get it to track reliably, and others who say they don't have any running issues at all. (Can't explain why you haven't heard those positive tales, Greg, but they're out there.) I can only write the review based on my firsthand account with the locomotive on hand. Others' experiences are hearsay. If I didn't witness it to know all the circumstances surrounding it, I can't support any conclusions I might want to draw, no matter how much I trust the source. With the review, I'm saying "this is what I found," not "this is a collection of unsupported anecdotal evidence I found on the 'net." The dangers of libel are real, and I've got to be able to soundly defend my statements to those who disagree with my conclusions. I can't do that telling a 2nd-hand story. It's not that I don't trust the source, but it's my reputation, and I won't risk it on someone else's story good or bad.
The reality is that a magazine product review is one tool in the consumer's playbook. That's where forums like this come in. This is where individuals can share their personal experiences in aggregate, and a consumer can read the good and the bad, and read about the circumstances surrounding different peoples' different experiences and how they frame their conclusions. That's precisely why this is the "Product Review" forum on MLS. Greg can post his experiences, I can post mine, Joe Schmoe can post his, and Sally Jane can read all of them and decide if the loco is right for her.
Also a question for Kevin... are there any suspicions that a sample heading for a reviewer may be "tweaked" beforehand?
No, in fact the evidence is overwhelmingly to the contrary. I've received product samples that are just outright defective. When I get locos from Aristo-Craft, Bachmann, or Accucraft, they're still boxed and wrapped as they left the factory.
Apparently it was a gift from Aristo to Kevin, after the review, since Kevin still has it.
It's the manufacturer's prerogative as to whether they want an item returned or not. It's used merchandise that's typically been abused to some extent that they can't sell as "new" anymore if they do want it back, it's a tax write-off if they don't. That's just how business is done. There's a lot of criticism of that model, but it's very common in many circles, not just model trains. All the more reason for us as reviewers to be able to remain vigilant about being able to defend any conclusions we might draw.
Dwight, I asked that because the wheels in both of your pictures don't appear to have a rounded fillet. The angle between the tread and the flange appears sharp, not rounded. It also looks as if a slight increase in the length would permit the wheel to drop into the gap between the frog and the rail. There seems to be ample room for the flange in the gap on the right side, with or without a fillet (if it isn't rounded is join still called a fillet?). If it won't work, it won't. Just an uninformed suggestion. Chuck
Chuck, all aristo locos with the "prime mover" gearboxes have tapered tips on the axles, so regauging the wheels is impossible without special parts.
But the problem is not only incorrect back to back (varies between locos), but overly thick flanges (at the base), so that it is mathematically impossible to get back to back AND gauge correct at the same time. (This is really at the beginning of this thread).
Now, this year some of the diesels came with PERFECT wheels... ALL dimensions were right on, back to back, gauge, flange depth, flange thickness.... these are on the Dash-9's shipped this year.
Unfortunately, there has been a radical change since then, and we have new problems on the SD-45... but I don't want to divert from the main point.
I had issue with the GR review, the wheel gauge was not specified in the review.
Virtually everyone on the planet had running and derailment issues with this loco. I bought one... it was clear what the problem was immediately, before putting calipers on.
Kevin was and is convinced that there is an alternate explanation, that the gauge is not wrong, the fillet is part of the tread, and since the loco is running on the fillet, then it's ok..
The consolidation setup is different from the previous steamers, the wheel contours (huge fillet, overly thick flange, poor flange contour, etc.) are pretty much the same, but older Aristo had proper gauge, but narrow back to back.
So with switches with overly wide flangeways (most toy-derived switches)... this was accommodated... they ran ok on track and pretty sloppy on switches. This is kind of the LGB legacy which we have inherited with USAT and Aristo cars and locos...
Now the machining of the fit between the axle and the wheel was changed slightly in the Consolidation, and the back to back was set properly... but with the existing wheel contour problems, now the gauge is wrong.
Until the wheel contour changes (like has been done on the diesels)... it will be IMPOSSIBLE to have both back to back and gauge correct at the same time.