Radius

[Doneldon]

Doneldon, I just personally checked the operators manuals for the following BLI locomotives:
NYC Dreyfuss Hudson, 2-10-0, 4-6-2 (heavy), 4-8-4 J & Northern
And not one manual lists a minimum radius of 18", they all state 22" minimum radius and in my experience that is pretty accurate.
I also have MTH ES44ACs, SD70ACEs, a GG-1, a Northern, a bigboy and a friend has the Erie Triplex and the paperwork included states 22" suggested minimum radius. I recently attempted to run the NS heritage units on 18" radius to no avail.
Although it is very possible you were able to run the locomotives you listed sucessfully on 18" radius, I think it is a poor idea to make a blanket statement like you made just because of the variability on the models. It is better to list off just what will run on 18" radius safely 100% even with the variability instead of hoping you get lucly and get one that will make 18" radius without derailing or excessive binding.

ACY-

I don't routinely run the locos I listed as able to run on 18" radius curves; I don't even own most of them. I took my information
from the BLI and MTH catalog pages about three minutes before I posted the information. I have to admit that I am more than a little
disappointed that people on this board would think I'm talking  through my hat on this.
                                                                                                                                 -- D

[jbrock27]

Great pics Sid!

-before someone goes out and purchases a large wheelbase locomotive and is disapointed when it derails on.18" radius even though someone here said it would be fine.

ACY, please let me point out that the converse can be true; that just bc you did not have success with a particular locomotive, does not mean it is a given that someone else might not either.

Let me ask you a question about your SD45s; are you still employing the long metal spring clip that traverses both trucks?

[ACY]

jbrock27, I have not modified them at all asise from installing a sound decoder in one unit since my layout has a minimum radius of 24" and my club has around 40" minimum radius on the mainlines.

Don, from the sounds of it there must be a misprint or error in the documentation. Not a week ago I tested my Broadway Limited Dreyfuss Hudson on 18" radius with it derailing incessantly and then ran it flawlessly on 22" radius. Even if the locomotive cold make 18" radius, there is no way the passenger cars would make anything less than 22" radius, infact my cars require 24" due to the underbody detail parts.

[jbrock27]

ACY, I am not sure whether your answer means the Athearn SD45s still have the metal spring clip I am asking about or never had them, can you clarify please? 

With regard to your B'man SD45s, I can't help you there, but know that one of my good friends can run B'man SD45s on 18"R curves w/no problems, so I don't know why you have problems running them.  I gotta believe he and I are not the only 2 out there who can run 6 axle locos on 18"R curves.

[Irbricksceo]

ACY, Are your curves laid correctly? Not that I don't believe you but I too used to have an SD45 from Bachmann and it handled 18 fine. Likewise my Chinese SY (and the one I had before) My Russian 2-10-0 (and the TWO i used to have) my two 2-8-0's (and the One i used to have) all ran flawlessly on 18.

[Jerrys HO]

I have 3 SD45's, 3 SD40-2's, 1 SD70 ACE all which would handle my 18r, but within reason.
Some rolling stock would not make it behind the SD's, too much swing. Had to alternate 50 footers and 40 footers in some areas.
Now my min radius is 26.

[ACY]

ACY, Are your curves laid correctly? Not that I don't believe you but I too used to have an SD45 from Bachmann and it handled 18 fine. Likewise my Chinese SY (and the one I had before) My Russian 2-10-0 (and the TWO i used to have) my two 2-8-0's (and the One i used to have) all ran flawlessly on 18.

My layout did not have 18" radius, however I had several Bachmann train sets that came with 18" radius of EZ track, so I used those to set up a temporary layout consisting solely of 18" radius. A friend of mine owns a hobby shop with a large iinventory of model railroad items. At one point he had 10 Baxhmann consolidations in stock, I test ran all 10 briefly and found 7 of them could negotiate 18" radius and 3 could not but ran perfect on 22" radius. I had a top guy from Lionel who happened to be present that day (he is in charge of all factory repairs and service for Lionel), he lived in the same city as me at that time before Lionel moved the facility to North Carolina. Anyways, he looked at all 10 locomotives and could not find anything wrong with any of them and said the reason some likely could not negotiate tighter radius curves while others could is because each part is given a certain tolerance it has to be within but even a small difference of a sixteenth of an inch can impact its ability to run on 18" radius. Although it was a small sample size, I found 70% could make 18" radius while 30% could not, so they made 10,000 units hypothetically, 3,000 of those would be unable to run on 18" radius.

[ACY]

ACY, I am not sure whether your answer means the Athearn SD45s still have the metal spring clip I am asking about or never had them, can you clarify please? 

With regard to your B'man SD45s, I can't help you there, but know that one of my good friends can run B'man SD45s on 18"R curves w/no problems, so I don't know why you have problems running them.  I gotta believe he and I are not the only 2 out there who can run 6 axle locos on 18"R curves.

I will have to dig them out sometime to check, I don't recall off the top of my head sorry.
As far as the issues go, I would venture to guess that somewhere between 1-3 out of every 10 units have trouble with 18" radius. So it all comes down to luck somewhat since even though 90% may run fine on 18" radius, someone may purchase 50 units and have no issues while someone else could buy 3 or 4 and have issues with them all. That probably explains why many have not had amy issues and sometimes it is not until there is a large sample that it can be seen that 10-30% of a certain locomotive does not handle 18" radius curves.

[Jerrys HO]

[/quote]
I found 70% could make 18" radius while 30% could not, so they made 10,000 units hypothetically, 3,000 of those would be unable to run on 18" radius.
[/quote]

So your saying that the 7 I purchased that all negotiate 18r the next 3 will not?
It's hard to swallow your evaluation as I believe tolerances may have a small, very small part in the equation but quality assembling is much larger. Mass production tends to have more mistakes than tolerance. I have had to loosen, tighten, or adjust to make things tolerable.

[Irbricksceo]

ACY, you bring up a good point in that there could be a small section of them with lower tolerances, manufacturing works that way. That said, the 2-8-0 surprised me because it used to ship in sets with 18 inch radius curves (I know because I had one)

[Doneldon]

So your saying that the 7 I purchased that all negotiate 18r the next 3 will not?

Jerry-

You're falling for the gamblers' fallacy. The chance that your next locomotive will be able to run on 18" radius track remains 70% regardless of how many locomotives you already have which do or don't negotiate 18 inches. It's the same with coin tossing. The chance of getting a head or tail is 50% no matter whether you have flipped 25 heads in a row or exactly a 50/50 split. It's called the gamblers' fallacy because it's what keeps gamblers feeding money into the slots, playing poker over their head, betting on the ponies or playing table games at the nearby casino. It's what makes losers say, "I've lost 200 quarters in a row in this slot. I must be ready to hit the jackpot."

You have to remember that every test (flipping a coin, dropping a coin in a slot or playing 29 at a roulette table) has the exact same odds of being a winner no matter how many times you have won or lost in the past.
                                                                                          -- D

[ACY]

So your saying that the 7 I purchased that all negotiate 18r the next 3 will not?
It's hard to swallow your evaluation as I believe tolerances may have a small, very small part in the equation but quality assembling is much larger. Mass production tends to have more mistakes than tolerance. I have had to loosen, tighten, or adjust to make things tolerable.

No, Doneldon actually provided a very good explanation however. Regardless of how many you buy, you have a 70% chance of getting one that runs fine on 18" radius. Keep in mind my test was of only 10 locomotives so the actual percentages could differ. It is not exactly easy to have access to more than that many locomotives unless I owned or worked at a major store like MB Klein or something.
And you are misinterpreting my use of the word tolerances it seems. To be more clear, I am stating that a given factory has a certain acceptable range for various production details and at either extreme is when you have your small percentage of locomotives that perform a little differently than the majority of the production run. In this case we were discussing minimum radius.

[jbrock27]

Speaking of Vegas, I am not accepting ACY's odds as being some sort of standard. Sorry man.

And I disagree that it is about luck; this is why I have been asking you the questions I have.  The answer bears importance.  Let me know how the trucks are set up to get power to the motor.  All it takes is taking of the shells.

Also, I am not really sure I would take the word or advice of a LIONEL guy on an HO problem.

Re: the production tolerances and issues; this is the reason I raised the question about checking wheel gauges.  I have read many times on the NET about brand new locos being received and not running properly (derailing) on the rails.  Instead of checking this for themselves, people waste resources (time and $$) to send such items back instead of looking into how easily they can be repaired (really the word is 'adjusted') at home with a little gumption and effort.  I am in Roger's camp when it comes to that thinking.

Doc, it is funny to see you display such knowledge about gambling and odds, from a guy who sticks his tongue in live lamp sockets...

[ACY]

Speaking of Vegas, I am not accepting ACY's odds as being some sort of standard. Sorry man.

And I disagree that it is about luck; this is why I have been asking you the questions I have.  The answer bears importance.  Let me know how the trucks are set up to get power to the motor.  All it takes is taking of the shells.

Also, I am not really sure I would take the word or advice of a LIONEL guy on an HO problem.

You don't have to believe me. All I know is I had the opportunity to test run 10 Bachmann 2-8-0 locomotives. All the wheels were found to be in guage by the way. No issues or differences could be observed with the naked eye. Some measurements were taken and all measurements were consistent within 1/16th of an inch between the models. Perhaps this 1/16th of an inch variability is what accounts for the differences in performance.

Until you or someone else can obtain or knows a way to obtain more than 10 locomotives to test, all we can go off of is what was found in the test I conducted with 10 Bachmann consolidations.

As far as it being ill advised to take the word of my friend who was with Lionel at the time, I am offended by that statement because you have no knowledge of his experience or background. He actually worked a great deal with HO scale, before Lionel made him a job offer he could not refuse. Even though he worked for Lionel, he actually had a large HO layout at his home.

The data is what it is, 3 out of 10 did not run on 18" radius, 7 out of 10 ran without any problems. After doing some statistical calculations, the tests show that with 98% certainty at least 10 out of 100 units will not run on 18" radius or with 99% certainty at least 5 out of 100 units will not run on 18" radius.

[electrical whiz kid]

Sid;
Great job of building those cars.  Like you, I am going to try the Tichy trucks; only with Kadee wheels.  I am using the ribbed 33" wheels.
I also decided to unload the #5s I had in stock.  They won't be coming apart, so why not?  I will have two of the "BACHMANN"...Moguls working the magnesium quarry and processing plant.
Rich