News:

Please read the Forum Code of Conduct   >>Click Here <<

Main Menu

Minimum radius and sound decoder question

Started by napa15, July 20, 2011, 01:54:48 PM

Previous topic - Next topic

napa15

I have two new engines and know that the minimum recommended radius for each is 22".

(Engines)
2-8-4 Berkshire Steam Loco
http://www.bachmanntrains.com/home-usa/products.php?act=viewProd&productId=1955

N&W Class J - but with no sound decoder, just DCC
http://www.bachmanntrains.com/home-usa/products.php?act=viewProd&productId=1889

What I would like to know is if the engines are run on 18" radius turns will it damage them? I know the answer is really going to be, "Yes, they must be run on 22" at a minimum"... but my currently built layout has no 22" turns, only 18". I have a 5 year old who doesn't quite grasp why we can't run them on there and thought about "occasionally" running them there for him to watch, but I don't want to break anything either. FYI - I do have some 22" EZ-track "loose" and have been setting it up on the floor for him to watch and run (you know, face planted to the floor, butt up in the air all the while making his own train sounds  ;D )

Another question is this: I eventually want to get a sound decoder for each of these engines and have no idea what I should get. Obviously I would like them to be as close to prototypical for each engine as possible, but I really just don't know where to start.

Thanks in advance.

jonathan

Running those locos on 18" radius track won't damage them, unless they jump the track and tip over.  The damage done is whatever happens when the locomotive hits the ground or rolls off the table.  A few have reported being able to run the larger locos on 18" radius.  It's a matter of luck in that case.  Try it, but stay close to the locomotive so you can catch it if looks like it wants to tip over.  Usually they just derail and no damage is done.

If you have a DCC system, the Soundtraxx Tsunami Heavy Steam sound unit is good for the Berkshire, probably for the Class J as well.  Tsunamis are not programmed to be dual mode and will not operate on DC, unless once knows how to reprogram them.

Regards,

Jonathan

ACY

If you want to run them occasionally you could set up a temporary layout with 22" radius track on a piece of plywood or something, that way you won't risk derailments therefore avoiding unnecessarily damaging your locomotives. The way I think of it is this, the manufacturer wouldn't say 22" minimum radius unless that is the minimum radius because limiting their market for no reason doesn't make any sense, so it must mean that the locomotives just are not able to run on anything less than 22" radius (well at least 99% of them).

napa15

Thanks for the replies. I agree with your comments ACY. One of the main reasons I am asking (besides my son wanting them to run on our current layout in progress) is because the N&W Class J had an issue the first time I placed it on the layout (18") and tried to run it. The front set of driving wheels bound up. That front set of wheel just got tweaked and stuck. Apparently that set and the third set back are placed on top of some sort of spring mechanism and it gets twisted to one side. The third set of driving wheels do not bind at all and it has the spring just like the front set. There seems to be a good amount of play in the front set of driving wheels when I move them with my fingers, compared to any of the other driving wheel sets. AND - the same binding happens on the 22" track as well. To make it even more mind boggling... the front driving wheel set ONLY binds up and stops moving when the engine is going around the curve Counter-Clockwise (turning left). It runs just fine when going Clockwise (right).

Ideas?

Also, I am very limited on space in my garage, which is why I don't have another board with the 22" track on it. Wish I had more room.  :-\

MilwaukeeRoadfan261

Quote from: jonathan on July 20, 2011, 02:04:54 PM
Running those locos on 18" radius track won't damage them, unless they jump the track and tip over.  The damage done is whatever happens when the locomotive hits the ground or rolls off the table.  A few have reported being able to run the larger locos on 18" radius.  It's a matter of luck in that case.  Try it, but stay close to the locomotive so you can catch it if looks like it wants to tip over.  Usually they just derail and no damage is done.

If you have a DCC system, the Soundtraxx Tsunami Heavy Steam sound unit is good for the Berkshire, probably for the Class J as well.  Tsunamis are not programmed to be dual mode and will not operate on DC, unless once knows how to reprogram them.

Regards,

Jonathan

I agree. I have a 2-8-4 and GS-4 and I have gotten the 2-8-4 to run on a flex-track turn that is SHARPER than an  18" radius turn just fine and at the "Track Speed" for my layout.

ACY

Quote from: MilwaukeeRoadfan261 on July 21, 2011, 08:35:51 AMI agree. I have a 2-8-4 and GS-4 and I have gotten the 2-8-4 to run on a flex-track turn that is SHARPER than an  18" radius turn just fine and at the "Track Speed" for my layout.
What your locomotive does on any given radius is irrelevant to what radius his locomotive may run on. If you don't understand why this is than I can explain it to you.

Len

Trying using a 22in radius curve to create an 'easement' between your straight sections and the 18in radius curves. It often helps "22in radius minimum" locos transition from the straight to the sharper curves with less problems. Sometimes it doesn't work, but more often than not it will. At any rate it wouldn't hurt to try, and see what happens. Just be ready to catch the loco if it does derail.

Len
If at first you don't succeed, throw it in the spare parts box.

WTierce1

I have one of the 2-8-4 berks and it runs fine on 18" radius and my class J will but non all that well.
A fan of the Tennessee Valley Railroad

MilwaukeeRoadfan261

#8
Quote from: ACY on July 21, 2011, 10:24:13 AM
Quote from: MilwaukeeRoadfan261 on July 21, 2011, 08:35:51 AMI agree. I have a 2-8-4 and GS-4 and I have gotten the 2-8-4 to run on a flex-track turn that is SHARPER than an  18" radius turn just fine and at the "Track Speed" for my layout.
What your locomotive does on any given radius is irrelevant to what radius his locomotive may run on. If you don't understand why this is than I can explain it to you.
I do understand. It's just that, if you look in the Bachmann catalog where it says "Works best on 18" Radius Curves" that is merely a recommended minimum radius turn for smooth and realistic operation and my 2-8-4 and GS-4 both are listed in the catalog as "Works best on 22" Radius Curves" but I have had no problem with them derailing on 18" radius turns or smaller and the GS-4 has larger drivers than the J. It's when they get to a switch where the turn enters the diverging track that would go to a siding when my engines are coming off of the siding onto the mainline because that is where I encounter derailments. But I have learned since to use wider switches.

ACY

Quote from: MilwaukeeRoadfan261 on July 22, 2011, 09:00:30 AM
I do understand. It's just that, if you look in the Bachmann catalog where it says "Works best on 18" Radius Curves" that is merely a recommended minimum radius turn for smooth and realistic operation and my 2-8-4 and GS-4 both are listed in the catalog as "Works best on 22" Radius Curves" but I have had no problem with them derailing on 18" radius turns or smaller and the GS-4 has larger drivers than the J.
So you pretty much just told me you don't understand. If you have a Bachmann J and I have a Bachmann J, the radius that yours can run on is completely unrelated to the radius mine can run on. Each locomotive is unique some may run on 18" radius, but most will not run on 18" radius. Bachmann's recommended minimum radius is usually the same as the actual minimum radius for large steam locomotives. If you wanted the large steam locos to look realistic running them on 22 compared to 18 won't do much to that effect, more realistic would be 30"+ radius and even then those are sharp turns in for the 1:1 locomotives. I have had several people send me emails (not sure why they chose me) because on the board someone (or I) said their locomotive ran on such and such radius and then when they get their locomotive they find it will only run on 22" radius and nothing less. The problem lies in that people (such as you) with good intentions post and say their locomotive will run well on this radius, but then a possibly somewhat inexperienced model railroader comes along and sees that someone said theirs runs on this radius so they assume it must be true for all of them. All this does is set them up for disappointment most of the time because, most of the larger Bachmann HO steam locomotives can't run well or at all on curves sharper than the recommended minimum radius. Someone will probably want to argue, well I have 8 of these and 7 of those and they all can run on 18" radius, and it just comes down to the fact that they just got extremely lucky. Each loco deviates in the amount of rigidity (or lack thereof) in the wheelbase. A few allow more lateral movement than others which allows them to safely negotiate sharper radius curves than most of the locomotives, a few may be extremely rigid and not run well even on the recommended minimum radius. When you make a huge batch of locomotives, this is what you get and there isn't anything anybody can do about it. I am tired of random people emailing me for no apparent reason, so in the end it is probably best to say Bachmann's recommendation and that the loco is by no means guaranteed to run on any sharper radius curves, but is possible if you are fortunate enough.

Pacific Northern

Quote from: Len on July 21, 2011, 03:03:23 PM
Trying using a 22in radius curve to create an 'easement' between your straight sections and the 18in radius curves. It often helps "22in radius minimum" locos transition from the straight to the sharper curves with less problems. Sometimes it doesn't work, but more often than not it will. At any rate it wouldn't hurt to try, and see what happens. Just be ready to catch the loco if it does derail.

Len


This is exactly what one member of the local Model Railroad club did on his home layout after he bought a Spectrum Mountain that did not run on 18" curves.

Rather than rebuild his layout entirely he created an easement using three 22" radius tracks and the remainder 18" curved tracks at each end of his 4' x 14' layout. The locomotive ran fine in the one direction only.
Pacific Northern

Doneldon

ACY-

You are so right. One would expect that modern manufacturing would be so consistent that your locos and my locos would all run on the same radius. Well, I suppose they do, as long as that radius is 30" or suchlike. The wrinkle comes in with tight curves and that's where the unexpected results show up. Hence, you have one which will make it around 18" but mine demands 22" and on and on. But I'm not convinced that all of the variation on minimum radius is due to manufacturing differences. My guess is that there are also differences in the tracks and the operators.

EZ Track is a swell product and it's harder to put it together wrong than is regular sectional track but there are still some issues. It's not hard to get a rail on top of a rail joiner rather than in it and not notice the problem right away; I know this because I have done it myself. It's l;so possible to get two sections of EZ Track joined but not precisely lined up. Such a minor misalignment as a degree or so wouldn't be a problem in most cases but it could cause a derailment if we're trying to squeeze a long loco through a sharp curve. And there may be track variations even if every rail is aligned true and tight. How can that be? Well, the problem then wouldn't be the rails per se; rather, it would be what the rails are doing before they hit that tight curve. For example, does the tight curve follow another curve, possibly even a reverse curve? Is there a grade on one person's pike when the sharp curve starts or is everything level? How well broken in and maintained are the locos? Even, what are they pulling? It's not hard for me to see that two identical locos on two identical model railroads might not perform the same at a sharp curve because one is pulling a heavy train or one with poorly maintained rolling stock while the other is meticulously cared for.

I won't belabor the issue but, let's face it, we don't all use the same practices when we run trains. Some of us run faster, some slower. Some of us slow down for fancy trackage; others just barrel on through. Some of us back up a Little faster than we should. Some of us maintain uniform speeds, others accelerate and decelerate more often. All of these operator differences can amplify tiny variations in trackwork, layout plan or manufacturing variance to the point that a given loco clears curvature x on my railroad but it needs x+y (or x-y) on someone else's.

So there are lots of reasons why two apparently identical locos perform differently. Throw in the minor manufacturing variance and the inconsistencies people talk about become more like predictable than unexpected!
                                                                                                                          -- D

ryeguyisme

I don't know if someone said it before BUT, its the rule of thumb to go the largest radius you can possibly go within your restricting space. You can say the locomotive won't be damaged if they can take a tighter radius, but the wear and tear on the wheels and the axles will occur more on sharper curves. I modify all my engines to just barely make an 18" radius but the layout I'm modelling will be strictly 22 inch minimal and that's on the yards, everywhere else, I'm shooting for 26 inches or greater. My railroad is being constructed into modules so it's less restricting if say I want to change the shape of things.

"Recommended Radius" in this hobby typically means the minimal it will go without serious wear on the drivers

Doneldon

Napa-

Running your trains on the floor isn't a particularly good idea. I expect that getting small ferrous bits into the motor is less of an issue with can motors but you can still pick up fibers and grit which wear your loco over time. Floor running was an absolute no-no for older HO trains; I advise against it even with newer equipment unless you run on a hard surface floor which can be cleaned before the trains come out or the trains are on a temporary solid surface.

You said your garage is pretty small but that doesn't mean you can't do a railroad on a board. Buy a piece of 3/8" plywood (best) or OSB which is four feet wide. (Some home centers sell plywood in smaller than eight-foot lengths.) Then cut it in two so you have two pieces, each four feet wide and half the length of the sheet you purchased. Reconnect these pieces with three or four strap hinges. Mortise hinges will work but they'll cost more, even if you only use two or three. Then put your 22" radius circle or oval on the other side of these sheets, omitting rail joiners where the tracks meet at the common edges of the wood. Add a feeder to each side of the track with a buss wire leading to the outside of the track for connection to a power pack and you're in business. You can use 3/8" plywood because the floor serves as your frame. When you're done, disconnect the power pack and fold the layout into a package only two inches thick. That should slide in most anywhere. As a temporary layout you don't need attached buildings or scenery, though you could certainly paint grass and roads on the wood and add loose buildings, a "mountain" made of a cardboard box and maybe a little plaster cloth, and a few vehicles. Do the box right (maybe make it a building!) and you can store the loose items, even the Berk in it. If you want a little more protection for the track, use a piece of 1x2 between the plywood pieces and two sets of three or four hinges. Put the tracks on the same side as the hinges, add a couple of bumper blocks along the distant edges and fold the whole thing up with the track protected inside. You'll need removable (two screws each) track sections on the 1"x2" bridge for folding clearance. You'll still have a small package (just over two inches thick) which is easy to store. Put some screws not all of the way into the edges and use stout string to keep the layout folded. Heck, you could even put carrying handles on it or get one of those cheap plastic sheet goods carrying devices to make hauling it in from the garage a breeze. Make this on a 4'x6' sheet, fold it and put it under any bed.  Even twin beds are 39" wide.
                                                                       -- D

tmiller

I recently bought a URSA Light Spectrum 2-10-2 steam loco with sound. Beautiful engine!! At first I had problems with the 18 degree curves. Took a lot of work to make sure the track was clear of an unnecessary ballast, etc. Just when I was considering tearing it all out and adding 22 degree curves, it started to negotiate the curves with little or no problem. Now I am sure I can't highball around those curves, but at a normal speed it does just fine.

Very much relieved it works, because I didn't want to let the engine get old on some siding!

Ted
See you down the tracks!