I was doing an HO Layout and posted a few questions here back aroun 2006/7 I ended up taking down my layout and now im totally rebuilding it. However, I forgot how to do one small item.
On Flex track..using the rail nippers...does the blade cut across the sides of the track? or do you put the blades on the top/bottom of the track, or does it matter?
Also on this new layout, I have 1 fairly tight turn I need to make. I can fit the turn in if I use 18" radius track. So my question is, I would be coming off of a 22" radius complete curve...transitioning into about 18" of straight track, and then 18" curves... is it ok to mix the two types? As I remember longer cars might have an issue on them? Is it maybe better to use Flex for that?
I can make this tight curve with 22" (then its not so tight" but I will have to modify my benchwork (add about 1-2 feet ..otherwise the track would run off the edge lol.
Thank you again for all of your help as I remember you folks were great before. looking forward to showing you photos someday.
Chuck
http://www.chuckcondron.com/CCLayout/index.html
For HO Code 100, it is top and bottom. Not sure about lighter rails, irrespective of size.
You would be far better to try to maintain some curvature all along and to thereby create an 'easement' into whatever final curve you need to avoid having to add more wood. Or, just use a transition/easement into and out of the 18" curve by using a section of 22" on both ends...an easement, IOW.
-Crandell
I've always cut railhead-base, not side to side. I also dress EVERY cut end, and even ends that I don't have to shorten. Taking the time to get rid of all burrs, and taking a little bevel out of the flange side of the railhead, will pay off in time you won't have to spend picking up derailed rolling stock.
I presume you were referring to an S-curve situation. If there is a tangent at least as long as your longest car between curves, that should be no problem if you're working with sectional track. Working with flex, I form two full spiral easements with no tangent between, which takes more space than a simple straight between curves (25 inches between theoretical points of curvature versus 9 inches for short cars, 13.5 inches for longer cars.)
Chuck (Modeling Central Japan in September, 1964)
So it looks like top to bottom on the rail nippers, thank you!
Yes on the S Curve... but what is an easment? like a transition between the one type of track and the other?
One suggestion was to make sure the straight track was at least as long as my longest car..it would be, it would be 18"
If I read the other suggestion correct it was to have a 22" curve on both ends of the 18" curves?
it would be...it would be one full radius of 22" plus one more 22" as if I was to start to complete a full circle....then 2 9" straights...then about 3-4 18" to go the other direction (the other part of the S...) then 1 22" final curve into a long straight section...
An eased curve is a curve that starts at an almost infinitely wide radius and then reduces to the desired mid-curve radius over the course of a certain distance using what is known as a cubic spiral curve. If you were to take a lath 3/8" thick, one inch wide, and three feet long, stand it on its side, and anchor it on both sides with stout nails driven into the board below it, and then deflect the far (free) end so that at that end it conformed to the needed radius, what happens between the two ends forms a very close approximation to the transition curve. In fact, that is what many of us use to generate such eased curves. We draw the centerline of the track to the point where the curve must begin, and then place the lath offset by a presribed distance (explained in other locations) from the centerline, and bend the free end to form your curve. Draw a pencil line along the curved edge of the bent lath. On the other side of the curve, you repeat in the other direction.
Ideally, you want to accelerate toward the curve, not instantly begin to travel around a radius from tangent track. This is what the easement allows, a transition that is more comfortable into the actual curve.
The topic is covered well in Kalmbach publications such as the late John Armstrong's Track Planning for Realistic Operation.
I did a search (under "search community" at right) typing "making easements" and the first hit was this one:
http://cs.trains.com/trccs/forums/p/37450/1259132.aspx#1259132
Awesome, I read through a lot of those links in those threads...one of them talked about a french curve which I used back when I took drafting a million years ago lol and now its kind of making sense with what i need to do...
ok last question... once i draw the easement...i take it I actually make this happen with the flex track? i dont see how I could do it with track segments... and I take it I will need a few straight pieces coming out of the first curve correct?
so first curve...straight, then easment curve (using the methods in those links) transitioning into my final track (in my case a long straight run).
correct?
Thank you all for your help! I remember a few of you from my last visit here 2 years ago.
I am not sure I follow you, but you must ease into and out of the curve because you can enter it from either direction, and passengers don't want to be jostled when running at high speed. So, if you have a wide curve that is uneased followed by a length of tangent (straight) track, and must then fashion a fairly tight curve, you would want to easy the tighter curve to the extent possible. The easing is into and out of curves, and is unnecessary for any straight track. It is unnecessary for hughely wide curves in the order of 150", but who has such things? Most of us are glad for the odd 30" curve, and they would want easing. Flextrack makes great easements if you anchor the one end and then bend the other to follow a fixed radius near the midpoint of your curve. Flex makes easements by itself, or at least a close approximation.
The sectional track is often of a fixed radius and doesn't transition very well. Some folks use 18" radii on some curves, but they place a length of 22" sectional on either end of the curve to create a pseudo-easement. It helps!