Track Laying

[trainnut57]

When I first began in this hobby in 1974, all I had was a partial HO set and a 4x8 sheet of plywood. Now it's a monster covering 2/3 of my basement and U shaped. I never had access (until recently) to such pubs as MR and therefore have the following questions regarding curves.

Most "modern" and some "older" steam locomotive (more than eight drive wheels) state in descriptions, etc that a radious of at least 24" is necessary. Since I do not have any drafting or engineering experience, I was forced to use that largest pre-made radius I could find-22". (I tried making curves with flex track but they looked more like eggs than semi circles) In order to slightly increase the actual radius, I added 3/4" sections of Atlas Snap Trak between each 22" radius section. Some "experts" I have talked to say this cannot work and will actually damage the driving gear on my Northerns and the Challenger I am considering. Also they say it will cause constant derailments with both my diesels and large steam locos, as the longer trucks will be passing over a curve at one point and straight in the middle. They say the curve-straight-curve is too radical. IS THIS TRUE? I have to admit I do have a slight problem with derailments once in awhile but nothing steady, and mostly on curves but not necessarily the curve described above. Which brings me to:

Question two; it seems simple and I'm pretty sure I know the answer-should the curves be banked with the high side to the outside rail?

Thanks in advance.

[Anonymous]

why don't you use the 22" track as a template and try laying flex on the outside edge, that should give you a reasonably smooth curve, and look better than your curve /straight combo. you can also try making your own compass by using a stick and cut it 26" long, drill a hole 1" from each end, find the center of curve and nail one end in center and use pencil to draw radius, with a little practice you'll have smooth curves. there are also some metal (I believe) radius guides for curves. yes elevate outer rail.

[Anonymous]

Atlas makes pre-made 24" radius curves.
The only thing that might not work out is that it is code 83(and you might have 100). To "bend" flex track the proper way, just buy a radius guage, that you can slide through the curve. If you look under "Ribbon Rail"(Just scroll down), you can see radius guages start at 15" and end at 48"!

[jeffrey-wimberly]

24" radius: if you make a full curve (180 degrees) with the track center measurement being 48" from track center to track center, that's 24" radius.

As for the curve-straight-curve damaging long wheel base locomotives and rolling stock, baloney. If that were the case, you wouldn't be able to use curves to transition your turnouts. I ran the curve-straight-curve on a layout for years with no problems with a N&W 2-6-6-2 Y6B making the run with a set of heavyweight passenger cars. And this was on 18" radius. It suffered no ill effects. I'm no "EXPERT", but it worked for me.

[cwclark]

all you need is to learn the trick for laying flex track..and yes..you have big equipment so a 24" radius will serve you well....take a small trim board (like a 1/2" x 3/4" and cut it about 4 ' long) ... take the board and about an inch from an end, drill a hole so that a nail can fit in the hole.....now, take a measuring tape and measure from the nail hole out to 24" at the other end of the board, make a pencil mark on the board at the 24" mark and then drill a hole in the board at the pencil mark that is large enough for a pencil to fit in and thru the board to the other side....now, take the nail side of the board, pu***he nail in, and lightly hammer it into the sheet of plywood you're going to use for your layout table top...now, put a pencil in the other hole in the board and with a sweeping motion, mark the curved line onto your tabletop..waahla! ...a perfect 24" radius center line that you can now use as a guide when laying your flex track....flex track is really versitile and it looks a lot better than sectional track because it can be bent into oddball curves that add more realism to the layout....the answer to your questions are they won't hurt your equipment but it may cause derailment problems..the objective is trackwork that doesn't derail anything...and the second question is that what that is called is super elevated track...all it does is make the train look really cool rounding a bend...chuck

[SpaceMouse]

I agree with the guys here. Just learn how to lay the flex once and for all. I did not hear you mention road bed. Once you draw the line with the stcik, lay your roadbed such that the pieces of the cork line up to the center line. Then when you use your flex, just make sure the center of the track follows the line in the center of the roadbed.

[Eriediamond]

[#ditto] on spacemouse's answer here. I do agree that the curve-straight-curve scenerio will damage the locos only in that you still have 22" radius curves and what may happen is that it may put drive shafts and running gear in a bind. I addition to what spacemouse said, if your not using road bed, just draw your 24" or larger radius line and use the nail holes in the center of the ties as a guide. Simple ounce you get the hang of it. Ken

[nbrodar]

I use templates I made from plywood to layout my curves. Templates work better then the tremel stick, for shelf layouts where there is no place to mount the tremel.

Nick

[larak]

Don't forget that easements will make all of your large engines and cars handle tight curves better and look better going into those curves. Less strain on couplers too.

An easement is a technically a gentle spiral from straight track (tightening down) to your main curve radius. In practice, sometimes a length of wider radius track at each end makes an OK easement as do turnouts. Do a web or forum search for techniques. Flex track is very amenable to them.

Superelevation does make trains look more realistic especially at moderate speeds. Don't over do it. Try 1/16" under the outer rail and see how you like it.

[Texas Zepher]

QUOTE: Originally posted by trainnut57
I was forced to use that largest pre-made radius I could find-22". (I tried making curves with flex track but they looked more like eggs than semi circles) In order to slightly increase the actual radius, I added 3/4" sections of Atlas Snap Trak between each 22" radius section.

No, this will not work. In fact it might be worse since now the locomotive is actually entering and exiting 8 curves for a 90 degree turn. If you switch to Atlas code-83 track they do make 24" radius curve sections.

QUOTE: Some "experts" I have talked to say this cannot work and will actually damage the driving gear on my Northerns and the Challenger

Depends on the unit. Which exact models are you considering?

QUOTE: Also they say it will cause constant derailments with both my diesels and large steam locos, as the longer trucks will be passing over a curve at one point and straight in the middle. They say the curve-straight-curve is too radical. IS THIS TRUE?

Equipment can always be pushed beyond it's tollerance and design specification. This does not mean it is good for the equipment. It could be grinding down the wheel flanges, wearing gears or u-joints excessively, or who knows ??? It is just generally not a good idea. A better idea is to get the minimum recommended radius and increase it by at least 2". If it says 18" go with a 20" minumum. In this case, bigger is always better.

QUOTE: Question two; it seems simple and I'm pretty sure I know the answer-should the curves be banked with the high side to the outside rail?

This is called super-elevation. It must be done very carefully with model trains. Raising one side of a curve (especially tight ones) can reduce the track gauge making all the problems mentioned above worse. If this is attempted get a really good track gauge and measure every millimeter of the curve for tightness. Also remember the gauge on a curve should be slightly wider than straight track.

[trainnut57]

Thanks to everybody. I received alot of good information here-these forums are great.
Generally, I run Northern and Mountain type steam locomotives, along with SD's (diesel) when I feel modern is necessary. I also have one UP DD40 that runs superbly on the curve-strait-curve section. I have way too much track to switch to code 83, and although I know a transition is possible to code 100, I would still prefer one type of track- easier to repalce and maintain in my oninion. THanks again, especially to jeffrey-wimberly for the answer I was looking for.
Trainnut57