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Okay, let me ask a question that may have an obvious answer to some, but unfortunately not to me (you know, the proverbial dumb question);
When making a curve with flex track, how does one know or make the radius that they would like. In other words, if I want a minimum of a 22 inch radius curve with flex track, how do I go about making it a 22 inch curve?
One way is to use a yardstick and drill a hole at 1 inch then the other at 23 to make 22inch curves and put a nail in the 1 in mark and use a swing arc to get your radius. A very simple tool with no need to buy anything. Of course 22 inch radius equals 44 inches total with 2 inch on each end of a 48 inch table.
Might try hitting up http://www.enginetender.com/170m.htm and check out the ribbonrail guages offered there? From the wording of the ad, I assume they are still in business with the product.
I used a piece of board about 2" wide X 1/2" thick and about 30" long.
I ran a screw through at one end, then I drilled a series of holes big enough to accept a felt marker. The first hole I drilled at 18" from the screw then at two inch increments up to 28"
I used the tool to scribe a curve to represent the center of the radius at a predetermined position. We don't need to achieve anything more accurate than that.
It worked well for me.
Hope this is of help.
Mac
The wooden lath strip with holes big enough for a pencil's sharp end to poke through far enough to mark wood or paper under the lath is called a "trammel". You can easily make one.
Or, you can drive a nail into the bench and tie a string around the nail. Use it as your radius center and stretch the string to the 22" mark to draw a penciled arc there. Or, tie a string around the pan head of a sturdy tripod very close to where you think your radius's center should be. Then, keeping a string taught at a measured 22" mark, pinch the string between your thumb and fingers with a pencil wedged in there as well. Swing your hand as the string permits and draw an arc.
Want better performance from your trains? Two things: use an easement (covered as a separate whole nuther topic), or cheat and add another 3/4" to your arc and make the ends on either side a bit longer to help close the loop to the tangents on either end. Any extra radius is a boon.
This is true and probably the easiest way to go about it. I don't have any 22" curves, may have to buy some.
Speaking of solder, I have done a lot of soldering in my job over the years, is soldering the joints really the best thing to do? I am not bad at soldering (if I do say so my self) but I just can not keep from melting the ties, even with a heat sink. Maybe I am just to new to this track soldering. The little bit of messing around I have done so far, I have found that pinching the connectors with a small pair of needle nose pliers makes them tight and not very hard to install on the rails. The joints seem to be very tight and a test run of an engine or two seems to go very well.
It's actually very easy, especially for someone who has soldered in the past. You use rail joiners and place the Iron directly on it. As you know the solder will do the work if it's the flux type. Solder a 1/4 circle section and don't use solder between the next section. Leave a small gap for expansion. I found that a 22 inch radius with flex track is a bit tight and takes a bit of experience since the track will fight you some. It will not have the same radius in some parts and in my experience results in time spent troubleshooting derailments etc if you have 6 axle engines. It doesn't help that the atlas flex I use doesn't have drilled holes in the ties to nail it down. I wound up ripping up the tighter sections and used soldered curved track. Much easier.
For larger radius turns flex is much easier to work with.
The best heat sink I've found for soldering track is a pair of vice grips. Clamp one on each side of where you're solder and, even for a klutz like me, I rarely melt a tie now. For very broad radius curves, say 28" and above, I've found flex track works fine. For smaller radius curves, I'll join HB in the soldered sectional camp. The downside is that every joint is a potential electrical and mechanical problem so good prep work is vital. The upside is that you can lay a very nearly perfect curve without having to fight flex track trying to spring out to a larger radius.
I actually think sectional track works best for smaller radii curves. Pinch the connectors so the sections join tightly and don't kink the joints. Solder them all and leave small gaps in the straight track. I think flex track is best used when making broad curves, or making a big bow in an otherwise straight portion of your layout, like prototypes do. As was said, the flex track tends to fight back and isn't perfectly curved unless you fiddle with it more than you want.
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