How do you lay a curve?

[Anonymous]

I am modeling in HO and I have no ideal on how to model a 26" radius curve with flextrack. I would like to know how you do it? I have read the template things and they just give me a headache? I just need input on how to lay a perfect curve?



THANK YOU

[Anonymous]

Find the center of the curve, and place a nail there. Tie a pencil to a string and attach it to the nail 26" from the end. Keep the string tight and draw the center of the curve with the pencil. Or use a yardstick with a pencil taped to one end, the 26" mark on the nail. Draw your curve.

Easy as that!

Bob Boudreau

[Anonymous]

I'm an N scaler myself, but I've used Flex Track a number of times on large radius curves. My advice is that if the template is over your head or too much to deal with, toss it in the trash and just jump in there and do what you have to do. First of all I would connect one end firmly and nail or soldier it in place, then gradually start curving it as close as you can to what you want by eye. The problem with Flex Track is that the ends of the track are going to become uneven as it's curved and both the ties and track will have to be cut and filed to even lengths in order to be connected to the next section of track. It's a process and a pain in the --- but the end results are worth it...

Hope this helps.

trainluver1

[jrbernier]

Here is what I just did at the club layout last Saturday. I needed to draw center lines for several tracks(36" radius). I used a tape measure to layout a 36" mark from the straight track I wanted to start from, and also one from the track I was going to. I then inserted a small nail in the benchwork where the centerlines meet and tied a line to it, measured out 36" and swung the line, marking every couple of inches with a pencil. I then got out the flex track and spiked it down following the new centerline.

Jim

[jwmurrayjr]

Dalas,

You can use a yard stick to make a large "compass" or trammel (I think it's called.)
Just put nail through one end and then drill small holes for a "Sharpie" (or pencil or whatever) where you want to draw an arc.

Just remember to compensate if you drill the nail hole at, say, the 1/2" mark. Then your 26" radius would be drilled at 26-1/2". Or you could attach a small piece of wood or tin so that you could put the nail at the "zero" point on the yardstick.

Once you have your radii drawn you can pin your flex-track down using the arc as the center-line of the track. You can also add "easements" to gradually transition from one radius to another.

Solder the ends of sections of flex-track together while the track is still straight to get smooth curves without kinks. This is almost another topic but you can do it. You'll need to remove some ties at the end of the section for the track to flex and fit.

A simple book like Basic Model Railroading by Kalmbach may be a great help if you're just getting started.

Have fun.

[selector]

Do your solders while the rail sections are mobile. Lay them in a straight line, and then solder them. Then, align one end with the end of the last completed section of track, and solder those two rails. You should now have three sections of aligned and soldered track, two free and one laid. Bend in your curve, pinning the track as you figure your radius and make the curve. One rail will begin to pull and slide so that when you fini***he curve, the outside rail will be much withdrawn at the far, free end. Trim ties and rail as necessary to get a nice square end.

This way, your track will have very few problems along your curves.

Edit- I was interrupted while compiling this, and posted just after Jim, not having refreshed and seen his post. Sorry for the repetition.

[Don Gibson]

1. TIE a string around a 'Sharpie and measure off 26" for a nail to act as a pivot. Make your curve.

2. LAY cork on the outside of the curve using the above line as a guide. Nail in place.
3. LAY cork on the inside - pressing against the above - then Nail in place.

4. SOLDER 2 section's of flextract together as Jim Murray said, and form your curve from the CENTER outward toward the end's. For 26"r. two should do it .

5. TRIM off the inside rail to size. Remove 3-4 ties from under track joint's. Replace with wood.

SIDE NOTES:
1.MY preferance is for stiffer flex on curves - such as SHINOHARA -as it hold's the continuous integrety of the curve better.
2.I DON'T solder rail joint's together - except to form a curve - having had to replace whole section's of flextrack from expansion. Once was enough.
3. Curve easment's look nice but make sense only on large layout's. Your 26"r. would be come 24"r -25''r with easment's,and Not worth it.

[dehusman]

About 15 years ago i took a cheapie wood yardstick and drilled holes at each of the inch marks down the centerline. Between the end and the 1 "mark I drilled a hole every 1/4". I used that as a trammel to layout curves as described above. Still use it.

Dave H.

[CraigN]

With Atlas flex track, one rail slides easily while the other rail stays put in the ties. If you keep the sliding rail on the inside of the curve, you don't need to remove any ties. I do slide a razor blade under each rail to seperate it from the ties so the rail joiner can slide onto the rail.

[IRONROOSTER]

Having done both, let me highly recommend the yard stick or a 1x2. I find that I never keep the string tight and the curve doesn't come out right. I took a 1x2 meaured off the distance I needed and drilled a hole for the pivot nail and one for the pencil. Worked great.
Enjoy
Paul

[Anonymous]

Some ideas on how to properly lay out a 26" curve, with easements.....

1. Buy some poster board and tape it together to make enough of a surface to "hold" your curves. Yes curves, you'll have two of them, a 26" curve and a 52" curve.

2. Using the string & pencil trick, lay out a "large" 26" radius curve on the paper. Make sure it's at least 90 degrees. Also lay out a 52" radius curve on a different part of the paper. This needs to be about 18" long. Using scissors cut the curves so you have some templates to work with.

3. Using a long straight edge, lay out your two straight sections of track, drawing a line down the center of each one. Draw another set of centerlines roughly 1" inside the original lines. These are the offset lines for the easements.

4. Using the 26" curve, draw the curves tangent to the two offset lines you just drew. This is the main section of your curve. Using the 52" curve, draw two curves tanget to the original straight track centerlines and the 26" curve you just drew. These are the easements.

The resulting curve is approximately an effective 27" radius, but is much easier on the eye AND operation of the equipment. It gives you a more flowing curves, with no sudden changes in direction.

Hope this helps!

Mark in Utah