curve radius

Model Railroader Layouts and layout building
1

hi 2 questions
1 I am building a shelf layout in HO. it is 1 foot wide around the walls. how large of a radis can i put up?
2 how can Idraw the radius if the center of it is in the middle of the room?
Thanks

2

Do a scale drawing.

Randy

3

To draw the radius on the shelf use a trammel on a tripod.
Enjoy
Paul

4

You can also make a template of the radius out of foam or cardboard. I made a couple of 1/4 circle templates of the most common curve standards that I use on my N scale layout (18" main, 12" industrial) and these speed up the laying out of the tracks immensely.
Ron

5

The center of your radius is not the center of the room. If it was you would wind up with one big circle based on the shortest distance to a wall. If you really want to lay it out accurately you need what is called a tramel and you can make one from a stick. here are the steps:

  1. Decide what radius you want
  2. find a stick longer than that - a yradstick is already marked and works well
  3. Drill a hole for a pencil at the correct radius for the curve you want.
  4. Drill holes on either side to mark the edges of the board it will go on
  5. Use a nail in a smaller hole at the other end as a pivot and stick the pencil in each hole and draw the lines on the wood and then cut it out

One word of caution if you want say an 18" radius and a 4" wide base board don’t drill at 18" for the radius and 16" and 20" for the edges. Put the three holes at 17", 19" and 21" so you can move the nail pivot in one inch at the other end and put it at 1" so there is lots of stock for the pivot point. With this device you can make any curve up through 35" in radius.

6

When I did my layout, I got a piece of 1x2 or 1x3 and clamped it to the benchwork. I added some bits of material to build it up to the height of the roadbed. (actually, I clamped it to the underside of the Homasote and used a piece of Homasote) Then move the bit with the material around until you get it where the curve centre will be, and put in a nail. Then draw your cuves with the yardstick or whatever.
You can get a larger curve than you might think. You can get a larger curve by aadding a triangular piece into the inside of the corner.