Track layout

[Markdel7]

I'm just starting out. I need some help with a layout. I want to make a simple oval to start. I'm using a 4 x 8 layout board. How many 18" radius tracks are need  for this?

[Terry Toenges]

12 pieces

[bbmiroku]

15" radius = 12 sections.
18" radius = 12 sections.
22" radius = 16 sections.

I've seen HO sectional track in 24" radius, and it is also supposedly 16 pieces to the circle, but I haven't used any personally, so I wouldn't be able to guarantee it.

[Terry Toenges]

This is a list of all Bachmann HO E-Z Track curved pieces and the number needed to make a circle.
Nickel Silver with gray roadbed
Part #               Radius inches                  
44505......................15" (12 pieces for circle)
44501......................18" (12 pieces for circle)
44503......................22" (16 pieces for circle)
44519......................26" (20 pieces for circle)
44506......................28" 18 deg (20 pieces for circle)
44509......................33.25" 12 deg (30 pieces for circle)
44504......................33.25" 18 deg (20 pieces for circle)
44508......................33.25" 6 deg (60 pieces for circle)
44507......................35.50" 18 deg (20 pieces for circle)
44532......................½ 22" (32 pieces for circle)
44531......................½ 18" (24 pieces for circle)
44530......................1/3 18" (36 pieces for circle)

[Len]

15" radius = 12 sections.
18" radius = 12 sections.
22" radius = 16 sections.

I've seen HO sectional track in 24" radius, and it is also supposedly 16 pieces to the circle, but I haven't used any personally, so I wouldn't be able to guarantee it.

Atlas makes Code 83 & Code 100 curves in 24" radius. They are 22.5deg arcs, so it would take 16 sections to make a circle. They come in packs of 4 sections, so it would take 4 packs to make a circle.

Len

[ebtnut]

Note that if you are using 4x8, then 18" radius is about as big as you want.  Track radii are measured to the centerline.  Therefore, a 22" radius half-circle winds up with the edge of the track being very close to the edge of the board.