Skip to main content

I am planning an O-scale Helix employing Gargraves 54" curved track.  I will be climbing 32" to run a train around my ceiling.  I found a Helix Design Calculator from modelbuildings.org which calculated with a 27" radius the ring diameter will be 58"; the vertical distance between rings is 6"; ring circumference is 182.12 "; the grade is 3.29%; rings needed is 5.33; length of each segment is 91.06".  Assuming the above calculations are correct, I do not have room for anything larger than a 54" diameter.   My questions are many; Does anyone manufacture an O-scale helix? What material should be used? are the calculations above correct? has anyone published an article on an O-scale helix? with a 3.29% grade, will engines be able to travel both up and down?  As you can see I am looking for any and all assistance.  Thanks!

Original Post

Replies sorted oldest to newest

I verified all the numerical values that you quoted, although the circumference (at the ring radius of 58") is 182.21". With a rise of 6" and a run of 182.21" the tangent of the elevation angle (at the ring radius) is 6/182.21 = 0.0329 = 3.29% grade and the elevation angle itself is 1.886 degrees. The calculator has added 4 inches to the nominal 54-inch center-rail diameter of O-54 track to get the ring diameter of 58 inches. This is equivalent to a center-rail radius of 27 inches which, plus 2 inches, gives a 29-inch ring radius (58-inch ring diameter). So, the calculated values are correct. If your ring diameter has to be reduced to 54 inches, the grade is increased to 3.54% and the elevation angle becomes 2.026 degrees. First of all, what are the center-rail radius and outer diameter of Gargraves O-54 track? If you want to know the center-rail radius/diameter, measure the distance (along a straight line) between the ends of the center rail of a curved piece of track and I will calculate the radius/diameter for you. Better yet, just lay down a circle of Gargraves O-54 and measure the actual diameter. I believe these grades are acceptable on straight track (with traction tires?) but you will have reduced load capacity on the O-54 helix.

MELGAR

Alan,  here are a couple pictures of my double helix,  I used 7/16' threaded rod as my vertical supports with nuts and washers.  I didn't use a lot of mathematical formulas just common sense and  trial & error.   The one on the left is 0-54  Lionel tube rail.  If I can help out with any construction questions my email address is in my profile. 

Doug 

2017-05-24 002 0172017-05-24 002 027

Attachments

Images (2)
  • 2017-05-24 002 017
  • 2017-05-24 002 027

Add Reply

Post
The Track Planning and Layout Design Forum is sponsored by

AN OGR FORUM CHARTER SPONSOR

OGR Publishing, Inc., 1310 Eastside Centre Ct, Ste 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
Link copied to your clipboard.
×
×