• J3-Cub.com is the largest community of J3-Cub pilots, owners and enthusiasts. With over 1000 active members, we have fostered a vibrant community and extensive knowledge base. J3-Cub.com hosts a library of over 13 years of technical discussions, J3 data, tutorials, plane builds, guides, technical manuals and more. J3-Cub.com also hosts an extensive library of J3-Cub photos.

    Access to the J3-Cub.com community is by subscription only. Membership is only $49.99/year or $6.99/month to gain access to this community and extensive unmatched library of knowledge.

    Click Here to Become a Subscribing Member

    You will also get two J3-Cub decals as well!

Wing Spar Questions

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Jim Dickinson

Well-Known Member
Supporting Member
Joined
Aug 5, 2020
Messages
56
Reaction score
13
As some of you know, I acquired a basket case 1936 J2 with no paperwork, that I am going to build back as a home-built. Right now I am in "discovery" phase, my current question is about wings, The wing parts that came with the plane are a mix of J2 and J3 pieces. A few are OK, however the rest are rather tattered. It appears that the J2 and prewar J3 wings had the same size spars, specifically 5 5/8 inches high by 13/16 inches thick for the Front Spar and 4 inches high by 7/8 inches thick. In comparison the WAG AERO Cuby Spars are both 3/4 inches thick, by 6 1/4 inches high for the front spar and 4 1/2 inches high for the rear spar. I am not sure which wing foil I am going to use or the inside wing ends configuration, the J3's sure looks simpler on the inside ends.

I have heard that the wooden spars have more damping ability and therefore nicer riding than the metal ones, I wonder if the deeper Cuby Wood Spars are more like the original wood ones or the metal? Right now I am trying to figure which way to go. I am likely to use either Western Hemlock or Grand Fir (lowland white fir, which has near identical properties as Spruce) for the spars. My family has about 1000 acres of conifer timber-lands with mostly Douglas Fir, Western Hemlock, some Grand Fir, and just a little bit of unusable Sitka Spruce with too many knots. I am going engage an excellent small mill operator to custom cut the wood to the proper specs and cure it myself.

Your opinions please. Jim
 

Latest posts

Back
Top