Heim Vs Aurora

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Steve D
Posts: 50
Joined: Sun Mar 05, 2017 9:50 pm
Location: Grand Republic of Texas

Heim Vs Aurora

Post by Steve D » Thu Jun 01, 2017 1:27 pm

I am going to order Rod End Bearings for my die spring replacement to the bungee landing gear. What is the difference between heim and Aurora bearings? there is a big difference in price.

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taildrags
Posts: 277
Joined: Tue Mar 07, 2017 10:39 pm

Re: Heim Vs Aurora

Post by taildrags » Thu Jun 01, 2017 10:26 pm

Steve; as I understand the term, "heim" has now become somewhat of a generic term for the ball-end fitting we're discussing. The original patent was to a German company (Heim), but the patent has since expired so others are making the same product. In the automotive world, if you say 'heim joint', it's pretty clear what you're talking about.

I checked one sample item, a Heim HME-5, which is a male threaded 5/16-24 piece. It has a maximum static radial load rating of 2,080 lbs. The Aurora equivalent is their MW-5TM-125 and it has an ultimate radial static load rating of 3,133 lbs. The usual interpretation of "maximum" and "ultimate" is that "maximum" is the highest working rating without deformation, while at "ultimate" load, the metal has transitioned from elastic deformation to plastic deformation (no going back! it's bent or fractured!)- so the two stated load ratings aren't really apples and oranges. However, the materials of construction and specs for the parts look very much the same. The Heim part that I looked at has an aluminum race (the part the ball rides in) while the Aurora part has a carbon steel race. Everything else is constructed the same.

The landing gear is a highly stressed assembly so it's important to use good stuff there. However, I would venture to say that most builders think along the lines of, "if Aircraft Spruce sells it and says the Aurora part cross-refs to Heim, it's OK". Perhaps someone who has built a setup like Terry's can speak up about whose ball-end fittings they used on their landing gear, and why they selected those parts.

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