The Impossible Rod Coupling - Does it exist? 5

[DistressedNerd]

Hello,

I am in search of 1/4" to 1/4" diameter Steel Rod Coupling with the following requirements:
1. Low profile (minimal expansion beyond 1/4" cross section of rod)
2. Quick connect/disconnect
3. Structurally sound and near equivalent strength to 1/4" steel rod itself
4. The catch all - practical to incorporate in mass produced product

Please send a hyperlink of a rod coupling that meets the criteria and I'll make custom rap about your username and grant an additional wish.

Thank you,

Edison

 

[MadMango]

I wasn't trying to engineer the OP's solution, only offering a suggestion. A snap ring would be better than the e-clip shown, and sharp corners should be removed to reduce stresses. The 3-lug features could be made with rotary broaching or standard CNC.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

 

[KENAT]

Seems there may be a US/rest of the world naming discrepancy related to the infamous cotter pin confusion.

This is what I'm talking about.

http://www.mcmaster.com/#pins/=12skwej

has a whole bunch of pins that may work.

One assumes you've spent a bunch of time googling similar items to see what worked for them? Obviously make sure not to intentionally violate any IP.

https://www.google.com/search?q=col...ved=0ahUKEwi-jbW95J3NAhUE9mMKHeUECrUQ_AUIBygC

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[JNieman]

I question the requirement of no tool being needed. It's really not inconvenient or risky if it's integrated into the overall product, like a drill chuck key on some portable or cordless drill motors.


Overall, I'm a big fan of rigid mechanical couplers like @MadMango modeled in the post a few spaces up. It's a semi-common strategy for such situations. When you /do/ want flex in the line, then I'd design something akin to your average automotive universal joint, so long as the angle of flexure isn't great. Without the flex though, you minimize clearance between mating lugs/fingers and come up with whatever manner of retention is practical. Using a 4-lug mate would be easier to make, but less rigid than the tri-lug coupler @MadMango suggests.

I believe that's generally the wisest approach, until someone else comes up with something better