Master Links

[kmcclary]

Originally Posted by imdunne8

Our team is having a dilemma over the strength/durability of master links. Please tell me about any good or bad experiences you have had using master links.

Better questions might be: "How much tension are you putting on the chain?" and "Is there any angular or offest misalignment between any sprockets?"

OOC, what size chain are you using, and for what purpose? You should be using #35 roller chain for most purposes on the bot. Anything smaller, and you risk chain failure *somewhere*. (...And any larger, and you're probably wasting weight allowance).

Second: Master links typically come in at least two flavors:
- C-clip locked
- Cotter pin locked.

I've yet to see a cotter pin locked master link fail. I have often seen C-clip master links come apart, but mostly due to either faulty installation, or angular/displacement misalignment of sprockets relative to each other causing side forces to appear on the clip.

If any side-side forces are present, the normal chain links can handle them better than the C-clipped master link. Therefore, the master link is normally what fails, first via unclipping, and then full chain failure via unbending of the remaining unsupported "U" until the chain separates.

The solutions are to verify:
(a) there is no angular misalignment of the sprockets relative to each other,
(b) that the sprockets are kept in the same plane via proper colleting or other spacers, and
(c) that the sprocket shafts are not "sagging" due to either overloading, lack of a bearing block at both ends (cantilever), or excessive unsupported lengths.

This last one causes intermittent "sprocket misalignment", which then typically manifests as a chain failure, often by the master link! This fools you into thinking it's a chain or master link problem, when it's really a sprocket "alignment maintenance" problem!

Does this make sense in your case?

- Keith