Fegve Titanium Keychainium

[Grant Lamontagne]

That's not actually the name of this keychain.  As far as i know, it doesn't have a name other than the ultra imaginative Fegve Titanium Keychain.  Still I think Titanium Keychainium sounds cool so I'm going to use it.

I've been trying to find more info on this plunger style detachable keychain doodad but mostly I'm finding Etsy listings, Amazon listings, some Ali Baba listings and a site that claims to tell you the difference between real and fake ones.  I don't know which I have, but I'm guessing it's real (enough) because it doesn't seem as poorly made as the site says the fakes are.

Mostly I was interested in the interestingly designed circular Carabiner that flexes to open and close.  It is a neat concept but I'm not sure about it in practice.

Def

[Grant Lamontagne]

Okay, continuing this on my laptop rather than trying to type all of this on my phone.

The carabiner is a very neat design, being circular like another split ring, but it has a number of alternating cutouts on one side of it, which flex and simulate a gate that you would find on a normal carabiner.  While it's a very cool concept, I have to wonder about the longevity, especially since anyone that knows about metal fatigue is aware that titanium suffers fatigue worse than most steels.  This could lead to the "gate" getting weak over time and contribute to the loss of your keys.

It would be interesting to know if this is some titanium alloy that may be more resistant to fatigue than straight up titanium would be.  Since I don't have any information from the manufacturer, I will just have to find out the old fashioned way and use the darned thing.   

Currently it seems to close up fairly well, but it doesn't really hold itself shut the way a spring loaded gate normally would on a standard carabiner, but then this one doesn't really open as wide as a typical one would either, so maybe it's still secure enough, in that the thing it's clipped on would have to be in exactly the right place at exactly the right time to escape inadvertantly.

This should be a fun one to test out.

As for the other part of this set- the plunger style keychain doodad is very well made, with seemingly super tight tolerances.  It goes together and locks into place while still allowing the keys to swivel on the bottom. 

This is extra important with this one as the bottom half actually has holes for two split rings for twice the key carrying fun.

You know, if that's your thing- I don't judge. 

Shine on you crazy diamond.

It also comes with a single hole on the bottom if that's your preference.

Getting back to the keychain doodad, I am going to start using it for a few things this week and see how the whole thing works out.  Currently it's hard to say because I've done nothing but play with the set since I got it a couple of weeks ago.  I'll be very interested to see what happens with it and how well the carabiner holds up.  I have more faith in the detachable key fob doodad as that's a typical, straightforward and time tested design.

More to follow.

Def

[Vidar]

I have to wonder about the longevity, especially since anyone that knows about metal fatigue is aware that titanium suffers fatigue worse than most steels.  This could lead to the "gate" getting weak over time and contribute to the loss of your keys.

Fatique depends on a number of factors. Three major ones are the number of movements, and the force used (ie the level of stress imposed on the metal), and whether or not the material has a fatique limit. If the material has a fatique limit then it can endure an infinite number of movements as long as the stress stays below that limit. Steel and titanium have such a limit. That means that if the design is properly made, and not abused beyond it's intention (thus exceeding the stress level), it should never fail due to fatique.

Examples of materials without a fatique limit is aluminium and most plastics. Even without such a limit the number of movements or cycles required to cause failure might be in the millons or billions - again dependent on the force and stress of the movements. Plastic packaging with so called living hinges are for example often made of PP (polypropylen) as that will endure way more opening and closing than normal use requires.

Nice key chain concept by the way. Looks like it is made with an EDM wire cutter (electro discharge machining). Interesting that the cost of using those has come down to keychain levels. 

[Grant Lamontagne]

Interesting and thanks for the information.

That is not my understanding, but I haven't got the experience that you do, so I find myself unable to argue or ask any more meaningful questions, so I will happily accept that this keychain doodad isn't likely to break!

Thanks for the info- I'll have more faith in this one now.   

Def

[Vidar]

Ah, it can certainly still break if the design causes stress over the fatigue limit when opening or closing. But how often do you change your keys? I'm just saying that if a design takes fatigue and normal use into consideration titanium shouldn't fail from fatigue. Whether that is the case here I don't know.

There is no disagreement between what you said earlier and what I said? Both steel and titanium can have their fatigue limit that allows infinite cycles, but the steel fatigue limit might still be considerable better than the one for titanium. Thus titanium could fail with a design made for steel. And as many products seems to keep the design and just give a choice of material that might cause some issues? There are certainly also designs out there too that don't stay below the fatigue limit in normal use and thus will fail eventually - and then faster for the weaker material. (Both steel and titanium have lots of alloys so maybe also some overlap somewhere).

A side note, and why this is so is way beyond my understanding, but the medium the material is in is apparently also a factor. I know because I once designed a metal spring to be mounted submerged in the sea. We even consulted a metal professor about the choice of spring metal and the use case. The forces was nicely within the fatigue limit in air, yet after some months in the sea they started failing. That cost lots of time, roughly USD 100000 to fix, and the replacement spring (then not metal...) was more expensive increasing the products overall cost ever after.

Some months later a colleague of the first professor said that the metal had no fatigue limit at all in sea water, and thus that failure was to be expected. Great, tell us that now... 

[Grant Lamontagne]

That sounds like a bit of a boo boo indeed.... 

I imagine the carabiner will by cycled a lot as it gets connected to my jeans of back pack and disconnected, likely multiple times per day.  It will be interesting to see what happens, and I will be sure to keep my Keysmart Pro charged so if it does get lost due to failure I have a decent chance of finding it again!   

Def

[Vidar]

In that case I would trust myself to somehow activate the unlock and loose the keys regardless of material. I'm gifted that way it seems.

The ring is a fun design so will be interesting to see how it goes long term. 

[Grant Lamontagne]

In all honestly I haven't really figured out how exactly I'm going to use it just yet.   

Def

[fullbreakfast]

Mostly I was interested in the interestingly designed circular Carabiner that flexes to open and close.  It is a neat concept but I'm not sure about it in practice.

I have one similar / identical, supposedly made by “Mec Army”, and I find it pretty good. Have been using it without issue for a few years.

[Grant Lamontagne]

That's good to hear!

If you get the chance, I'd love to see it! 

Def

[fullbreakfast]

That's good to hear!

If you get the chance, I'd love to see it! 

Def

I missed this earlier.  I use it for my work keyring, which has a key for the building a fob for internal doors:



The size of the 'carabiner' means I can slip it onto a finger, or even a thumb if I want:



Comes in handy, because if I let the key and fob hang at the back of my hand, I can use the fob to open doors when I have both hands full of a laptop and a coffee. Nothing ever came off the ring when it wasn't supposed to.

I kind of hate having a big keychain these days, so keep it minimal: carry a single house key generally and keep this in my work bag. My days of having six keys, a Minichamp, a Photon light and a mini Sharpie bunched up on a keychain in my pocket are definitely over.