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Smartbolts

smartbolts.com

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Re: Smartbolts

#31

Post by blamazon »

auxym wrote: post #29
blamazon wrote: post #23

Earlier quoted context omitted.

First, I love the plain text diagram! (Edit: not fatigue) This failure should be predictable during the design phase and that fastener is either wrongly specified or should have a recommended number of cycles after which it should be inspected and replaced if found to be out of specification. Of course, many items in our built world do not receive the same level of design scrutiny as I would wish, nor the maintenance…

Unless I'm misunderstanding the diagram, it does not look like fatigue at all but rather yielding from shear loading. The definition of fatigue is a small crack (in fact microscopic in the beginning) that grows through the application of cyclical loading (typically about 10k cycles is the lower bound for high cycle fatigue, which does not involve macro yielding). Thus a fatigue failure would look like a fully rupture…

You are correct, I had a brain fart.

Re: Smartbolts

#32

Post by oneplane »

thom wrote: post #14

No pricing on the site, but I hope it's in the region of five thousand wrappages of Cardassian yamok sauce for a hundred gross.

I think the bolts listed in the article are less expensive than self-sealing stem bolts.

Re: Smartbolts

#33

Post by dalrympm »

I would love to see these on chair lifts. I wonder if the indicators can remain valid with the types of temperature swings you see on a ski mountain.

Re: Smartbolts

#34

Post by karaterobot »

It's annoying that, as you scroll down the page, the bolt animates to show it turning, but it scrolls out of view before it gets to the point where the main feature of the product would be shown.

Re: Smartbolts

#35

Post by samstave »

blamazon wrote: post #3

I’m a mechanical engineer - smartbolts are cool but rarely used in my experience. Much more commonly used are DTI washers: https://en.m.wikipedia.org/wiki/Direct_tension_indicator Due to the washer style can be used with a wide range of fasteners. The most common type, in my experience, due to the ease of use, has a little bit of colored goo inside the arched cells. The goo squirts out when the specified torque is re…

Just curious = how do these SmartBolts handle under full tension load AND fire conditions...

You have effectively drilled out the core of a bolt and replaced it with "goo" and you are using this as an indicator of the health of that fastening node?

So what if you burn out the goo? What if you get side/compression damage on the device -- what does the thing do when you over-tight/strip?

isnt a "goo core" less structurally strong than a solid bolt? Is a bolt tightened to a setting using a SmartBolt vs a regular bolt with tension wrench going to manage the same loads or not?

Re: Smartbolts

#36

Post by Freak_NL »

lttlrck wrote: post #6
blamazon wrote: post #3

I’m a mechanical engineer - smartbolts are cool but rarely used in my experience. Much more commonly used are DTI washers: https://en.m.wikipedia.org/wiki/Direct_tension_indicator Due to the washer style can be used with a wide range of fasteners. The most common type, in my experience, due to the ease of use, has a little bit of colored goo inside the arched cells. The goo squirts out when the specified torque is re…

Smartbolts seem to be useful in applications where there is an expectation the bolts will loosen over time/the maintenance lifetime, reducing/easing inspection time. Similar to the tell-tales used on truck lug nuts: https://www.dealsonwheels.co.nz/trucks/features/1302/new-tyr...

Ah; so that's what those are for. I've seen them on lorry wheels, but never got around to formulating a sensible query for a search engine. These becoming commonplace seems like a recent thing (as in last decade or so).

Re: Smartbolts

#37

Post by rsync »

blamazon wrote: post #27
mojomark wrote: post #17

Earlier quoted context omitted.

Out of curiosity, on a somewhat related topic, have you tried nord-lock washers [1] in any of your applications? We looked at them for a small work boat we designed and built, but they were a bit pricey and it was just a prototype, so we ended up just using a dab of lock tight to avoid vibration. Was always curious to find someone who had practical experience with these things. I may use them on an upcoming autonomou…

I have used Nord-lock washers, they are demonstrated to be one of, if not the most effective thread locking washer devices under heavy vibration, but as you say they are quite pricey. I would certainly recommend them if you have the time/cost budget, especially for something like an autonomous boat where vibration is expected and routine inspection is challenging or impossible. When I’ve used them, it’s been for crit…

"I have used Nord-lock washers, they are demonstrated to be one of the most effective thread locking devices under heavy vibration, but as you say they are quite pricey."

Which is odd, given their simplicity and ease of manufacture, etc.

Can you get them stainless or just HDG ?

Re: Smartbolts

#38

Post by mc32 »

auxym wrote: post #29
blamazon wrote: post #23

Earlier quoted context omitted.

First, I love the plain text diagram! (Edit: not fatigue) This failure should be predictable during the design phase and that fastener is either wrongly specified or should have a recommended number of cycles after which it should be inspected and replaced if found to be out of specification. Of course, many items in our built world do not receive the same level of design scrutiny as I would wish, nor the maintenance…

Unless I'm misunderstanding the diagram, it does not look like fatigue at all but rather yielding from shear loading. The definition of fatigue is a small crack (in fact microscopic in the beginning) that grows through the application of cyclical loading (typically about 10k cycles is the lower bound for high cycle fatigue, which does not involve macro yielding). Thus a fatigue failure would look like a fully rupture…

What I was trying to convey, which I didn’t do well in the diagram, was you have a bolt holding two plates together or a splice, and you have wear on the bolt shank -not necessarily shearing.

Re: Smartbolts

#39

Post by rsync »

dalrympm wrote: post #33

I would love to see these on chair lifts. I wonder if the indicators can remain valid with the types of temperature swings you see on a ski mountain.

In my experience, the most common safety practice on chairlift (poles) is a double-nut. It's very common to see all through North America - no washer, just two nuts stacked.

I've never inspected them to see if they have indicators painted on, etc. - one would assume they should ...

Re: Smartbolts

#40

Post by blamazon »

rsync wrote: post #37
blamazon wrote: post #27

Earlier quoted context omitted.

I have used Nord-lock washers, they are demonstrated to be one of, if not the most effective thread locking washer devices under heavy vibration, but as you say they are quite pricey. I would certainly recommend them if you have the time/cost budget, especially for something like an autonomous boat where vibration is expected and routine inspection is challenging or impossible. When I’ve used them, it’s been for crit…

"I have used Nord-lock washers, they are demonstrated to be one of the most effective thread locking devices under heavy vibration, but as you say they are quite pricey." Which is odd, given their simplicity and ease of manufacture, etc. Can you get them stainless or just HDG ?

You can get them in various stainless alloys. My understanding is they have a really defensible patent.
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