Some crazy canuck cut one in half to show how they (don't) work: https://www.youtube.com/watch?v=ClPwlpa86bY
When you said "some crazy canuck", I immediately knew it must be AvE
Smartbolts
11–20 of 150 posts
Re: Smartbolts
#12Earlier quoted context omitted.
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...
Installing to a known torque and painting a line on the fastener is a lot less expensive, which becomes important when your project has potentially tens of thousands of key fasteners, like a bridge. But for something like an MRI machine where there’s fewer fasteners and higher stakes - would make a lot of sense to use Smartbolt I think. Tangential: related to trucks, there is a somewhat similar product to easily moni…
Yeah, a quality torque wrench isn't cheap (particularly the kind you find in fixed installations like auto repair shops and factories) but there's got to be some crossover when you are buying enough bolts that you're better spending money on tools that are more idiot proof.
Re: Smartbolts
#13Earlier quoted context omitted.
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...
Installing to a known torque and painting a line on the fastener is a lot less expensive, which becomes important when your project has potentially tens of thousands of key fasteners, like a bridge. But for something like an MRI machine where there’s fewer fasteners and higher stakes - would make a lot of sense to use Smartbolt I think. Tangential: related to trucks, there is a somewhat similar product to easily moni…
A problem with installation is that torque is only a proxy for tension. Torque alone is not incredibly accurate, so there are a lot of cases that could benefit from an easier way to accurately indicate tension than by externally measuring the stretch of the bolt (which often is not an option)
Re: Smartbolts
#14No pricing on the site, but I hope it's in the region of five thousand wrappages of Cardassian yamok sauce for a hundred gross.
Re: Smartbolts
#15Earlier quoted context omitted.
I'm not an ME or anything, but it would seem washers attest to pressure (tension) at some point in time (when the nut was tightened -unless the washer is "springy", which I doubt as it seems it simply yields at some point), whereas smartbolts attest to the tension when you look at them --so during maintenance and not only during installation, so from that PoV, they are more useful (informative).
That’s true, but you can have a qualified inspector mark bolts with goo with a paint line that straddles to the fastening surface. Then you can just inspect the paint line for movement, which gets you most of the same functionality at significantly lower cost. Of course, that requires a trustworthy inspector, which is one application where smartbolts become useful, if you don’t have a trustworthy inspector available…
Yes, that seems like a cheaper option; however, I think when you have constant stresses over time, bolts can stretch or simply parts can wear over time and a paint score or even a frozen nut won't reveal lessened tension. Though maybe in this case the issue would have become a concern way before the bolts start to indicate a problem?
Re: Smartbolts
#16Earlier quoted context omitted.
Installing to a known torque and painting a line on the fastener is a lot less expensive, which becomes important when your project has potentially tens of thousands of key fasteners, like a bridge. But for something like an MRI machine where there’s fewer fasteners and higher stakes - would make a lot of sense to use Smartbolt I think. Tangential: related to trucks, there is a somewhat similar product to easily moni…
Yeah, a quality torque wrench isn't cheap (particularly the kind you find in fixed installations like auto repair shops and factories) but there's got to be some crossover when you are buying enough bolts that you're better spending money on tools that are more idiot proof.
[deleted]
Re: Smartbolts
#17I’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…
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 autonomous boat project where there's nobody around to do rounds and tighten loose bolts that have shaken loose unexpectedly.
Re: Smartbolts
#18Some crazy canuck cut one in half to show how they (don't) work: https://www.youtube.com/watch?v=ClPwlpa86bY
Really informative comment on that video:
"Nice video. Couple of points: 1: As per the title of your video, its worth emphasizing that these are tension indicating bolts, not torque indicating bolts. 2: With any bolted connection its the tension that is important. Whilst torque and tension should be correlated, that relationship varies considerably from bolt to bolt, lubricant to lubricant, hot to cold, state of corrosion etc... 3: So a bolt torqued to say 100NM may well have a tension variance of over 100%. The result is that bolts are often over or under tensioned, which can compromise the entire bolted connection. 4: Bolts like this (I've personally used Rotabolts, which are similar in concept but in my opinion better as they rely on a mechanical indication rather than a subjective color hue.) are very useful for certain applications, for example, sub-sea connections where divers have limited time and feeling, and sea conditions affect the bolt lubrication. 5: Other uses are for ensuring correct bolted connections on sensitive flanges, again offshore and sub-sea sees a lot of this. 6: Bolts like this are, in summary, brilliant for when you need a good quality bolted connection with correctly tensioned bolts. For most applications however they are unnecessary. Keep up the good work! :-)" - drawingboard82
Side note: youtube mobile when I tried to copy the comment wants me to sign in, to just copy a comment! wtf youtube! I just opened it in newspipe instead and copied from there
Re: Smartbolts
#19Earlier quoted context omitted.
That’s true, but you can have a qualified inspector mark bolts with goo with a paint line that straddles to the fastening surface. Then you can just inspect the paint line for movement, which gets you most of the same functionality at significantly lower cost. Of course, that requires a trustworthy inspector, which is one application where smartbolts become useful, if you don’t have a trustworthy inspector available…
Yes, that seems like a cheaper option; however, I think when you have constant stresses over time, bolts can stretch or simply parts can wear over time and a paint score or even a frozen nut won't reveal lessened tension. Though maybe in this case the issue would have become a concern way before the bolts start to indicate a problem?
Interestingly that has kind of moved upstream to a design phase consideration in modern times due to the incredible depth of understanding we have about materials. Structures can be designed such that their expected loading will not stress fasteners beyond their ‘yield strength’, which is well characterized.
Fatigue complicates the analysis, but we understand that too nowadays, although that is an understanding forged by many unfortunate consequences, such as: https://en.m.wikipedia.org/wiki/Aloha_Airlines_Flight_243
Re: Smartbolts
#20Earlier quoted context omitted.
Yes, that seems like a cheaper option; however, I think when you have constant stresses over time, bolts can stretch or simply parts can wear over time and a paint score or even a frozen nut won't reveal lessened tension. Though maybe in this case the issue would have become a concern way before the bolts start to indicate a problem?
Interestingly that has kind of moved upstream to a design phase consideration in modern times due to the incredible depth of understanding we have about materials. Structures can be designed such that their expected loading will not stress fasteners beyond their ‘yield strength’, which is well characterized. Fatigue complicates the analysis, but we understand that too nowadays, although that is an understanding forge…
Maybe the following has been designed out; however, I've on occasion seen the following wear pattern which compromises the initial strength of a fastener (usually due to friction over time):
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_ _______| |
_| |__/ |
| ______ |
|_ ____/ |_|
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