Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Smartbolts

smartbolts.com

Post reply on HN
Print view View original

61–70 of 150 posts

Re: Smartbolts

#61

Post by throwawayboise »

PaulHoule wrote: post #12
blamazon wrote: post #8

Earlier 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.

A problem with many torque wrenches is that they click (or beep) when the set torque is reached, but they do not prevent tightening beyond that, nor do they have any way to indicate how much overtightened the fastener might be. It seems to me that these bolts have the same issue.

Ever wonder why the tire shop has tightened your wheel lug nuts so tight that you can't get them off with the hand wrench when you need to change a tire? They spin them on with a pneumatic impact wrench, and then "check" the torque with a torque wrench. Of course it clicks, because the nuts are already way too tight.

Re: Smartbolts

#64

Post by dalrympm »

rsync wrote: post #39
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 ...

I've also noticed that the nuts go on top. I've always wondered if this was so it was completely obvious if a bolt dropped out (i.e. sunlight coming through the hole).

Re: Smartbolts

#65

Post by choonway »

dmkolobov wrote: post #58

I was one of the folks who put together the steel for a waterslide in a certain amusement park in California. Our method consisting of putting a mark across the bolt and nut after tightening it all the way down with a spud wrench, and then using a breaker bar until the mark on the nut was at the 4 o'clock position( or maybe it was 8, I don't recall ). The inspectors would then use a telescope to check every mark. Com…

or you could use a drone with a sufficiently zoomed in and stabilized camera.

Re: Smartbolts

#66

Post by dmkolobov »

choonway wrote: post #65
dmkolobov wrote: post #58

I was one of the folks who put together the steel for a waterslide in a certain amusement park in California. Our method consisting of putting a mark across the bolt and nut after tightening it all the way down with a spud wrench, and then using a breaker bar until the mark on the nut was at the 4 o'clock position( or maybe it was 8, I don't recall ). The inspectors would then use a telescope to check every mark. Com…

or you could use a drone with a sufficiently zoomed in and stabilized camera.

Totally, but the crazy part is that there is nothing preventing you from making these marks without following the appropriate tightening procedure. When the project is several months late and people are working 16 hour days, the temptation to cut corners is high.

Re: Smartbolts

#67

Post by hinkley »

If you think the head of a bolt with an indentation in it is going to stay clean, especially one that has to stay tight, then you have not held a wrench often enough, my friend.

Once that red spot gets dirty, you're not going to be able to tell if it's brick red because it's loose, or brick red because it has dirt on it. It's probably going to take you longer to clean the bolt than to get the torque wrench on it.

Re: Smartbolts

#68

Post by hinkley »

dmkolobov wrote: post #66
choonway wrote: post #65

Earlier quoted context omitted.

or you could use a drone with a sufficiently zoomed in and stabilized camera.

Totally, but the crazy part is that there is nothing preventing you from making these marks without following the appropriate tightening procedure. When the project is several months late and people are working 16 hour days, the temptation to cut corners is high.

> making these marks without following the appropriate tightening procedure

If you didn't torque the bolt tight enough then it will come loose sooner, and the lines won't line up. I'm sure there are situations where the torque of the bolt is critical for handling peak load on the system, but for a lot of situations where a torque wrench keeps you from damaging by over-tightening, and makes sure you got it tight enough that it stays tight.

I should say there's one other failure mode a torque wrench can test that that the paint doesn't by itself, and that's a failing bolt. If you've ever seen a broken bolt, and the entire surface isn't uniformly shiny, then you've seen a bolt that cracked a long time ago and then failed recently. That crack is going to show up as less torque. So if the bolt hasn't spun but the torque has dropped, you might have a problem, rather than having a freak incident where the nut spun exactly 360° since you checked it last.

I could see an argument for using paint and smartbolts for fasteners with epic failure modes, like people dying or generators exploding.

Re: Smartbolts

#69

Post by WalterBright »

At Boeing, I learned that bolts should be lubricated before torquing them in order to ensure an accurate torque. I initially thought wouldn't the lubrication allow the bolt to unwind itself? Surprisingly, no.

Since then, on my car, I always put a bit of grease on a bolt beforehand. It keeps the water out, preventing the bolt from rusting itself together. It makes for an accurate torque. I've never had one unscrew itself, and I can always get the lug nuts off!

Of course, you still need to use lock washers. For critical bolts, use a cotter pin or a safety wire.

Re: Smartbolts

#70

Post by WalterBright »

blamazon wrote: post #8
lttlrck wrote: post #6

Earlier 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…

If you look at a tire from the side, you can precisely see the bulge of the tire, which I do all the time to check the pressure.
Post reply on HN