CT Scans of New vs. Used SawStop • Hacker News Board

Re: CT Scans of New vs. Used SawStop

#161

Post by DannyBee » Mon, Dec 09, 2024, 5:29 PM UTC

close04 wrote: post #78

DannyBee wrote: post #38

Earlier quoted context omitted.

They've pretty explicitly been willing to release all of the relevant patents. The truth is it was always a red herring for their competitors. The major players all have systems that don't rely on these patents. Lawsuit discovery showed all of them had developed their own technology that was fine, patent wise. But it would have eaten into their profit. Personally, I have an altendorf handguard sliding table saw, whic…

I think free access to use the patented tech is only a part of the answer to building such a mechanism, and definitely a good first step. Looks to me like the build quality would make an even larger difference to the success of the device. For example: > The fuse wire is designed to be stable enough to resist stretching or thinning over time despite the intense repeated vibrations from the saw use, ensuring it doesn’…

I agree on all of this. But the others had already done the r&d. Take a look at the documents in the Massachusetts table saw injury lawsuit, from 2006, an example.

Re: CT Scans of New vs. Used SawStop

#162

Post by elzbardico » Mon, Dec 09, 2024, 5:42 PM UTC

Macha wrote: post #151

bluGill wrote: post #138

Earlier quoted context omitted.

The space between houses is smaller, and the houses have much smaller garages. However the house themselves are similar size.

They really aren't. My house is a 1250 sq ft 4 bedroom house. It gets comments from friends and family for being relatively large for a 4 br here, since the norm is 1000 sq ft for a 4 bedroom. Similar style houses in the US seem to be about 2000 sq ft from a property search.

Yes, even in a lot of south american countries, for a upper middle class perspective, 1000 sq ft for a four bedroom house is a bit on the small side.

Re: CT Scans of New vs. Used SawStop

#163

Post by aidenn0 » Mon, Dec 09, 2024, 5:46 PM UTC

My shop teacher seemed to think the band saw was more dangerous than the table saw. Was he wrong, or is it just that table saws are used so much more than band saws that they dominate the injuries?

Re: CT Scans of New vs. Used SawStop

#164

Post by toast0 » Mon, Dec 09, 2024, 5:48 PM UTC

bigstrat2003 wrote: post #152

mlyle wrote: post #6

Earlier quoted context omitted.

> Of these 30,000 injuries per year, how many happen when the blade guards are removed? How many happen when a push stick is not used? Seems like you don't buy into the swiss cheese model of accidents. Because other safety mechanisms and good practices exist, it doesn't mean that there's not reasons to add additional safety. In aviation, we always blamed the pilots for a long time, and it wasn't entirely wrong. Howev…

> Seems like you don't buy into the swiss cheese model of accidents. Because other safety mechanisms and good practices exist, it doesn't mean that there's not reasons to add additional safety. I think it's reasonable to say "we have done enough" at some point though. We can debate where the point is, but safety is not an unalloyed good. It has a cost, and reasonable people can disagree over whether a particular safe…

> I think it's reasonable to say "we have done enough" at some point though. We can debate where the point is, but safety is not an unalloyed good. It has a cost, and reasonable people can disagree over whether a particular safety invention has enough ROI to justify its existence.

That has to be a point in time decision though. Closed circuit TV backup cameras in cars have been possible since I dunno, probably the 70s, certainly 80s technology could have done it; but they weren't a reasonable intervention (outside of say armored cars for currency transports) until more recently as cameras and displays have gotten less expensive and quality has improved. Also helpful as modern vehicle design has resulted in significantly reduced visibility compared to the past, but that's a rant for a car article :P

Re: CT Scans of New vs. Used SawStop

#165

Post by andrewflnr » Mon, Dec 09, 2024, 5:52 PM UTC

zo1 wrote: post #94

andrewflnr wrote: post #3

Usually those fancy 3D displays are miserable on my phone, but the ones on this page pretty much just work. Lovely surprise.

Ironically, previous ones worked beautifully for me but this one fails on my desktop Firefox. Couldn't even select text on the page to copy paste, utter failure.

Just checked. It was indeed a lot worse on my more powerful linux desktop than my android phone. Firefox in both cases. Computers are stupid. :D

Re: CT Scans of New vs. Used SawStop

#166

Post by rewsiffer » Mon, Dec 09, 2024, 6:01 PM UTC

grues-dinner wrote: post #82

orbital-decay wrote: post #71

Is it feasible to stop the blade in comparable time by reversing the motor?

A basic consideration of the energy involved should tell you. 355mm radius disc, mass 1kg, moment of inertia is 1/2 mr², so 0.06 kg.m² [1]. This ignores all inertia of the arbor and motor rotor, mind, which is possibly significant (smaller radius but dense, depends on the transmission whether the motor is part of the blade system - if there's a clutch or belt to let go, then the motor isn't really part of the problem…

Meta comment: I really appreciate comments like this that breakdown problems to the first-principles physics and show their works. Thanks!

Re: CT Scans of New vs. Used SawStop

#167

Post by kurthr » Mon, Dec 09, 2024, 6:07 PM UTC

Blackthorn wrote: post #141

miunau wrote: post #98

Earlier quoted context omitted.

I'm not sure how comparable these alternatives are when two of them are "request a quote" kind of pricing, and the Altendorf is $7000+, unless you're considering an entire cabinet. None of them will go on a job site with you, for example. I would love to test the Felder system though.

Yeah, they aren't comparable in the least. These companies use it for market segmentation. You'll only get this on the ridiculously expensive table saws. Whereas a Sawstop cabinet saw (the industrial one!), still expensive for an American-style table saw, is a fraction of the price. In the case of Felder, 10% the price!

Totally agree, and wouldn't really comment on it except to say that the cheapest Sawstop is $1-3k even on blackfriday. That's not really in the same league as other jobsite saws that are $100-300.

Each one really is a ~10x step in cost above the other. Of course quality and safety/reliability are higher too, and I know which I'd buy. But, comparable only sort-of.

Re: CT Scans of New vs. Used SawStop

#168

Post by tstrimple » Mon, Dec 09, 2024, 6:08 PM UTC

aidenn0 wrote: post #163

My shop teacher seemed to think the band saw was more dangerous than the table saw. Was he wrong, or is it just that table saws are used so much more than band saws that they dominate the injuries?

Table saws are dramatically more dangerous than band saws. When a band saw blade makes contact with whatever it's cutting, the force is in a single direction. Down at the table which provides material support. Table saws use a rotating blade and often a fence system. Lots of things can go wrong there, but it typically involves binding between the fence and the blade which can lead to kickback which can send chunks of wood through a wall or potentially more dangerous is it can cause the wood to twist violently into the blade risking bringing your hand towards the blade.

Here's a saw stop in action, so it's not gory. But look at how FAST things go wrong here and how violent the interaction was.

https://www.reddit.com/r/Whatcouldgowrong/comments/11s53ew/w...

Compare that to a band saw in use, and you can see fingers quite close to the to the cutting edge and still have good control over the work.

https://www.youtube.com/watch?v=JlHe9gOphBw

Re: CT Scans of New vs. Used SawStop

#169

Post by dylan604 » Mon, Dec 09, 2024, 6:10 PM UTC

miunau wrote: post #98

jasode wrote: post #87

>, I have an altendorf handguard sliding table saw, which will stop as fast as the sawstop, The alternative approaches from other industrial saw manufacturers that are "non-contact non-destructive" are interesting: - cameras and machine learning used by Altendorf "Hand Guard": https://www.altendorfgroup.com/en-us/machines/altendorf-hand... - inductive proximity (same science as Theremin[1]) used by Felder "PCS Preven…

I'm not sure how comparable these alternatives are when two of them are "request a quote" kind of pricing, and the Altendorf is $7000+, unless you're considering an entire cabinet. None of them will go on a job site with you, for example. I would love to test the Felder system though.

There's no way I'm trusting the safety of my fingers to today's ML abilities reading a live camera feed.

Re: CT Scans of New vs. Used SawStop

#170

Post by oplav » Mon, Dec 09, 2024, 6:12 PM UTC

aidenn0 wrote: post #163

My shop teacher seemed to think the band saw was more dangerous than the table saw. Was he wrong, or is it just that table saws are used so much more than band saws that they dominate the injuries?

I haven’t used a bandsaw a lot, but I have seen some photos of gnarly lost fingers.

I use a table saw quite a bit and think there are more ways things can go wrong, most of which stem from kickback which happens in a split second. The wood will either fly back and hit you, or your hand will be pulled into the blade and you will likely lose a finger.

Both machines can be safe with the proper precautions. That said, I still enjoy my SawStop as insurance for my fingers since I still write software for my day job.