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My kickback happened in High School shop class. The piece I was cross-cutting was pinched between the blade and the fence. It flew over my right shoulder and dented the wall behind me. I will never forget it. My shop teacher made sure I was ok before asking me what happened and what I learned. I was given the rest of the period off to let the adrenaline dissipate. Thank you Mr. Heinrich.
@@weekendwarrior3420woke!!! Doesn’t surprise me your call sign is weekend warrior Without this incident the author would never have learned. Why is your first focus to blame the teacher….. he’s teaching.
@@dannyarcher Because the teacher shouldn't let students use the saw before he made sure they know how. This thing can literally leave someone without an eye or fingers - I'd not like my child to be in that position. You obviously are OK with it.
You do have to spend some time setting the saw up... blade, fence, etc. But once done, the saw is great. Fairly compact which is Nice ru-vid.comUgkxXh-4_3-ZT1fFWP91ZV7iVqzElr0lEb-a I did get an Incra Miter Gauge which takes some setup as well. The stock miter gauge can be adjusted in the miter slot with a little painter's tape... this tightens up the side to side play a lot.
That YT video should be shown to EVERY person who buys a table saw. They are a really dangerous tool used in the wrong untrained hands. Well done JKM and thanks for all your time and effort to put it together.
also that company that built the “auto” stop needs to be told to allow all table saw manf to install there product in thee products. yes at a low price. as it will save many fingers snd lives.
First: awesome video! Second: you asumed the piece of wood took the entire 60cm to accelerate. But effectively the wood only accelerates while in contact with the blade. Shouldn't we run the numbers only for that short distance? Without counting frames I assume the acceleration would be much higher.
@@mal-tYou're right. Also, this is just estimating the force the blade places on the piece, not the force the piece will put on the operator. Since we don't have any information about the impact we can't calculate forces/impulses there. Instead, you might calculate the velocity of the piece _after_ it leaves the blade, then calculate energy the block has, and compare that to the energy in the bullet or the energy of a JKM falling from various heights. If you really want the force from the blade on the piece, and we allow the constant acceleration assumption for convenience, it might be more accurate to get the velocity after the piece leaves the blade and divide by the time from the instant the piece starts to move backwards to the instant it leaves the blade. Last one, and I'll get off my soapbox. The force of 130 lbf should really compared to (some fraction) of a JKM standing on your chest, not dropping from some height.
@@gcranston83 You are right, too. The force on the Operator can be computed, if you divide the change of momentum of the flying piece by the time it hitting the Operator. The correct numbers would be very interesting.
@@JR-xt1bj right, but we have no information about that impact, so all we can talk about--at least in terms of numbers--is the energy (or momentum) the block has when it leaves the blade.
Great video Jonathan! Lots of food for thought! Though, are we not going to talk about how the ballistic gel dummy, from sheer shock and confusion alone, fell forward into the running blade? While a kickback is awful, let's not forget that getting knocked out in the workshop can have lots of other unforeseen consequences.
Boy do I wish I found your channel a few months ago. Amateur wood worker, who had a board kick back and nearly cost me a finger… Really appreciate your videos and the safety tips in them.
Great video! Before retirement, I took care of 4 DIY home woodworkers in the operating room (anesthesiologist), one of the workers we saw twice. He was a lifetime woodworker, and after seeing this video I wonder if his table saw was not adjusted properly. These were horrible injuries, one man partially losing his thumb, and later his index finger to Kickback injuries. We never saw any fingers lost to the spinning blade. These injuries usually occurred after 9pm, when they were working in their workshops, after working their regular shift day job.. I can only guess that they were tired and therefore less careful.
I wonder if tablesaws are particularly prone to fostering "normalization of deviance" behavior w.r.t. safety protocols. I.e., the protocols seem unnecessary for 1000 cuts, so why bother with them?
I lost just the tip of a finger and a fingernail to a dado blade. I learned two important things. Do not work late at night or when you are tired. Do not try to feed small parts by hand.
@@fastcode1772 I just saw your comment. I have never even had any formal training in table saw use(high school woodshop). So I try to learn everything I can.
Jon, Just experienced this very thing. My mistake entirely. Mistake #1. I was working while tired Mistake #2. I was using the fence instead of the crosscut sled. The wood piece was short and I should have realized it but go back to mistake #1. I pushed it through and by the time I realized what was happening it was over. The piece of Meranti bounced in some weird way and I wound up with a bruise on my right arm from the wrist area to about 6” to my elbow with it being from 1”-4” wide AND somehow the piece struck my right abdominal area about an inch to the right of my belly button and about 2” north of there and left a gash about 3.5” long. It’s almost healed but damm …it hurt. Not fun. Thanks for the video!
Years ago I heard my neighbor working in his garage, the table saw and vac system was always noticeable. I was on my back patio cooking chicken on the grill. I thought I heard something screeching like a belt on a pully, I walked around that side of my house but all I could hear was his shop tools running, so I went back to my patio. About 10 minutes later I heard a woman screaming and I ran towards my neighbors house. As I entered the open door of his garage/shop, I saw his wife on her knees back in the corner, still screaming. I ran in and saw my neighbor laying on his back with a long narrow strip of wood sticking out of his neck by his collar bone. I walked to the wall by the door into the house and used the phone on the wall and called 911. I went to her and got her to stop screaming. I knelt by him and checked his pulse and realized he was breathing, but slow and easy like he was just sleeping. After about 10 minutes Fire & Rescue showed up. They revived him with smelling salts and a whole lot more screaming ensued. They calmed him, packed around the wood with gauze pads and placed him on a board and took him away in the ambulance with the wood still sticking out of his collarbone area. That was a case of kickback that I will never forget. I didn't see that the wood had went clear through his shoulder blade in back also. No arteries or veins were hit, didn't see a lot of blood at all but he had a 14 inch long, 1 3/4 inch square piece of maple in him. He also had a broken nose and concussion from hitting the floor. He survived but the garage shop didn't. His wife put her foot down. The garage became a garage only after that.
So did you become a woodworker after that incident, or had you already been one, or are you not one? I know it would certainly affect how I saw woodworking either way.
I was an outlier. Working in the carpentry shop on USCG base NOLA 1979 and I was at the end of a 114-degree day in New Orleans and dreaming of cold beer. I was almost done with a bunch of boring repetitive cuts and was hurrying to finish. I ran a piece through and got the bang! kickback. I was hit right in the brass belt buckle. If I was a skosh taller I would never have met my son. No riving knife, no blade guard, no safety glasses, a cabinet Delta Unisaw. EXTREMELY LUCKY. Great video. Thanks for the link to the professor too.
Yes, these are no toys. Bandsaws do not have these issues. A major reason for kickback was not mentioned, if I recall correctly - tension in the wood that is released when ripping solid woods. Tension is released, the piece of wood expands, presses against fence and teeth. In Europe, many pro saws have a slidable second fence. You position it at the middle of the saw blade. It creates a gap between main (ripping) fence and the adjustable fence attached to it, so wood can safely expand at/ after the cut. Had a kickback on a small chop saw with a tiny piece of oak 1x1 inch diameter. Hit my hand hard, made a cut and bled. Shock was worse than pain actually. Thanks for great video!
Thank for this. I had my first kick-back earlier this year. Hit me in the ribs and left a gnarly bruise and an abrasion the exact size and shape of the 3/4” plywood I was using. Luckily, no broken ribs. It scared he bejesus out of me and I have even more respect for the tool. Making sure I take all your pointers!
Been looking forward to seeing this ever since you first announced it. Nailed it once again, great work! No doubt this will change some of the bad practices/information that we've all grown far too comfortable seeing 👏
Yeah, I did an "experiment" 20 years ago kind of like this. I was ripping maple table legs about 2 inches square. I was not using a proper push stick and my old 1954 table saw an elderly neighbor gave me had no blade guard. The push stick was a 3/4 inch by 3/4 inch by 18 inch length of red oak. With a 45 degree end which I was holding. After I finished the forth leg I got sloppy bringing the push stick back, and I let it swing a little and it caught the top of the blade. Bang! It shot right into my forearm. Sank in about 3 inches, in and up my arm, almost to the crook of my elbow. I now have proper safety equipment on the saw, and proper push sticks, feather boards, etc. And a very health respect for kickbacks. I still have the bloodstained "push stick" in my workbench for a reminder. And of course I should add: Never stand in the line of fire. Great video.
Guy I used to work with was pushing a piece about twice the length of the piece you were using in the video through a 5 HP saw and got it right in the ribs. He had two broken ribs and a cut about 3 inches long. The bruising he had was hard to even look at. Ive had kickback on the miter saw that messed my fingers up pretty good but nothing broken. Ive never personally had it with the tablesaw but I was taught from a young age to keep control of the work piece. Safe cuts everyone and happy holidays
Three or so years ago, I was rip cutting a short (9") 2 x 6. I always use a riving knife but in this case I had been lazy and hadn't retracted the blade from a cut I had made previously on a 3 x 3 piece. I also hadn't taken the time to clear some chippings from the bottom edge of the fence. Needless to say, the riving knife saved me from a potentially more serious injury but the piece rolled over the top of the knife and rode the top of the blade and caught my right arm just above the elbow. Thankfully I got away with some serious bruising but it made me completely rethink and then revamp my entire workshop specifically to preserve life (namely mine) and avoid as many future issues as possible. Needless to say, laziness in a workshop WILL MDK you. Don't be like the old me, take the time you need to make safe cuts, it WILL save your life.
The one and only time I’ve had a kickback on a table saw is when I was rushing and cutting corners so to speak. This is the best video on table saw kickbacks ive seen on RU-vid, thank you very much Jonathan, you will save some people serious injuries with this video.
Thanks Jonathan, that was the definitive anti kickback video. I will be making sure all of my students watch this in the future. It is as important to know why something happens as to know what to do to prevent it. Keep control of your wood at all times the wood is contact with any blade. Professional!
Great job Jonathan and team. 2014...~600 hours behind a PM66--insufficient downward force on a dado stack. 1 lb chunk of mahogany hit me in the gut and caused internal bleeding and three days of constipation. A push block would have given me the confidence to push the workpiece down hard enough to have avoided the kickback.
Thanks for this. A huge thanks. I shared on a big Facebook beginner group of woodworkers, hoping it will help people quit the “I know what I am doing, it won’t happen to me” attitude.
Sorry to fact check, but the math is all wrong. The acceleration induced by the blade is not only calculated wrong, but is irrelevant to the impact on the body. The only thing that matters is the kinetic energy of the object based on the mass (M) and the velocity (V) ... Energy = (1/2 MV^2). If you assume that the velocity is .06m/.035s, then the kinetic energy is about 97 Joules, or about that of a baseball at 81 MPH.
Absolutely and it’s embarrassing! You don’t get hit with the force used to throw an object! You get hit with the momentum it has at the moment of collision! All that’s needed is speed and mass to calculate this! (And then dampening effect in the colliding materials can soften the impact!) Once the pice is moving, it is only accelerating SLOWER (aka slowing down) due to air resistance and gravity… the initial force used is not relevant-and cannot even be calculated - only the velocity achieved by the initial force… The force of the saw blade has to do with the mechanics of the blade itself.. but once it strikes the object, the questions becomes 1 Can it throw the object (overcoming the object’s inertia), and if so, what is the speed of the saw because that will become the speed of the object! Then the object will be slowed by gravity and resistance against the table and the air. So the force at the blade is relevant when determining whether the object will be thrown or bog down the blade. Internal motor force capacity vs inertia of the workpiece.
@capnjs yeah this European clown must not have very good credentials they didn't say anything about him other than "he's good at math and does woodworking" plus an eastern European accent must make him a genius! Sarcasm
Why would you assume velocity is 0.06m/0.035s? (1) it is 0.6m distance, (2) that is the average speed, not the speed at the end. the speed at the end is simply a*t = 34 m/s, which comes out to 390 J.
Another outstanding video Jonathan. While I’ve not experienced the dramatic kickback incidents that others have reported I have experienced some. That’s one reason I was among the earplugs purchasers of a SawStop. In addition to the brake it also has, as you pointed out, a riving knife. I know many woodworkers don’t realize the value of having one on their saws and often leave it off like they do with their guard. Hopefully some of those people will see this video and realize why that’s a dangerous practice. The reply from the medical worker who noticed that many table saw accidents happen at night when people are tired. It’s been my practice for many years not to work with any shop power tools when I’m tired. I’m sure that’s helped me to prevent any accidents so far. As I’ve gotten older that practice has become even more important and I’ve done even more to prevent accidents. If I’m going to do a major operation on any of my tools I set up the matching for the operation I plan to do then I leave it, if possible over night, and go back later to perform the task after rechecking everything for accuracy and safety. I’m never in a hurry or tired when working with any power tools.
Nice video! To me, the really key safety technique is to not stand in "the line of fire". Kickbacks will occasionally happen even with precautions, and not being in the way is a great backup safety plan. One of the best ways to accomplish that is to be using a European style sliding table saw, rather than the American style fixed-table saw that's common in the USA. Unfortunately sliding table saws in the USA tend to be expensive. To my knowledge, Grizzly makes the cheapest one, which will still run you ~$4500. So they're not really accessible for amateur wood workers. But for anyone running a professional woodworking shop, the price is less of an issue, and the safety improvement is immense. Used machines will cost less, of course. And readers in Europe will have an easier time finding affordable machines.
The most important lesson of all: never fall over the spinning blade like the dummy. 😳 Fantastic video and tips, Jonathan! Thanks a lot! Merry Christmas! And stay safe there with your family! 🖖😊
Thank you for this video. August 23rd 2015 I was careless and paid for it by getting impaled by a piece ¾"X¾"X40"ish hickory. It penetrated my abdominal cavity an inch. What's really impressive is that I almost got out of the way. You can see the angle of trajectory in the scar. It took 16 years to get my first severe injury from carpentry. It was so preventable that
I had bad kickback a couple of months ago had a board hit me in the shoulder. It cut me open and left a bruise for over a month I still have a knot it the spot it hit. Thank you for breaking it down now I know what happened to me. Love your channel keep up the great work.
Put a hole through the wall in my garage due to a bad kickback. I was using a pushstick and standing to the side so no blood was shed in the learning of this lesson, thankfully. Thanks for this video!
I once had kick back from a home made table saw that I built. The piece shattered on the wall behind me, it missed my face by inches. My solution was to dismantle the table saw and I have never had the confidence to use another one. Very interesting video, thanks.
Thanks for doing this, Jonathan. This information is so vitally important! Now it’s up to all of us to spread the word to all of those that think table saw safety is not important.
I would think that case-hardened wood* also poses a danger of kickbacks. *Improperly dried lumber can cause the surface of a board to be in compression and the inside to be in tension and lead to a board pinching when being cut. (As I understand the process as explained by Stumpy Nubs)
My Great Grandfather was killed in his Reno NV cabinet shop by a TS Kickback. It happened in 1920. From what my great aunt told us it was a 1"×1" piece the hit him in punctured his gut and he died of infection. You bet you I respect TSs. And use a riving knife, googles, thick shirt, etc and stand to one side. Definitely makes me a careful user of a TS.
Tablesaw accidents are so common, yet most of them are extremely preventable with these "basic" safety techniques and proper equipment (like push sticks, featherboards, and Micro-Jigs). BTW: Forrest actually recommends to run their blades high (just past the gullet) to keep the carbide cool. Good info man!
Awesome video... I got a kick back this time last year and had a nasty bruise on my stomach that left a life time scare to remind me that I was lazy in the shop and didn't re-install the riving knife. Keep up the great video's and Cheers to the New Year..
Great vid! In a scary irony, I just got a new grizzly saw to replace my very scary saw from the '70s, which featured a terrible fence, an absence of a riving knife, and a constantly vibrating blade. During the second day of use, I had installed the dust collection guard incorrectly - I failed to insert it all the way and so the spring-loaded dowels did not seat themselves properly - and during a cut, my out feed board lifted the guard into the blade, and threw the damn thing at me at a frightening speed. I now have an impressive bruise on my rib cage and a broken blade guard. I was very nearly killed by my safety equipment!
Poor Danny got throat punched by that wood! Thank you for the explanation of the various guides (different guide sticks and feather board) and their purposes. That was very helpful for me.
Excellent - scary - education. I have an old (1980) Craftsman table saw. No riving knife. Guard with kickback pawls and splitter mounted to an extension at the back of the table - impossible to align, dangerous to use (when board hung up). After replacing the fence, I added Jess Em stock guides. Pull board against fence. Wheels only turn one way to prevent kickback. Also use a magnetic feather board. So far (years) they have done the job - except for once (proving stupidity can overcome even the best prevention). I also stand to the right as far as possible without jeopardizing control. I remember from when my daughter played Little league baseball that taking a solid hit to the center of the chest (like a line drive) could have fatal results - even if it only left a bruise. Called “Commotio Cordis”.
I heard you mention this camera and your plans for this video on Steve Ramsay’s podcast. This video was fascinating to watch. Thanks so much for making it.
My kickback experience: After the board just passed by the cheap Harbor freight featherboard, one of the feathers came into contact with the blade. The thing exploded off the table and flew past my face at mach 1. Two lessons learned.
Although I’ve never been hit with a flying chunk of wood, I’ve had a pretty scary experience with kickback that doesn’t get talked about all that much. I have a yellow contractors saw and it’s really not that powerful. Well, one day I was rushing through a cut(3/4” plywood) because I was too comfortable with the tool and boom… it happened. Here’s where it gets worse. Instead of immediately removing my hands from the danger zone and crouching or moving out of the way, I thought I could overpower the saw and hold the workpiece down with the crappy little push block I was using. Turns out I was right… that time. I was beyond lucky that I didn’t lose a hand or an eye doing something so incredibly stupid. It’s not always the dangers you know about that will get you. Sometimes it’s something that you never even think about doing that could cost you. Now, I practice every cut before I make it(thank you Steve Ramsey) and I go through my project plans to anticipate what could most likely go wrong with each operation. May seem like overkill, but I’m not taking any chances. Edit: Forgot to say thank you, Jonathan, for all of your contributions to safety in the woodworking/making community.
As a dude who dealt with dado blade kick back (my fault) got my hand shoved on the blade and had a nice exfoliation of my thumb and thumb nail (my fault) after I got over it and replaying how bad it could have been, I got back to building, but I’ve been waiting for this video everyday for a month. This made a great Christmas, better because I see something like this and learn how I messed up. Thanks for doing this. Glad your thumb looks good JKM. Mine as well. Happy new year.
Videos like this are really helpful in becoming more safe while woodworking. Ever since I cut my finger on a small table saw a few years back, using one in the shop is a bit of an inner struggle. I would say these days I spent at least 4-10x as much time setting up a cut than actually cutting, all the while worried the thing will rip into me. With me not wanting to have my hands even 40cm within the reach of the blade, kickback becomes one of the biggest issues as the push sticks I use are rather long. I have to think about a better shape to supply down force, I did not consider the geometry of forces and you video demonstrated the issue very well. Maybe a down force roller attached to the fence would help. Ideally, I don't want to push any part of my body towards the blade at all.
Recently on a youtube channel the producer freehanded a long four quarter x12" ash board through the 12" blade of an old high hp table saw .I commented on the dangers of this and offered an alternative method then two of his subscribers berated me as being saftey police etc. One of these misguided experts informed me that he helped a friend that had a pallet shop and they free handed all the time and had never had a kickback . My answer was with his luck he should invest in some lottery tickets . Thank you for the video
Your ambiguous title had me thinking you meant "feet per second" and I was just thinking "this guy doesn't understand physics if he thinks a kickback can send a board at 50k feet per second"
Kickback sucks happened once to me and almost broke my rib. It was my fault, newbie mistake. Thanks for the video! Btw wife got me your apron for Christmas. 👍
Lincoln St.Woodworks told me to come here and check your videos and I have to say WOW! I'm loving it. Haven't used my Parklife table saw yet (might have ended up being a waste of £150) but I was always careful of kickback with my mitre and circular saws. This video however was on another level!
Something that happened to me when I was working in a cabinet shop, many many years ago. They had an old delta sliding table scoring table saw run off 3 phase,600W (I think). The thing was a monster. Because it was old, and it had the sliding table, the blade tilted towards the fence, so the motor wouldn't foul on the slider. One job I was working on required 2x2 material to have miters meeting at the peak of each board. If you can picture the setup being the blade tilted towards the fence, the fence moved very close to the blade, and not much room between them. We had a push stick, but it was the tiny birdsmouth kind, made out of rock maple. So off I go cutting these pieces... the first cuts were fairly easy, there was enough wood to hold the push stick against the fence and it cleared the blade. The fun happened on the second pass... Now the push stick had to be held at an angle and the blade would kiss the side of the push stick. That is, until I tried to reposition the push stick on one cut because it felt like the board wasn't supported. I have never felt such pain in my hand. Imagine getting hit in the palm with a baseball bat at MLB strength. The push stick shattered on the blade, sending most of the force through my hand, and throwing the rest with suck force in the cinderblock wall behind me to crack a block. I had twisted the push stick while it was engaged with the blade, and because it was had wood, it had zero give. My had was useless for 3 weeks. It bruised instantly, and I had problems moving my fingers. I now only use push sticks made out of easily chewable material... laminations of hardboard, pine, etc. If it happens again (probably won't, because I know better now) the blade should chew the push stick more than eating my hand.
Great video as always! You’re right, we’ve all had kickback stories. Mine was a 1x3 that went past me (of course I was off to the left side), and almost went through a hollow basement door about 8’ behind the tablesaw. But anyway, my complaint is that you should’ve used Nicholas Cage instead of Danny Devito. Nick’s career wouldn’t be as affected. All hail Danny!!!
Hey Johnathan, I appreciate your video! The slow motion is very cool and making people take this risk seriously is important work! Thanks for what you do with your channel and your foundation! I felt like you neglected a few key things though… all your examples where short chunks. That’s definitely the highest risk for kickback but it can happen with long strips too. I’ve seen videos of board lodges in the wall… Also, my kickback experience wasn’t the whole board, I had a knot from a pine 1x4 come loose when it hit the blade at it hit my eye before I could even blink. Luckily I only had a minor abrasion but I could have lost my eye. Needless to say I never forego my eye protection anymore. Finally, vertical feather boards!!!! I think they have been the most important prevention improvement I’ve made since push sticks! I use the one from MagSwitch but clamping a board to the fence works great too
I destroyed two finger tips this way. Had lots of stiches. Was notching a solid PVC/Plastic block to allow it to knock in Laminate floorboards better on a older table saw. It picked it up and spun it into my two fingers smashing (pointer and middle) them into mush. The doctor at urgent care joked that I would never be a hand model now. I still have that block around as a reminder and you can clearly see where it spun off the top of the blade. Since then I bought the Jobsite model Sawstop tablesaw.
I can't remember how many bruises I've had on my tummy from kickback. I volunteer in a 50+ woodshop, and now a riving knife is mandatory when the cuts allow it. However, as you know, not all cuts allow for a riving knife to be used. So, I've bought leather and a friend is going to make me an apron. Kick back is NO joke. I've seen entire jigs thrown 30 feet across a shop. Luckily, there was no one in the way or there would certainly have been significant injury to anyone in the path of the jig. While I get that the magnetic feather boards are great, but sometimes (because of the distance from the miter slot to the blade), the mag jig ends up over the slot and the magnets don't hold. Making an old-fashioned feather board is a must. An aux fence that extends just past the blade is an option we've found helpful. Place a sacrificial fence to extend just beyond the blade, but not far into where the riving knife lives. This way, as you feed through the entire cut, the piece will end up in a wider space and thus, not get trapped against either the riving knife or the blade.
Great video Jonathan. Definitely much easier to watch than videos of actual near miss kickback. Great comment about wearing PPE, including an apron. A 1/2-inch cutoff piece kicked back into my Katz-Moses woodworker's apron and I didn't feel a thing. Standing to the side also helped.
Watching kickback videos is why I bought the Jessum clear cut stock guides right after getting back into wood working and buying a new table saw. They cost a lot, and are in the way with short narrow pieces, but I can use a sled for those.
I appreciate all your videos! I want to get a table saw eventually and all of your videos (not just on table saws but wood working in general) I’ve learned so much. How to be safe, how to be more precise, and how to just be a better wood worker in general. So much knowledge that you could just keep to yourself, but you teach so many! I really appreciate it so much, I’m a really big fan and just so appreciative!
My kickback story is a little different than others: it was on the miter saw! I was just starting out and I had heard of table saw kickback, but I had never heard of miter saw kickback. I changed the blade to a higher quality one, wanted to do a test cut on a scrap (which was small), and was not holding it down since it was so small. I heard a loud BANG, felt my cheek sting, and watched the piece fly 20ft and slam into the wall behind me. I'm fortunate that it was a glancing blow and not in my eye, but even then it broke the skin! Lesson learned: if it's too short to safely hold down, it's too short for the miter saw.
My most memorable kickback was also on a miter saw. We were replacing flooring and I was cutting a piece late one night--small, like yours. It wasn't clamped down well, so as the blade made contact the piece vibrated briefly and then BAM! Instead of the piece flying at me, it jammed between the fence and blade, bent the one-piece fence, got absolutely shredded, and sent the sliding carriage back toward me. I gained a lot of respect for miter saws that night.
I think this should include a discussion of sliding table saws. They are more save because the operator is not right behind the blade. Super important for safety.
You are 100% correct about standing to the side. I had a kickback and I couldn't find the piece of wood after. The next day I found it propped against the mailbox across the street. Luckily I had been standing to the side and the garage door was open. That certainly increased the clinch factor.
Danny D taking one for the team. Respect. On a serious note.....thanks for all the work that went into this video. Good job. If you are thinking collabing.....you might want to check out the SloMoguys.
Thanks Jonathan. What is missing on my opinion is a real time speed video where we can understand how fast all of this happens. You surely remember the video of the woodworker that causes kickback on purpose: that has been very important to me to learn what could be and how fast... I learned new things here today, thank you a lot! Stay safe and hugs from Italy 🌞🙏🏻
@@katzmosestools 🥴 the first one I was concentrated on the ballistics of Danny's homicide... Then the other three rapidly shown did not fix in my mind... sorry... 🙏🏻
I suffered a bad kickback while crosscuting 1/4” plywood on an old Powermatic with a well in the surface plate about 2 months ago. Put a bruise the size of a volley ball on my hip. My hip and my back are just now getting back to normal.
Good video. Very dangerous situations. Have been hit several times from kickback and can certainly believe your calculations. Riving knives and careful “forethought” are essential. From a 74 y o WW with all ten. Be safe & THINK AHEAD ! 😀
That seems a rational response to any testing involving ballistic gelatin dummies! :) The plate is particularly a good idea with that heavy chunk of wood that took out Danny! (Danny definitely needed the throat protection. Not sure what cal be done for his face though…maybe a fencing helmet)
I got very confident with my little Dewalt tablesaw and would cut without thinking it was a big deal until one day when cutting dados I got a little careless going back and forth and experienced kickback for the first time. The good thing is, I was using a Gripper pushblock, so that's what got sucked into the blade, and not my hands. However it also shot the Gripper like a rocket right into my belly giving me a very large bruise. I still have all my limbs but it could have been much worse (my Gripper now has a large gouge). Now, lesson learned I never feel 100% "at ease" when using the tablesaw, and I take that as a good thing as I'm much more cautious and mindful.
Another great video, JKM. I'm curious, have you tried to get your jig to create a kickback with the riving knife on? If so, were you able to do it? Just wondering how effective riving knives are. Thanks for all you do!
They're VERY effective. Bulletproof? No, but nothing is. But a riving knife/splitter is incredibly important in terms of not letting the wood get pinched behind the blade.
Love the Mythbuster level camera work and science explanation! Also thanks for giving me another good reason to stick with my hand tools. That's scary af!
Man, some rib cage analogs in that ballistics gel would have made those impacts a lot more informative considering that it's like 130lbs of force. Still, great work with what you had!
More fingers are lost do to kickback then actually getting cut off by the Blade! I've known of many woodworkers who have lost fingers or have badly damaged hands from it! Good video!
Jonathan, Your effort to warn the community of the dangers of this, and your first aid videos, places you amongst the elite people on YT. This video should be included with each table saw sale. Just to add a few numbers here. (Please double check me) It looks like the acceleration is just over 100G’s and the average speed toward Danny’s head is almost 675mph. The force that isn’t discussed here is the rotational force, which adds to the linear force on that one edge of the piece.
@@magnusericsson Yes, I think so. But that is why the calculation of nastiness might be low. The dummy has to absorb the energy of the flying wood, which includes the rotational energy as well as the translation energy.
@@bobd5119 I see what you mean. I think it would be more correct to calculate the directional? energy for the whole piece, and then add the rotational energy. But I think since the calculation is sort of adding the rotation already in the velocity, it's even more incorrect to add additional energies to the equation.. Maybe?
@@magnusericsson I might have missed something in Flammy's presentation, but I'm pretty sure he calculated the translational speed of the kicked chunk of wood, and ignored the work the saw blade did to make the wood spin. That work is the energy we calculate for the spinning wood. His ignoring spin is reasonable, because there isn't much energy in the spin. In a different scenario, imagine the blade throwing a wood chunk slowly, but making it spin rapidly, say 1200 rpm. Stopping that spin would be uncomfortable. Also, I think Flammy calculates the force the blade applied to the wood. But we care about that less than we care about the force needed to stop the flying wood. The blade applied its accelerating force through several inches. However, the person has to apply a decelerating force through a short distance. Perhaps the person is willing to let the wood sink into his body 1/4". If the blade applied force to the wood through 10 inches, the person has to apply 40 times as much force to stop the wood. You can see that stopping the flying wood requires substantial, injurious force.
@@bobd5119 I agree that the stopping force is what’s more relevant and could’ve been calculated with a slow-mo shot of the ballistics dummy being hit (measure the time the dummy took to decelerate the block to 0m/s). Additionally, the initial acceleration should’ve been calculated for only the time the wood was in contact with the blade, since there’s no more acceleration after the blade loses contact with the wood. It looked like the blade/wood contact was approximately 1/2 of the total distance, which I believe doubles the accelerative force.
Great video!! I had kickback last year and surgery on my hand one year ago on the 30th from a nasty kickback had to have a plate and 14 screws put in. Kickback is no joke!
