You can polish a shaft on a lathe with a strip of sandpaper, but it's not very safe. Full video on shaft polishing (on lathes) here: • Machinist's Minutes: L...
The man knows a thing or two. I'm a forestry consultant, and I'll tell folks (guys) who are allergic to poison ivy that "if it can get on the tree, it can get on your nuts." That's just a fact when you work in the woods all day.
I agree never touch moving parts. I had a job at Micro 100 tools where we made carbide milling bits such as boring bars and tools for CNC machines. We used diamond impregnated grinding wheels to grind and finish our blanks to pre grind and plunge set them, and these diamond wheels were very large and expensive and once the flats and angles got to the point of needing to be trued and re-dressed.we would put them on the dressing machine. Basically one diamond wheel would sweep across the diamond wheel that needed to trued. Both wheels would also be spinning. We use Dykem layout paint on the wheel to gauge and visually see when the chatter is getting cleaned out. One employee would constantly use his finger to "feel" the chatter, while ignoring the obvious safety issues of doing it. I do the night shift, and one day walked into work and barrier tape was strung around the machine. Place looked like a crime scene, with blood all over the machine and up on the wall clear to the ceiling. Needless to say, when he finally came back to work, he never did that again. How he kept his finger after getting it pulled between two grinding wheels with zero clearance I'll never know. Remember,when in a machine shop, you're the softest thing there.
@@MMBRM some of the end mills- corner radius ones (reduced neck) ,were as small as 0.8mm and the neck less then 0.78mm. Looked like sewing machine needles and took 4 days to make.
@@Bowfinger6383 That's crazy. None of my machines could spin them close to fast enough for proper use. Well, my router could but somehow I doubt it would survive a manual feed rate! I hope the dust extraction in that shop is amazing(or you had clean air PPE). The amount of diamond and carbide dust they create must be enormous.
@@MMBRM oh for sure. The whole shop was setup on a wet vacuum system. All the wheels were wet, and most of the machine operators wore N95 masks before it was cool. Lol
My cousin has titanium pins in both arms from sanding a shaft in an engine lathe while wearing gloves and getting sucked in. Broke both arms in multiple places and is now the most reliable weather man I know.
Ahhh, all his old wounds are sensing the change in barometric pressure. A friend of mine has a good sized Bridgeport lathe in his basement and he works with it, but he doesn't want to watch the bad luck videos, of lathe accidents.
A dark humor bit a coworker who worked as a machinist told me. “Man comes in to work on a Tuesday with his arm bent like a pretzel and half his scalp torn off. Buddy asks, what happened to you? Man says, smiling “I got lathe last night.”
That almost beat the old instructor at my school. "In order to Lathe, you gotta first get her started at edge, then yon grind her from one edge of the stock to the other." I kegit thiugh he was trying to crack a joke only to get the "what joke look"
Id say the only thing moving you can touch is maybe off set an edge finder. And seeing as how even that is more of knuckle bump, its honestly pointless unless you wanna have sometthing to kind of safely overcome intrusive thoughts. Give that a poke 1500 rpm and even that will kind of pull your finger in. Nott enough to take it but enough to get you to spook and respect it.
I was taught never to wear gloves whilst using any machine in the shop. And now that you mention “old-timers” there wasn’t a one who wasn’t missing a digit somewhere in their hand
I worries me somewhat to see people repowering those little hobby lathes with 1-2 hp motors. At least with a 400W one it will probably stall if you get caught in it The point being that most hobbyists work alone. There's usually someone else around in a commercial workshop
@@sjbachar15 eh, I wear lomg sleeve sweatshirts when it's cold in the shop in the winter, but I roll them up before turning on the lathe or any time I need to be near spinning equipment.
@@cjhowell6406man, i wish my shop got cold while i work It was 25°c in there without a massive AC bill once. It was the only part of my farm without snow on the roof at -32°c.
I have a deep respect for anything that has a great amount of anything. Like velocity, mass, current, potential energy, volume, or he’ll even fat content.
@@joshd2013 almost thirty years in the trade and have worked with a couple hundred machinists now. I've only saw a couple missing fingers and one bad limp. The limp was from my foreman got pulled into our 90" vertical lathe. The chuck is about 8" out of the floor and a stringer chip caught his leg and pulled him in then spit him out into the chip bin. This shop I just left recently had about 30 machinists, most had been there 20 plus years and not one missing appendage. We turn medium to large work pieces up to 17' with large vertical lathes, horizontal lathes up to 68" diameter, 28' long and large floor type horizontal boring machines. Common job for me was to line bore stainless feeder housings. These were around 38,000 pounds and the tapered bore was around 54" at large end almost 9' long. So I don't feel it is so uncommon to keep the digits. I got quite a few years left, hope to keep mine lol. I run an engine machine shop now, so the danger factor is quite a bit lower than a real machine shop as the machines are basic and simple and so is most the work. Still a chance to get bit, but mich safer.
This kind of safety awareness video is so important to see here on youtube where loads of people tell you how to become a hobby machinist but rarely do they warn you about things like this
Keep posting the safety tips. So many people have home workshops these days, with no formal training, and taking instructions from other non formally trained RU-vidrs. Short videos like this is providing a good service
There are so many graphic videos of machinists making mistakes it really makes you respect a machine if you’ve seen someone painted round the inside of the workshop
I used to wear my ring in the shop. I knew the danger of it, but I guess I just had the "it won't happen to me" attitude about it. Well, one day my coworker called me out on it, and described, in vivid detail, watching his buddy get degloved by his ring on a lathe. He said it took all the skin and the last bone of his finger. When they finally found it in the chip pile, the EMTs washed it in saline, rolled it up inside out, filled it with basically super glue, then shoved it back on his finger bones, and rolled it down like a condom.
My high school machine shop teacher would always do a demo ( story)on what would happen if you got your shirt/ ring/ hair caught while machining. On the odd occasion he would toss a hammer at you if he saw that you weren’t following his shop rules. 45 years later it’s still as clear in my head today.
When I was 12, my shop teacher demponstrated bench saw kickback by yeeting a piece of 2x4 through a (closed) window on the other side of the room 45 years ago and I can still clearly remember it
Barber: “what cut are we doing today? Machinist: “anything just as long as you cut around my glasses cause I ain’t takin’ em off.” Barber: “say no more”
My mentor once told me if you want to see how smart a butcher and a machinist are, ask them to hold up their fingers. After noticing the workplaces a few years I can honestly say this stuck with me.
You truly start handling machinery with respect after hearing horror stories of someone not doing that. Our teacher in mechanics class told a story of an older man, who was spreading manure on a field with his grandson, who was about 5 years old. The spreader suddenly stopped, and wondering what went wrong, he went to the back to take a look. He had left the pto spinning, which didn't have a shield. While he went to check the back, his grandson climbed out of the tractor, wondered to the pto, grabed it and went with it. The grandpa didn't hear a thing, and when he was going back to the tractor was shocked by the crusome sight. After many years, telling the story to my teacher he was still bawling his eyes out.
I have a thick old book from the 70s and it's about woodworking. in this book, it has a section on using the wood shaper, and the man is holding a piece of molding with the fresh cut he achieved, but he's also an old timer with less fingers than normal. that part of the book would also work to teach in the safety section. I've worked in machine shops and now I'm a maintenance mechanic in a millwork shop that also does granite. we've had many lost fingers, many cuts, a couple smashed feet from dropped granite and one lost toe from one of those accidents. I've broke my back in many spots one incident, but fortunately they weren't the paralyzing kind of spots. once I had a small piece of carbide hit my safety glasses and if I didn't have them on it would have been real bad.
We had our most senior tool room machinist de-glove himself using emory just like that. It was the end of the day and he was alone. “I had done it millions of times. I’m not even sure what happened”. He was 60-something at the time and about to retire. We were lucky we found him or he would not have made it. Although I’ve done it piles of times myself just seeing you do it in the video made me pucker.
When I was 13 I got my thumbs pulled into a piece of bar stock by sandpaper doing that exact thing. Luckily nothing broken but it hurt like crazy and took like 6 months to heal.
Working with tools like this will pretty much ensure that you never make the same mistake twice. They will usually either: 1) Remove the part of your body that went where it shouldnt've went, or 2) Ended your shift. Permanently.
Having seen pictures of the aftermath of a pull in... Listen to this guy.....the other guy was everywhere...... Ceiling, floor, walls, bedway, chuck....I just hope it was quick. 😭
When I started at the shop I'm at a few years ago I spent a lot of time on forums and other sites reading as much as I could. I'll never forget the "human spaghetti do not look if squeamish" thread that someone posted about a lathe accident.
the first time around will break your wrist and every bone in your hand, the second time around will break every inch on bone in your arm and the third time around you will turn into a pink mist on the ceiling and walls.
I always put the emery cloth under a file that way it will spit out the cloth instead of pulling ur hand in also doing it without a file can make little tiny grooves but by using a file your applying even pressure i mean its safer and works just as good lol
Thank you for bringing that up!!! My first, and only accident on the lathe, was exactly on my very first day as an apprentice, by a lack of my master to realize that it would be my natural instinct when polishing a shaft I’ve just cut at the time. I practically wrapped the abrasive strip on the part, it caught up on itself and finished the wrapping, I tried to pull it back, almost took my thumb and nail off!!! One of the most severe pains I’ve ever experienced in my life!!! Luckily, neither my thumb or my nail got pulled in and no damage was permanent, just a vivid memory of what a machine can do to you in a second! That applies to any size machine!!! Please, don’t fool yourself while using a mini lathe, a Sherline type/size machine, not a watchmaker’s lathe!!!! Metal is harder than your bones!!!! It was my first day but the lesson was for a lifetime!!
At 18 I was polishing a shaft with emery in a cold shop with gloves on. In half a second I had 2 broke arms, broken right thumb, and fractured neck. Lucky to have all my parts. I'm 55 now and that injury has plagued me my whole life.
Knew a guy that almost lost a hand in a CNC using sandpaper that way. The paper wrapped around his wrist somehow and sucked him in. He ended up getting a bad infection post-op too. He's definitely lucky to be alive.
Never wrap the emery just pinch it between side of finger and thumb. As you get older this gets harder and harder to do for long stretches . But in your youth your forearms show the results guys lifting weights will envy what you have earned just from working.
Very frightening what I saw students do in school. Very true, your fingers can lock themselves around a spinning shaft and rip your hand right off in a split second. Don’t mess with the lathe.
Ya, always press down on the shaft with your thumb and up and towards yourself with your first two fingers like you're reaching over and pinching the shaft. Only hold on to the bottom tail end of the tape and never have any more than a few inches of loose tail end. Don't hold onto both ends of the tape, that way will definitely pull your arm in and pinch your thumb between the job and the tape - I've done it lol. Also there's never any reason to wear gloves with rotating machinery, any injuries you get from not wearing gloves will be minor compared with a glove getting wrapped up in moving parts.
I respect all my machines....i Fear the 200 ton hydraulic press and the unassuming Radial Drill the Most As they are very easy to feel comfortable aroung and thats when you get NAILED
Only two things I recall stopping a lathe, 1 a big red button and 2 , a miss directed cross slide ( expensive crunching and shuddering noises )...followed by unemployment.
Every year at Underground coal mine retraining they show a clip of a man pulled into a lathe. They wore jersey gloves and hand polished the material his glove caught and he was mush. These machines have no remorse no feelings they will kill you if given the opportunity. Stay safe!
I used to run a 25ft long by 38” lathe. Had to polish things often. It’s all about where you put pressure and how much wrap you have. I was doing 10” diameter shafts. Never had a sketchy moment. I also wore short sleeves and no gloves.
Safety, with his sleeves down!!! Over 50 years ago, I saw an apprentice with his sleeves down caught by the lathe and wrap his arm around the workpiece. Fortunately it was a light powered machine, so he kept his arm, but his hand was mangled
Lathe is the most dangerous machine in the shop by far!!!!! 35 yr. Toolmaker , and seen a lot of lost limbs . I didn't know what to think at first with you having gloves on , was like --this is not gonna end well -- Sooo glad you took um off and addressed the potential for disaster.- The absolute second you lose respect for a machine , its gonna bite your ass. - believe it!!
The most dangerous practice we do as machinists is lathe polishing. It has me on my toes every damn time. Even my belt drive lathes… I think I’ve seen too many videos, but each is it’s own cautionary tale.
those foam sanding blocks are my go to. they give enough reach with out gouging are easy grasp lightly and easy to find by the lathe with an abrasive that holds up to some oil
I almost lost "something" polishing a test piece like this as an apprentice. I had it wrapped around my finger, but I stopped and thought about what my grandad told me and took it off my finger. The very next second I started polishing again and the lathe grabbed it and it wrapped. My grandad who was a machinist told me "never put your finger anywhere you wouldnt put your cock"
I still remember this safety lesson from shop class 25 yrs ago, I still can't believe they let us highschool kids use lathes, mills, and welders mostly unsupervised. We only ever had 1 finger taken, from a band saw.
Reninds me of when a guy working at the shop my dad worked at decided to grow a beard. Dad told him how dangerous it was & sure enough he had part of his face ripped off.
I've always used the fingertips grab approach, if it grabs, the abrasive just pulls out and no harm done. Downside is you can get as much pressure on the part so it takes longer to finish.
I made a tool to fit into my tool holder. Has a 10mm by 10mm shaft that leads to a circle with a hole cut into it. That circle has a split in the end that had a smaller hole drilled and one end threaded. It fits my high speed rotary tool and I use it to grind, sand, and polish anything in my lathe. It takes a long time (depending on the margin of error im allowed) but I'm never grabbing a moving object that could rip my fingers off without skipping a beat.
I was in college studying industrial design, zero shop experience, allowed to use a very old lathe unsupervised. I tried to sand a bar just wrapping sandpaper around it with my hand. I was wearing a worn out shop glove that was leather palm and cloth other side, thank god the cloth had holes in it. The bar grabbed my hand and began wrapping it around, sure to turn my arm into sausage at the least-if not my whole torso. I pulled away and the glove ripped, I fractured my hand on the lathe and had the biggest adrenaline rush of my life up until that point. There was zero respect to the danger in that setting. Still get shivers thinking about it. Would’ve liked to have an experienced old coot like this guy around.
100% correct! These machines need to be operated with the utmost respect!! In my 28 years as a tool &die maker Ive seen some very gruesome injuries!! These machines don’t have feelings and don’t care about hurting or killing a person!
For lathe sanding we use what I would describe as a large metal paddle (a 1’ by 6” 3/16” plate welded to a piece of square tubing that fits in the tool holder.) The paddle goes between you and the workpiece and there are horizontal slits in the paddle. You feed your sandpaper strip through one slit, around the workpiece and back into another slit. Then you just hold the ends of the sandpaper strip like you would do normally, but if anything goes wrong your hands will just hit the paddle. Of course the bees knees would be one of those handheld electric/pneumatic belt sander
You might be stronger than the abrasive roll but your reflexes take .5 to .75 seconds to react, by that time your hand has wrapped around the shaft several times. But you do you, it's your livelihood.
I generally like to hold the Emory paper ends at 90ish degrees apart. Old timer told me this shortly after I started and he had all his digits, so I figured he knew what he was talking about. I’ve seen guys hold tag ends together and get wrapped up around the part many times in my 40+ years in the shop.
I would hold a file backward, and spin the lathe backward to take the edge off. I worked for a guy that insisted I should spin the lathe forward while reaching over. After a discussion about the possibility of the file shooting back at me he insisted so I did what he said. The lathe caught my flannel shirt and ripped the arm right off my shirt. The lathe had a good break and stopped instantly when I stopped it with my other hand. My armpit was right up next to the piece. He turned around and said, "OK do it your way". Never reach over the spinning lathe.
Put the emery around a tool in the tool holder and use the cross-slide to tension it, then use the machines feed to polish the part evenly and perfectly, use the back of the emery for your final
I watched a guy get caught up in a loom in a weaving shed when I was a kid and I did not apply for his old position. Must have been soooo lethal years ago
Dude at my company got wrapped up in a lathe wearing gloves and lost a hand. Almost died bleeding out because nobody was in the room at the time. Never wear gloves but bad shit can still happen to you in many ways on big pieces of machinery.
When I went through shop class in middle school there were a dozen lathe machines shoved to the back. No one was allowed to touch them, and the instructor made it pretty clear they were awful dangerous.
In the shop I worked in was a very old machine, kinda laid out like a small chainsaw withe an electric motor to spin the belt and “handlebars” to hold on to. Done a great job quick, very safe and controllable. Looked like it was from the 1940’s or 50’s.
There are many jobs where is you're not afraid, you shouldn't be doing it. As an electronics and RF tech I can tell several electrical horror stories. but the worst was the guy who got too close to the antenna terminals on a 5kW shortwave transmitter whilst tuning it - a nice inch-wide _cooked_ strip of flesh down to the bone from his hand down to his knee. He smelled like pork and was off work for 10 months Complacency kills
I was taught to use a small piece with a pinch grip between my thumb and index fingers. That way, when it grabs the emery, it just pulls it out of my hands.
On the rare occasion I use a strip of sand paper on the lathe I keep my hands well apart making the contact area of sand paper on the shaft being polished smaller thus greatly minimising the risk of being drawn in.
