I asked my tribology professor about the chamfered edges today. The edges are chamfered to prevent cracking/notching them when handeled. They are also made to make the surface hardening more even, not as much stress concentration without them harsch edges. Love your videos, greetings from Sweden!
It's essentially a more technical version of why when you forge a sword, you leave the transition between blade shoulder and tang a fillet. A right angled transition leaves a stress point that could cause cracking during the heat treat.
Chamfering the edges also reduces contact friction, therefore heat on the gears (less surface area contact). You would be surprised the difference ot can make on gears that are heat sensitive due to speed.
I was told it just makes the gears last longer somehow, so I'm glad to get a better answer than that. I was also told it had something to do with gears thrusting, but I dont know if that is true
9:25 I've actually had to use this technique to start a mill. The fuses were to small so they blew immediately upon starting the rotation anything over 400 RPM. But by giving the spindle some speed before engaging the electric motor it was avoided. :D
You notice it took a couple of tries. Obviously TOT is using the cheap oil. Such a tight wad. Real machinist use the unatainium oil. Somebody should report him him to Abom79, or Keith Fenner.
I'm really loving how much of machining boils down to "This sucks, so I'm not going to do it." I've seen more shortcuts and exploits in my semester of machining classes than I have in a decade of playing video games.
Back in medieval times, when I was king of Texas and New Mexico (it's a long story), I commanded my armorer to make a torque multiplying gear drive for a trebuchet so I could win the Punkin Chunkin trophy. He made the gears from "the bones of my enemies" and they were just too brittle to hold up under the strain. I had him executed and enslaved his family. I often reflect back on those days with remorse. I really wanted to win the Punkin Chunkin trophy,
Sounds like your enemies either needed more calcium in their diet, or they were little old ladies with osteoporosis................not gonna judge, I'm sure those broads at the bingo game had it coming!
In all seriousness, I always considered myself pretty stupid. Math was something that always confused me. Yet machining is a dream of mine to start one day. Here recently I have been pretty down thinking I would never understand it. But I was you to know that you are the first that has managed to demonstrate something in a way that i understand it. I can't thank you enough. Gives me hope that one day I can too be a hobby machinist.
Math involved to do basic machining is trigonometry, addition, subtraction, division, ratios and sometimes squares and powers. It's definitely not beyond you to learn and enjoy. I'm not gifted in the language of logic, mathematics, but I've worked hard at it. You can improve your logic by just using simple arithmetic everyday. As an example, calculate your change at the grocery store before the teller reads it to you off the screen. Oh, and buy a lathe , go make some stuff.
FWIW, I too was inspired by TOT videos and bought a machine and tons of other stuff to go with it. Tony cost me a lot of money. 😂, but damn it’s fun!!! Next purchase... gear cutters!!!
It is stupid how much better at math I am now that I am a machinist. Every time you cut you need some kind of math. If I have a 12 foot piece of A36 that needs to be cut to 10 inches I divide and add at the same time using an equation, length of stock÷(length of piece+blade thickness)=useful stock length. This tells me how much material I can actually use from a piece of stock. But first i have to convert the stock length from feet to inches. So i multiply the feet by 12 inches to get 144 inches.So 144÷(10+0.125)=144÷10.125=14.2222222222. I cant use the extra 22222s at the end because they represent what i have left on the stock so I can get 14 pieces of 10 inch part blanks per stick of A36. And the customer wants 100 pieces. So I divide 100÷14 which gives me 7.1428571429 which just means 7 full sticks and one that wont be cut up completely. Lets assume that the customer actually sent the 8 sticks I need and I dont have to tell my boss that I need one more stick because we're also out of 0.5 inch A36. NOW WE CAN CUT oh wait i have to set the stop, ok stops set at 10 inches. NOW WE CAN CUT METAL! This is just the first step in most jobs period.
@@zennyblades Imagine if this question was on a test and don't work with metal. You would be angry to see these numbers. But since you work with this everyday, these numbers make sense. That is what is missing in school with math, real world application. So you now are a master at converting units, you now understand rounding very well and you understand division.
They knock the edges off the teeth to reduce the tip load on the end of the tooth, which reduces the chance of chipping. Something about more support for the end of the tip... Or at least that was what I was told many years ago when I was working as a gearset fitter.
i would have guessed that it was so your lubricant of choice would be slung into the bottom lands of the opposing gear, but reduced chipping makes sense.
My initial thought was a gear mfg not knowing the application the end user would use the gears for, if they were placed on a shifting gearset such as transmission the chamfer would help with shifting of gearsrts. But your explanation makes more sense.
You are awesome. My son really enjoys watching your videos and I enjoy tagging along so I understand what he is talking about. :) We both can't wait until he is old enough to have his own machine shop. He is taking automotive in high school and really enjoys that class. Someday he will be able to machine his own parts.
Because of these videos I now have a home made idler/reverse gear for my little lathe. When I need a left hand thread cut in ten years I'll be sure to tell everyone to thank Old Tony.
My old DO-All band saw has a speed chart for asbestos... I'm sure it has speed setting for enemies bones next time I'm in garage I'll take a look for you.
I bought a Chinese bandsaw about a month ago and it had speed settings for asbestos. I guess they just dont care over there in the big rock candy mountain
I don't really know much about this, but here is my guess why gears should be chamfered: Both deburring and accurate chamfering is quite important (and each tooth should actually be chamfered on all sides) - Sharp load bearing corners can be work hardened during use, causing breakage. - Sharp corners gets hardened too much during hardening process - If gears are to be engaged and disengaged axially, chamfering geometry is important, oterhwise: - higher wear - Assembly of gears is faster and simpler with correct chamfering geometry - Injury during handling - Less damage during transport - Problems clamping gears in downstream manufacturing steps. (only clamp the disk, not the teeth) - More noise in fast running gear - Post hardening processing requires chamfering to improve process and tool reliablity
I thought putting a bevel on the gears helps them mesh together in applications where they have to engage from the side. And to help with material rolling over. For the same reason putting a bevel on a hammer helps with mushrooming. But I'm no machinist. I'm not even a machine. I'm just a dude, playing a dude, disguised as another dude.
Corner bevels and leading edge bevels assist in side meshing as stated above. Reduced burr formation reduction causing that may cause galling of adjacent plating or gears also as stated above. Corner bevels also assist in oil and debris escapement in gears walled in on both sides. Preventing hydraulic loading and the forcing of walls away from gear. Can reduce noise in some applications. Makes them look and feel way better. Some of these factors are not present on a lot of gear applications and as such you wont see the corner bevel on things like crown gears or 'Bevel' gears, or gears with a shank or standoff.
@@another1commenter770 makes good points. In tough ductile materials, chamfers are important to prevent damage to 90 degree corners, which will raise a bruise adjacent to the ding (which, as he points out, may then damage the part in contact with it); in brittle materials, they're important to prevent chips or cracks when the gear is accidentally knocked or dropped. As other have said, these chips can migrate through the entire gearbox (they may not break off at the time of the damage) causing mayhem when they pass through the mesh or get jammed in bearings. These rules are true not just for gears but for machined parts generally. Also a perfect 90 degree corner is unsafe for human contact. There are other reasons, well traversed in this (typically excellent, for a ToT video and against the general "run of play" for UA-cam) comments section
Lesson(s) learned....1. get a better rope to start the mill. 2. you can't do anything properly without a monogrammed space suit. 3. and most importantly to make proper videos you must be of the Mesmer Clan. Thanks TOTM!
Ahh, I remember my first pull-start End Mill. I believe it was a Troy-Bilt....horrible for cutting spur gears, but worked surprisingly well on grass. Also, Tony, it's done to avoid breakage: The burrs along the tooth edges can often cause breakage when the gear is running, so chamfering de-burrs and extends life, not to mention avoids chipped gear teeth flying all over the joint.
a tip for when you're cutting smaller gears (like for clocks, as I do) cut in a little bit with your parting tool. This doesn't need to be the whole depth of the tooth, just a slight, but it'll decrease the chance of the teeth getting mangled when you're parting it off after you've cut the teeth. bigger teeth usually are strong enough, and the involute gearshape helps as well, but making cycloidal teeth the base of the tooth is quite small, especially when making pinions (Z
It has to do with hardened teeth: that corner is weaker (because of nog support from the side) and breaking/chipping is done easier. You dont want that because hardened metal between the teeth is like sand between you veggies. So: chamfer them to prevent breaking the end of the teeth, especially with hardened steel of not perfectly align gears.
@@eddyerkelens - Huh, I had thought it was from the requirement for gears that slide into mesh like automotive transmissions. More reasons than I knew, thanks :)
@@somebodyelse6673 automotive transmission gears don't actually move into/out of alignment. The synchronizers between them are pushed by the forks to engage the right gear to the shaft. the bears themselves are always meshing and almost always helical.
@@andrewmalaty8 - I guess my knowledge is a little out of date. I've always thought of automotive transmissions like this. ua-cam.com/video/JOLtS4VUcvQ/v-deo.html Can you tell I'm not a car guy? :)
Dear Tony, Thanks to the generosity of People such as yourself who take the time to make edifying videos for the education of the great unwashed such as myself I have learned much via youtube. This was a really good and useful video mostly in my opinion of the utterly succinct explanation of dividing. Thank you very much. Yours are definitely the most humorous offerings in the engineering field too.
I will be 74 at some vague point later this year... but I'm convinced I will be history long before I learn all the interesting stuff I want to... But you're helping my CAUSE... Thank You!!! :-) :-)
Three speed band saw pusher, how interesting. I was thinking about reverse gears for my hammer...you know so it can suck the nails back out of the wood.
I had a shop teacher tell me with a completely straight face that, if I cut too much off on a lathe pass I should put the lathe in reverse and sprinkle the chips on the work so it would weld them back on. Took me a second...
Artūrs Savickis if you’re asking, I’d like to think not only did I get it, but added to it? I’m no machinist, but I recall my dad refer to “machining” as if in theory, everything done with fancy machines could somehow be achieved by merely “filing”... so his joke about being a “real man” struck me as particularly funny
The chamfer on the corners of the gears is because that is a weak area. Under load any shaft deflection can put very high loads on the corners of the teeth, and for hardened steel gears or cast iron the edges would simply break and you end up with bits of hard material passing through gears, so best to remove them from the start by putting a chamfer or radius on them. Not really a problem on aluminium or nylon gears. Finally something I learned during my apprenticeship turned out to be useful...
Two guesses on why gears are chamfered: 1: To reduce oil flinging, without the corner the oil is more likely to fling onto the other gear. 2: To remove a stress riser. Helps keep your gear from looking like a Hockey Player.
Stress risers (for everyone's information, not as a rebuke to this post) arise (ha!) from INTERNAL corners, not external ones. So the root fillet of the gear tooth moderates the stress raising tendencies at the root, but there is no such need at the tip. Sharp external corners are delicate by a different mechanism: because they're not well supported by the part, because they present a small cross sectional area (which *does* expose them to increased stress, but only in proportion to the area, like any contact stress) and because they're protruberant by nature and hence damage prone.
I work with a powertrain engineer. He says "stress strain blah blah, prevents corners from cracking, blah blah, tip load, blah. Always entertaining Tony, thanks.
I would think other then some technical stuff I don't know about, that the chamfer would also direct oil and what not into the groovy part of the gear... maybe.
It's now 2 weeks since I found this channel and just finished watching all your vids. I've never thought machining can be so interesting and all these while I was never interested until I watched your videos. Keep up the good work Tony I can't wait for more videos.
While I enjoy other machining/shop based channels for colorful language and educational content, TOT weaves plots and storylines through his videos in a way that should make many Hollywood writers take note.
@7.29 the reference to Cogswell’s Cogs (again from the Jetson’s) made me grin. I’m compelled to re-watch your other videos again to search for more of these Easter eggs. You certainly put a lot of effort and humor into your videos. Much appreciated.
The bevel on the gear depends on the application. You don't always have to do it, and you can always add it later. 1: It helps retain oil by adding surface area and changing geometry. When they're flat and tightly meshed, they foam up the oil faster. That little bevel lets surface tension do its job, and then oil on the following rotation will clean out any junk from the prior turn. Same thing for when gears are submerged where they mesh away from each other. You'd be amazed how hard it gets to turn a shaft under that kind of condition. 2: On geartrains with lots of shock loading and harshness, like on motorcycles, the teeth chip on the corners of the tooth tips.
Never realised engineering could be so psychadelic! Male acuity to both detail and visuals of shot looking straight down the axis of the shaft while cutting the teeth. Wow!! Thank you.
I just watched it, second times. It’s a great video, superbly done. I don’t have a dividing head, never even worked with one. Two gears were done by me only, during a life time, using the lathe as a shaper. I am planning to make a special gear without dividing head, most likely never will be done. Thanks again for this most enjoyable video, I can appreciate the work you put in and the excellent photography. Bob
i really like that tony went into detail of why you need the tooth profile on the teeth to be exact, it happened about 40 years ago, but i still remember it with my 32 years of age, i tried putting a 100 tooth gear and a 5 tooth gear in my grandmas meat grinder so that she wouldn't need to be so long in the kitchen, low and behold when she tried it out i heard a loud crack and the bigger gear yanked out my tooth
U ruined me for other vid publishers... the way u approach the topic is amazing.... always looking forward for new vids .... thank you for doing this gr8 job
Thanks for these videos, Tony. I don't have much for tools so I've been making them from scratch building up to a point where I'm gonna have to cut some bevel gears. That thing about concentricity error is golden! Honestly, there's a very high probability of failure, so I'll take every bit of info I can get lol. Thanks again! 👍😊👍
And one day we will all upgrade to the 6 speed push stick with reverse, self-aligning flux shifters, AND gps controled gyroscopic thrust vectoring rotor system for that perfect cut every time. :-)
@@stevenarango6319 Mine is a 13 speed forward, 3 reverse, double dry clutch robitisized sequential shift push stick. Like an auto, only better with computer control.
Dang Tony. I literally said out loud watching this; 'holy crap, that's some amazing filming' (the static cutting head, in particular). Your sense of cinematography is criminally undervalued. Well done, chap, well done. 'Top Secret: Cogswell's Cogs' Lolololol. Brilliant.
This raises so many more questions than it answers! For one - how did you get into Cogswell's Cogs' secret files? Are you secretly spying for Spacely Sprockets??
Old Tony you need to be writing, directing, acting and editing your own big budget Hollywood movies. But on second thought, we would dearly miss your UA-cam channel so please continue your brilliant work on UA-cam.YOU'RE ONE OF A KIND!😁
I just love watching youtubers making things I will never need or want to make. This Old Tony, Colin Furze and Frank Howarth with a little bit of jimmy diresta - man I have watched hours of you guys and honestly I am in awe. Not just for the skill and creativity you demonstrate in your craft, but the videos themselves are so well made, often as funny as they are informative. Who knows, maybe I WILL want to cut my own gears some day...
That was a great video. Now do a worm gear. No cheating using a tap for a hob. Nice square threads. Then put it in a cute machine to show it working. Due in 30 days. Grade depends on fit and finish as well as fancy video editing. This project will be 1/2 your grade this semester.
That's not all that hard. Make worm and hob as one piece on lathe. Remove, heat treat, reinstall. Gash wheel blank using slitting saw to provide a start for the hob. Mount wheel blank on workholder on lathe cross slide, turn on lathe, slowly feed wheel into hob until desired depth achieved. Lap on worm if desired. Part off hob. Matched worm and wheel!
Simply put Tony you make the best videos out there that I have ever seen. The first time I saw your channel I was like this dudes crazy. But now I can’t wait to see the videos you produce. I love em man. they’re absolutely awesome. Was actually having a shitty day today. Got a notification that this old Tony put up a video boom my day got better. Thanks
11:23 I've seen this video literally dozens on times and I never took a moment to pause and read these. ToT, you're the absolute best, thank you for being youtube editor MVP of the Year.
Just a guess on why the chamfered edge, but if the axis of rotation aren't perfectly aligned I think the force being put through the gears would be borne by the outside corners of the teeth and for hardened gears might cause them to chip. With a chamfer, even if they're not perfectly aligned, you increase the contact surface and reduce the force/area making a tooth less likely to chip/crack. Again, just a guess. You could test it with a set of gears with and without chamfer, misaligne them intentionally and measure the contact area with blue dye.
Re: teeth chamfer - first thought is to ease assembly when inserting / meshing gears. Second guess would be clearance for gear oil / grease to pass around.
"Why" doesn't come into it with a home machine shop alright! Its like they say, "its the journey, not the destination".😁 Love the videos, great content and well explained as usual.
If you're being serious, perhaps hit AvE up. He's got himself a 5 axis CNC for community projects, for which you submit requests by making a youtube video.
I just wanted to say that, while I'm certain many of your jokes fly right over my head, the ones I do catch are very much appreciated. Entertainment that is also educational! It makes me feel less guilty for spending hours bingeing on youtube.
I wait for him to make me laugh some how. It usually takes about 20-30 seconds... Then he makes me laugh more so I have to unlike, and then like it again
Tony, long time listener, first time caller. Thanks for the rad videos, man. I appreciate the educational content recently. Gears are not something I would have looked up or tried to understand, but you've managed to make it funny and interesting. Thanks!
Hey this this old Tony I know this is going to sound like e begging but it's not just throwing it out there to see what happens if there ever comes a time you decided to part with the mini lathe keep me in mind and why I say that is I have mental and emotional issues that prevents me from working and earning a living and working with my hands at home on my own projects is therapy for me and short of someone donating a mini mill or lathe I'll never be able to afford one on my own 90% of the tools I have now are hand me downs or junkyard salvage and it's always been a dream of mine to get into machinist project for around the home simple basic stuff so just keep me in mind when throwing out old tools anything you could possibly send my way would be greatly appreciated more than any one person could ever believe thank you and your videos have been a great inspiration to me keep up the amazing work
Hawkeye, I love your videos, and I'm a wood turner!Back in the day, when I was taught clockmaking, I failed the theory. Watching this, it all came back to me...hypocycloidal gears....Argggghhh!
Buy a gear for a dollar? I am designing stuff right now and need gears. They are crazy expensive! When I was a young kid, I could buy all kinds of small gears from Boston Gear for real cheap. I would get several gears, some shafts, collars etc for I think under $10.00 usd. Now, everywhere I search, just a single gear is like $12.00 and up. Search gears on McMaster or similar. So I decide I will make my them here. And again, total mind freak, the price of a Diametrical gear cutter set. Just a single cutter is the same price of the whole 8 piece set of Module cutters. And so, I will go module. I am making stuff for in house projects, and so, module is fine, fortunately.
Maybe a bit off topic, but I strongly suspect the high cost of gear production is behind auto makers aggressively pushing out CVT's (Constantly Variable Transmissions). IMHO, CVT's are not the correct technology for automotive applications. I also think some auto mfg's may be hiding CVT's behind high count computer generated tactile 'shift points'... ever notice how many 'gears' some newer automatics are claimed to have? Rant rant rant...
Re: The CHAMFER. It will reject foreign objects better, and more importantly, protect the gears when they are ever so slightly misaligned. But I'm pretty sure you knew that! A thing of beauty. Thanks.
Congratulations Mr Smith, that's quite an achievement. I can rest easy knowing what you've done today and how much you've drank. I also wish I could drink as much Guinness as you, you're so cool.
I love your sense of humour mate, been watching your videos for a few days now, great entertainment, and I'm learning stuff to boot! : ) Merci TURK from France
You should machine a few replacement gears for the ones used in a drill, get rid of the powdered metal or plastic ones that it comes with and give your tools an upgrade.
I asked my tribology professor about the chamfered edges today. The edges are chamfered to prevent cracking/notching them when handeled. They are also made to make the surface hardening more even, not as much stress concentration without them harsch edges.
Love your videos, greetings from Sweden!
Beat me to it.
@@nakedanimegirlspls Sorry mate
It's essentially a more technical version of why when you forge a sword, you leave the transition between blade shoulder and tang a fillet. A right angled transition leaves a stress point that could cause cracking during the heat treat.
Chamfering the edges also reduces contact friction, therefore heat on the gears (less surface area contact). You would be surprised the difference ot can make on gears that are heat sensitive due to speed.
I was told it just makes the gears last longer somehow, so I'm glad to get a better answer than that. I was also told it had something to do with gears thrusting, but I dont know if that is true
9:25 I've actually had to use this technique to start a mill. The fuses were to small so they blew immediately upon starting the rotation anything over 400 RPM. But by giving the spindle some speed before engaging the electric motor it was avoided. :D
Did you start it by hand, or use a different machine to start it.
Pullstart on the mill got me big time! Tony, you are hilarious!
Right?
I was going to ask Tony if his miller is 2 stroke or 4 stroke. And, if it is a 4 stroke, does it have timing gears.
I was just wondering the other day how long it would be before we saw that.
@@jlucasound No it has a Morse chain driving an encoder. You can hear it tippity tapping away.
You notice it took a couple of tries. Obviously TOT is using the cheap oil. Such a tight wad. Real machinist use the unatainium oil. Somebody should report him him to Abom79, or Keith Fenner.
I'm really loving how much of machining boils down to "This sucks, so I'm not going to do it." I've seen more shortcuts and exploits in my semester of machining classes than I have in a decade of playing video games.
That shot looking straight down the centerline of the blank while the gears were being cut was great.
I second that !
Seth Bracken I third that !
Let us go forth and get a fifth.
@@Scynthius137 I wanted to fifth that so I just went and got some Makers Mark.
I'll settle for 6th.
Edit: or should that be sixth...🤔
100% understood everything that was said. 0% chance I could reproduce it.
0% i understood everything, 100% i still like it!
Yeah, my chance to reproduce what was talked about in this video is pretty limited.
Owning a lathe or mill might help
Back in medieval times, when I was king of Texas and New Mexico (it's a long story), I commanded my armorer to make a torque multiplying gear drive for a trebuchet so I could win the Punkin Chunkin trophy. He made the gears from "the bones of my enemies" and they were just too brittle to hold up under the strain. I had him executed and enslaved his family. I often reflect back on those days with remorse. I really wanted to win the Punkin Chunkin trophy,
Michael Lloyd 😂 TOT, this is your fan base! Nice.
Sounds like your enemies either needed more calcium in their diet, or they were little old ladies with osteoporosis................not gonna judge, I'm sure those broads at the bingo game had it coming!
and who can blame you, it is the LARGEST TROPHY IN ALL OF SPORTS!
@@mrdumbfellow927 Back then we didn't eat as well as we do now. Now we have Taco Bell, McDonalds, Burger King,,, ok not Burger King...
Ah, his mistake was likely that he didn't chamfer the ends of the gears. Rookie mistake.
In all seriousness, I always considered myself pretty stupid. Math was something that always confused me. Yet machining is a dream of mine to start one day. Here recently I have been pretty down thinking I would never understand it. But I was you to know that you are the first that has managed to demonstrate something in a way that i understand it. I can't thank you enough. Gives me hope that one day I can too be a hobby machinist.
Math involved to do basic machining is trigonometry, addition, subtraction, division, ratios and sometimes squares and powers. It's definitely not beyond you to learn and enjoy. I'm not gifted in the language of logic, mathematics, but I've worked hard at it. You can improve your logic by just using simple arithmetic everyday. As an example, calculate your change at the grocery store before the teller reads it to you off the screen.
Oh, and buy a lathe , go make some stuff.
FWIW, I too was inspired by TOT videos and bought a machine and tons of other stuff to go with it. Tony cost me a lot of money. 😂, but damn it’s fun!!! Next purchase... gear cutters!!!
Do it. Math is a tool just like any other tool. You will learn it when you need to apply it.
It is stupid how much better at math I am now that I am a machinist. Every time you cut you need some kind of math.
If I have a 12 foot piece of A36 that needs to be cut to 10 inches I divide and add at the same time using an equation, length of stock÷(length of piece+blade thickness)=useful stock length. This tells me how much material I can actually use from a piece of stock. But first i have to convert the stock length from feet to inches. So i multiply the feet by 12 inches to get 144 inches.So 144÷(10+0.125)=144÷10.125=14.2222222222. I cant use the extra 22222s at the end because they represent what i have left on the stock so I can get 14 pieces of 10 inch part blanks per stick of A36. And the customer wants 100 pieces. So I divide 100÷14 which gives me 7.1428571429 which just means 7 full sticks and one that wont be cut up completely. Lets assume that the customer actually sent the 8 sticks I need and I dont have to tell my boss that I need one more stick because we're also out of 0.5 inch A36. NOW WE CAN CUT oh wait i have to set the stop, ok stops set at 10 inches. NOW WE CAN CUT METAL! This is just the first step in most jobs period.
@@zennyblades Imagine if this question was on a test and don't work with metal. You would be angry to see these numbers. But since you work with this everyday, these numbers make sense. That is what is missing in school with math, real world application. So you now are a master at converting units, you now understand rounding very well and you understand division.
They knock the edges off the teeth to reduce the tip load on the end of the tooth, which reduces the chance of chipping. Something about more support for the end of the tip...
Or at least that was what I was told many years ago when I was working as a gearset fitter.
i would have guessed that it was so your lubricant of choice would be slung into the bottom lands of the opposing gear, but reduced chipping makes sense.
That was my assumption too. Plus reduces the chance of any stress fractures on a sharp end under load.
My initial thought was a gear mfg not knowing the application the end user would use the gears for, if they were placed on a shifting gearset such as transmission the chamfer would help with shifting of gearsrts. But your explanation makes more sense.
So, you're saying "Just the tip"?
Sounds right since it removes a stress riser at the points of the teeth.
"Why? Isnt a really valid question in the context of a home machine shop."
-TOT
Quote of the year? Quote of the year.
This Old Tony - one of the few youtubers you can click like before watching the video and know afterwards you were right!
Hard to disagree! :-)
Indeed.
have you watches ninjas lates fornite video? he allways brings out bangers.
Totally agree. That's what I always do
That ain’t no joke
You are awesome. My son really enjoys watching your videos and I enjoy tagging along so I understand what he is talking about. :) We both can't wait until he is old enough to have his own machine shop. He is taking automotive in high school and really enjoys that class. Someday he will be able to machine his own parts.
_"Why?" is not a valid question when it comes to a home machine shop._
Hilarious.
you should ask why not
Why not is tho a valid answer...
Because of these videos I now have a home made idler/reverse gear for my little lathe. When I need a left hand thread cut in ten years I'll be sure to tell everyone to thank Old Tony.
Could you go over speeds and feeds for an enemies bones? Asking for a friend.
GTX Machine I am actually interested in that
My old DO-All band saw has a speed chart for asbestos... I'm sure it has speed setting for enemies bones next time I'm in garage I'll take a look for you.
GTX Machine ua-cam.com/video/lpvT-Fciu-4/v-deo.html
Baudfaust Babelfish, Asbestos is great on toast! Especially if it’s ground up really fine and layered on thick. I do freely give it out to enemies.
I bought a Chinese bandsaw about a month ago and it had speed settings for asbestos.
I guess they just dont care over there in the big rock candy mountain
I don't really know much about this, but here is my guess why gears should be chamfered: Both deburring and accurate chamfering is quite important (and each tooth should actually be chamfered on all sides)
- Sharp load bearing corners can be work hardened during use, causing breakage.
- Sharp corners gets hardened too much during hardening process
- If gears are to be engaged and disengaged axially, chamfering geometry is important, oterhwise:
- higher wear
- Assembly of gears is faster and simpler with correct chamfering geometry
- Injury during handling
- Less damage during transport
- Problems clamping gears in downstream manufacturing steps. (only clamp the disk, not the teeth)
- More noise in fast running gear
- Post hardening processing requires chamfering to improve process and tool reliablity
I thought putting a bevel on the gears helps them mesh together in applications where they have to engage from the side. And to help with material rolling over. For the same reason putting a bevel on a hammer helps with mushrooming.
But I'm no machinist. I'm not even a machine. I'm just a dude, playing a dude, disguised as another dude.
ua-cam.com/video/CFG5dk1GyRo/v-deo.html
Corner bevels and leading edge bevels assist in side meshing as stated above.
Reduced burr formation reduction causing that may cause galling of adjacent plating or gears also as stated above.
Corner bevels also assist in oil and debris escapement in gears walled in on both sides. Preventing hydraulic loading and the forcing of walls away from gear.
Can reduce noise in some applications.
Makes them look and feel way better.
Some of these factors are not present on a lot of gear applications and as such you wont see the corner bevel on things like crown gears or 'Bevel' gears, or gears with a shank or standoff.
@@michaelandersen7535, that was the first thing I thought of too...
@@another1commenter770 makes good points. In tough ductile materials, chamfers are important to prevent damage to 90 degree corners, which will raise a bruise adjacent to the ding (which, as he points out, may then damage the part in contact with it); in brittle materials, they're important to prevent chips or cracks when the gear is accidentally knocked or dropped. As other have said, these chips can migrate through the entire gearbox (they may not break off at the time of the damage) causing mayhem when they pass through the mesh or get jammed in bearings.
These rules are true not just for gears but for machined parts generally. Also a perfect 90 degree corner is unsafe for human contact. There are other reasons, well traversed in this (typically excellent, for a ToT video and against the general "run of play" for UA-cam) comments section
thewoodshed exactly, like in tony motorcycle transmission, chamfered edges help the gears mesh together on a side to side motion
Lesson(s) learned....1. get a better rope to start the mill. 2. you can't do anything properly without a monogrammed space suit. 3. and most importantly to make proper videos you must be of the Mesmer Clan. Thanks TOTM!
I learned that how to make a hormone, and how to get stabbed in the gears by a machinist with a parting tool is exactly the same.
Ahh, I remember my first pull-start End Mill. I believe it was a Troy-Bilt....horrible for cutting spur gears, but worked surprisingly well on grass.
Also, Tony, it's done to avoid breakage: The burrs along the tooth edges can often cause breakage when the gear is running, so chamfering de-burrs and extends life, not to mention avoids chipped gear teeth flying all over the joint.
By far the most entertaining, insightful and encouraging channel on UA-cam!
Been watching for some time. What I’m happiest about all these videos is, I’m glad you use your powers for “Good”!
You obviously haven't seen him digging out his machinist's voodoo dolls...
@@mhe0815 Even then he only uses those for mischief :P
Love the sight gags in these videos, like starting the spindle with a rope. Classic!
Wow, I wouldn't be able to endure having a machine without a started built-in.
What a man.
Absolutely LOVE your work. One of my top ten favourite UA-cam channels. Been watching almost daily for the last few weeks 😀
Out of the 155,976,675,323,221.334 UA-camrs, This Old Tony has to be the best overall.
that .334 part is kinda scary
@@John-ik2eg Yup, I've seen them, too. I believe he is from Wisconsin, and was a full 1.0 prior to the Polar Vortex.
.334? You converted this from imperial?
a tip for when you're cutting smaller gears (like for clocks, as I do) cut in a little bit with your parting tool. This doesn't need to be the whole depth of the tooth, just a slight, but it'll decrease the chance of the teeth getting mangled when you're parting it off after you've cut the teeth. bigger teeth usually are strong enough, and the involute gearshape helps as well, but making cycloidal teeth the base of the tooth is quite small, especially when making pinions (Z
Should I wait for the re-upload before commenting?
Lol burn
I'm glad to see that you have embraced the simplicity of the metric system. USA vs just about all the rest of the world!
you chamfer gears because if you dont your teacher take off marks from your project...
It has to do with hardened teeth: that corner is weaker (because of nog support from the side) and breaking/chipping is done easier.
You dont want that because hardened metal between the teeth is like sand between you veggies.
So: chamfer them to prevent breaking the end of the teeth, especially with hardened steel of not perfectly align gears.
@@eddyerkelens - Huh, I had thought it was from the requirement for gears that slide into mesh like automotive transmissions. More reasons than I knew, thanks :)
@@somebodyelse6673 automotive transmission gears don't actually move into/out of alignment. The synchronizers between them are pushed by the forks to engage the right gear to the shaft. the bears themselves are always meshing and almost always helical.
@@andrewmalaty8 - I guess my knowledge is a little out of date. I've always thought of automotive transmissions like this. ua-cam.com/video/JOLtS4VUcvQ/v-deo.html
Can you tell I'm not a car guy? :)
if you dont chamfer a 40mm shaft and try to put it in 40mm hole with no chanfer on the edges ......ehm well good luck :D
Dear Tony,
Thanks to the generosity of People such as yourself who take the time to make edifying videos for the education of the great unwashed such as myself I have learned much via youtube. This was a really good and useful video mostly in my opinion of the utterly succinct explanation of dividing. Thank you very much. Yours are definitely the most humorous offerings in the engineering field too.
I will be 74 at some vague point later this year... but I'm convinced I will be history long before I learn all the interesting stuff I want to... But you're helping my CAUSE... Thank You!!! :-) :-)
The ToTstronaut...The genius is truly in the details.
Also the wide view. And the editing. And font selection. Most parts, really.
Three speed band saw pusher, how interesting. I was thinking about reverse gears for my hammer...you know so it can suck the nails back out of the wood.
There are already commercially available hammers with a two-teeth reverse gear.
you'll only need two gears for that! :D
I had a shop teacher tell me with a completely straight face that, if I cut too much off on a lathe pass I should put the lathe in reverse and sprinkle the chips on the work so it would weld them back on. Took me a second...
somebody else that's like telling the apprentice mechanic to change the blinker fluid
increase forward geer with less teeth would be best so you can blow on your thumb when you hit it with the hammer 😆😆
I really enjoy your videos. Thanks so much for sharing your time with us.
G'day I'm Chris.. today were gonna hand file some gears like real men.. unlike that machine tool using slacker TOT.. ;)
Bwahaha! "real men" more like "real stupid" LOL
@@Studio51media I guess you totally missed his joke, did you.
@@zusurs Yoda?
Artūrs Savickis if you’re asking, I’d like to think not only did I get it, but added to it? I’m no machinist, but I recall my dad refer to “machining” as if in theory, everything done with fancy machines could somehow be achieved by merely “filing”... so his joke about being a “real man” struck me as particularly funny
@@Studio51media
Check out "Click Spring", your welcome. Seriously, Chris is amazing and he gets referenced on this channel like every 3 videos.
The chamfer on the corners of the gears is because that is a weak area. Under load any shaft deflection can put very high loads on the corners of the teeth, and for hardened steel gears or cast iron the edges would simply break and you end up with bits of hard material passing through gears, so best to remove them from the start by putting a chamfer or radius on them. Not really a problem on aluminium or nylon gears. Finally something I learned during my apprenticeship turned out to be useful...
Two guesses on why gears are chamfered:
1: To reduce oil flinging, without the corner the oil is more likely to fling onto the other gear.
2: To remove a stress riser. Helps keep your gear from looking like a Hockey Player.
Stress risers (for everyone's information, not as a rebuke to this post) arise (ha!) from INTERNAL corners, not external ones. So the root fillet of the gear tooth moderates the stress raising tendencies at the root, but there is no such need at the tip.
Sharp external corners are delicate by a different mechanism: because they're not well supported by the part, because they present a small cross sectional area (which *does* expose them to increased stress, but only in proportion to the area, like any contact stress) and because they're protruberant by nature and hence damage prone.
I always assumed (not a good thing to do actually) the chamfer is for reducing friction
I work with a powertrain engineer. He says "stress strain blah blah, prevents corners from cracking, blah blah, tip load, blah. Always entertaining Tony, thanks.
A new TOT video? Just in time for coffee? How serendipitious!
I love your videos. Man i had a shit day this always is the best way to gear down after a shafting of a day.
"Why?" is a valid question, with the equally valid answer: "Because I can!"
A mountain climber climbs a mountain because it's there. A machinist makes a 15T M2 spur gear because it's not there.
@@gcewing I saw where a gear was not, and said "This will not do."
I would think other then some technical stuff I don't know about, that the chamfer would also direct oil and what not into the groovy part of the gear... maybe.
I just love your videos, Tony!
It's now 2 weeks since I found this channel and just finished watching all your vids. I've never thought machining can be so interesting and all these while I was never interested until I watched your videos. Keep up the good work Tony I can't wait for more videos.
While I enjoy other machining/shop based channels for colorful language and educational content, TOT weaves plots and storylines through his videos in a way that should make many Hollywood writers take note.
TOT the movie??? I'm against it. They always ruin the story lines when it goes 'wood. The group dancing may be fun though...
@@squelchstuff Esther Williams hob dancing ?
@7.29 the reference to Cogswell’s Cogs (again from the Jetson’s) made me grin. I’m compelled to re-watch your other videos again to search for more of these Easter eggs.
You certainly put a lot of effort and humor into your videos. Much appreciated.
Back in my day all we had were those pull-start mills.
I cant get a 2 pull start on my lathe without a shot from ether can
@@rwbimbie5854 Ah, once you start down that road, they get to like it and won't start without the stuff
If it had been a Honda mill, it would have started on the first pull.
And yes, I know I'm repeating myself.
Felt like I was watching Musty1 there.
In India, the ones with the turban are the rope starts, the ones with the red dot are push button start.
The moment of tooth...nice;)
Aaaaah, I missed that one!
That's the best pun in the video :D
@@Abrikosmanden How could you missed it, it was even written on the screen for the deaf :)
The bevel on the gear depends on the application. You don't always have to do it, and you can always add it later.
1: It helps retain oil by adding surface area and changing geometry. When they're flat and tightly meshed, they foam up the oil faster. That little bevel lets surface tension do its job, and then oil on the following rotation will clean out any junk from the prior turn. Same thing for when gears are submerged where they mesh away from each other. You'd be amazed how hard it gets to turn a shaft under that kind of condition.
2: On geartrains with lots of shock loading and harshness, like on motorcycles, the teeth chip on the corners of the tooth tips.
Have not touched any fabricating tool since I finished school 8 years ago, but I'm still watching every single of your vids :D
I love the smell of fresh spur gears in the morning!
Never realised engineering could be so psychadelic! Male acuity to both detail and visuals of shot looking straight down the axis of the shaft while cutting the teeth. Wow!! Thank you.
I just watched it, second times. It’s a great video, superbly done. I don’t have a dividing head, never even worked with one. Two gears were done by me only, during a life time, using the lathe as a shaper. I am planning to make a special gear without dividing head, most likely never will be done. Thanks again for this most enjoyable video, I can appreciate the work you put in and the excellent photography. Bob
i really like that tony went into detail of why you need the tooth profile on the teeth to be exact, it happened about 40 years ago, but i still remember it with my 32 years of age, i tried putting a 100 tooth gear and a 5 tooth gear in my grandmas meat grinder so that she wouldn't need to be so long in the kitchen, low and behold when she tried it out i heard a loud crack and the bigger gear yanked out my tooth
U ruined me for other vid publishers... the way u approach the topic is amazing.... always looking forward for new vids .... thank you for doing this gr8 job
thanks!
Thanks for these videos, Tony. I don't have much for tools so I've been making them from scratch building up to a point where I'm gonna have to cut some bevel gears. That thing about concentricity error is golden! Honestly, there's a very high probability of failure, so I'll take every bit of info I can get lol. Thanks again! 👍😊👍
I'm not a machinist and i have no idea what are you doing... but i love it all!!!!!!!!!!!!!!!
Best videos on the Internet. Combined with humor most will never get. Pure awsome!
well that was a whole lot of nothing.... I have a 4 speed push stick with reverse AND self-aligning flux shifters
And one day we will all upgrade to the 6 speed push stick with reverse, self-aligning flux shifters, AND gps controled gyroscopic thrust vectoring rotor system for that perfect cut every time. :-)
if you think thats great my push stick is Automatic......
Carbon " Neutral " ?
@@stevenarango6319 Mine is a 13 speed forward, 3 reverse, double dry clutch robitisized sequential shift push stick. Like an auto, only better with computer control.
I use the Quadroplex from the retired B42.
Dang Tony. I literally said out loud watching this; 'holy crap, that's some amazing filming' (the static cutting head, in particular). Your sense of cinematography is criminally undervalued. Well done, chap, well done.
'Top Secret: Cogswell's Cogs'
Lolololol. Brilliant.
Happy New Gear 🔥♥
allow me to show you the exit
You uploaded this video precisely at the same time I started to think about making a gearbox, how serendipitous.
This raises so many more questions than it answers! For one - how did you get into Cogswell's Cogs' secret files? Are you secretly spying for Spacely Sprockets??
Years since I've heard that one!
@@saddle1940 Are we in the future already?
No, it’s still yesterday.
@@jimc3688 :-)
Old Tony you need to be writing, directing, acting and editing your own big budget Hollywood movies. But on second thought, we would dearly miss your UA-cam channel so please continue your brilliant work on UA-cam.YOU'RE ONE OF A KIND!😁
Tony - the reason they chamfer gears is so the end grain doesn't chip.
I just love watching youtubers making things I will never need or want to make. This Old Tony, Colin Furze and Frank Howarth with a little bit of jimmy diresta - man I have watched hours of you guys and honestly I am in awe. Not just for the skill and creativity you demonstrate in your craft, but the videos themselves are so well made, often as funny as they are informative. Who knows, maybe I WILL want to cut my own gears some day...
Mill must be warm... didn’t even have to use any starting fluid to get it going....
Doesn't need it with the choke on.
I think this mill is fuel injected.
@@PorkBarrel. nah, it's a hit and miss 5hp McCormick behind, no fancy injection or choke needed
I have to suggest my boss to replace the old clunky wheel loader with Tony's mill. We could save so much on reduced starter fluid.
I am sure its the glow plugs or it ran backwards, maybe the hinted video at 11:23 reveals how Tony fixed it! :D
Must see video series! Thanks for making these.
That was a great video. Now do a worm gear. No cheating using a tap for a hob. Nice square threads. Then put it in a cute machine to show it working. Due in 30 days. Grade depends on fit and finish as well as fancy video editing. This project will be 1/2 your grade this semester.
That's not all that hard. Make worm and hob as one piece on lathe. Remove, heat treat, reinstall. Gash wheel blank using slitting saw to provide a start for the hob. Mount wheel blank on workholder on lathe cross slide, turn on lathe, slowly feed wheel into hob until desired depth achieved. Lap on worm if desired. Part off hob. Matched worm and wheel!
@@ThomCat316 shhhhh!!!! Don't give Tony any hints! *sigh* Now we have to make the assignment due in 15 days.
You make me wanna leave the comfort of my warm home and go to that cold shop and cut some gears... Thank you This Old Tony!
"Top Secret- Cogswell Cogs". Effin' hilarious! I love your references n puns.
Simply put Tony you make the best videos out there that I have ever seen. The first time I saw your channel I was like this dudes crazy. But now I can’t wait to see the videos you produce. I love em man. they’re absolutely awesome. Was actually having a shitty day today. Got a notification that this old Tony put up a video boom my day got better. Thanks
The chamfer is necessary, because it´s more aerodynamic. No need to thank us, we are here to help....
My mind is blown! Thank you Tony, I love having a giggle in the shop with you!
You’ve really got to upgrade to the kick start. You’ll never go back.
11:23
I've seen this video literally dozens on times and I never took a moment to pause and read these.
ToT, you're the absolute best, thank you for being youtube editor MVP of the Year.
Just a guess on why the chamfered edge, but if the axis of rotation aren't perfectly aligned I think the force being put through the gears would be borne by the outside corners of the teeth and for hardened gears might cause them to chip. With a chamfer, even if they're not perfectly aligned, you increase the contact surface and reduce the force/area making a tooth less likely to chip/crack. Again, just a guess.
You could test it with a set of gears with and without chamfer, misaligne them intentionally and measure the contact area with blue dye.
Best channel I use to watch. I love the good humor in every videos!
This is a teaser for a more in-depth three-speed push stick build, right? I have so many questions that need answers.
Watching ThisOldTony pull-start his machines is priceless. How is this guy so creative and hilarious? How does someone even think of that?
Re: teeth chamfer - first thought is to ease assembly when inserting / meshing gears. Second guess would be clearance for gear oil / grease to pass around.
Absolute gold. Thanks for sharing your talent for teaching and video making!! Best regards from Brasilia, Brazil.
I love the McMaster tip, I steal dimensions from their drawings all the time
"Why" doesn't come into it with a home machine shop alright! Its like they say, "its the journey, not the destination".😁 Love the videos, great content and well explained as usual.
I need you to cut me some module 4 gears for my threading dial! I mean after cutting module 2 gears cutting module 4 should be twice as much fun!
That is wrong! It is actually 16 times a much fun. Fun increases proportional to the square of the module number.
If you're being serious, perhaps hit AvE up. He's got himself a 5 axis CNC for community projects, for which you submit requests by making a youtube video.
I am very serious! Thanks for the heads up.
@@dansimpson6844 HaHaHa, yes! sweet jesus, ToT comments are the best, haha thanks for that.
Still the best channel on UA-cam. Learning a lot. Thanks Tony
I know everything there is to know about gears but still i just love watching your vids TOD! Keep it up!
"I know everything there is to know about gears"
(doesn't divulge the secret of the chamfer)
I just wanted to say that, while I'm certain many of your jokes fly right over my head, the ones I do catch are very much appreciated. Entertainment that is also educational! It makes me feel less guilty for spending hours bingeing on youtube.
im a simple man, i see a this old tony upload, i click like
I wait for him to make me laugh some how. It usually takes about 20-30 seconds...
Then he makes me laugh more so I have to unlike, and then like it again
hahaaa,,,so do i
stop with this meme already :|
Tony, long time listener, first time caller. Thanks for the rad videos, man. I appreciate the educational content recently. Gears are not something I would have looked up or tried to understand, but you've managed to make it funny and interesting. Thanks!
3 gears on a push stick? Doesn't that give you a 180 degree phase shift and make it a pull stick? I'm confused.
it is intended for advanced pushers.
No phase margin. If not experienced it will break into oscillations. Advanced users only.
Hey this this old Tony I know this is going to sound like e begging but it's not just throwing it out there to see what happens if there ever comes a time you decided to part with the mini lathe keep me in mind and why I say that is I have mental and emotional issues that prevents me from working and earning a living and working with my hands at home on my own projects is therapy for me and short of someone donating a mini mill or lathe I'll never be able to afford one on my own 90% of the tools I have now are hand me downs or junkyard salvage and it's always been a dream of mine to get into machinist project for around the home simple basic stuff so just keep me in mind when throwing out old tools anything you could possibly send my way would be greatly appreciated more than any one person could ever believe thank you and your videos have been a great inspiration to me keep up the amazing work
It would make for a good project/video to put a starter on that mill
If it had been a Honda mill, it would have started on the first pull.
Or a Stihl @@bryoncase4656
He could just go full project farm and start it with a 1/2 cordless impact. Save your elbows for some detail hand filing, nowatimean?
In the good old days when mills were driven by waterwheels, you never needed to stop them.
@@Gottenhimfella Even steam driven ones.
Hawkeye, I love your videos, and I'm a wood turner!Back in the day, when I was taught clockmaking, I failed the theory. Watching this, it all came back to me...hypocycloidal gears....Argggghhh!
Buy a gear for a dollar? I am designing stuff right now and need gears. They are crazy expensive! When I was a young kid, I could buy all kinds of small gears from Boston Gear for real cheap. I would get several gears, some shafts, collars etc for I think under $10.00 usd. Now, everywhere I search, just a single gear is like $12.00 and up. Search gears on McMaster or similar. So I decide I will make my them here. And again, total mind freak, the price of a Diametrical gear cutter set. Just a single cutter is the same price of the whole 8 piece set of Module cutters. And so, I will go module. I am making stuff for in house projects, and so, module is fine, fortunately.
If you really want to do it on the cheap you can use a fly cutter with a form tool.
When I was a kid I could walk down to the penny gear store. 🤣
Maybe a bit off topic, but I strongly suspect the high cost of gear production is behind auto makers aggressively pushing out CVT's (Constantly Variable Transmissions). IMHO, CVT's are not the correct technology for automotive applications. I also think some auto mfg's may be hiding CVT's behind high count computer generated tactile 'shift points'... ever notice how many 'gears' some newer automatics are claimed to have? Rant rant rant...
I believe steel in general has risen in price. Price a lite gage metal stud, more expensive than a wooden stud.
Look into replacement change gears for myford and southbend style lathes .. they seem pretty cheap
Re: The CHAMFER. It will reject foreign objects better, and more importantly, protect the gears when they are ever so slightly misaligned. But I'm pretty sure you knew that! A thing of beauty. Thanks.
6 pints of Guinness in front of the fire at my local boozer, a chip butty and come home to a new This old Tony flick! A bloody good Saturday so far!
Congratulations Mr Smith, that's quite an achievement.
I can rest easy knowing what you've done today and how much you've drank. I also wish I could drink as much Guinness as you, you're so cool.
Fries in a bun. Only in the U.K.......
I love your sense of humour mate, been watching your videos for a few days now, great entertainment, and I'm learning stuff to boot! : )
Merci
TURK from France
You should machine a few replacement gears for the ones used in a drill, get rid of the powdered metal or plastic ones that it comes with and give your tools an upgrade.
Love the close up. Also my Q regarding cut depth in prev video answered here. Thank you.