Why Harmonic Drives Are Awesome.
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- Опубликовано: 30 сен 2024
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Today we cover Harmonic Drives, Planetary Gears, and Worm Gears.
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Notes:
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One of my favorite uses of the planetary gear-set is the Sturmey-Archer 3 speed bicycle hub patented in 1903. It used ratchets to give an underdrive, one to one and then an overdrive giving the bicycle 3 speeds. Later a coaster brake was incorporated into the mechanism eliminating the need for a separate brake mechanism for the rear wheel.
However, being a retired ASE Master Technician who ended his career as an Automatic Transmission specialist, my absolute favorite use of planetary gears is in the 700-4R/4L60 & 75 transmissions used in GM vehicles in the 80's, 90's and 2000's. Unlike all other 4 speed overdrive automatic transmissions, the 700-4R design, which continued in the 4L60/75 transmissions, uses only two planetary gears to achieve 4 forward speeds and the requisite reverse gear. All other automatic transmissions used a 3rd planetary gear-set to get overdrive. It's one of the tightest and most compact automatic transmissions ever designed and it was a huge success, once all the bugs were worked out, most of them lubrication issues.
I have a GM 2500 van, which has a 4/80. I often wondered if it had a secret gear. Its a 1995, still works well, easily repairable. Love the van, put a Positraction into it, works in hail, sleet, or snow, and it may very well outlive me. I intend to be buried in it, one way or another. Wife says no way, but kids want it anyway.
so that's how they work! always wondered about that as a kid but haven't even thought about sturmey archer gears as an adult. if you want a busman's holiday - precision transmission is back up and running on youtube - i think the guy has spent 46 (might be 48 now) years servicing automatic transmissions and watching him go through an 4L60E is something to behold!
I think my grandparents had one of them, but if I remember right it only seemed to work on two speeds. There was some form of cam lever on the side of the hub assembly if I remember correctly that looked like it pressed in a button in the center. I was barely tall enough to ride it and it's been at least 40 years, but your comment brought back some memories!! Can almost smell the old chicken coupe the bikes were stored in.
I had one of those in the 60's. Twist grip shifter.
I have to say Jeremy, you are a brilliant example of a self taught engineer. You have conveyed so much info, in such easy to understand format, that I am sure (and hope) you have inspired dozens, if not hundreds of young people to take up engineering- especially robotics - as a career. I'm and old school engineer, who learned my trade "at the bench" mostly, but nowadays RUclips is a big factor in teaching people. Keep on doing what you are already a master at- and I am sure many more young potential enginners will get the inspiration and confidence- just because of you - to take up this subject as a either a hobby or a job. Well done Sir!!!
Jeremy, you are a brilliant example of a self taught engineer.... And, this is why Jeremy's videos are so appealing to me and all the other "backyard" engineers. Watching Jeremy expands my realm of what I think I can do. LOVE watching what Jeremy does.
Why does he not have millions of subscribers? Amazing Channel for engineers and inventors of all ages. PLEASE SUBSCRIBE!
Fantastic view of the harmonic drive; I have been wondering. Good to see you.
Thank you Mr. Fielding. Very good tutorial.
In respect of the harmonic gearbox, I remember seeing a documentary about 20 years ago that spawned the idea of this type of reduction.
Guy having drinks in a bar. Spun a coin on the bar-top and watched as it slowly tipped over doing its wibbly-wobbly thing. He noticed the rotation of the coin in relation to the bar-top surface. The light-bulb lit up.
The original concept was a little different to what you have shown in this video. It was two ring gears but one of the gears had one less tooth than the other. One of the gears was tilted on its rotational axis by a cam to mesh with only two or three teeth on the other.
Same idea, different implementation. 60/61 teeth = 60:1 reduction.
Really interesting!
I hadn't seen that one before (the harmonic drive)
It's almost useless. Limited to low power and not critical applications. Sensitive to overload = it cracks.
If you wanted to show one of those kind of Gears take apart an oscillating sprinkler one of those ones that you just put in your yard. They have the same type of design that you're talking about but they also have three stages of it inside of it too that's all powered by the water flow
It still baffles me how harmonic drives are so smooth and free. You would think the elliptical bearing having to actually deform the cup would make it stiff to turn and add a ton of resistance but somehow it doesn't.
At a guess, its because turning it doesn't cause more deformation, just shifts the deformation around. Where the spline on one side of the apex takes force from the elipse to deform, the other side is exerting a force back on the elipse while it relaxes.
Ball bearings are also a hell of a drug. You can jam a wedge between two surfaces very easily, but getting a wedge to jam between two rollers with ball bearings is close to impossible.
Probably worth noting that many worm-drive gearboxes have a dual output shaft option which is pretty useful for some applications.
Indeed. The two large ones I showed in the video were like that.
I just subscribed after seeing your last video 👌
My question is: how long does that flex gear last before that cup fractures (thousand of flexing, tens of thousands...)?
Excellent video. Thanks.
wow, well done..
Igus sells a robotic arm with worm gear reducer.
Ive never seen those strain wave gears before, clever for sure but how reliable are they, would they not be prone to metal fatigue?
As long as you design your machine with an appropriate safety factor and you keep them lubricated you should not have issues with fatigue. However, just like every decision in engineering you need to make trades. If you want the most durable gear over precision you have other options. Specifically you would want gears with larger teeth and thus larger gears. You need to look at your design needs and make choices accordingly. Most importantly though, the further you are operating from the designed limit of the gear, the longer ANY gear will last including this one.
I'm one of the engineers for the actual Lunar Roving Vehicles, made by General Motors and Boeing. Harmonic drives were used on all four wheels, and were used to be able isolated the DC brush-motors from the vacuum on the Moon. Brushes do not work well in vacuum, since they are lubricated on Earth by a thin film of water, from the humidity. On Moon there is no H2O, so the brushes turn to dust and wear rapidly. The motors and the harmonic drives were half-pressurized with a partial atmosphere, with a specific humidity installed. Garrett-AiResearch did the motor assembly. Gear ratio was about 80-to-one. Motor turned up to 19,000rpm max, but usually ran at less than half of that during actual on Moon motoring. The drives would work just fine if somebody went to the Moon and energized them, but the wheel brakes are probably locked-up now, due to vacuum cold welding, so the vehicles probably could not move.
Very cool! Thanks for that.
Why not use brushless motors?
@@ivanradojkovic1705 At the time the LRV was developed, power semiconductor technology was not what it is today. Given that, and the complexity of the required control system, brush motors would have been a better option overall.
@@ivanradojkovic1705 Additionally, semiconductors don't fare very well in space. The ISS orbits within the Van-Allen-Belts that shield a lot of radiation and still has to regularly replace laptops because they start to malfunction. The control module of a brushless DC motor would fare similarly bad or worse.
So how do ISS, and satellites, continue working so long, but not laptops.
And don't tell me Shielding, I'm a consulting Physicist.
Kids don't realise how lucky they are to have people like Jeremy teaching them engineering. I'd have sold one of my brothers kidneys to have this when I was younger.
it's not too late. it's never too late.
And then still, Most of them would rather watch some idiot dance on tiktok 🤣
Absolutely agree. Fesz electronics, Eddie Woo mathematics are 2 other examples. One can self-educate now. I wish some forward thinking university would step up to coordinate areas of study built around these and other online resources, and then certify students that successfully test-out on those areas of study.
If your brothers are still alive, there’s still time to sell their kidneys on eBay 😂
STFU and square dance! we are are learning long division today kids!!!!
Worm gears can be quite precise at high reduction ratios, but it comes with a price of small teeth and low max torque for the size. Gears like that are often used in telescope mounts.
Thanks for sharing.
They can be used in high precision applications like rotary tables on a milling machine where the worm is mounted in an eccentric and "cammed in" to the gear, which is how the output can also be disengaged for quickly setting up the rotary table.
It won't eliminate the backlash, but it can be minimised. Typically you would only operate the input wheel in a single direction and clamp the output so the part being milled won't be shaken about in the backlash.
The backlash can theoretically be (mostly) removed by creating a ball worm gear (similar to ball screw). It should offer reduced backlash and higher efficiency compared to normal worm gear. I found some patent applications and prototypes, but no finished product. I guess it is too complicated and expensive fot it's performance or there are some other downsides to this design. Regardless I like this concept ;-)
I need a stepper reduction for an optical system and someone already mentioned a worm gear system so I'm glad to see that confirmed. Thanks!
Harmonic drives are coming into vogue for mounts - there are half a dozen new models introduced recently because they're so compact and lightweight compared to worm driven mounts. The torque is high enough that they often don't need counterweights at all.
Who else goes ahead and clicks “like” right at the start because you know you won’t be disappointed and don’t want to accidentally forget to support Jeremy?
Hear you.
Only @Jeremyfieldingsr, @StuffMadeHere, and @tomstantonengineering get this treatment from me.
I was doing robotics at Carnegie Mellon in the late 80's and early 90s and I do like strain wave gearing as well. I would propose a slight revision to your description of precision. You seem to equate it to a lack of backlash. I'm sure you know this is a gross oversimplification. We were trying to do some very high precision work over long distances and this magnified the imprecision of the strain wave gearing. It turns out that due to the mechanical drive of the flex spline, there is a tiny sinusoidal error added to the output, in addition to the gear ratio function. We were measuring the input and output positions very precisely with resolvers and could characterize the transfer functions of each gearbox. Love this series Jeremy, THANKS!
Indeed it is a over simplification, but I still think appropriate for the conversation here. The series is a introduction to the gear types and why you would generally choose one over the other. There are many exceptions and what ifs to each gear type that would have been way too much for this series. Thanks for the input here. I love it when experts add detail and value in the comments. We all learn from each others experience that way.
Thank you Jeremy, I need over simplification 😂@JeremyFieldingSr
You nerding out over taking that gear apart is pure joy.
My question is, did he put it back together?
Interesting. Thanks. And thank you for clear, no nonsense explanations with no 'background' music competing with your voice and no jerky video / needless transitions. .
Your enthusiasm is contagious - i found you 96 hours ago and haven't stopped binge watching your programmes. THANK YOU.
Not an engineer here, my usual method for disassembly of something new is brute force & ignorance. It warms me to see an experienced engineer use the same method! :)
i never use brute force, i just use a bigger hammer
and if the hammer doesnt fix it,your problem is electrical
We call it "research". Our research yields results that teach us thousands of things that don't work.
Thanks for taking the time to disassemble the planetary gears. Great video!
Fun fact, big radial aircraft piston engines often had planetary gearsets on both ends of the crankshaft. The prop gearbox reduces the speed to keep the blade tips subsonic and the supercharger gearbox increases speed.
Makes sense, auto transmissions are often the same. An old school automatic 4spd transmission is essentially multiple sets of planetary gears that can sync up in different ways to give you different drive ratios.
a very common use and excellent simple example of worm gears only being drivable one way but seizing up from friction if you apply torque on the other end are the tuning machines on stringed instruments like guitars. you can put a lot of string tension torque directly on the wheel gear shaft and they basically don't slip at all, while the tuning knobs fixed to the spiral gears are easy to turn without much force. on a lot of guitars and double basses, the whole apparatus is open to look at, too.
I don't know how I got here, but as soon as you changed your mind and said, alright we're committed, I was like, no, no sir, you're the one that's dedicated to helping and teaching, and I applaud your efforts. I'm a subscriber now, just because of that. Continue to wake up, and do good things sir.
The Matrix has you. *32889😊 In good hands.
Regarding the Space Mouse, *ABSOLUTELY!* Having it on my viewport camera *_(NOT the model!)_* is an absolute MUST HAVE now. It makes it SO easy and SUPER FAST to zip around and view things from anywhere in 3D space. It's also really satisfying to just fly around using a 6 axis controller. Also try it with Unity and Unreal and Google Earth and Elite Dangerous and... I see people doing things in 3D without one and feel a little sad for them.
I attended the SIGGRAPH conference in Las Vegas in around 1991 or so and saw one of these for the first time. The hardware was ungodly expensive back then. The concept disappeared for many years and only recently seems to have turned up again.
I've been leery. I liked the devorkian keyboard, discontinued. Liked the ms optical mouse wheel, discontinued. I don't want to find myself liking it, and can't get another one when it dies.
My favorite part was watching you take apart the gear box for the first time, with real live reactions 😂. ❤
Very interesting and no unnecessary talk. I am impressed with the content. Thank You!
Very cool! I watched this through the lens of an amateur astronomer where these gear types are used in robotic telescope mounts. Most of the consumer grade mounts are worm gear and belt based, but there's a lot of excitement around harmonic drive based mounts that are coming onto the market, especially for lightweight, portable setups. In either type, terms like precision, backlash, and periodic error are important to consider, especially for astrophotography where sub-arcsecond pointing precision is often needed. Thanks for the awesome videos as always!
In a bicycle hub gear system, several types of gears are used to facilitate smooth and efficient gear shifting. The specific types of gears typically include:
Planetary Gears (Epicyclic Gears): This is the most common type of gear used in hub gear systems. The planetary gear setup consists of a central 'sun' gear, multiple 'planet' gears that rotate around the sun gear, and a 'ring' gear that encircles the planet gears. This arrangement allows for multiple gear ratios in a compact space within the hub of the rear wheel.
Sun Gears: These are the central gears around which the planet gears revolve.
Planet Gears: These gears revolve around the sun gear and are mounted on a movable carrier which rotates them around the sun gear.
Ring Gear: This is a large gear that encircles the planet gears, typically fixed to the hub's casing.
Clutch: A mechanism used to engage or disengage various gears to achieve different gear ratios.
Shift Ring: Used to change gears by moving the clutch to engage different combinations of these gears.
Hub gear systems are enclosed within the rear wheel hub, protecting the gears from dirt and moisture, leading to less maintenance compared to traditional derailleur systems. They offer a range of gears suitable for various riding conditions and are particularly popular on urban, commuter, and utility bikes.
E-bike motors are starting to use strain wave reduction gears. They allow a much smaller form factor and reduced noise from gear lash while coasting. Unfortunately the motors that use them are not as efficient with their use of battery power. I don't know if this is related to the strain wave gearing.
Hey there, I'm an IT manager at a construction company, all of our cad guys use the space mouse, and the keyboards/mice. I am just starting to deploy windows 11 to our machines. Had a guy who was having the weirdest issue with the photos app, where it would just crash when trying to open a photo. My guys couldn't figure it out, so I stepped in; the faulting module was the space mouse driver! So keep that 3dconnexion software updated.
The little things😊*32889
I used to work in a printing facility, and was part of a crew that worked on a Heidelberg Harris m3000 printing press. There are some really really neat things about different parts of the press, but like you, one of the things that fascinated me the most was the harmonic drive used to set timing in the folder.
It's been years so hopefully I'm remembering the details correctly,
The cutting cylinders and delivery fans were driven by a 40 ish horsepower motor. The cutting cylinders were driven directly by the motor.
The belt that drove them then continued downward and wrapped around the outer ring of the harmonic drive and the fans were attached (through additional gears and shafts) to the cup side, the eccentric side was coupled to a small motor that would freewheel when timing was good and rotate it faster than the ring or slower than the ring when timing needed adjusted which would advance or retard the fan timing relative to the cutting cylinders. Seeing the gear train and the harmonic drive opened up for maintenance was quite impressive to see in my early 20s.
Thanks for doing this video. Very cool
Jeremy- You are a great teacher. Thank You for all the effort you put into these videos.
I love my Space Mouse. It's as close as you can get (right now) to having your hands on a digital model.
Thanks, Jeremy.
Great video ! Love your 3D connection, I have the small one and can not work without it anymore...
9:02 Wow! The confidence on display here is remarkable. Yeah, you were hesitant to begin disassembling it but you’re not even organizing and labeling all the parts as you remove them! I recently helped my brother disassemble his desk fan for maintenance and cleaning. Labeled every screw, bracket, etc. I was absolutely terrified of losing parts or reassembling it incorrectly. I’m sure glad I did it though. He was considering buying a new one and the last thing we need is more plastic in a landfill.
🇨🇦/🇺🇸... Hey there Jeremy! In the past I've enjoyed your many vidz about electric motors. While perusing for information about gears, looked what RUclips tossed my way. EXTRA BONUS... I had already been looking at and considering the Space Mouse and so I figured I'd give YOU the affiliate click and get the 10%! EXCELLENT! I'm quite excited!!!! Cheers, bro!
Great channel! I graduated from two famous universities with two different engineering degrees. Every time I watch one of your videos I ask myself, why wasn't I taught that in engineering school? Kinda frustrating.
Love your videos. Your enjoyment in it is shared and spills out in every video. It's not often I mention the sponsor used in a video, but 3DConnexion Space Mouse is amazing. SOme years into using one, I just can't believe everyone isn;t using them ( I am sure 3DConnexion thinks the same - LOL)
Black Tony stark over here. I love this dude❤
One of my favorite content creators!
Just came across your channel, the enthusiasm you have is infectious. Very good video
I used to work for a manufacturer of industrial robots. So, I have replaced many gear reducers, including harmonic, rotary vector, cyclonic, and another antiquated type I can't remember.
We only used harmonic on the minor axes of small robots. Once you get to 6kg capacity robots, the major axes are RV (rotary vector) reducers.
On 50kg capacity (and above) robots, no harmonic reducers were used. From there up, we used RVs.
I know this is true for the two major Japanese brands. I'm not sure what the European manufacturers do.
That is consistent with what I have seen as well. I had one on my desk as you saw but didn’t mention it was used in robotics.
Never heard of RV reducers, really have to look those up.
I heard Harmonic Drive reducers have issues with longevity, the flex spline tends to break in the roots of the teeth at some point.
Edit: seems like those are the same as cycloidal drives, right? Didn't hear them called that before, but I am familiar with those afterall.
@CatNolara
Look up a RUclips video called "The Nabtesco RV Principle". It will give a description and animation of its operation.
I understand them a bit better than this video can describe, but it's too difficult to describe with words. Hopefully, you get the concept through the video.
There is nothing flexible within this drive (gear reducer). This is precisely why I have replaced so many of them. If you put the wrong grease in them, everything shatters. This is because there is maybe 0.0001" of clearance between the sprockets and the pins. Thicker grease creates too much interference, and things shatter.
Contrary to what the video shows, the pins don't rotate along their axes. All the pins are mounted stationary to the outer plate. For some reason, the video shows all the pins rotating around their own axes.
@@cornpop7805 Seems not terribly difficult to grok; it's much like a strainwave gear, but instead of deforming the cup to engage teeth, it uses a cam system to move the inner gear. And those cams can be very beefy and spread the load out across many bearings, rather than just the point load behind the teeth.
@oasntet
I suppose you could call them "cams", but I see them more as sprockets. But, instead of the rollers being attached to chain, the rollers are replaced with rigid pins. Also, there are 3 sets of sprockets, each running off center (eccentric) on their own bearings. The three sprockets are timed 120⁰ apart from each other. The sprockets are not all on the same plane, they're kind of stacked, in reference to the center input shaft. The output is basically the body of the reducer, which is the largest casting.
The smallest RVs have two sets of sprockets.
Regardless of how many sprockets, each sprocket only pushes on one pin at a time.
The output is always fairly low speed, but high torque.
There is actually double reduction, the input gear to the sprocket(s) ring gear, and the sprocket(s) to pin reduction.
There is significant backlash between the input shaft and ring gears, but that backlash is mitigated by the final gear reduction. The resulting total backlash of the reducer is usually less than one arc minute (1/60⁰). Some are as low as 1/180⁰.
My first encounter with a strain wave gear was, of all places, in a Lego Technic motor. Part 2986. It was part of a multi model kit that came out in the early 90's
I took the motor apart cause I was fascinated by how small it was (I think to this day it's the smallest motor to be produced by Lego) and was amazed by the TINY coreless motor and microscopic gearing. it was fantastically engineered!
Hey great stuff man. I was hoping you might be able to point me in the right direction in finding a company that makes and sells custom drill bit Drill bit Guides (bushings?). I wore out mine on the template guide I have and the company does not sell replacement parts . It only sells the complete jig. Which is over 1K. Soundes like a scam to me for a part that is probably pennies on the $.
I'm not an engineer by any means. But your content has sparked an interest in builing beyond the realm of my welding/carpentry/automotive knowledge. Keep it up. We need more wizards in our world!
Jeremy, you're the very BEST!
Nice Video, My favorite "gearbox" is the "Constant speed drive" basically two axial hydraulic pumps acting as a gearbox to rectify for older aircraft generators. That thing is just amazing.
Toyota has now adapted this concept into their hybrid drives. It just used two electrical motors and a gear train to accomplish the same thing. The Weber State car website has amazing details about that transmission. Will replace all mechanical transmissions pretty soon, for car-like vehicles (not heavy power).
Well I didn’t need to know this for anything in foreseeable future… but you are a great teacher and i really feel like I learned a lot about gears. Can’t wait for this to come up randomly during conversation at some point in the future and feel knowledgeable.
Excellent video good sir. I really like your instructional videos.
Thanks for the sacrifice and lessons :) For science!
That 40:1 sounds like me getting out of bed in the mornin. Lol *328889😂
This is the first I’ve seen of your stuff. You’re good, I love gears. I build rc rock crawlers just to learn about the lockers and trans systems. Subscribed.
That butt-clenching moment when he takes the planetary gear assembly apart and then you wonder if it can be put back together...
Ten thumbs up Jeremy. Keep imparting your knowledge. You have an ability to convey knowledge that is absolutely fantastic.👍👍👍👍👍👍👍👍👍👍😎
Very cool! Thanks for sharing!
This was really interesting, and your presentation was excellent!
I wanted to ask, What tools would you consider to be essential to a "Jack of all trades"? I am building a shop, with an eye towards electronics, small to medium dc motors and small HP AC. I have most of the components that I need to build the place; here's the issue. It's about the size of aq holding cell at County Jail lol. Drill press, check. Table saw, welder (small, cheap all in one),and I have the stuff for a lathe. How, exactly, does a vacuum work. I know this is simple physics, but I can only do complicated for some reason and thus can't just build That, though I have all of those parts as well. How thick should my top be? How far apart the clamp holes, and what size are they? Should I top my bench with disposable plywood? I have a rather large robot arm already, a Bruno, that I inherited and am trying to hack it's driver board. I'm thinking of hanging it on the wall, but then the controls work differently lol. ANY kind of advice is very welcome. Thank you for your videos, they are very informative and understandable.
These are good questions. There are too many for the comments, but this might make a good video. Perhaps members only or a full channel video. I don't know yet.
@@Jeremy_Fielding that would be good to see. I figured there was no way to get any decent answer in a comment, so no blame, sir. Thanks for what you do.
Can't believe I was blessed with a J.Field video this morning. Sankyuu.
Well Jeremy your explanation of harmonic drives really resonates with me. You are very well-spoken, organized, and clear with your explanations. It was a pleasure to learn from you. Mind you I am long retired so this is not my first rodeo. Now I want to get myself a harmonic drive to play with!
I'm glad you reviewed the strain wave gearing. I'm an amateur astronomer and I've been looking into telescope mounts that are using stream wave because they can carry so much weight and the backlash is basically nothing
As always, I love your way of explaining everything in a way that makes it easy to understand. Thanks for making learning fun and engaging 👍
Haven't seen your channel for awhile, glad to see your progress and number of subscribers!!!
I am SO glad I found your channel. I need to show this to my son. He loves working with mechanical items. This video will make him so happy!
I try to follow along with what he says, but my goodness, a lot of it goes over my head.
I first heard about harmonic drives when reading about the Apollo lunar roving vehicle. Each wheel had its own motor and harmonic drive.
In a post above one of the people working on that rover talks about the motors and hydraulic drives. From the few things I remember was that the motors were brushed, and that brushed motors didn't work well in vacuum as they require some humidity in the air that lubricate the brushes. Both the harmonic drives and the motors was pressurized to half an atmosphere using some gass and a calculated amount of humidity. He wrote that the motors and the harmonic drives were probably still fine, but the brakes were probably stuck because of vacuum welding. Sounds wrong when I write it so he probably used some other words. anyway look at the comments above. it shouldn't be hard to find the actual comment.
Wowzers! I've never even heard of harmonic drives except as technobabble in sci-fi. But to see the real thing in motion is a thing of beauty!
When that part went flying out of the planetary gear as you disassembled it, I got a flashback to old AvE videos.
I love my space mouse but I need to use it more
Great video as usual!
I had a 1964 flat windshield Chevy van, final drive geared for around town. I turned it into a camper and wanted to reduce RPMs for use on the highway. I could have installed a lower geared rear end, but I found a 1957 Chevy overdrive transmission first. It essentially snapped into place, all bolts and controls were identical to the original. Chevy saving a buck, updating was anathema.
The point? Inside the OD transmission was a two speed planetary gear controlled by a solenoid, you pushed a button to shift into OD, and it worked for each gear. Six gears! unfortunately the lower gears were almost duplicates, still, it was useful on a snowy or Icey road.
It also had a freewheeling clutch in the transmission. After first gear you didn't need to clutch to change gears! Great for learning how to double clutch on the downshift. In hilly terrain it gave surprising fuel economy. Power up the hill for volumetric efficiency, off throttle to coast down with the engine idling. It also had a cable to lock out the freewheeling clutch, very important on longer descents, the brakes were barely adequate.
I wish he was my neighbor.😂..
This episode is all about balance and learning the price of precision. 😉
Bearings, lubricants and balancing wear could be one of the most difficult design considerations.
Jeremy, You are such an Engineering Geek You should Market Your Own Action Figure. A Calculator in one Hand and a NASA Issue Laser Hammer in the Other. I am am not greedy. I just want 5% for the Idea and for You to stop My VCR from blinking 12:00, 12:00, 12:00....... Thanks for the video.
I ALWAYS "change my mind" when it comes to opening up things up so I can better understand. So much so, I typically buy two now if I know there's a chance I'm going to break it open. I also scout for parts from thrift stores and I'm never disappointed. I just bought a $300+ roomba for $10 at Goodwill. just needs a new battery pack, which I'll build from my excess stock. I'm going to mount a prop on it that'll follow ppl around our halloween haunt.
Astounded, absolutely Mind expanding… your extremely comprehensive “abstract” of these gears completely opened up a tier of mechanical knowledge I had no concept of. So obviously, I’m not an engineer; but a very mesmerized and extremely appreciative (hack-mechanic) observer, Jeremy… Thank you so much
Your explanations are so clear and educational with the gearing and at nearly 70 yrs old I've seen a lot of mechanisms. Love yer channel! I bought this hand operated chain hoist, which I will try to explain is one such type of ratio in a chain form. I was so excited once I discovered how it worked, I showed my daughter. She said, "oh. that;s nice" and walked away... ha ha!
I bought a hand operated.chain hoist (with a loop of single chain) which had a top solid pulley with two parallel chain link depressions in the circumference. The one side has 10 link depressions and the other has 9 depressions, i.e. 10D or 9D.. (There is a hook on this pulley that hooks to the rafter or whatever.) These depressions fit each chain link. So, the hoist chain is able to turn the pulley with the 10D or the 9D pulley is in the single loop of the chain. Every time the pulley turns once, the chain is tightened up or loosened depending upon the the direction the chain is pulled. The ratio is 9:10 or 10:9. And idler pulley connects to the load with a hook and rides in the chain loop.. I was so amazed by that old technology that I had to buy the thing at a junk shop. I went home and immediately geeked out and took it apart to see how it worked!
Will you make a video converting a 3phase motor into a generator? Possibly building a regulator, depending on the type built. Or build a adjustable regulator for a alternator such as a delco.10si I can find a working motor at the scrap yard, but finding a generator is very rare, especially working. I'd like to find a 5-10 or even 20 hp 3phase motor to convert to a generator, connect it to a car engine, with electronic govenor to supply power to my off-grid home and shop. Using a 200 HP engine to generate 20kw isn't very efficient but the power output should be steady . I think I would also include a heavy flywheel possibly 100 lbs so a 5hp air compressor starting shouldn't cause any issues, I wouldn't mind building a transformer to convert 480v to split phase 120/240 between each leg of the output and use 3 breaker boxes, it would be for bad weather and poor sun times when solar doesn't provide. Maybe a average run time of a month or two per year. Run the shop from a phase, house from a phase, and possibly help a neighbor with a phase. Not going to be a large load. A 8 kw generator could power everything. It would mostly be used to wash clothes, what I really want is a 10 kw belt drive generator. Like some ppl use on a tractor powered from the PTO. I would also like to build a DC generator to charge batteries, I have several Delco alternators, 21si, the HD version of the 10 & 12si models. with regulator mods it can easily charge a 48v battery, I only need 24/28.4v I'm not looking to fully charge the battery, only to about 80-90% at most. A cloudy day can finish it off most if the time. However ,10% can last a night and day normally. Sorry to ramble, have a awesome day!
Really fascinating stuff , and VERY well explained . Well Done Young Man .
And obviously the Robot Arm is called " Jarvis " , right ?
Just great videos. Glad I happened upon them. Funny timing too. I just purchased a 3D Connexion Space Mouse and you are right - total game changer. I use it for Point Cloud work and it is indispensable. Never going back to mouse skating.
You should do a video for kids about who you are and what your journey was. Remember being a kid and being asked "What do you want to be when you grow up?". Dumb question - they don't know, primarily because they lack the exposure to what is out there. And as adults we rarely share the inflection points that gave us a tangent and momentum. What was your sense of wonder? Were you the kid that HAD to take stuff apart to figure it out? You can see where I'm going. Share that journey. Light the spark. Show the steps.
Toyota's prius driveline is a great and frankly genius example of multi drive planetary. Road, ICE, electric, always doing the right thing. :-)
Imagine guys like Jeremy when they're like 80 years old. A mind incomprehensibly dense with knowledge
Hi, Jeremy. I'm an EE not a ME, but I thoroughly enjoyed this video. I have a much better understanding of these fascinating topics. Thank you for making it!
The 3Dconnexion CadMouse is a great tool too. I’ve completely worn out many mice, but the CadMouse just keep going. It’s perfect with the SoaceMouse.
I'm still getting used to my 3DConnexion spacemouse. Incidentally, one was used in the TV show _The Expanse_ for flying a spaceship, the Rocinante.
I agree, the 3D mouse is useful. But I have to say, 3dconnexion's software is horrible. Capital H. And as far as I can tell, they update their drivers every ten years, max. Some companies act like they really, really don't want you to use their awesome product.
I don't know how this got into my feed, but... nice explanations. Easy to follow.
The space mouse is interesting, recommended to someone I know who does CAD stuff.
I really appreciate going back to this kind of content, Jeremy. What I love is that this can help all kinds of people in different situations. (My planetary gears are in Hobart mixers and my worm gears are in meat grinders, for instance.) I think you lose a lot of regular people (who followed you through junk yards and broken vacuum cleaners) with the robotty stuff.
I never knew that about the 3D modeling device. I kill my wrist when working on 3D models, especially when using software like MeshMixer to sculpt in 3D.
Jeremy, I believe I have uncovered your colusion with Google to infiltrate my mind. I'm in the process of Designing retractable Outriggers and Jacking for a drill barge. I have been doing Google searches for right angle drives T-drives and gear reduction for the last month or so .How is it that all of the sudden this video and your channel has showed up in my feed?
Looking at it I'm assuming that the harmonic drive isn't very efficient? It looks like you're having to forcibly deform/remould the cup during every rotation.
18:58
Oh sir, I vehemently disagree
Absolutely love this series and your work. Fascinating stuff!
Your presentation is smart and accessible, and you are not the usual image that an inner city schoolkid would see. So, how do we get your content into city schools to help inspire lives to strive for a non-welfare, non-prison, non-broken home upward trajectory? I lived in several "po" neighborhoods in Philly in the 1970's, and I saw thousands of kids who were trapped in a defective culture of false identity. You might say to me, "brother, that's not my job," but if not for good men like you, who else will reach these kids? RUclips is a good start, yes, but if these kids need anything other than Jesus, they need to see a strong male role model who makes good decisions and uses his mind. Let me encourage you to follow up on that observation.
Nop! It’s obviously some sort of wizardry. I’ll stick with electronics, far simpler.
I'd never heard of the harmonic strain gear and would have doubted its commercial production if told by a sketchy source. Thanks for an authoritative explanation. Awesome.
Superb presentation and enthusiasm. Engineers Rock Business Studies Suck unfortunately they have the money.
Just kind of a cool factoid, the headlight motors on my 1966 Charger use a harmonic drive system to rotate out the headlights. They are an amazing piece of engineering especially for a mass manufactured consumer product but also virtually impossible to repair or replace if damaged mechanically.
I really like that Jeremy does not try to be scientific. He just casually is scientific by cramping a lot of information into one video. I know all the gears, and the video is still informative. Had I not known the gear types, I would know them now.
So many RUclipsrs need to tell everybody that they are great and informative. Instead of having to listen to unnecessary stuff and wasting my time like that, Jeremy just showed me the inside of a planetary gear :D. I know planetary gears. However, I am not experienced in having seen all of them, so it was still nice to watch, and now I am more educated and might know how to open gearboxes without having to figure it out myself :)
As a worker at HIWIN precision. making that Flex Spline Cup is one of the hardest for me. it really needs to be precise from it OD to its tooth engagement to achieve the zero backlash even a slight off in the size will be considered no good.
I just stumbled and fumbled through the disassembly and replacement of a servo motor, and it was this type of drive we encountered.
Mystery solved.
I knew there had to be an explanation for how it engaged for delivering torque to the articulated waterjet mount.
Be careful kids, don't mess it up.
The parts need to be handled carefully.
The one sort of round part fitting into the flex tooth ring needs some patience.
Super interesting video! I'm a computer engineer and I always enjoy learning about the mechanical side of robotics
Oh there's a snap ring!
My brain engage safety squints - cos you know...
And, you did!