I Made An Eccentric - And it's A Wonderful Thing! 

Apparently this is an eccentric - but that doesn't seem to be the complete name somehow. I mean, any cam or crank is eccentric, surely? The thing that makes this different (and amazing!) is the collar that runs round the outside of it - lined with bearings. I think it should be called an eccentric collared cam wheel (or something!).

I can't believe people hassle you about the pace of these videos - there's a new one every couple of weeks, with several different experiments in it (the sharp bolt teeth, the crescent slicer, then the sickle, and finally the eccentric), where some RU-vid channels would just have the one thing and stretch it out to 15 minutes. There's a treasure trove of invention in each video which makes this channel really stand out - you keep doing what you like doing and we'll keep watching!

Personally, I like the random delivery of your channel. It means that there is always the possibility of an entertaining spark in my day. I think moving the chopper away from the wheel is a great idea. If something goes wrong there's less chance of bending spokes or getting bits of chopper catapulted around the farm. It's an epic project that will take as long as it takes. Good work!

Another fantastic video. Don't over work yourself and definitely don't regret not posting often! I think we all prefer to see a happy Tim than a stressed Tim! ;)

Excellent design! Seems much better to have the chomping action away from the wheel, and that gives you an easy attachment point for other contraptions in the future. You might consider making the chomp happen on the pull stroke so there's no issue with flex in the shaft.

eccentric disc and eccentric strap is the name. I am flummoxed myself building them for my engine. They were invented in the Middle Ages on water mills and wind mills.

Oliver Postgate reincarnated as a tinkering blacksmith, complete with Ivor the engine. Lovely stuff!

That was FUN! Just like re-inventing the wheel. Keep up the inventing,

Thank God you moved on and developed your idea further… I won’t say anymore other than I love watching and listening to your videos.

Take the chomping at the video bit as a compliment, but don't feel rushed- make them whenever you feel like it. The power developed by that beautiful wheel scares me- I wonder if there is a way to make it safer with some sort of mechanical fuse between the wheel and the destructive stuff. Maybe a weak link that will break or clutch that will slip. (and actually, a clutch could also allow you to quickly disconnect power without having to bring the wheel to a stop- might also be useful in your process, for changing bins or whatever.) Of course it is a complication... Looking forward to the next exciting episode, whenever that may be. Have a great day Tim!

Beautiful work, thank you for the upload!!!!

Ingenious! Keep up the great work Tim. We live in an instant gratification era. To the impatient ones simply reply, All in good time. Rome wasn't built in a day!

Does not matter what you call it Tim. Its brilliant !

Sorry to hear you’ve been feeling both poorly.We just love the wheel it’s so good for our blood pressure.My husband loves watching you Tim best wishes to you both your videos are great and good for our health.Best wishes and GodBless.❤️❤️👍👍🤧🤧🤧🤧🤧🤧😴😴😴

I hope the bearings hold up - there are going to be some serious forces on them.

Love you, guys! Keep doin' what you're doin'! 👋😁👍

Im so hyped for the wheel!

If you haven't already, definitely get the book "507 Mechanical Movements". Or, just go find the animated online version. Well worth your time in solving dilemmas like this. I suppose, if asked, I would call this a cam. But what do I know? Nice work though! Please keep at it. I love the concept of kinetic energy storage. Please stay safe around that big old wheel. :)

Thanks Tim Can't wait for the next video.

Hello Tim, An eccentric sheave converts rotary motion to linear motion & is used to drive water pump rams or piston valves on steam engines. You have built a very clever version. Best wishes

How could you possibly think this would bore us? I find this absolutely riveting viewing and could watch the entire build and operation in one sitting! Thanks for including us in your inventing .

Fascinating! You have the Good - Cheap - Quick triangle ..... You can chose any 2 of them! I think you have chosen wisely! Intuitively I think a cam always pushes something. A Crank can push and pull (or be pushed and pulled). Your eccentric (good name) will, I think work well as a prototype but when spinning on your wheel may get heating problems with lateral forces causing metal on metal rubbing. Maybe a judiciously placed few blocks of wood, suitibly greased might solve it for little cost eather £ or time! ;o)

Hello from Detroit Michigan brother thank you for sharing your knowledge and expertise and GOD-BLESS

Brilliant video! I like the solution you came up with. I did some research myself into wood chopping for a project and the best solution I could find is basically a cheese grater design. I.e. you feed a log vertically into the machine. The machine has a pipe with a slot cut into it that's sharpened. The cylinder turns and slices the log during every rotation. The faster you want it to go, the more edges you cut into the cylinder as well as turning up the rpms of the machine. I liked this idea, because it's relatively easy nowadays to acquire a large diameter pipe. I find your solution fascinating though as I can see the steam engine influence. Also, don't apologize for projects taking too long. Sometimes that is how it is. You make mistakes or you imagined a mechanic working in a way that in reality it doesn't. That's how you learn. That's why you've got to show a lot of determination and tenacity when making something with your own hands. Often things don't go your way. From my own experience at least.

Simply amazing!!!

Using the ring of bearings is simple genius; I've been puzzling for a while now on how to make an eccentric but never got past the need for a bearing surface machined directly on the shaft. Since I don't have the machining capability to do that, my ideas never progressed further. It seems so obvious now that I see your system but I never would have thought of it on my own!

This whole workshop is insanely inspiring, good job. Take your time for everything, dont rush. If it takes some more time its fine and it makes every single video more valuable and worth waiting for it! Greetings

What a wonderful solution. It's really amazing how the cam/crank combination spreads all of the heavy load over a larger area. I feel like I've seen this somewhere but can't think where

Oh to get 3 hours a day in the workshop. Tim, you are living the dream! Love your enthusiasm, you explanations and all that you share on here, Sir 👏

Folks, it is said that: "Patience is a virtue". So, ponder on that, relax a spell and begin to enjoy your life.

I´ve seen this type of mechanism on Stephenson´s valve gear for steam locomotives. Hope that helps in your research.

Very clever!

A collared eccentric is a Priest who has gone a bit batty. A regular eccentric is just a man who builds wonderful machines in an unusual way.

You (accidentally?) said what this mechanism is called in the video, its an eccentric. The centre bit is the eccentric sheave and the outer is the eccentric strap. Normally they are just plain bearings, you see them on steam engine valve gear.

Poor people are crazy, but Rich people are eccentric. This video is rich.

While the nagging can be annoying, remember that's it a good thing because it means people are really enjoying the videos you make

i like it....your crank could power an external log slicer...it would cut through most log diameters....until it jams.....then those forces would be scary.....think of a design that does not jam up.

thank good the eccentricity offsets the crankiness

Looks good, keep up the good work

i learned something from this video today. thank you.

A way to ensure it never has a catastrophic sudden stop could be to get your impact force from springs, and just use a fibonacci like cam or eccentric to provide the stretch force, and then immediately let go. If it fails to pull a full stroke, it won't shock the wheel and will just chop again on the next loop. You'll never put more stress on the cam surface than the spring force, but you'll also never be able to strike harder than the spring force. Orienting the impact vertically and adding mass to the chopping head could add the momentum assist that you're wanting from the wheels mass, but without the rapid disassembly potential if it catches a good knot or something.

Great video. Thanks a lot

Reminds me of a Whitworth quick return mechanism

I see possibilities, endless possibilities! This wheel is so much fun to watch!

You found a great solution, whatever you call it. But given that you are transferring a huge force, you need as many of the small ball bearings as you can pack in. You might even want bearings to back the bearings, considering how much inertial torque you have. It has the potential to be a rock crusher!

My first thought when I saw you working with the blade was to move it more to the outer edge of the wheel so that it would gain additional torque and do the chopping/grinding farther from the frame to avoid jamming. But, seeing the updated plan, I think that will work out much better. One thing you might consider for your eventual blade mechanism is to make it a two sided plate with a central connection to the crank shaft; make one side a full edge blade for taking full slices out of bigger logs, the other side set up more like a large cheese grater with holes that have edges to them suited for taking smaller chops to break up the charcoal. Then to switch between them you just have to flip the blade around.

I add comments because apparently it helps with the RU-vid algorithm. Your cam design is brilliant!! Once serious forces will be applied to the cam there will be tendency to force the central plate out of the nice bearing races. I would want to restrict any sideways play of the central plate inside the cage. Just my thoughts as I was watching your very interesting video. Work at your own pace you don't owe anyone anything!!!

That is an impressive eccentric!! Very well done sir! I’m always impressed with your machine design! I believe those eccentrics are used in hammer mills (power hammer) like black smiths use. Your wood chomper could possibly use similar mechanism at the action end where a heavy spring will compress if wood is too much to chop in one blow. The spring would compress then encentric would rotate and then hit the log again. This will help protect that beautiful wheel you have made and prevent jams. (0:

your 'steam punk limb removal contraptions' define a whole new category in the maker sphere

If tim builds eccentrics... That does make tim an eccentric builder, am i right? I believe that is how this works. :D

Amazing.

Some people would say you are a bit eccentric. They would be right, but that's wonderful too.

Your lengthy explanations are much appreciated.

NO apologies needed for the frequency or content of your videos. Your detailed explanation of your thinking (and the prototyping) improves the enjoyment of your videos. Keep up the good work and best wishes for continued success.

When it is time to build the chopping system. You have to design a timed feeding control. So the pieces are some what the same length. Two feed dogs. Maybe take a look at a diesel tree chipper. One last thing is some kind safety disengage. As this huge wheel will hard to stop. Cheers from across the pond.

brilliant!

I enjoy watching your videos but those who keep nagging you about your field railway and building a locomotive for it clearly don't listen because said before you build one once it is finished and you actually need it, but of course you want to spend time with your wife and family plus like you said you've got other projects to finish as well your farm to run with animals to feed, also you can't really work on your railway in the cold and wet winter weather.

this should really be mounted on a separate mechanism, connected to the flywheel by another belt. otherwise the forces involved further risk it breaking violently. also, just generally having the sharpened elements on a separate mechanism will likely make it safer to stop both the bladed element and the flywheel in case of emergency.

Very cool! I never knew about this concept. Thats what your channel is great for.

Indeed that person is, these mechanisms have been around for centuries, as they're used on locomotive valve gears, and on traction engine waterpumps

A crank can go either way. I would say the main difference is the connection. A crank has an axle which rotates around the primary axle. Something else is then attached to this secondary axle (which could just be a hand), such that either the secondary axle moves to rotate the primary, or the primary rotates such that the secondary moves. Importantly, this means the connection point (the secondary axle) just follows a circular path. If this is connected to something constrained to linear motion, such as a piston providing power or a cutting blade, then this will also have a fairly common linear motion based upon that circle. This is because the linkage is always attached to the same point. And if you have something moving on the linear portion, you need an extra linkage. It can't be attached directly to the crank. This also means it is a 1:1 relationship. i.e. if the wheel rotates once, then the linear component will move back and forth once. And it will be fairly simple, simply moving out then back in. A cam instead is effectively an irregular disk. This presses against something to convert the rotational motion to linear motion. This is one way only, it can't be back driven (at least not in general). It also only has the cam push the object outwards, something else, such as a spring, is responsible for the reverse motion. Importantly, the linear component is pressed against the disc at a certain angle, so as the disk rotates, different parts come into contact with it. This allows a more complex motion than possible with a crank. e.g. it could slowly push out and then very quickly get pushed back in by a spring. It could move out all the way, get pushed in a bit, and then push back out, before going all the way back in. It could also have 2 or 3 (or more) copies of the same profile around the disc rather than the profile spanning the entire disk. This means the wheel could rotate once while the linear part moves back and forth multiple times. Based upon that, what you have is effectively a crank with a very large secondary axle. You can get the same result with any crank by taking the secondary axle and making its radius larger than the sum of the radius of the primary axle plus the distance from the centre of the primary axle to the centre of the secondary axle. If you removed the outside ring, and instead had a rod (with a bearing at the end), constrained to move in a linear motion, pressed against the disk (such as with a spring), then you would have a cam.

I agree a genius idea. No scrap yards around Australia now. Governments world wide say we must recycle then put all the rules in place so you can't get the old stuff to give it another life. John

"Huge forces concentrated into a tiny area breaks things" is the story of my life. There was quite the laughter at this utterance.

Very well explained, well done Tim.

The weak point is where the point of the teardrop is attached to the conrod. Be careful it does not buckle here under compression.

eccentric strap used a lot in model steam engines also, I don't know why, but driving stuff straight off the flywheel seems to be a bad idea, better to have stuff run off the shaft. look at other lineshaft driven workshops, you'll find more ideas in there too

You mention in this video that there are no longer scrap yards in Ireland? Is that just a business/market thing, or is it due to some regulatory burden? I live in the countryside on Ontario, Canada. There are two scrap-yards within 10 minutes drive of my house, and a couple more within an hours drive. My area isn't particularly industrial, either. I mean, was there a St. Patrick of scrap-steel or something? If I were a wealthy man, I'd load up a sea-container full of "useful bits of scrap" and ship it to you. I truly love all the things you're doing, and the way you're doing them, and the splendid inventiveness.

Okay. Not nagging. But a weird approach for installing the pointy-eggcranck. Without the need to disassemble the torque wheel. It should be possible to cut the pointy bit in half. Also the outer rings. You'll figure it out. Because I don't know how to get it clear in this comment. Like the half-sprockets for go-karts/pitbikes/deathtraps.

AWESOME AWESOME AWESOME, " The Wheels Out west Go Round and Round, Round and Round, Round and Round,😵‍💫 The Wheels Out west Go Round and Round, All The Day long."😵‍💫😉

Thankyou so much for your videos ! They’re incredibly interesting and inspiring

That thing to reminds me of Stevenson Valve gear.

I'd not worry about building as much as you can like the railway but to make use with what you have and not let anything rust away. its best parts with Tims creations is that its solved in either an unexpected way or goes well with other uses.

Great video Tim! I am very glad to see that you recognized the need to use the flywheel as a flywheel and nothing more. Grinding charcoal may have been fine, but processing wood with the flywheel was a recipe for disaster! However you tie the eccentric rod to any job, make sure to put a weak link of sorts between the shaft and the job so as not to risk damaging the flywheel. Maybe if the rod was two pipes where one slides inside the other so you could have a shear pin to pass thru them? That way if the rod "needs" to stop, the pin will shear off and the flywheel can keep moving without a sudden stop! Keep up the good work and stay safe! 👍😁👍

That was a great story of engineering

Don’t just like it, I love it! I also love the decision to move the cutting away from the spokes. Have you considered a planned ‘failure point’ somewhere between the cutting blade and the eccentric cam? I may be taking it too far :P. I’m imagining a case where the cutter fails to cut through a log and something else is able to break/give way so the wheel can keep spinning.

Might have to play with stroke length some, which should be as simple as changing the bore on the eccentric cam, closer to center would give shorter stroke but more power? though you'll be limited by how big a log you intend to chop... Think I'm gonna need a cnc plasma table someday, the mind wanders with the possibilities.

I fancy the idea of covering the sides of the wheel with thin plywood, to keep delicate limbs from being caught in it, leaving useless bloody stumps that would make a surgeon shake his head as he wept. Perhaps a guard would do the trick too. In the first setup, without a guide between the wheel and blade, it would seem that if wood became caught, the end might swing inward, coaxing any limb between it--between the wheel spokes to be snagged by something else. You are good at designing and making things. Please be careful with this one.

make the chomp action happen when the eccentri is at its lowest poinnt, that way you will have less force that wants to pull up the cuttung end, and consider some kind of bushing on the eccentric those bearings wont last long I think

more calculations for you when using green wood it can cut bigger but dry wood needs to be smaller chunks or driven at different speed

Your channel is the best tinkerer/fabrication that I truly enjoy watching, In my eyes Tim and Will too, are 'Geniuses'!👍👍👍

Yours is my favorite channel to follow on all of RU-vid. I am always amazed by your explanations, your approach at breaking goals down into ideas to try and get there, and your wonderful narration! Thank you for sharing.

It is an interesting notion Tim that there are no scrap yards in Ireland. Having grown up there I remember going to the dump, before that became unsafe and inquisitive kids were no longer allowed. There was some motor breakers yards, but that was mostly a closed shop and you had to have a part in mind before you were entertained. Where I am now in England the local scrap metal merchant has a great big scrap yard full of big things and small, but they will not sell. they have a skip full of forklift batteries ready for off gridding, but they will not sell. I am not sure why, possibly it is just hassle. Some yards will sell but the scrapheap challenge type of yard does not seem to exist anymore, with a bus balancing on top of a boat. Luckily, living in the city people never stop throwing things out, so if you know where to look there is a constant supply. But scrap yards....

I'm no engineer, but I was just about to comment that there is no way the wheel would stand up to the abuse from the sickle blade when you showed the second plan. I'd just find a large circular saw blade and make the wheel turn it, I've got one around here somewhere that must be 32 or 36" made to go on an old gravely tractor. I looked it up, they are only 26", they are out there for sale but I'm sure shipping would be cost prohibitive.

HI Tim! Another thing instead of your "inverted crank cam" was to have just a cam as you made at the steam engine, and then a push rod to split the firewood! :-) Or even could be double cams so it hits twice/ rotation! :-)

Well it's still a Brunel engineering puzzle I like the idea of the rotational collared camshaft but it looks like something from steam engine of a train or a steam pumping station 🤔🤔🤔🤔🤔🤔🤔

Now that you've sorted out the eccentric cam/crank jobby (amazing by the way!) the attached push rod could be used to push wood/charcoal/anything through a different set of attachments designed specifically for the job in mind. A sold upright blade to split logs in half (or quarters or eighths). Different sized grids to push the charcoal through to make it progressively smaller smaller.. and another crank coming off the push rod could be attached to an articulated and slanted table top which could "shake" whatever's on the table top down towards blade/grinder/etc. You could stuff the worlds largest sausages if you wanted to.

Absolutely amazing,totally enjoying your content, you have a wonderful way of explaining things, Also love the graphics, very easy to understand the process you have gone through, I am very curious what software you use

Stephenson’s valve gear seems to use eccentric rods with an arrangement similar to this to allow reversing. I knew I’d seen it somewhere. A good old googling of valve gear arrangements will probably turn up some random useful ideas for you. All the best Tim.

brilliant! what a ?? way to fix ideas

I have read the comments, and I do note that there have been quite a few who have expressed the same kind of thoughts as I am about to. But I'd like to add my support to them. Although you did it with a generous measure of good humor, I'm so sorry that you feel the need to justify yourself on the publishing your videos and also on getting the nomenclature correct. Personally, I don't come here for a lesson in terminology. I am a retired motor mechanic who transitioned to operating plant ( Bulldozers and front end loaders , mainly.) Moved from fixing them to f***ing them, one could say.🤣. just ignore the haters Tim, but please continue to show us the workings of your incredible mind! I guess thats my big concern... if it all gets too much, the easiest way to deal with that would be to just keep it to yourself. I hope you never do that. All the best from hot Queensland, Australia.

This is awesome. I'm loving the refinement of the concept, and I'm excited to see it in use!

Excellent and informative work 👍👍👍Thank you for sharing. Take care of yourselves 🇨🇦

⚠ *@Way Out West - Workshop Stuff* 7:37 I think you want this machine, or similar: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-F4S8RnoNfAc.html it makes: roofing shavings (or Shingles ) (Trick: just copy that videos title into the search bar, to hopefully find more similar videos, from Sweden) ( You have coal, and I think a forge too.... all you need is a big enough rod to bend into shape... ;)

Wonderful Tim! What a treat to watch your projects develop! We can’t expect a regular schedule of videos and then they wouldn’t be a surprise! I’m getting the feeling that this version is somewhat like my mother’s old bean slicer, which I still have and use for runner beans. One thing I know is that it doesn’t work very well if you go too slowly, so if it kind of works at slow speeds it will likely work way better once up and running off the engine. Now I am wondering if your project would improve the design of bean slicers.

Ingenious, but isnt it just a cam? Its the same as a crankshaft in an engine pushing the vale rods.

Very interesting video. I agree with other comments, it is an Eccentric Mechanism with an Eccentric Sheave, Eccentric Strap and Rod. Thanks for interesting channel, cheers Peter.

Could it be a Scotch yolk? I appreciate that the collar distinguishes it, so perhaps a collared Scotch yolk? Here's a "what is a Scotch yolk?" video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4iP_ZPBduSo.html

Impressively frightening victorianan style machinery 👍.

Your big flywheel is to increase inertia, but you don't need to drive directly from that. It would work just as well as a stand alone flywheel, allowing you to take the drive from another belt and pulley on the engine. This opens up a complete blank page to design your chipper however you wish, but without modification to your big wheel.

I'm flabbergasted that you don't have scrap yards in Ireland. How absolutely Ghastly! 🙄 Luckily we still have some scrap yards here in Chiang Mai, but I can see that the voracious metal dealers could elbow out the mere _"annoying little DIY consumers"_ who pester them for access to scramble around the piles looking for the odd bit of steel. I shall continue to resist all attempts to _"Clean up all that junk, whaddayagonna use it for !@#$?"_