Imagine taking a college course with this guy as the professor. Talk about getting your monies worth. So much learned from Mr. Fielding videos. Thank you so much.
Well said. I'm a high school teacher who is in awe of his uncluttered easygoing approach, and I'm eating up his technical knowledge at the same time. Huge, huge help to me.
I’m not hating at all. I love this guy’s channel. He does a great job and is insanely smart. With that being said, you can learn everything you need to know about the projects he does with an associates of applied science in industrial systems or something similar. Or even a diploma which takes less time to get. Sure you’ll need work in the field to sharpen those skills you learn but it all comes together eventually and fairly quickly if you’re willing and wanting to learn. And if you’re interested in it.
College is boring no matter who is yor teacher , the reason it's boring is because the things you are studying are not interesting to you which is not the case here on TH-cam you only watch what you like what exists you of course Jeremy is super great teacher but you can find great teachers in school as well and still get bored
@@idiyerbill1968 if you are getting that bored then it is probably be a use you are studying a subject you aren’t really interested in. If you are passionate you won’t get bored unless it is a bad lecturer.
Who needs college. This is what I needed growing up. I'm 49 years old. Now own my own machine shop. I learned everything I know in tool and die works, own my own. rolling up my sleeves and getting dirty. I have always wanted to learn the electronics side of things to build my own machines. That is now possible. Thanks to TH-cam and this good gentleman Jeremy Fielding.
This is the stuff that makes me feel better about the internet spreading stupid stuff like antivax and flat earth. You are spreading high grade engineering information to the masses. Great work as always.
Reno Simpson you might want to refrain from watching these truly intelligent vids, your mind is too simple. Knowing WHERE to find pertinent information is a better use of your limited grey matter than wasting calories/time learning/knowing/storing information. Going to your phone/w.w.w. for information is probably the wisest choice most ppl make all day, knucklehead.
KEEP YOUR PSEUDOSCIENCE GARBAGE OUT OF HERE ENGINEERING HAS NOTHING TO DO WITH HELIOCENTRISM THE EARTH IS FLAT AND STATIONARY VACCINES ARE POISON AND YOU SHOULD DEFINITELY NOT EAT ANIMAL PRODUCTS NOW START CRYING ABOUT CAPITAL LETTERS
@Reno Simpson YOU ARE WHAT YOU EAT IT'S AS SIMPLE AS THAT YOU CONSUME THE DNA THE FLESH THE BLOOD OF AN ANIMAL YOU HAVE A SIMULATED THAT DNA INTO YOUR DNA JUST DOESN'T HAPPEN INSTANTANEOUSLY COMIC LEE LIKE YOU WOULD THINK ON THE MOVIE WHERE YOU TURN INTO A GIANT TURKEY AS SOON AS YOU EAT A CHUNK OF TURKEY BACON 🤣😂 IT'S MORE LIKE IF YOU FEED A NATION A CONSTANT SUPPLY OF ULTRA FEMINIZED FEMALE BABY BOVINE 4 GENERATIONS YOU'D KIND OF WIND UP WITH A ULTRA FEMINIZED FEMALE BABY BULLVINE / PEOPLE HYBRID NOW LET'S LOOK AT THE CHARACTERISTICS OF A ULTRA FEMINIZED FEMALE BOVINE BABY FRIGHTENED EASILY-🤔 DIDN'T YOUR RELIGION JUST PREDICT A GIANT ASTEROID WAS GOING TO HIT THE EARTH AND NOTHING HAPPENED JUST YESTERDAY? EASY TO MANIPULATE-DID YOU KNOW THAT EVERY PICTURE OF A SATELLITE IN SPACE IS A PIECE OF ARTWORK AND CGI AND THEY TELL YOU THIS AND IF YOU LOOK CLOSELY AT IT YOU WILL REALIZE YOU'RE LOOKING AT A FUCKING CARTOON? THE FEMALES IN PARTICULAR BELIEVE STRONGLY BECAUSE THE HERD BELIEVES STRONGLY ABOUT PARTICULAR THINGS THIS IS WHY COWS HAVE A HERD MENTALITY AND NOW SO DO YOU BECAUSE YOU CONSUME THEM FLESH AND BLOOD REASON NUMBER TWO 🤣😂 ADRENOCHROME I'M HOPING THAT YOU'LL ASK ME FOR INFORMATION ON ADRENOCHROME
I just watched your newest vid with the cnc table saw and then this one was suggested. Man, as a recovering addict building up tools for my little apartment workshop from nothing, I’m so jealous of your shop and tools. You’re living the dream, making all this cool stuff. I hope to get there someday soon. Right now I’m still in the “search through trash to find stuff to tear apart so I can hoard the components for later use.” Phase of things.
I worked in the electrical field for 30 years. I love watching videos from different people in the field of electricity and electronics. I don't understand why I just found your video collection...Well I just subscribed !! Keep up the good work.
I think I've stumbled onto a genius in action. No hyperbole, no bs....just useful, understandable information laid out in layman's terms and enjoyable to watch...and LEARN. Thank you very much.
I would have loved to have you as a teacher when I was in high school 25 years ago... I really love the format of your videos. No music, no bullshit, just technical knowledge transmission. Thank man 👍🏻
Great video! You didn’t shy away from the necessary compromises, or excuse the experimental nature of this project. This, IMO, is engineering at its best.
I have the same servo drive on my retrofit milling machine. Use the servo tuning software to help dial in the position holding. This will get rid of the annoying buzzing noise. Awesome content!
The other thing that dedicated servo motors have that many non-servo permanent magnet motors don’t is that they are designed to have low to zero “cogging” - when you turn the shaft, it doesn’t want to stick to the poles of the magnets. This results in better accuracy overall and lower power consumption when holding a position.
My thought was that gearing reduction and code that accelerates and decelerates would help. If you wanted to move a really big mass relatively precisely but not at a high duty cycle, this setup could be fantastic. I suspect it might not be ideal for the x and y on a CNC where sudden starts and stops and high accuracy/repeatability are all important. MAYBE, you could design two motors that are electronically and mechanically coupled to work together. Lots of things are possible if you have time, motivation, and willingness to discover dead ends for the sake of learning :)
It depends on if the position is being held in a low or high reluctance position. A high detent force motor will have higher holding force with better efficiency in low reluctance positions, a low detent motor will have better accuracy and less vibrations in high reluctance positions. If micro stepping is not wanted or needed for accuracy (or if surfaces finishes aren't impacted) , higher detent force will actually make for a better servo motor.
@@RyanVasquez6089 Right, that was why I thought of using two that "fight" each other. I realize purpose built equipment will always be better, but if you have the stuff sitting around and the cost is basically creativity and a few standard parts, then I think that is an OK time to leave the more orthodox methods for those with the budget.
The noise is called Dithering and it happens because the encoder keeps sending adjacent readings and does not settle on a single one. Its like a ping pong match between two adjacent encoder positions.
Jeremy, you asked for comments. Here is mine. As a physicist who has worked in industry a long time in R&D and various engineering roles, I'd like to offer the following feedback: Servo motors exist because they can do well what non-servo motors cannot do well. They are engineered to handle the demands of the applications for which they are intended. True, one can make just about anything do something similar to something properly designed for a job but it won't last. You cannot simply sidestep the physics and engineering that goes into building proper motors for the demands of the intended application. To Jeremy's credit, he acknowledges this up front. That motor will burn up if used this way except in the lightest of loads and low duty cycle. This is a very informative overview of how these kinds of closed loop systems work. However, you cannot simply make a motor designed for a specific application play nice in an altogether different application by trying to make it act like the appropriate motor. Except in the most general sense, they are not that interchangeable. This is why there are complete industries that revolve around different types of motors. You could argue "That's nonsense and hype for the sake of revenue generation" but you'd be wrong. Motor design is very application specific and rightly so. There is a right motor for every application and one should seriously consider the long term cost/benefit analysis when it comes to the investment. Sure you can cut corners and try to make a motor do what it was not specifically designed for (and watch it under perform and eventually fail) rinse and repeat, or do the research and buy the right motor once and be happy for a long time. Of course there is a lot of good learning that CAN happen if one pursues the trial and error approach and if that is what one wants to do for the sake of tinkering then heck yes, forge ahead. However, if you have the math competency/comfort and a technical inclination, spend some time reading up on motor designs and their applications. It could save you a lot of money in the long run. Whichever path you decide, I wish you a pleasant journey! Peace all and Jeremy keep up the excellent channel!!
While I agree with you statements above and acknowledged these facts in the video. I was hoping for a more specific discussion of problems for the sake of learning. I wanted to tap my community of knowledge with what I thought was an interesting question.
I have had a bare (cutting) plotter for years (with servo motors). Good buddy of mine sent me a servo controller, power supply and software. I have been staring at it for several years. I think during this time of 'trouble' while I hunker down I will try it. You made so much sense. Thank you. Stay safe!
Outstanding video yet again. Very few people on YT seem to be willing to actually 'Make' something vs just videoing some bits or bobs they've bought. These are the types of videos that inspire people to experiment with 'junk' and learn to do cool stuff. Keep up the good work.
Quite interesting. I would think the windings would eventually overheat, even with cooling. I base this on frozen motors from turntables, antenna rotors, starters, and other consumer & industrial equipment I have worked on for decades. I do agree, you must have a motor designed for the job. Great video. Please keep them coming!
Heat is created by amps, if you have a given amount of airflow then it will cool regardless of motor rpm, so long as the airflow remains the same regardless. If the motor itself is providing its own airflow through a direct drive fan like most treadmill motors then applying torque to hold a position is much more likely to cause the motor to overheat than the same motor with externally driven airflow.
I've been trying to make a servo out of a car wiper motor using an arduino, with a potentiometer as the "encoder". After watching this, I think I might get a digital encoder...
Use a Pololu JRK 12V12 motor driver (around $100 each...) with a precision potentiometer that rotates continuously. That’s what I use in my sim racing motion rig and it works great. They hook up via USB (or serial...) and have the control software built in. The continuous pot was expensive - $45 each - but they have been operating without fail for years now. Note: you CAN use a non-continuous pot, but in the event that something goes wrong and the motor keeps turning past the stops of the pot, your pot will be broken and the signal to the motor driver will be missing. Continuous rotation pots prevent that from happening. FWIW, the arduino can work, but I used a MotoMonster driver when I tried that route. Not enough power through the MotoMonster for my needs, but it DID work while I was using it. The JRK12v12 has the ability to detect if the pot becomes disconnected, for example. It also is smart about monitoring current overloads etc.
@@michaelkeymont501 what? Whuut? Whuuuuuuuut? When you guys make casual conversation out of tech stuff you remind me that I can adjust the dial on the toaster, and chew gum... But not at the same time. I am so glad for you smart people. Peace
Thanks for a great video! I like how you use readily available components to employ in a wide variety of applications and explain the function of each component as well as alternative approaches. Also providing details such as wiring diagrams, component sources and warnings really help to let your subscribers duplicate what you are demonstrating. Awesome!
Pretty cool. Haven't messed with servos since my Navy days (60 years ago). They impressed me then, they impress me now, as does your explanation. Nice vid.
Something to look for is an RJ-45 "Keystone" jack if you're looking for something more permanent than that breakout board (for an enclosure or a carriage install for example). Keystone jacks are designed to snap into a hole on wall plates, patch panels, and it's VERY easy to cut a matching hole in metal plate or wood. They're also quickly replaceable if you manage to break one. You will need a small tool called a 'punch down tool', but they are cheap (and you can actually get by with a small flat-head screwdriver in a pinch).
You are just so friggen dang brilliant. I absolutely appreciate you sharing all of this knowledge and info in a way anyone can understand without being condescending or overly technical
This is such a wildly beautiful explanation on servos. Thank you so much for actually including all the possibilities and potential things as opposed to just “here is a servo motor for arduino’s” ….and thank you for actually explaining what it actually is better than anyone else.
I'm apprenticng under my inlaw who's an electrical engineer. I love your matter of fact way of expaning things very down to earth and I'm loving seeing how much i can follow what you're saying on my own. Thank you so much for this content
I've made this control exactly same way with a different dc motor meter you suggested works great. I've made my bandsaw, drumsander, a cement/concrete mixer from old washing machine and treadmill motor, router table and table saw all worth treadmill motors. I guess it's a over sized cnc machine now. I wanted to make a water cnc with a cheap 79.99 harbor freight pressure washer over seen it done. Not this size tho. Saved me thousands thanks so much
I’m really enjoying your videos! I have one small recommendation: it would be very helpful if you would briefly mention the meaning of some of the acronyms you use in your videos, at least once per video, for newcomers (e.g. PLC = Programmable Logic Controller, CNC = Computerized Numerical Control, PWM = Pulse Width Modulation). Your videos are so well done, I’m thoroughly hooked!
25 years ago my very first job was a Motion Control Engineer and I worked on many projects providing the servo motors and their control, including aerodynamic robotic arms for wind tunnel testing, automated headlight testing rigs, satellite tracking TV transmission vans, X-Y plasma torch cutters, air to air missile testing rigs, tank tracked robots that would craw inside nuclear reactors for testing and maintenance, Formula 1 car testing rigs, etc etc. Unfortunately in my mid 20's I was chasing the cash so got into IT *yawn*, a decision that in many respects I regret. Videos like this take me back and make me wonder how life would have been different had I made other choices. Keep up the good work Jeremy!
This is awesome. Basement workshop engineering at it's best. Video editing with titling, is good. Easy to understand. I don't recall the specs, but I worked in a company that made DC servo motors. These had a range of applications from motion picture camera motors to the older tape drive systems. Some used optical encoders, some were just driven.
Great info. I can see this working fairly well in some applications. Having been a machinist for 44 years I see metal chips and dust being a problem with open face motor. However if properly gaurded this could make for a cheap and easy way to go. Thanks again for the easy to understand info.
Your new video space is working out great Jeremy! That angled ceiling works for the lighting and sound, with plenty of wall real estate for white boards and other things! This video is a great topic, thanks!!
Thanks for all your curiosity. An inspiration for problem solvers everywhere, and another reason I believe that arts and sciences need to be further linked in our education. I see these videos as a precursor to more knowledge being shared and I hope you get as much pleasure working these projects as they bring to your viewers! Best wishes for more great tours in the future. Yaksawa robotics was great!
Jeremy, thanks for bringing us to a higher level in DIY projects. It makes for interesting ideas this close to Halloween & Christmas. Still have to get my shop set up the rest of the way & all of these ideas must be considered. Take care brother! 😊👍
The names of the jacks and wire are all heavily used interchangeably. You will see the proper names used more in connector/cabling manufacturer catalogs or large electrical supply houses (e.g. digikey). However for those who like to research things (pedantic warning): RJ45 is registered jack 45 (from Bell labs USOC standards) It is the the female jack only (and registered refers to the pin on the back for directional registration). The male connector is actually called an (Bell USOC) 8p8c connector for 8 position, 8 conductor. RJ11 was used in serial and US phone service and typically used a 6p6c connector (although typically used with only 2 or 4 wire flat cable or early twisted pair) and wired in USOC wiring standard (predating tia/eia specs). Category 1-7 (CatX) are cable standards for twisted pair cabling. The category rating specifies the minimal gauge of wire, quantity of conductors, and twists per inch (to cancel crosstalk) and the speed rating in MHz that the cable should be tested to without getting significant errors from electrical impedance. Having an E at the end of the spec means enhanced speed rating. Although sometimes resellers will try to confuse the actual cable rating to make it sound like their cable is better (better in cabling really is only relates to how much quality control to the standard they test for, and ability for the cable to withstand stress under various hostile conditions). Ethernet is a low level standard relating to the physical encoding of electrical pulses, signal clock timing, framing of bits on a shared wire, and signal congestion control (what happens if two things energize the same conductor at once). This data protocol does not specify the physical media (when I started in the industry it was 10base5 over coax and AUI cables, and in school we even did things like: Ethernet over laser, ultrasonic, and once even once over a barbed wire fence).
Cool stuff. Thanks for the servo 101. I have a project down on the do-list that will require a servo. Preliminary looking left me a little confused on terminology. This really helps. Will still be several months before I get a chance to start.
And I think I read somewhere that most of what's referred to as RJ45 isn't technically RJ45 but something else (I don't remember what), but it's just so commonly referred to as RJ45 that everyone calls it that
@@reaganharder1480 It might be the phone cable and its sisters. They have very similar looking connectors, only with less than 8 pins, and I can imagine people look at it and think RJ45 is the group of connectors which look like that (transparent and rectangular, used on coloured twisted cables, latch on top, connection row on bottom). RJ45 is specifically the 8-pin connector used for computer connections.
That was the most intriguing thing I've seen on YT in a long time,, Thank You, JF! While viewing your demonstration the immediate concern I had was the heat generated by this system. As setup, prolonged use, that's gonna get hot Hotter than any stepper motor, I would suspect. In other words,, that fan has to stay somehow
I think the DC servos we use at work are multi phase DC, so I think this gives them greater control and precision.... But they are thousands! We further improve things by using gearboxes (very precise practically zero backlash) of the order 30:1 ish ( I forget exact ratio). Good hack, love the philosophy.
I'd prefer a fan or blower, directed into the winding area, using a thermostat control, that's Attached on the motor housing. Maybe when the motor is actually connected to the mechanical load,that chatter will be eliminated. Neat little project you have. Thanks for sharing.
This gives me so many ideas. I started watching this with a headache, but couldn’t stop. I’m sending this vid to my goto geek Greg from themakerslife so he can ponder this with a clear mind.
Man you the only one I would trust because you are a damn good engineer. What would be better a 3060 engraver , or 3060 milling for stainless steel? I'm new on the cnc machines. And spindles is best. Thanks man ,keep on,keeping on.
Neat project. It might be good as an auxiliary axis where you can turn it on, get to a position, then shut it off. Maybe use it to roll out sheet metal for example. The limitations of course are with the heat & holding a position. It also might not be too persice between rotations (assuming the torque of a motor that size is needed & expecting repeatable accuracy). For example I wouldn't want to use it for a DIY robot axis, (Ha). It might be good for an application that just goes back & fourth. Great use of the encoder to achieve a certain angle. The size of the motor would have the umph to go back the other direction, yet not causing the strain of holding a stopped position. Thanks for the brainstorm & asking us the audience to chime in!
The treadmill itself was a good source of electronic controls. It already has a motor controller and they do all sorts of things. The treadmill will have all the pushbuttons on the control panel. Not sure if any use encoders. But you can install a longer belt on the treadmill and use that as an automated conveyor.
I'm impressed that you could use a large generic motor for precision ( more or less ) control of speed and position. An actual servo motor is carefully engineered for lowest possible inertia and precision balance to stop on a digital count. I believe that is why they are so expensive. However, if the application doesn't require star ship navigation through space and time, then the setup you have here may be justified. I always enjoy your experimenting video's. You are a bright young man.
Work in an EMC lab and our turntable busted! going to spend about 6-7grand to get a new system. Replacing the encoder first to see if it will work.. 100 to 400 bucks. Then purchase the 7k unit. what a waste when you could build one of these and a backup unit.. or two. I'm just a Ship and Rec. clerk I have skills that could save them bucks and these guys are engineers, but can't figure out they can pick up some of this stuff so cheap this exact unit would work well. PS I've picked up about 5 motors now the one you have is the largest one I've seen. Most I have are about 1.5 to 2hp. On is dinky and states 2hp.. not sure to believe that! Fantastic video !!
This is a great start! I would add fan cooling by separate electric fan, a reset that only affect the motor and a motor or spindle lock could get this maybe 30% of the way to a DIY CNC lathe! Just add a couple of stepper motors to control cutter X and Z would get the basics covered. Thank you for this video. It has got me thinking about what to do with my treadmill motor!
Wow, this is awesome! Although, as I work professionally with motor control in industrial machinery a DC motor holding at standstill gives me the shivers. As they are not frequency dependent, any current will apply a dynamic torque, if you compare to 3 phase AC motors that will have standstill just by applying DC current (although they too will get hot holding) So the buzzing at standstill is actually the motor bouncing back and forth. Still really cool that it actually work, and I love this channel and all the things you manage to do with salvaged electromechanics! I think this will be difficult to not try at home :s
@glyn hodges yes, youre right there. but in that case because the gear ratio, turning the output shaft takes so much force you barely need to apply any holding torque.
@glyn hodges agreed. To optimize this, he needs a little feedback filter or hysteresis. Although this video is of course to show that this setup is possible, not that it's optimal :)
Great video thank you Jeremy. My thinking is that it might be better to have a belt drive reduction on the output and have the encoder mounted on that. I'm thinking that the amount of reduction should be whatever gives a sensible speed output for a lathe head (say 1000-2000 rpm?) when the motor is going full blat. This'll give more torque on the output and help with the precision on positioning. I'm suggesting belt drive because of the unavoidable on the backlash in geared reduction. As it is, this is inspiring stuff though.
@jeremyfielding Hi Jeremy, it seems like you've already got a lot of the stuff figured out with Ethernet cabling and the breakout boards, but if you have more questions, feel free to reply to this. I work with telecom and data stuff professionally, so I understand a lot of the background stuff and the terminology/lingo that is used in and around these things. Anyway, seems like you've got a good handle on it already, but if you have more questions, feel free to let me know :)
@daniel letterman In another post Jeremy mentioned tuning, which he hadn't done, but it worked anyway so he made the vid. Another source can be the motor-encoder linkage. I think he was just so happy to get it running. :)
@daniel letterman the Buzz is usually an oscillation between two adjacent encoder points as the DC is switched in polarity to maintain the zero motion. The motor's inertia makes this tougher. A 'fix' is in the controller usually called Stop Counts or similar. Make that number larger and the controller can say, "within 2 counts is close enough" and it will stop trying to hold a position so tightly , and stop buzzing. Trade Off is position accuracy, of course. That Buzz draws lots off power with no cooling , so should be avoided. Cheers.
Thank you both @AlucardPawpad ClownWorld an @SoloSailor for the info. I built a robotic arm and my servos buzzed whenever they held position, and now I know why.
Usually the servo driver is tuned for some load. If you run the motor without a load on the shaft the driver oversteers and you get this buzzing oscillation.
I wonder if an electronic shaft clutch, like the ones found in big printers would be a better "holding" force. Could cnc software handle that specific task instead of using the motor?
Hi Jeremy, are you self taught or an academic? Either way I could sit in the corner and watch you work all day (nothing weird about that is there??!!!) Respect from the U.K.
You know, Jeremy... I've been scavenging parts and fabricating or "re-engineering" stuff for years. I've known what I was looking for most of the time based on what I was LOOKING for. It's nice to find out (finally?) what the hell it's called!!! Thanks, and keep up the good work. You're probably going to be a great litany of reasons I don't light myself on fire as often as I used to. ;o)
Usually there is a common mode inductor between the switching controller and the motor. The brushes can overheat, there is usually a setting to reduce the current when in holding mode.
I've long been waiting for someone to work out the finer points of implementing a servomotor with hobbyist grade parts, this isn't it, but it's a perfectly worthwhile exploration of the topic.
Look into the Odrive project, it seems to be very similar to what you're looking for. It takes a hobby size BLDC combines it with an encoder and effectively makes a DIY servo for home use.
For sudden stops at that power, you might want to consider a dump resistor. Basically, you use a couple of relays to switch the motor over to a big resistive load. I believe HAAS uses what are basically the heating elements from electric stoves. Using that, you can go from full blast to dead stop almost instantly without damaging your controller. The only drawback is the heat. When you stop that fast, the backcurrent can be substantial. Good for emergency stops.
Great video Jeremy, I'm going to keep my eye out for discarded treadmills. I would definitely wire up an external fan - the motor was obviously designed to pump air through it when it is running. Try running it in "hold position" mode for a few minutes and I'll bet it will be pretty hot. Can you measure the amperage going through the motor?
When it comes to anything about a Electric Motor or controls Jeremy's videos on TH-cam is my choice as #1 first source. I believe it would be important to have a fan that runs the same speed no matter how fast or slow you run your motor. That means it doesn't necessarily have to be connected on the same shaft. Maybe use a separate independent fan that has it's own motor. Thanks for the videos.
Jeremy, your videos are super informative, creative and well presented - thank you! I have about six channels that I have dedicated as my “go to first” zones! Top Shelf!!!! Inspirational, gets me thinking!! Keep up the great work!
Omg I cant tell you how much I love your videos!! So exciting to watch someone with Macgyver kind of creativity like me but the knowledge I keep learning from youtubers, books and professors like you!! Thank you for being AN EXCELLENT teacher, guide, and mentor to complete strangers. I agree with a prior comment ... I would be like the old Burger King commercial where the guy got so excited that he won a Corvette that he exploded into confetti pieces! Ha ha You're awesome!!
There will always be pros and cons to each type of setup, but the cons are probably the more interesting, so: Startup torque on steppers is generally higher versus pmdc motors pmdc motors are generally not linear and require feedback (the encoder ($$$)) whereas steppers can be "dumb" rotor inertia of pmdc motors is generally higher than that of a stepper, possibly resulting in overshoot if not tuned pmdc motors aren't as 'nice' as steppers at holding a position / not being back-driven The video was great though and you offer a relatively simple solution; I have a few treadmill motors lying around myself.
Just my 2 cents. External fan for cooling. Mount the encoder directly to the motor. I don't know if clocking the encoder makes a difference but its worth a try. I think your servo would work well as a lathe 4th axis and wouldn't over heat on quick rotary position jobs. I suspect that your servo would over heat doing 3d 4th axis milling. The motor is kinda big for your little chuck. Cool video.
Yes unlike our stupid scientists nowadays where they only give us ideas and irrelevant theories trying to explain everything and take tons of $ without any real result or proving experiments Hating science without experimenting prove ☠️
I think that motor is fine for the application. It just needs PID control, which Mach 3 isnt giving you. Thats why its buzzing the motor. A PID could be tuned to decelerate the motor as it neared its destination, etc.
Imagine taking a college course with this guy as the professor. Talk about getting your monies worth. So much learned from Mr. Fielding videos. Thank you so much.
Well said. I'm a high school teacher who is in awe of his uncluttered easygoing approach, and I'm eating up his technical knowledge at the same time. Huge, huge help to me.
I'd pay that tuition!
I’m not hating at all. I love this guy’s channel. He does a great job and is insanely smart. With that being said, you can learn everything you need to know about the projects he does with an associates of applied science in industrial systems or something similar. Or even a diploma which takes less time to get. Sure you’ll need work in the field to sharpen those skills you learn but it all comes together eventually and fairly quickly if you’re willing and wanting to learn. And if you’re interested in it.
College is boring no matter who is yor teacher , the reason it's boring is because the things you are studying are not interesting to you which is not the case here on TH-cam you only watch what you like what exists you of course Jeremy is super great teacher but you can find great teachers in school as well and still get bored
@@idiyerbill1968 if you are getting that bored then it is probably be a use you are studying a subject you aren’t really interested in. If you are passionate you won’t get bored unless it is a bad lecturer.
Who needs college. This is what I needed growing up. I'm 49 years old. Now own my own machine shop. I learned everything I know in tool and die works, own my own. rolling up my sleeves and getting dirty. I have always wanted to learn the electronics side of things to build my own machines. That is now possible. Thanks to TH-cam and this good gentleman Jeremy Fielding.
This is the stuff that makes me feel better about the internet spreading stupid stuff like antivax and flat earth. You are spreading high grade engineering information to the masses. Great work as always.
Yeah. Tell em. You gotta vax it mon.
Reno Simpson you might want to refrain from watching these truly intelligent vids, your mind is too simple. Knowing WHERE to find pertinent information is a better use of your limited grey matter than wasting calories/time learning/knowing/storing information.
Going to your phone/w.w.w. for information is probably the wisest choice most ppl make all day, knucklehead.
KEEP YOUR PSEUDOSCIENCE GARBAGE OUT OF HERE
ENGINEERING HAS NOTHING TO DO WITH HELIOCENTRISM
THE EARTH IS FLAT AND STATIONARY VACCINES ARE POISON AND YOU SHOULD DEFINITELY NOT EAT ANIMAL PRODUCTS
NOW START CRYING ABOUT CAPITAL LETTERS
@Reno Simpson YOU ARE WHAT YOU EAT
IT'S AS SIMPLE AS THAT
YOU CONSUME THE DNA THE FLESH THE BLOOD OF AN ANIMAL
YOU HAVE A SIMULATED THAT DNA INTO YOUR DNA
JUST DOESN'T HAPPEN INSTANTANEOUSLY COMIC LEE LIKE YOU WOULD THINK ON THE MOVIE WHERE YOU TURN INTO A GIANT TURKEY AS SOON AS YOU EAT A CHUNK OF TURKEY BACON
🤣😂
IT'S MORE LIKE IF YOU FEED A NATION A CONSTANT SUPPLY OF ULTRA FEMINIZED FEMALE BABY BOVINE 4 GENERATIONS
YOU'D KIND OF WIND UP WITH A ULTRA FEMINIZED FEMALE BABY BULLVINE / PEOPLE HYBRID
NOW LET'S LOOK AT THE CHARACTERISTICS OF A ULTRA FEMINIZED FEMALE BOVINE BABY
FRIGHTENED EASILY-🤔 DIDN'T YOUR RELIGION JUST PREDICT A GIANT ASTEROID WAS GOING TO HIT THE EARTH AND NOTHING HAPPENED JUST YESTERDAY?
EASY TO MANIPULATE-DID YOU KNOW THAT EVERY PICTURE OF A SATELLITE IN SPACE IS A PIECE OF ARTWORK AND CGI AND THEY TELL YOU THIS AND IF YOU LOOK CLOSELY AT IT YOU WILL REALIZE YOU'RE LOOKING AT A FUCKING CARTOON?
THE FEMALES IN PARTICULAR BELIEVE STRONGLY BECAUSE THE HERD BELIEVES STRONGLY ABOUT PARTICULAR THINGS
THIS IS WHY COWS HAVE A HERD MENTALITY AND NOW SO DO YOU BECAUSE YOU CONSUME THEM FLESH AND BLOOD
REASON NUMBER TWO 🤣😂
ADRENOCHROME
I'M HOPING THAT YOU'LL ASK ME FOR INFORMATION ON ADRENOCHROME
@@Jason_Family_Man Boomer begone
I just watched your newest vid with the cnc table saw and then this one was suggested.
Man, as a recovering addict building up tools for my little apartment workshop from nothing, I’m so jealous of your shop and tools. You’re living the dream, making all this cool stuff. I hope to get there someday soon.
Right now I’m still in the “search through trash to find stuff to tear apart so I can hoard the components for later use.” Phase of things.
Gifted guy, to an inspiring level. We need more of these...
So true.
I worked in the electrical field for 30 years. I love watching videos from different people in the field of electricity and electronics. I don't understand why I just found your video collection...Well I just subscribed !! Keep up the good work.
One of the smartest engineering presentation he delivers in the TH-cam.
1:34 "So let's make a servo motor out of this treadmill motor ... OBVIOUSLY!" I don't know why but that made me so happy.
Same here lol.
America is built on this sort of ingenuity and this man is a genius!
I think I've stumbled onto a genius in action. No hyperbole, no bs....just useful, understandable information laid out in layman's terms and enjoyable to watch...and LEARN. Thank you very much.
I would have loved to have you as a teacher when I was in high school 25 years ago... I really love the format of your videos. No music, no bullshit, just technical knowledge transmission. Thank man 👍🏻
Great video! You didn’t shy away from the necessary compromises, or excuse the experimental nature of this project. This, IMO, is engineering at its best.
I have the same servo drive on my retrofit milling machine. Use the servo tuning software to help dial in the position holding. This will get rid of the annoying buzzing noise. Awesome content!
25 seconds in and I have already clicked "like" button.
I have only done a few projects with toy servos, so this was a fascinating lesson on the mechanics of servos at a larger scale. Thanks!
The other thing that dedicated servo motors have that many non-servo permanent magnet motors don’t is that they are designed to have low to zero “cogging” - when you turn the shaft, it doesn’t want to stick to the poles of the magnets. This results in better accuracy overall and lower power consumption when holding a position.
My thought was that gearing reduction and code that accelerates and decelerates would help. If you wanted to move a really big mass relatively precisely but not at a high duty cycle, this setup could be fantastic. I suspect it might not be ideal for the x and y on a CNC where sudden starts and stops and high accuracy/repeatability are all important.
MAYBE, you could design two motors that are electronically and mechanically coupled to work together. Lots of things are possible if you have time, motivation, and willingness to discover dead ends for the sake of learning :)
It depends on if the position is being held in a low or high reluctance position. A high detent force motor will have higher holding force with better efficiency in low reluctance positions, a low detent motor will have better accuracy and less vibrations in high reluctance positions. If micro stepping is not wanted or needed for accuracy (or if surfaces finishes aren't impacted) , higher detent force will actually make for a better servo motor.
@@joetransue ideally you don't use gearbox's in a servo application. They have backlash. Most servos should be direct drive.
@@RyanVasquez6089 Right, that was why I thought of using two that "fight" each other. I realize purpose built equipment will always be better, but if you have the stuff sitting around and the cost is basically creativity and a few standard parts, then I think that is an OK time to leave the more orthodox methods for those with the budget.
The noise is called Dithering and it happens because the encoder keeps sending adjacent readings and does not settle on a single one. Its like a ping pong match between two adjacent encoder positions.
@Jeremy Fielding why hasn't TH-cam led me to you much sooner? I'm so glad I found you. Your material is gold ✨
Jeremy, you asked for comments. Here is mine. As a physicist who has worked in industry a long time in R&D and various engineering roles, I'd like to offer the following feedback: Servo motors exist because they can do well what non-servo motors cannot do well. They are engineered to handle the demands of the applications for which they are intended. True, one can make just about anything do something similar to something properly designed for a job but it won't last. You cannot simply sidestep the physics and engineering that goes into building proper motors for the demands of the intended application. To Jeremy's credit, he acknowledges this up front. That motor will burn up if used this way except in the lightest of loads and low duty cycle. This is a very informative overview of how these kinds of closed loop systems work. However, you cannot simply make a motor designed for a specific application play nice in an altogether different application by trying to make it act like the appropriate motor. Except in the most general sense, they are not that interchangeable. This is why there are complete industries that revolve around different types of motors. You could argue "That's nonsense and hype for the sake of revenue generation" but you'd be wrong. Motor design is very application specific and rightly so. There is a right motor for every application and one should seriously consider the long term cost/benefit analysis when it comes to the investment. Sure you can cut corners and try to make a motor do what it was not specifically designed for (and watch it under perform and eventually fail) rinse and repeat, or do the research and buy the right motor once and be happy for a long time. Of course there is a lot of good learning that CAN happen if one pursues the trial and error approach and if that is what one wants to do for the sake of tinkering then heck yes, forge ahead. However, if you have the math competency/comfort and a technical inclination, spend some time reading up on motor designs and their applications. It could save you a lot of money in the long run. Whichever path you decide, I wish you a pleasant journey! Peace all and Jeremy keep up the excellent channel!!
While I agree with you statements above and acknowledged these facts in the video. I was hoping for a more specific discussion of problems for the sake of learning. I wanted to tap my community of knowledge with what I thought was an interesting question.
I have had a bare (cutting) plotter for years (with servo motors). Good buddy of mine sent me a servo controller, power supply and software. I have been staring at it for several years. I think during this time of 'trouble' while I hunker down I will try it. You made so much sense. Thank you. Stay safe!
Outstanding video yet again. Very few people on YT seem to be willing to actually 'Make' something vs just videoing some bits or bobs they've bought. These are the types of videos that inspire people to experiment with 'junk' and learn to do cool stuff. Keep up the good work.
Quite interesting. I would think the windings would eventually overheat, even with cooling. I base this on frozen motors from turntables, antenna rotors, starters, and other consumer & industrial equipment I have worked on for decades.
I do agree, you must have a motor designed for the job. Great video. Please keep them coming!
Heat is created by amps, if you have a given amount of airflow then it will cool regardless of motor rpm, so long as the airflow remains the same regardless. If the motor itself is providing its own airflow through a direct drive fan like most treadmill motors then applying torque to hold a position is much more likely to cause the motor to overheat than the same motor with externally driven airflow.
I've been trying to make a servo out of a car wiper motor using an arduino, with a potentiometer as the "encoder". After watching this, I think I might get a digital encoder...
Try old ink jet printer encounter. it may work
Use a Pololu JRK 12V12 motor driver (around $100 each...) with a precision potentiometer that rotates continuously. That’s what I use in my sim racing motion rig and it works great. They hook up via USB (or serial...) and have the control software built in. The continuous pot was expensive - $45 each - but they have been operating without fail for years now. Note: you CAN use a non-continuous pot, but in the event that something goes wrong and the motor keeps turning past the stops of the pot, your pot will be broken and the signal to the motor driver will be missing. Continuous rotation pots prevent that from happening.
FWIW, the arduino can work, but I used a MotoMonster driver when I tried that route. Not enough power through the MotoMonster for my needs, but it DID work while I was using it. The JRK12v12 has the ability to detect if the pot becomes disconnected, for example. It also is smart about monitoring current overloads etc.
@@michaelkeymont501 what? Whuut? Whuuuuuuuut? When you guys make casual conversation out of tech stuff you remind me that I can adjust the dial on the toaster, and chew gum... But not at the same time. I am so glad for you smart people. Peace
You can use two photo interrupters and a encoder wheel built to your specification. There's a video on it by Homofaciens.
@@patri0t1776 encoder
Thanks for a great video! I like how you use readily available components to employ in a wide variety of applications and explain the function of each component as well as alternative approaches. Also providing details such as wiring diagrams, component sources and warnings really help to let your subscribers duplicate what you are demonstrating. Awesome!
Pretty cool. Haven't messed with servos since my Navy days (60 years ago). They impressed me then, they impress me now, as does your explanation. Nice vid.
Something to look for is an RJ-45 "Keystone" jack if you're looking for something more permanent than that breakout board (for an enclosure or a carriage install for example).
Keystone jacks are designed to snap into a hole on wall plates, patch panels, and it's VERY easy to cut a matching hole in metal plate or wood. They're also quickly replaceable if you manage to break one.
You will need a small tool called a 'punch down tool', but they are cheap (and you can actually get by with a small flat-head screwdriver in a pinch).
I wonder if he is using CAT5, and whether there is interference from the unshielded cable. Good thought on the keystone, they are very handy indeed.
Wow, I've learned far more here about electric motors and CNC stuff here than anywhere else. In one video. You are awesome. Thanks!
You are just so friggen dang brilliant. I absolutely appreciate you sharing all of this knowledge and info in a way anyone can understand without being condescending or overly technical
This is such a wildly beautiful explanation on servos. Thank you so much for actually including all the possibilities and potential things as opposed to just “here is a servo motor for arduino’s” ….and thank you for actually explaining what it actually is better than anyone else.
I'm apprenticng under my inlaw who's an electrical engineer. I love your matter of fact way of expaning things very down to earth and I'm loving seeing how much i can follow what you're saying on my own. Thank you so much for this content
You are one smart man. Hats off to Mr. Fielding.
I've made this control exactly same way with a different dc motor meter you suggested works great. I've made my bandsaw, drumsander, a cement/concrete mixer from old washing machine and treadmill motor, router table and table saw all worth treadmill motors. I guess it's a over sized cnc machine now. I wanted to make a water cnc with a cheap 79.99 harbor freight pressure washer over seen it done. Not this size tho. Saved me thousands thanks so much
I’m really enjoying your videos! I have one small recommendation: it would be very helpful if you would briefly mention the meaning of some of the acronyms you use in your videos, at least once per video, for newcomers (e.g. PLC = Programmable Logic Controller, CNC = Computerized Numerical Control, PWM = Pulse Width Modulation). Your videos are so well done, I’m thoroughly hooked!
What a Godsend Jeremy Fielding is, THANK YOU JEREMY!!!
25 years ago my very first job was a Motion Control Engineer and I worked on many projects providing the servo motors and their control, including aerodynamic robotic arms for wind tunnel testing, automated headlight testing rigs, satellite tracking TV transmission vans, X-Y plasma torch cutters, air to air missile testing rigs, tank tracked robots that would craw inside nuclear reactors for testing and maintenance, Formula 1 car testing rigs, etc etc.
Unfortunately in my mid 20's I was chasing the cash so got into IT *yawn*, a decision that in many respects I regret.
Videos like this take me back and make me wonder how life would have been different had I made other choices. Keep up the good work Jeremy!
Do you answer questions?? Your videos are simply outstanding. Thanks
This is awesome. Basement workshop engineering at it's best. Video editing with titling, is good. Easy to understand.
I don't recall the specs, but I worked in a company that made DC servo motors. These had a range of applications from motion picture camera motors to the older tape drive systems. Some used optical encoders, some were just driven.
Great info. I can see this working fairly well in some applications. Having been a machinist for 44 years I see metal chips and dust being a problem with open face motor. However if properly gaurded this could make for a cheap and easy way to go.
Thanks again for the easy to understand info.
Your new video space is working out great Jeremy! That angled ceiling works for the lighting and sound, with plenty of wall real estate for white boards and other things! This video is a great topic, thanks!!
👍 Treadmill motors also can be rigged as mini wind turbine generators! But your use is MUCH cooler....! Thanks for the info! 😎
Thanks for all your curiosity.
An inspiration for problem solvers everywhere, and another reason I believe that arts and sciences need to be further linked in our education.
I see these videos as a precursor to more knowledge being shared and I hope you get as much pleasure working these projects as they bring to your viewers!
Best wishes for more great tours in the future. Yaksawa robotics was great!
Thank you Mr Fielding. Jeremy. Make me smile.
He really knows his stuff! Learning so much Jeremy thank you!!!
So happy I found this guy..
Jeremy, thanks for bringing us to a higher level in DIY projects. It makes for interesting ideas this close to Halloween & Christmas.
Still have to get my shop set up the rest of the way & all of these ideas must be considered.
Take care brother! 😊👍
I'm so glad that you decided to pay attention in school your a very very smart young man
Jeremy, I remember watching you when you were just a kid. You amazed me then and still amaze me.
The names of the jacks and wire are all heavily used interchangeably. You will see the proper names used more in connector/cabling manufacturer catalogs or large electrical supply houses (e.g. digikey). However for those who like to research things (pedantic warning):
RJ45 is registered jack 45 (from Bell labs USOC standards) It is the the female jack only (and registered refers to the pin on the back for directional registration).
The male connector is actually called an (Bell USOC) 8p8c connector for 8 position, 8 conductor.
RJ11 was used in serial and US phone service and typically used a 6p6c connector (although typically used with only 2 or 4 wire flat cable or early twisted pair) and wired in USOC wiring standard (predating tia/eia specs).
Category 1-7 (CatX) are cable standards for twisted pair cabling. The category rating specifies the minimal gauge of wire, quantity of conductors, and twists per inch (to cancel crosstalk) and the speed rating in MHz that the cable should be tested to without getting significant errors from electrical impedance. Having an E at the end of the spec means enhanced speed rating. Although sometimes resellers will try to confuse the actual cable rating to make it sound like their cable is better (better in cabling really is only relates to how much quality control to the standard they test for, and ability for the cable to withstand stress under various hostile conditions).
Ethernet is a low level standard relating to the physical encoding of electrical pulses, signal clock timing, framing of bits on a shared wire, and signal congestion control (what happens if two things energize the same conductor at once). This data protocol does not specify the physical media (when I started in the industry it was 10base5 over coax and AUI cables, and in school we even did things like: Ethernet over laser, ultrasonic, and once even once over a barbed wire fence).
Cool stuff. Thanks for the servo 101. I have a project down on the do-list that will require a servo. Preliminary looking left me a little confused on terminology. This really helps. Will still be several months before I get a chance to start.
Jeremy, you have one of the coolest channels on YT!
Your channel is *THE BEST*!! So much great information. Your explanations and demos are top notch. Thank you *at least* five or six times, Jeremy.
Ethernet cable is actually Cat5 or even Cat6 cable with RJ45 connectors
And I think I read somewhere that most of what's referred to as RJ45 isn't technically RJ45 but something else (I don't remember what), but it's just so commonly referred to as RJ45 that everyone calls it that
@@reaganharder1480 It might be the phone cable and its sisters. They have very similar looking connectors, only with less than 8 pins, and I can imagine people look at it and think RJ45 is the group of connectors which look like that (transparent and rectangular, used on coloured twisted cables, latch on top, connection row on bottom). RJ45 is specifically the 8-pin connector used for computer connections.
@@reaganharder1480 8P8C connector 😁
wow impressive tutorial ....you certainly know your stuff and you're a natural teacher too Great video
Hello from UK. Great video Jeramy as usual. Thanks for teaching us.
Dude you're a BAMF! Only recently found your channel and I'm loving it! Wish I had you as a teacher! Keep up the great work man! ❤️
That was the most intriguing thing I've seen on YT in a long time,, Thank You, JF!
While viewing your demonstration the immediate concern I had was the heat generated by this system.
As setup, prolonged use, that's gonna get hot
Hotter than any stepper motor, I would suspect.
In other words,, that fan has to stay somehow
There you go again, explaining things I never thought I would understand, thank you.
You're a genius, good sir. I love the channel
First time watcher...I think I may love this guy.
You Sir, are expanding minds and changing lives!👍
i used to work at a life fitness plant years ago. Those treadmill motors alot of times are tore down and rebuilt. pretty durable motors.-Kip
I think the DC servos we use at work are multi phase DC, so I think this gives them greater control and precision.... But they are thousands! We further improve things by using gearboxes (very precise practically zero backlash) of the order 30:1 ish ( I forget exact ratio). Good hack, love the philosophy.
Just wanna say that you're AWESOME and keep up such good work!
I'd prefer a fan or blower, directed into the winding area, using a thermostat control, that's Attached on the motor housing. Maybe when the motor is actually connected to the mechanical load,that chatter will be eliminated. Neat little project you have. Thanks for sharing.
This gives me so many ideas. I started watching this with a headache, but couldn’t stop. I’m sending this vid to my goto geek Greg from themakerslife so he can ponder this with a clear mind.
Man you the only one I would trust because you are a damn good engineer. What would be better a 3060 engraver , or 3060 milling for stainless steel? I'm new on the cnc machines. And spindles is best. Thanks man ,keep on,keeping on.
This is an excellent video. Made me aware of other options for a project I have in mind. Thanks for that.
You are very inspiring and its fascinating to see what you will do next. I want to convert my car to electric.
You are a really good educator.
Neat project. It might be good as an auxiliary axis where you can turn it on, get to a position, then shut it off. Maybe use it to roll out sheet metal for example.
The limitations of course are with the heat & holding a position. It also might not be too persice between rotations (assuming the torque of a motor that size is needed & expecting repeatable accuracy).
For example I wouldn't want to use it for a DIY robot axis, (Ha).
It might be good for an application that just goes back & fourth. Great use of the encoder to achieve a certain angle. The size of the motor would have the umph to go back the other direction, yet not causing the strain of holding a stopped position.
Thanks for the brainstorm & asking us the audience to chime in!
This guy deserves a TV show at Discovery Channel or something
I hate that videos like this aren't at the top of the list when searching
The treadmill itself was a good source of electronic controls.
It already has a motor controller and they do all sorts of things.
The treadmill will have all the pushbuttons on the control panel.
Not sure if any use encoders.
But you can install a longer belt on the treadmill and use that as an automated conveyor.
I'm impressed that you could use a large generic motor for precision ( more or less ) control of speed and position. An actual servo motor is carefully engineered for lowest possible inertia and precision balance to stop on a digital count. I believe that is why they are so expensive. However, if the application doesn't require star ship navigation through space and time, then the setup you have here may be justified. I always enjoy your experimenting video's. You are a bright young man.
This was a golden suggestion from Google. Subscribed :-) Thanks!
Love it!
I have my servos did a software reset when they do not need to hold/stall.
Work in an EMC lab and our turntable busted! going to spend about 6-7grand to get a new system. Replacing the encoder first to see if it will work.. 100 to 400 bucks. Then purchase the 7k unit. what a waste when you could build one of these and a backup unit.. or two. I'm just a Ship and Rec. clerk I have skills that could save them bucks and these guys are engineers, but can't figure out they can pick up some of this stuff so cheap this exact unit would work well. PS I've picked up about 5 motors now the one you have is the largest one I've seen. Most I have are about 1.5 to 2hp. On is dinky and states 2hp.. not sure to believe that! Fantastic video !!
WHY COULDNT YOU BE MY BROTHER?🤦🏾♂️🥺😖😭 that would’ve been the greatest thing. You are 💯 % inspiring.
THANKS A WHOLE BUNCH
I am so happy TH-cam led me to your videos! Amazingly clear and interesting video again. Great job Mate!
found this in my feed this morning. Great content and nice down to earth 'no BS' presentation. Keep up the great work.
This is a great start! I would add fan cooling by separate electric fan, a reset that only affect the motor and a motor or spindle lock could get this maybe 30% of the way to a DIY CNC lathe! Just add a couple of stepper motors to control cutter X and Z would get the basics covered.
Thank you for this video. It has got me thinking about what to do with my treadmill motor!
Wow, this is awesome! Although, as I work professionally with motor control in industrial machinery a DC motor holding at standstill gives me the shivers. As they are not frequency dependent, any current will apply a dynamic torque, if you compare to 3 phase AC motors that will have standstill just by applying DC current (although they too will get hot holding) So the buzzing at standstill is actually the motor bouncing back and forth. Still really cool that it actually work, and I love this channel and all the things you manage to do with salvaged electromechanics! I think this will be difficult to not try at home :s
@glyn hodges yes, youre right there. but in that case because the gear ratio, turning the output shaft takes so much force you barely need to apply any holding torque.
@glyn hodges agreed. To optimize this, he needs a little feedback filter or hysteresis. Although this video is of course to show that this setup is possible, not that it's optimal :)
Great video thank you Jeremy. My thinking is that it might be better to have a belt drive reduction on the output and have the encoder mounted on that. I'm thinking that the amount of reduction should be whatever gives a sensible speed output for a lathe head (say 1000-2000 rpm?) when the motor is going full blat. This'll give more torque on the output and help with the precision on positioning. I'm suggesting belt drive because of the unavoidable on the backlash in geared reduction. As it is, this is inspiring stuff though.
@jeremyfielding Hi Jeremy, it seems like you've already got a lot of the stuff figured out with Ethernet cabling and the breakout boards, but if you have more questions, feel free to reply to this. I work with telecom and data stuff professionally, so I understand a lot of the background stuff and the terminology/lingo that is used in and around these things. Anyway, seems like you've got a good handle on it already, but if you have more questions, feel free to let me know :)
@daniel letterman In another post Jeremy mentioned tuning, which he hadn't done, but it worked anyway so he made the vid. Another source can be the motor-encoder linkage. I think he was just so happy to get it running. :)
@daniel letterman the Buzz is usually an oscillation between two adjacent encoder points as the DC is switched in polarity to maintain the zero motion. The motor's inertia makes this tougher. A 'fix' is in the controller usually called Stop Counts or similar. Make that number larger and the controller can say, "within 2 counts is close enough" and it will stop trying to hold a position so tightly , and stop buzzing. Trade Off is position accuracy, of course. That Buzz draws lots off power with no cooling , so should be avoided. Cheers.
Thank you both @AlucardPawpad ClownWorld an @SoloSailor for the info. I built a robotic arm and my servos buzzed whenever they held position, and now I know why.
Usually the servo driver is tuned for some load. If you run the motor without a load on the shaft the driver oversteers and you get this buzzing oscillation.
I wonder if an electronic shaft clutch, like the ones found in big printers would be a better "holding" force. Could cnc software handle that specific task instead of using the motor?
Hi Jeremy, are you self taught or an academic? Either way I could sit in the corner and watch you work all day (nothing weird about that is there??!!!) Respect from the U.K.
Stuart Hossack If it IS weird, then there are a lot more of us “weirdos” that would be sitting in the corner with you, watching Jeremy all day long!
You know, Jeremy... I've been scavenging parts and fabricating or "re-engineering" stuff for years. I've known what I was looking for most of the time based on what I was LOOKING for. It's nice to find out (finally?) what the hell it's called!!!
Thanks, and keep up the good work. You're probably going to be a great litany of reasons I don't light myself on fire as often as I used to. ;o)
Usually there is a common mode inductor between the switching controller and the motor. The brushes can overheat, there is usually a setting to reduce the current when in holding mode.
I've long been waiting for someone to work out the finer points of implementing a servomotor with hobbyist grade parts, this isn't it, but it's a perfectly worthwhile exploration of the topic.
Look into the Odrive project, it seems to be very similar to what you're looking for. It takes a hobby size BLDC combines it with an encoder and effectively makes a DIY servo for home use.
Precision, digitally controlled table saw fence? Check. So many cool applications for affordable servo motors!
For sudden stops at that power, you might want to consider a dump resistor. Basically, you use a couple of relays to switch the motor over to a big resistive load. I believe HAAS uses what are basically the heating elements from electric stoves. Using that, you can go from full blast to dead stop almost instantly without damaging your controller. The only drawback is the heat. When you stop that fast, the backcurrent can be substantial.
Good for emergency stops.
You can buy braking resistors for this controller. I just didn’t need it for demonstrating the concept
Great video Jeremy, I'm going to keep my eye out for discarded treadmills. I would definitely wire up an external fan - the motor was obviously designed to pump air through it when it is running. Try running it in "hold position" mode for a few minutes and I'll bet it will be pretty hot.
Can you measure the amperage going through the motor?
With some fancier motor controllers the hold current is a configurable setting. With some systems it has its own g-code commands.
When it comes to anything about a Electric Motor or controls Jeremy's videos on TH-cam is my choice as #1 first source.
I believe it would be important to have a fan that runs the same speed no matter how fast or slow you run your motor. That means it doesn't necessarily have to be connected on the same shaft. Maybe use a separate independent fan that has it's own motor.
Thanks for the videos.
Jeremy, your videos are super informative, creative and well presented - thank you! I have about six channels that I have dedicated as my “go to first” zones! Top Shelf!!!! Inspirational, gets me thinking!! Keep up the great work!
Omg I cant tell you how much I love your videos!! So exciting to watch someone with Macgyver kind of creativity like me but the knowledge I keep learning from youtubers, books and professors like you!! Thank you for being AN EXCELLENT teacher, guide, and mentor to complete strangers. I agree with a prior comment ... I would be like the old Burger King commercial where the guy got so excited that he won a Corvette that he exploded into confetti pieces! Ha ha
You're awesome!!
Came here from your collaboration with smarter everyday. Love your channel!
There will always be pros and cons to each type of setup, but the cons are probably the more interesting, so:
Startup torque on steppers is generally higher versus pmdc motors
pmdc motors are generally not linear and require feedback (the encoder ($$$)) whereas steppers can be "dumb"
rotor inertia of pmdc motors is generally higher than that of a stepper, possibly resulting in overshoot if not tuned
pmdc motors aren't as 'nice' as steppers at holding a position / not being back-driven
The video was great though and you offer a relatively simple solution; I have a few treadmill motors lying around myself.
Just my 2 cents. External fan for cooling. Mount the encoder directly to the motor. I don't know if clocking the encoder makes a difference but its worth a try. I think your servo would work well as a lathe 4th axis and wouldn't over heat on quick rotary position jobs. I suspect that your servo would over heat doing 3d 4th axis milling. The motor is kinda big for your little chuck. Cool video.
You are my electric motor guru.
Science is awesome and this is science, hypothesis, experimentation, documents.
Yes unlike our stupid scientists nowadays where they only give us ideas and irrelevant theories trying to explain everything and take tons of $ without any real result or proving experiments
Hating science without experimenting prove ☠️
I think that motor is fine for the application. It just needs PID control, which Mach 3 isnt giving you. Thats why its buzzing the motor. A PID could be tuned to decelerate the motor as it neared its destination, etc.
This is fantastic, great project. I'd like to see more of your CNC!
The guy is a legend.