What is a Prioritising Mechanical Multiplexer?

26 apr. 2021
132 845 Weergaven

Check out Thangs: thangs.com/?
This is an idea that I had some time ago, and originally built as part of Project Ultron. I thought I'd redesign it now and ask for your help in deciding what we can use it for. This is a Prioritising Mechanical Multiplexer which allows us to use one large drive motor to control multiple outputs, and prioritise which outputs we solve first based on the inputs.
CAD and code: github.com/XRobots/MechanicalMultiplexer
You can support me on Patreon or buy my Merchandise:
Patreon: www.patreon.com/xrobots
Merchandise: teespring.com/stores/james-bruton
Affiliate links - I will get some money of you use them to sign up or buy something:
Matterhackers 3D printing supplies: www.matterhackers.com?aff=7500
Music for your NLworld videos: share.epidemicsound.com/xrobots
Other socials:
Instagram: instagram.com/xrobotsuk
Facebook: facebook.com/xrobotsuk/
Twitter: twitter.com/xrobotsuk
CAD and Code for my projects: github.com/XRobots
Huge thanks to my Patrons, without whom my standard of living would drastically decline. Like, inside out-Farm Foods bag decline. Plus a very special shoutout to Lulzbot, Inc who keep me in LulzBot 3D printers and support me via Patreon.
Below you can also find a lot of the typical tools, equipment and supplies used in my projects:
Filament from: www.3dfuel.com/
Lulzbot 3D Printers: bit.ly/2Sj6nil
Lincoln Electric Welder: bit.ly/2Rqhqos
CNC Router: bit.ly/2QdsNjt
Ryobi Tools: bit.ly/2RhArcD
Axminster Micro Lathe: bit.ly/2Sj6eeN
3D Printer Filament: bit.ly/2PdcdUu
Soldering Iron: bit.ly/2DrNWDR
Vectric CNC Software: bit.ly/2zxpZqv
Why not join my community, who are mostly made up of actual geniuses. There’s a Facebook group and everything: facebook.com/groups/287089964833488/
Former toy designer, current NLworld maker and general robotics, electrical and mechanical engineer, I’m a fan of doing it yourself and innovation by trial and error. My channel is where I share some of my useful and not-so-useful inventions, designs and maker advice. Iron Man is my go-to cosplay, and 3D printing can solve most issues - broken bolts, missing parts, world hunger, you name it.
XRobots is the community around my content where you can get in touch, share tips and advice, and more build FAQs, schematics and designs are also available.

  • A vending machine robot

    Dr. EnigmaDr. EnigmaDag geleden
  • You could make your design more compact, lighter, cheaper by using dog gears as in manual transmissions ?

    shodanxxshodanxxDag geleden
  • I think you would be better with a differential or clutched controlled by N solenoids, then you can move 2 joints at once

    jamcdonald120jamcdonald1202 dagen geleden
  • Such an useless creation yet so fucking educational, love it

    KikelabordeKikelaborde2 dagen geleden
    • Thanks, it would make a good coding challenge at worst !

      James BrutonJames Bruton2 dagen geleden
  • I've seen 2 other comments with good ideas for why/how to add 1 or N clutches. I'll add a 3rd. It would be nice if you could work in a way to add "holding" on each of the outputs that are not being driven.

    Bruno BronoskyBruno Bronosky2 dagen geleden
    • That's why there's a worm gear and another gear on each one.

      James BrutonJames Bruton2 dagen geleden
  • Потратил 15 минут времени, но так нихрена и не понял нахрена эта штука. Это примерно как рвать гланды через жоппу.

    Окань ВиталийОкань Виталий2 dagen geleden
  • Hydraulics would be better. valves open and close to turn hydraulic motors. Only one electric motor driving a hydraulic pump.

    Walter GreenWalter Green3 dagen geleden
    • Yes but it's not really a 3D printing project

      James BrutonJames Bruton2 dagen geleden
  • Use the outputs as inputs and it will become a nice useless machine that try to keep the knobs on the predetermined position

    Felipe NavasFelipe Navas3 dagen geleden
  • Multi-segment, multi-legged robot. Think caterpillar.

    GeirGunnarssGeirGunnarss3 dagen geleden
  • What if instead of having a linear row of outputs, why not make a ring? Then the input can move around inside. It should be quicker to get to each output, but I have absolutely no idea how you'd achieve this!

    Will JonesWill Jones3 dagen geleden
  • I think it is a interesting idea, when you want to have a system that is a little bit lighter ant hav less parts , but due to the big wight shift it is probably better to use a gear system to get the force to the outputs. Depends on the system.

    do dodo do3 dagen geleden
  • This almost looks like it would be an interesting mechanism to use a lock system for a door or something else

    biggamer11biggamer114 dagen geleden
  • You could put a hammer on each of the outputs and have it play whackamole really poorly. It would be probably be so useless that it would be funny.

    Ken FullmanKen Fullman4 dagen geleden
  • it's a transmission w multiple output shafts instead of multiple ratios more or less

    krugtechkrugtech4 dagen geleden
  • Rotary encoders would work better than pots if you want to have greater than one turn for each shaft. Multi turn pots *could* work, but rotary encoders have no min or max position to limit the range of measurement. You just need to have a stored known initial position. Everything else is done by difference.

    xenomancerxenomancer4 dagen geleden
  • You could use this multiplexer as some sort of delivery pay load method... so for example put it on the top of your robot dog... have three buckets of materials, when the dog gets to a location.. dump whatever bucket it needs to dump... etc etc. Like a multi-bucket dump truck

    AkaSoggyBunzAkaSoggyBunz4 dagen geleden
  • Make a cup of tea

    John EckerJohn Ecker4 dagen geleden
  • something that jhacks me ohff

    TeHzoArTeHzoAr4 dagen geleden
  • Small items or specific type of item sorter. Add a sort of scanner system or mechanical separator that allows you to use this to select which screw you want.

    SlaydesilverSlaydesilver5 dagen geleden
  • A potential application for your multiplexer might be some type of peristalsis pump array. I'm thinking of watering my indoor plants and I have a couple dozen plants, flowers, herbs that all need different amounts of water at different times. Building this array with just two-motor would be ideal. This could also translate into molecular biology microfluidics or a simple bartending robot.

    S James Parsons JrS James Parsons Jr5 dagen geleden
  • How about for the axes motors for either cnc or 3d printing?

    Jennifer KelloggJennifer Kellogg5 dagen geleden
  • robotic snake

    ja stoddartja stoddart5 dagen geleden
  • My reaction when seeing all the steel fasteners: are dovetails hard to make or don't they work in printed parts? I imagine dovetails would look great in your brightly coloured projects 😎😁

    BbonnoBbonno5 dagen geleden
  • Furbies did it better

    CalburnoCalburno5 dagen geleden
  • Here's an interesting thought. If it is passing a lower priority that still needs to change, have it turn the driver motor while it's passing, in order to get a little change done while passing, lowering the total time required to complete all change.

    Paul TaylorPaul Taylor6 dagen geleden
  • You should use a single motor drive shaft with a system of clutches to allow for independent engagement.

    TaziusTazius6 dagen geleden
  • This reminds me of the Prusa MMU.

    Jo DeanJo Dean6 dagen geleden
  • Idea for this: a gardening water regulator, sensor data from either hydrometers or flowmeters to decide which arears of the garden, and which hoses to open valves for, and how much to open them.

    Kai WeixelmanKai Weixelman6 dagen geleden
  • Possible improvement for the programming part: instead of only considering the largest angle to decide which motor is prioritised you could also include a penalty for travel time. With travel time I mean the time it takes for the driving gear to move to the next gear. For example to get the highest score you could write something like "score = angle_deviation - K*travel_time" or "score = angle_deviation/(1 + travel_time)". Doing it this way has two advantages. Firstly you don't need additional code to ensure the motor finishes whichever gear it is currently doing. The current gear has travel_time==0 so it will always finish the current gear. Secondly in the current setup it is possible to have the scenario with priority left>right>center. The motor will first go to left, then to right and finally to center. It is much quicker to do left -> center -> right. Only when the center gear has a very small deviation would it be sensible to skip over it.

    spammer spammerspammer spammer6 dagen geleden
  • Car transmission gear does similar thing but with planetary gear. Please try that it is more efficient and fun

    Sanmveg SSanmveg S6 dagen geleden
  • Have you tried visual reflexes for that type of motor

    Jimmy HernandezJimmy Hernandez7 dagen geleden
  • idk why but this made me think of robotic eyes, left to right, up to down, and focus

    Uneasiest DaisyUneasiest Daisy7 dagen geleden
  • A rock crawler style remote vehicle with outputs for suspension height!

    Isabella Electrum - Virtual YouTuberIsabella Electrum - Virtual YouTuber7 dagen geleden
  • One thing MECHWARRIOR

    Piotr NodPiotr Nod7 dagen geleden
  • The brushless motor looks similar to the technics 1210 motor

    Darren MurreyDarren Murrey7 dagen geleden
  • Vending machine. User chooses which output delivers their product and your mechanism moves to that output.

    Rupert BruceRupert Bruce7 dagen geleden
  • 3 speed transmission

    Rc off And on roadRc off And on road7 dagen geleden
  • Millipede leg groups split into 3 sections. It'd be cooler the more motors/sections it has. Same design concept though

    alamppmalaalamppmala7 dagen geleden
  • This is almost identical to the power bench seat setup on my 68 buick. They have a simple synchronizer made up of a bit of springs and some lugs on the gears. They use double ended shafts and on each end of those is a flexible cable drive to each of the elevating or sliding gearsets on each side of the bench.

    Some GuySome Guy8 dagen geleden
  • I don't know about the robot but I think you could utilize it in your ping pong machine somechow.

    Jim SmithJim Smith8 dagen geleden
  • You could also have the motor run two knobs at the same time. In this build, with a longer gear, it could turn two knobs in the same direction until one of them reaches the correct position, then slide over and finish turning the other one.

    russellrussell8 dagen geleden
  • 2 ideas 1. A slow moving robot platform with 8 or more legs thats both moves and self levels 2. A device for dispensing various ingredients on a line for making different drinks or doing food prep

    Bored SaiyanBored Saiyan8 dagen geleden
  • Could you build a catapillar?

    Angus CameronAngus Cameron8 dagen geleden
  • would it not be easier to just use solenoids to push a gear between the worm gear and one large main drive gear, making it possible to adjust multiple outputs at once so long as they are going in the same direction, and allow for much faster switching between the outputs

    Emma_Da_BeanEmma_Da_Bean8 dagen geleden
  • 12:00 Makes me think of the Useless Box people have built. The ones with personality. Depending on the situation, your machine started at knob 1 that was in chaotic change, whereas knob 3 had a problem but wasn't changing, therefore it was better that the machine corrected the constant problem first and came back to the chaotic one. I suspect there are times when the chaotic one needs more attention than the constant one, as it might be more vital; but different scenarios require different solutions.

    madDragon08madDragon088 dagen geleden
  • Useful for an Omni-directional car {mecanum wheels} with only one motor

    KU MAILKU MAIL8 dagen geleden
  • Might make for an interesting display piece to have a humanoid puppet robot with plenty articulations that "dances", switching into a new pose whenever it finishes setting the all the body joints one by one to match the current pose.

    TiagoTiagoTiagoTiago8 dagen geleden
  • You could use two drive gears and adjust the spacing of the screw gears to create a system that would reach the next desired transfer gear more quickly. A pattern like this |->||. Three drive gears would work to really tight timing but I guess that would make the gearbox longer. Or you could arrange everything in more of a 3D structure that would make it fatter but shorter if space is an issue.

    IRMacGuyverIRMacGuyver8 dagen geleden
  • Nice work mate, what software do you use for modeling and printing - can you suggest some free one? Thanks in advance!

    Bon ViBon Vi8 dagen geleden
  • It looks like an electronically operated gear box. Made use it as an electric transmission? 🤔

    Sriharsha GadiyaramSriharsha Gadiyaram8 dagen geleden
  • It could be used as a refreshable Braille Display if you could make it smaller. The shuttle could move to each character position and then the rotation position could activate different character diplays. Maybe design the character to reset on backwards motion and then set the character with a mechanical algorithm for the readout.

    cliffcheneycliffcheney9 dagen geleden
    • Or a musical instrument... the shaft rotates a drum with spikes to pluck those tuned musical "combs" to produce a note, but here there would be "Combs" of different octaves in each of the three positions.

      John ClaytonJohn Clayton6 dagen geleden
  • An interseting improvement would be to arrange the whole system in a linear fashion: with the output gears facing each other with their shaft one inside the other (much like several gears with the shaft in common but this time the shafts are indipendent and one inside the other) . The drive gear should be a gear with teeth facing inwards that slides back and forth around the output gear it wants to transmit the movement to. Much like the speed change in an electric screwdriver with an orbital gearbox. This would make the mechanism much more compact and more robust. I hope I have explained myself well, regards!

    Edoardo PastoreEdoardo Pastore9 dagen geleden
  • It seems like if you have to sweep the entire distance anyway, you can process the middle output partially on its journey across.

    TheInevitableHulkTheInevitableHulk9 dagen geleden
  • This reminds me of the Armitron robot I had (twice) when I was younger, and tore apart (twice) - One motor running one shaft with a bunch of freely rotating gear trains. Two joysticks with 3 axis each just moved tabs that jammed the appropriate gear groups in place with shafts running through the arm. Loved it. Sad that I didn't keep at least one intact, and thinking I may have to make my own now :-) www.theoldrobots.com/armatron1.html I can see the multiplexer being activated with some careful path planning to line up everything such that the final movement is a tangential single axis slide into place. Thanks for the ideas James!

    James CannJames Cann9 dagen geleden
  • The absolute best use of this device is for NLworld video content, and showcasing the possibilities of 3d printing. So I think you nailed it first try.

    PowerScissorPowerScissor9 dagen geleden
    • Or a coding challenge :-)

      James BrutonJames Bruton9 dagen geleden
  • Great build ! I think if the logic addressed the middle gear while passing to the third the whole set would end up adjusted faster then if going to the most offset ( depending on the overall status , of course )

    Jim ViauJim Viau9 dagen geleden
  • Could be used for an automated football table? The hard part is detecting the ball position.

    bleepblorpbleepblorp9 dagen geleden
  • Nice video and prototype! I am interested to know which applications would make sense for such system... There are some serious limitations: it needs all the outputs to be aligned (or at least share a common axis) and it is very bulky. It looks like it would always be simpler and far more flexible to just have individual motors.

    Geek DetourGeek Detour9 dagen geleden
  • Hi I'm a robotic Engineers well and I just love the idea of prioritizing these motors maybe we can collaborate on a robot my email is John raffaelli77@gmail.com

    John RaffaelliJohn Raffaelli9 dagen geleden
  • You built a differential computer. If you can map the inputs to variables in an equation, you could solve equations?

    David MenasceDavid Menasce9 dagen geleden
  • Aw FFS! So the "prioritising" is done in software. Well, duh! I could have written that myself, knowing as I do, the bigger-than operator. I thought this was some extremely clever device. I've genuinely seen much, much better in Lego Technic or Meccano. Two 3D printers and they're wasted on you. You've made a knob-twiddler. Wow. An ugly, enormous, obvious multiplexer of a type I don't think is ever used in any engineering ever. You haven't even figured out how to use one motor, so turning this-way selects an output, and that-way turns it. I created better than this when I was 10, with less resources than your enormous workshop full of stuff. A "prioritising mechanical multiplexer" would *prioritise **_mechanically!_* That would be something worth seeing. Do you not understand grammar, or are you clickbaiting, with nearly a million subs?

    greenaumgreenaum9 dagen geleden
  • Since you build such chunky things, would you not benefit from a 3D printer with a much wider nozzle? Like maybe 3mm or 5mm or even more? You'd still have the precision, but it would make much stronger prints much quicker, rather than scribbling with spider-webs layered over each other. I'm not sure they make nozzles so large, but you're the mechanical genius, get on it!

    greenaumgreenaum9 dagen geleden
  • This man is a mad man, sleep my guy, its okay to relax 😂😂

    smilefreakifysmilefreakify9 dagen geleden
    • Dude builds ultron and Boston dynamics spot

      smilefreakifysmilefreakify9 dagen geleden
  • Suggestion for you - Remove the lead screw setup and replace it with a fixed rotating shaft with straight cut gears at each power take off position. Have a hinge at the end of each worm gear bearing so that the worm/straight gear assembly and be pulled/pushed down by an electromagnet/pneumatic source to engage the output. The worm gears will still mesh fine at a different angle. This will mean multiple simultaneous drives can be used, reduce parts cost, increase switching speed, remove lag between engaging and disengaging gear sets and enable outputs to be selected without moving other outputs on the way as is the case in the current setup. Really cool idea though, hadn't thought about that.

    KennyKenny10 dagen geleden
  • How about a hexapod with the fewest motors. Whatever that is?

    William HustonWilliam Huston10 dagen geleden
  • I think a good allocation would be moving different systems on a satellite, such as a space telescope where you can have a single heavy motor move around and manipulate lenses and filters and save weight.

    Matt the 2ndMatt the 2nd10 dagen geleden
  • Very cool! What about putting multiple drive gears on that lead screw in a Vernier arrangement to reduce transition times? You could even set it up so that different alignments of the 'Vernier gears' would drive different combinations of outputs by having 'bald' spots on your drive gears. So for example if 0 and 2 are out by 150 and 100 respectively, you could select a lead screw position that engaged 0 and 2 for 100 units, then switch to just 0 for the remaining 50. Although I guess that would produce weird transition artifacts that might be hard to correct for, and there'd be a limit on the number of combined outputs you could achieve.

    µJoeTheMeanµJoeTheMean10 dagen geleden
  • A back scratcher.

    Goldpenny1Goldpenny110 dagen geleden
  • Why move the drive motor? Use the a common drive shaft with electronic clutches. Am I missing something?

    Matthew MusanteMatthew Musante10 dagen geleden
  • we did this in 1800s when on stem motor was driving it all ... look back !!

    roy larsenroy larsen10 dagen geleden
  • that reminds me of the way the old radio shack super armatron was built.

    Christopher DChristopher D10 dagen geleden
  • Useless Box

    Brian LinkBrian Link10 dagen geleden
  • man 3d prints clutch in home.

    Charles BallietCharles Balliet10 dagen geleden
  • So... a gear shitfer, like in a car

    Juan C LealJuan C Leal10 dagen geleden
  • Armatron from radio shack used a system like this. However, it was all mechanical. Meaning the control stick physically engaged whatever gears were needed for a particular direction. Pretty sure it meant you could only go one direction at a time on either control stick.

    pikadroopikadroo10 dagen geleden
  • If you connected the input and output rotation and set the programming to restore the potentiometer to 0 you can make a pointless machine woth knobs instead of switches

    radnukespeoplesmindsradnukespeoplesminds10 dagen geleden
  • I love to see the maker movement developing.

    Charles AshurstCharles Ashurst10 dagen geleden
  • usless box

    Odd FellowOdd Fellow10 dagen geleden
  • rather poor CNC machine

    Odd FellowOdd Fellow10 dagen geleden
  • if you used clutches you can power all three outputs at the same and just selectively turn off outputs

    ADRIAAN1007ADRIAAN100710 dagen geleden
  • how about exploring budget junkyard motors such as used power window and windshield wiper motors.

    judgeomegajudgeomega10 dagen geleden
  • You could use it for an motorised louver roof (for an outdoor area) so you could turn them with two small motors rather than a very large one one. The sequential nature would look spectacular.

    Machin3DMachin3D10 dagen geleden
  • Would static loads on the outputs result in the gears being driven in reverse?

    David NilssonDavid Nilsson10 dagen geleden
  • Well, a dispensary system that controls multiple valves was my first idea. Be it liquid, gas, or solid material. A vast amount of uses there. and the more dispensaries the more economic the use. How about a robot that has both mobilities as well as separate isolated functions. Like a robot arm that is also on a mobile platform. First, connect to the drive shafts to move then switch to the arm for operations. This would be a workable option if the primary drive motor and multiplexer motor combination is either cheaper or less weight than having 2 primary motors. If the system had 3 independent functions then it's even better. Say an arm on a mobile platform that picks up an object and then moves it to a machining tool on the platform that does some work on the object. So a robot in a greenhouse. moves around picking up plants that it removes dead leaves, checks moisture then waters the plant before putting it back

    Daniel DeGagneDaniel DeGagne10 dagen geleden
  • I think a significant improvement would be more drive gears on the main shaft. Ideally you only want to have to move enough to disengage one gear and engage the next. Any extra motion is wasted time. But it does mean it may need to have a main drive shaft roughly equal to the length between all the gears, plus the width of the gear multiplied by the number of gears.

    Jeffrey BlackJeffrey Black10 dagen geleden
  • This could be used as a 3D printer system. Possibly bed leveling or keeping the tool head level.

    HaploHaplo10 dagen geleden
  • Maybe a 7deg of freedom robot arm with only the two motors at the base , without motors on the arm it could theorichally lift more weight

    Pietro SaporitiPietro Saporiti10 dagen geleden
  • Make a tortoise robot 😂

    AZHAGU05AZHAGU0510 dagen geleden
  • I wanted to do this

    Max MyzerMax Myzer10 dagen geleden
  • 12:08 ...or you could have it prioritize the closest one to the motor's current position with any error above a defined threshold

    Amateur ProgrammerAmateur Programmer10 dagen geleden
  • I have made something similar in the past, it wasn't exactly a multiplexer like you made here, but it was designed to take one bidirectionnal input and have two unidirectionnal outputs. The way I made it was by using a sort of variant of a ratchet mechanism. The use I had for this mechanism was because I had a limitted amount of motors I could use (it was for a Lego mindstorms competition called Zone01, I was like 14 back then) But this allowed me to make two movements with one motor. And since we were limitted to 4 motors, this was a big plus

    Civelier AlgonCivelier Algon10 dagen geleden
  • I'm thinking maybe a crane-like robot where you only need to move the X Y Z co-ords individually, or a centipede-like robot where you only need to move a few sets of feet forward or back at a time.

    F4ngelF4ngel10 dagen geleden
  • This would also be really useful in hvac ducting, you could measure each rooms temperature and redirect heat/cooling to whatever room in your house that needs it the most.

    grimsdaggergrimsdagger10 dagen geleden
    • Awesome Idea. I was wanting to do that very thing in my house. You know, the wife upstairs says she's freezing when I'm burning up then 10 minutes later we both switch.

      John ClaytonJohn Clayton6 dagen geleden
  • This would be really good for a multiple fillament extruder.

    grimsdaggergrimsdagger10 dagen geleden
  • Sir make full series on robotics for biggner to learn

    Mohit JoshiMohit Joshi10 dagen geleden
  • I've got an idea, but it's a tricky thing.... Basically, you use centrifugal force to send ball bearings further away from the shaft of the motor and they index on different outputs. So the output is changed based on the speed of the motor.

    Helena Of DetroitHelena Of Detroit11 dagen geleden
  • I know its just a proof of concept but instead of wasting the traverse while its in route you could keep it moving but check for the direction while in route. That would solve the making the delta worse. Would only be necessary if moving over an internal gear. E.g. going from 0 to 2.

    Hunter ParmleyHunter Parmley11 dagen geleden
  • I didn't see it at first, you did a great job presenting every step....then it clicked. Nicely done. Could you add two more axis, a joystick(or integrate like a game controller) and an arm with a cup? Excavator, or those could be the programing inputs for like a pick and place arm, safe cracker, laser guided drill press, etch a sketch with retractable pen....damn the possibilities.

    Flav MFlav M11 dagen geleden
    • Have your TV or PC screen oriented at optimal position. With the proper sensors it could follow you around the room. This would be awesome in a home gym where one has multiple exercising machines spread throughout the room or while working on a project in the garage/shed.

      Flav MFlav M11 dagen geleden
  • @James Fantastic Works ,i wonder if this can be arranged in a way that all of them can run at the same time, flip direction ,lock in place or vary its gear-ratio separate from each other in relation to the main motor rotation so an entire robot or arm would be able to run of one Main Engine

    aé Aonaé Aon11 dagen geleden
  • It would make a cool split flap display mechanism!

    Jonny PooleJonny Poole11 dagen geleden