Here is the list of parts and the number of prints needed for 1 right hand and forarm:

  • 1x Thumb
  • 1x Index
  • 1x Majeure
  • 1x Auriculaire
  • 1x Pinky
  • 1x Bolt_entretoise
  • 1x Wristlarge
  • 1x Wristsmall
  • 1x topsurface4.stl
  • 1x coverfinger
  • 1x robcap3
  • 1x robpart2
  • 1x robpart3
  • 1x robpart4
  • 1x robpart5

Here is the list of parts and the number of prints needed for 1 right wrist:

  • 1x rotawrist2
  • 1x rotawrist1
  • 1x rotawrist3
  • 1x WristGears
  • 1x CableHolderWrist

Print wristarge, wristsmall, Thumb, with an infill of 30%, 3 shells, best with no support, no raft.

Print  index3, majeure3, ringfinger3, auriculaire3, with an infill of 30%, 2 shell, best with no support, no raft.
Print robpart2, robpart3, robpart4, robpart5 with an infill of 30%, 3 shell, best with raft, no support.
Print coverfinger with an infill of 30%, 3 shells, with support. To get the best printing result on the covers is to print them standing up, instead laying them flat.

The wrist parts are good printed with an infill of 30%, 3 shells, with no raft, no support. The Gears of the wrist should be printed with the best quality your printer can give you.

Big bolts are now printable. (Strong enough for tests and even more!)
You can replace the 16x3mm for the fingers with pins/pegs of filament instead of bolts, it’s cheap, easy, and strong enough.
It was a suggestion of FreddyA.

  • 1x8mmx8cm bolt  to attach wristlarge to wristsmall.
  • 1x8mmx4cm bolt to attach wriarge to thumbbottom.
  • 1x8mmx6cm bolt  for to attach wriarge to robpart1.
  • 16x3mmx2cm bolts  for all fingers hinges(I have recut each bolt to adapt to finger width)

These instructions are for the right hand. The left hand is similar but parts are mirrored.


DSC06390 Remove the antiwarp supports and trim with a knife, RobPart2, 3, 4 and 5

DSC06389Assemble together Robpart2 and Robpart5


DSC06391Help yourself with pliers to hold the parts together while you glue them with Acetone or Zap-A-Gap (ABS) or Epoxy 2 components or Zap-A-Gap(PLA)DSC06392Avoid using glue on the outside other wise it won’t look clean. Control that your parts are correctly aligned.

DSC06401Do the same with Robpart3 and 4.

DSC06393Redrill the holes on the side of Robpart2 with a 6mm drill. These are for to fix an extra servo to get a double actuated thumb. See:


DSC06394Use the little rubber silentblocs that came with your servos.

DSC06395In Robpart5, insert two bolts for 4mm screws in the printed cavities. Mine were not fitting, due to overhang, I heated them with a flam to make them fit.

DSC06397Trim/Fill the holes of the simple servo bed if there is overhang.

DSC06399Set in Robpart5 the simple servo bed, make sure it is completely seated on the bottom.

DSC06400Glue or screw the simple servo bed with 2 wood screws.



InMoovTensioner2This is a new addon(Tensioner.stl) I designed in january 2015. The purpose is to keep constant tension on the tendons using a extension spring 0.5mm diameter, 1cm length(13/64″x13/16″). Use a small piece of tube to drive the tendon, this will avoid the erosion of the braided fishing line. I used SuperGlue to keep the piece of tube settled in the ring of the spring.

So screw that addon on the simple servo bed and follow the next steps.

DSC06416At this point we can mount the servos on simple servo bed.

DSC06417As you can see on my picture, I’m not using the HK15298 but some MG946r instead, for this tuto. The reason is that Hobbyking Europe is out of stock and I couldn’t wait.

DSC06419When you download my parts on Thingiverse, you can either choose to print RobRing or ServoPulley. It all depends, if you received with your servos the black actuator shown in my hand.


DSC06423I personnaly use the ServoPulley. Redrill the holes with a 2mm drill.

DSC06421Use the screws that came with your servos to mount the black actuator.

DSC06422Cut the screws in the back with cutters.

Now use this script with your Arduino to set all your servos at 90 degrees. Set screw all the ServoPulleys in place as shown. Once the ServoPulleys are fixed, using the script again, set all the servos to Zero degrees. This will be for later when we attach the fishing lines. Avoid moving them during the next steps, otherwise you will need to reset them to Zero later.DSC06441

DSC06446Mount on Simple servo Bed, RobCableFront and RobCableBack.



DSC06424On RotaWrist1 remove the support.

DSC06425Redrill if necessary the holes for the lining.

DSC06426Make sure it fits on the Robparts.

DSC06428You can use a fill to adapt it perfectly.

DSC06427This is the correct way to mount it, see, the black holes are aligned with the squary part of RotaWrist1.  I have seen many assembly where the wrist was mounted the opposite way.

DSC06434Back to RotaWrist1. Glue it to Robpart2. When doing this it is good to also set the Robpart3/4 cover to make sure the RotaWrist1 is correctly placed.

DSC06435Insert your MG996 servo. Here we want a servo with 180 degree rotation. The HK15298 only rotates of 90 degrees.DSC06437Set the wood screws to fix your servo in place.

DSC06436Redrill with a 2.5mm drill RotaWrist2.

DSC06438I like to spray paint in black RotaWrist2 because the grease used inside makes the part become yellow after some time.

DSC06439This picture is to show where to set the extra servo if you use the thumb with double actuation.

DSC06440Redrill with 8mm RotaWrist3.



With your downloads there is two different small gears, use the one you think is most appropriate for your needs. Here is a previous tuto you might want to read.


DSC06443Use Epoxy two component glus to fix CableHolderWrist on the servo.DSC06444DSC04917 Use grease between the components. Using a white silicone grease will avoid showing a yellowish effect on the outside of your print. White_silicone_grease

Because I used yellow grease, I spray paint in black mat that part.


DSC06445Mount RotaWrist3 to the big Gear.




See also this tutorial to create silicone finger tips.

DSC06429Time to redrill the finger hinges. I keep the fingers in seperate bags to avoid mixing them.

DSC06430The outside hinge is redrilled with a 3mm drill.

DSC06431The inside hinge is redrilled with a 3.2 or 3.5mm drill.

DSC06432 DSC06433Fill the hinges to really adapt them the best.

DSC06469Glue the parts together with Acetone(ABS)

DSC06471Use your 3mm filament to make pegs.

DSC06472Cut with a knife the filament. If you don’t have 3mm filament you will need to do this with bolts of 3mm. I recommand the filament, it’s perfect, cheap and fast.

DSC06403Redrill all holes of the covers with a 3mm drill.



Redrill Wristmall and Wristlarge with a 2.5mm drill for to adapt the covers. If you don’t have exactly these size of screws, it doesn’t really matter. Use whatever you find at you hardware shop. Remember that the covers have a purpose and are necessary to have a correctly functional hand.  They restrain Wristmall from going to the back of the hand. If you don’t understand read this.



Redrill the hinges of Wristmall and Wristlarge with a 3.2 or 3.5mm drillDSC06411


DSC06412Redrill the big hinges with a 8mm drill.

DSC06413Ensure Bolts or printed Bolts run smoothly with no resistance but without wobbling.

DSC06402Cut 10 pieces of 75cm long of your braided fish line 200LB. Don’t use standard nylon because it stretchs.

At this point it is good to decide if you want to have sensors on the tip of the fingers or not. You must have seen three holes above each other for the linings in WristLarge. The third hole (middle one) is for running electrical cables to wire up the sensors.

DSC06407Insert the braided fish lines in the holes of Wristlarge. In this picture,  I don’t have electrical wires for sensor fingers because it was a previous version.

DSC06408I have designed a little hole which can help you to guide the linings.




DSC06474The electrical cables are running in the middle holes.

DSC06475Run the linings into Wristmall. Make sure not to twist them on the way through. If you mix them up, the servos won’t be able actuate the fingers correctly.


DSC06448Repeat the wiring with the thumb. If you are using electrical cables don’t use the “Entretoise”, as shown above, otherwise you won’t be able to run the electric cables.DSC06449

DSC06451Line up the hand to the wrist.




DSC06459Now wire up the Wrist to the forarm, each lining has a slot.

DSC06478If you have electrical cable it will be like this. Using color ribbon is a good idea because you know what wire correspond to which finger and connection.

DSC06454Add the “Entretoise” between the cablesDSC06455

DSC06457Use the “C” ring to end stop the bolt from coming out.

DSC06473This is the back of the hand, you can see how I have set the cables. I’m not sure it is the best solution but, like you, I’m learning and discovering.

DSC06483Here is how the lining should look up to the wrist.

DSC06482 When you assemble the wrist make sure the servo is set at 90 degree and that the two screws on the picture are aligned. Until now I never did recomandation about this, and unfortunatly many of the gestures I created can’t be reproduced by other InMoov because the wrist isn’t set the same than mine.

DSC06484Glue RobCap to  ElbowShaftGear.

DSC06485Aligning the squarry hole is the way to do it. If are using ABS and acetone, I can tell you there is no need to add screws if both of your surfaces are correctly flat.

DSC06487Now glue this assembly to RobPart5, make sure it is correctly aligned in the slots.


 Step 4DSC06489

When assembling the fingers there is marks that can help you to see in which order it has to be done. I won’t go in those details here but you can find more instructions in the finger starter tutorial. The finger starter has numbers for an easy comprehension, the normal fingers don’t have those numbers, but the parts are the same.


DSC06491 Now that you have all your  fingers  assembled, for those that want to add sensors here is how we are going to proceed.

DSC06481Finger sensor prints. Download them.

DSC06493Glue the tip of the finger to the hinge tip. Make sure to align the nail lines, it will look better :)

DSC06494Sorry for the blurry picture.

DSC06517Redrill the holes of the hinge with a 2mm drill.

DSC06518Redrill the hole of the tip hinge with the same bit.

DSC06495Add the hinge to the tip hinge and redrill them together to make sure they fit nicely.

DSC06519I used non flat metal nails instead of filament here, because the size of these parts are small. I just cut them at the size needed.

DSC06507Cut some strips of copper of about 3 to 4mm large. DSC06509Recut those strips in tiny triangles. These are going to be contactors for the antistatic foam.

DSC06510Cut with scissors some nice little rounds in your 4/5mm thick antistatic foam. This foam is sold with electronic components to avoid electric shocks. Most of the time we just throw it away when we buy components, you can also buy it in many electonic shops. It contains carbon which is an electrical conductor. When the foam is pressed against the 2 contactors, the carbon lets the current flow between them. More the foam is pressed and more current goes through. This is the info we will send to the Arduino Analog pins.

Glue with 2 components epoxy the foam to tip hinge part as shown on the picture.

DSC06512Try to assemble the two parts and see if it move. The hinge design is supposed to stop the hinge from opening further than the 5mm thickness of the foam.


DSC06496Time to mount the finger to Wristlarge. Notice the last hinge of the finger, this will receive the finger tip sensor assembly. All the holes in those finger parts should be cleared and large enough to have the 2 tension cables and the 2 electrical cables.

DSC06498Run the tension cables and the electrical cables. One of each on the up side and one of each on the down side. Make sure to avoid any twisting of cables, this would cause to get unfunctional fingers.

DSC06497The color ribbon again is handy in this task.

DSC06499Fold the fingers to smooth up a bit the cables in their path.

DSC06500Make knots with the tension cables.

DSC06501A bunch of them is necessary because we don’t want them to go through the holes when the servos are pulling hard on them.

DSC06502What I do is even add glue to ensure any bad surprise. I also glue the electrical cables at the same time. When doing so, it is good to have the finger folded otherwise the electrical cables could later restrain the full motion of the finger.

DSC06516Cut the remains of the tension cables. Now glue the hinge of the finger tip to the last hinge of the finger. Notice the position, don’t glue them upside down. Remember I mentionned the tip hinge was design to avoid opening further than the thickness of the foam.

DSC06514Cut each electrical wire at a 4/5mm length. Scary moment because too short would mean to redo all the wiring. :)

DSC06522Cut and clear up the plastic on the electrical cable and solder the copper triangles.

DSC06523Once done, fold the cable and lay the copper triangles in a flat position.

DSC06528Add 2 component glue under.

DSC06529To maintain them flat during the time the glue gets hard, I used some tape, Look out for the tape you use as it maybe glued as well to the finger tips.

DSC06521This is the result.

DSC06480Now you can add the finger tip with the nail and you should have a sensor ready to be pressed and give feedback.

DSC06526Glue the finger covers on the fingers.

DSC06525These are used to avoid the finger going to much in a backward position and they also add a llok to the design :)

DSC06524Do the same with the Thumb cover and Wristsmall. Actually I glue them first and then I add the screw, that keeps them well in place. Recut with a knife the two corners on the thumb hinge. If you don’t the hinge will be forcing against the hand cover.

DSC06527Add the hand cover and check if the fingers are moving nicely.

You can add Sugru on the finger tips or see this tuto, and ping pong surface in the palm of the hand for a better gripping.  I found also some kitchen heat protectors for 1,50 euros with silicone surface. It is even better.



Hey it looks like you are set to tension the fishing braided lines!!

In the next tuto there is steps I’m going through again and they might also look a bit different. The reason is because of updates. Actually the next tuto was done before the tuto you just followed above.

You never used Arduino before, use this introduction.pdf or find more info on the Finger Starter tutorial

Go to this tutorial for tensioning the Linings.

Go to this tutorial to create your silicone finger tips.

Using MyRobotLab with a minimal script

Comments 87

  1. Hi, Gael
    Awesome work! I’m going to print the parts and make one. But where should the Arduino Uno be settled in Inmoov’s hand? I didn’t find it in this tuto. Maybe u could give me some directions? Thank u.
    BTW, for 3D print, are these 4 files enough for this tuto?

    Thanks again! Hope I can finish it.

    • Profile photo of Gael Langevin

      Yes this 4 files are enough. You can fit an Arduino Uno inside the forearm, there is space enough although it isn’t designed to do that. I had difficulties to get the USB cable inserted. If you want easy set up, go for Arduino Nano.

  2. Profile photo of Tom

    Hi, Gael
    Nice work and I really want to make one. But I find out that it is really expensive to print these things (I mean hand) totally, since I have no 3d printer myself. I ask a company to print this, but need 18000 hkd, which is about 2400 us dollar. So I want to ask whether it needs such money? How much may this cost by yourself? It is too big number for me , since I’m steel student… I thought this may cost me about 200 us dollar. Or do you have any suggestion? Thank u very much!! Really love your work!

  3. Profile photo of Tom

    Thanks! But I have no 3d printer right now, and it is really expensive to print by company outside, about 1000 euros or even more. So will you sell these parts? Maybe estimate the price first and then I could buy these 3d print components from u. I don’t know whether this is possible? Anyway, thanks for reply and I really appreciate your work.

    • Profile photo of Gael Langevin

      The process of 3D printing isn’t very expensive in material cost but it is excessively time consuming. This will improve rapidly, I’m sure. It is the reason why printing companies have high rated prices. I don’t print parts for builders because I would just spend my time doing that, and I rather keep working on the project instead. What I suggest, you can either find a somebody with a 3D printer in your area and do somekind of exchange of help or you buy yourself a second hand small 3D printer for about 300 euros, which will be usable for your future various other projects.

  4. Profile photo of

    Firstly I wanted to thank you for this extraordinary project open source robot to make in 3d printing … Many Thanks!!!
      I start printing my first pieces of hand inmoov and it went well …

    However I have three small questions:

    First: About Electrical wire : what type of wire I should buy and how long of wire to put all the robot (wire tape or twisted ribbon)? (Maybe the electric wire supplied with the servos enough?)

    Second: Do you know if it would be possible to connect the robot inmoov to database cloud RoboEarth (the worlwide web for robot) to connect all inmoov robots all owners to learn from them even faster?

    Third: Is there a forum Inmoov in French language?

  5. Profile photo of Konstantin Akhmadeev

    Hello, Gael. Thank you for detailed explanation! I’m very impressed by your project.
    I just would like to ask a short question: have you tried to drive the hand, feeding the arduino from computer’s USB hub? Do you know approximate maximum value of current which passes?
    I feel like I’m asking a stupid question. But every time I write to servo some angle, the voltage falls and board reboots. I though USB hub is able to provide enough current, but it seems to not. Am I write or I should re-check the way I’m connecting the servo? It’s MG946 and it seems to have the same contacts as HK…

    Merci beaucoup, Gael!

  6. Profile photo of Daniel

    I have created the Hand and Forearm of this Inmoov collection. I have a DC power supply connected to the Arduino to provide power to all servos (set on 6v), and the voltage from the Arduino itself powers the flex sensors. All works well, other than if multiple flex sensors are flexed. This causes multiple servos to move (e.g. 3 Servos from 3 Flexed Sensors); when this happens, the system stops working and bugs out. I think it is due to the drawn current from the multiple servos acting at the same time. Would you know anything on this to prevent it? I am very stuck.

    Any help would be appreciated, thank you.

  7. Profile photo of Bruno.Ash

    Hello Gael,
    “… using a extension spring 0.5mm diameter, 1cm length(13/64″x13/16″)”
    Do you confirm this ? 0,5 mm ?
    And second question : Do you have a picture of the connection between the spring and the tendon ? I don’t understand this part…
    Thanks for answer ;-)

  8. Profile photo of Leo Garstman

    Great Job !
    I’m printing now and have almoust the arm and hand.
    But i have problems to print the cover of the hand.
    I printed like te stl file position.
    I get spaces in the top survase .
    I print it with 30% infill no support.
    Can you tell me what i do wrong?

    Sorry for my bad english.
    Leo Garstman

  9. Profile photo of deeta

    Hello Gael,
    I have to say this is an amazing design and I am currently printing the right hand for my EPQ project at college.

    I was just wondering how you stop the print from warping because when I was printing the palm-part yesterday and the edges started to warp a quarter of the way into the print so i had to stop it .

    • Profile photo of Gael Langevin

      Hello, I’m glad you enjoy the project.
      Warping is a very common issue related to many variables. Heat, air, material, printing surface…
      I would suggest heading to the InMoov forum, make a search with keyword “warp”, “warping”. If you don’t find your answers, post your question there, many people enjoy explaining stuff about 3D printing issues.

  10. Profile photo of Scott Hodges

    Hi Gael,

    I’m assembling my first hand/arm arm and have a couple of questions. First, There isn’t really a location for the Arduino in the arm, correct? I printed the little Arduino tray but I don’t see anything indicating it should go inside anywhere or how to route the servo wires. Should they just be run through the larger hole in Robcap and then directly into the Arduino?

    Next question. I plan on building the bicep and shoulder, but the entire planet is out of HS805BB servos at the moment. The TS-80 looks like a decent equivalent. Have you heard of any issues with it?

    Next question. Have you tried and do you approve of the little dual-track servo pulley creations available on Thingiverse? It seems like a simple solution to the back-side slack me, but I thought I’d ask before hooking them up.

    Last question. The Nervo board system looks awesome! Are you running all of the power to run the servos through the ribbon cables or is there a separate power lead? I’ve used servo-to-cat-5 adapters in the past but have always had to run a separate lead for power. Just trying to figure out how it works before I invest in a set.

    Keep up the terrific work!


    Scott Hodges

    • Profile photo of Gael Langevin

      Hello Scott,
      -Indeed there is no specific space for the Arduino Uno tray. Actually the Uno trays remains in the downloads mostly for people who want to only built tha hand and forarm.
      If you plan to build the robot, I suggest using 2 Arduino Mega. There is trays available for the Mega as well on my site(??) I need to check if I did add them in the recent website…

      -I haven’t got any bad feedback about the TS-80, but nothing that ensures the fact it fits correctly. I think most people have been able to get HS805BB until now.
      Before I started InMoov, the HS805BB was available everywhere and for a very reasonable price. With the increqse of purchase of HS805BB, the prices went up and they became rare.
      -I didn’t try the dual channel servo pulley, but I’m pretty sure it is a good option. Test it on one and give us feedback, I would be interested to know.
      -The Nervo Board powers the servos through the 14 cable ribbon. 3 cables are dedicated for Vc+ and 3 are dedicated Gnd, the rest are for the PWM pins.

      Remember you will need a heavy Amp power supply if you don’t choose to use the 6V12Ah battery. For the whole robot you will need around at least 20 Amps. The more is better.

      • Profile photo of Scott Hodges

        Hi Gael,

        Thank you for the prompt and courteous response. I’ve got a couple of questions at the end.

        I do have a couple of Arduino Megas but they are deep inside some Halloween animatronics at the moment. I probably have 6 or 7 spare Unos, so I’m using them for now. It looks like there may be room for an Uno or nano in the bicep structure, but I’ll need to finish printing and assembling that to figure it out.

        I do have two item that I think you might want to recommend to people who plan to just build an arms. The first is a sensor shield for the Arduino. It has pin-outs for servos and even stepper motors. It eliminates the need for a proto-board and wiring, and allows you to run a separate PS right into the board. I think I paid $4.00 each for a couple of them on eBay. Just look up “Arduino sensor shield” there. Drop it onto an Uno and the pin-out puzzle is solved.

        The other thing I recommend is an S-200-5 single bus power supply to run the servos. This thing looks just like most 3d printer power supplies and some include a fan. I used to use PC power supplies to run my animatronics but they have limitations on the amperage on a single bus and I would constantly blow them out. 5v might be a little low, but there is a pot that will let you dial it up a little. The one I have is rated at 5v and 40 amps.

        Oh, and I am trying the dual track pulleys. There is a very slight clearance issue with the center reversed servo, but I’ll work that out.

        OK, lots of talk, finally a question. I loaded the little centering sketch but have not yet run it. (I should have run it on the wrist servo BEFORE I installed it…. Anyway, here is the question. Which rotation is close fingers and which rotation is open? Clockwise? I see the numbers in the sketch but am having a brain cramp. “All to rest”, (0 degrees) would be open hand? All to max would be closed hand and 180 degrees clockwise, right? And all to 90 would be a cupped hand? I’m using these beta-pulleys, so I’ll have to figure out limits myself, but does it generally require all 180 degrees to get from open to close on all fingers? A little clarity there would probably save an hour of messing around.

        I’ll post some pictures over on Google when I get the pulleys working correctly.

        Thanks a bunch.


        • Profile photo of Gael Langevin

          Hello Hodge,
          You want to look over for the Nervo Board which is a Arduino shield dedicated to InMoov if you want to move the whole robot.
          Of course any shield can do the job, but it solves a lot of pain figuring the pinout. The shield you mention is a very good price for someone who wants onty to actuate a hand!.

          I recommend powering the servos to 6V instead of 5V, it makes a big speed difference when InMoov is moving around his arms.
          There is a power supply I have been using for almost two years on InMoov that does pretty well the job for now. But it is almost not enough anymore. It has a range between 5.5V to 15V at 20Amps. It is discribed in the BOM.
          Batteries are actually the best specially when InMoov is moving around. The 6V12Ah are very cheap and do a good job for at least 35 to 45 minutes depending on what you do.

          All to rest, (0 degrees), is indeed a open hand.
          And all to 90 is a cupped hand.
          All to max is closed hand at 180. This varies a lot depending on the servo you use, the pulley you use, and how you did the tension.

          Adjust each servo and map them in MyRobotLab when you make your own script.

  11. Profile photo of Mike D

    Gael, Thank you for all the great design and information.
    Question- When the wrist turns the fingers do not operate as well (do not fully open or close) as they do when the wrist is not turned. How can I compensate for the wrist turning in tightening the tendons?

  12. Profile photo of Dominique Bagnato

    Hello Gael,
    This is amazing project !
    It feels that I am creating somebody pieces by pieces.
    I have a questions concerning the setup of the poulies in to the servos to control the finger and wrist.
    Shall i run this program with 90 instead of 0 then place the poulies then put back 0 ?
    void alltorest() {
    servorotate.write(90); //Never less then (20 degree)
    servoshoulder.write(30); //Never less then (30 degree)
    servoomoplat.write(10); //Never less then (10 degree)
    I am confused in the step:
    Now use this script with your Arduino to set all your servos at 90 degrees. Set screw all the ServoPulleys in place as shown. Once the ServoPulleys are fixed, using the script again, set all the servos to Zero degrees. This will be for later when we attach the fishing lines. Avoid moving them during the next steps, otherwise you will need to reset them to Zero later.

    Thank you again !

    • Profile photo of Gael Langevin

      Hello Dominique,
      Set your servos to zero to have the fingers spread flat. When the pulley rotates to 90 it then close the hand or finger. MyRobotLab has a mapping control which allows you to define and adjust precisely the movement in order to avoid over pulling on the tendons.

  13. Profile photo of Patuko!

    Hi there!

    My HK15298B’s had just arrived!

    I know they only spin 90º…but when I gave order servo.write(25); and servo.write(155); it does spin from one top to another.

    I would love to know if is normal for the servo to not spin from 0ºto20º and from 160º to 180º.

    Also seems motor controller does some kind of mapping of angles as over those 120º it really makes a 90º spin.

    Hope is everything ok.

    Thanks again Gael!

    • Profile photo of Gael Langevin

      Hello Pablo,
      The mapping is done by MyRobotlab. If you only use the Arduino sketch, there is no mapping but it does look like a mapping effect.
      Therefore you can write servo.write(0); and servo.write(180) and it will do the full 90 degree movement.

  14. Profile photo of Klaus Wagner


    About the tensioner: Once i mount RobCableFront to the servo bed there is not enough space between RobCableFront and the part of robpart2 (v3) where the servo for the thumb with double actuation is fitted. When the 2 walls touch about 2-3 mm are still needed. Maybe I missed a corresponding new part or I’m wrong with how I think the tensioner should be mounted. Of course I could just shrink it a bit.

  15. Profile photo of Prasad

    I have couple of questions regarding the hand build.
    1. I am using a MG996R for the wrist rotation and I was wondering if you are referring in to center position(90) of 0-180 servo as 90deg or the 180 position as 90deg in this tutorial. I asking because due the gear ratio used we get only a total of 90degress of rotation. If I set center position as 90, I get 45deg movement in either direction compared to 90deg to & fro motion when setting it to 180 position.
    2. I am having trouble with finger tension along with wrist rotation. If I turn the wrist the line tension is high and affects finger movement and the line may snap. But if I try to keep the line loose to enable the wrist to rotate, the finger movement is not correct due to slack in the line. I am also using springs like its mentioned in the tutorial but problem persists. Is there any way to achieve both – good finger tension and wrist rotation?


    • Profile photo of Gael Langevin

      Hello, I am indeed refering to center position(90) of 0-180 servo as 90deg. As you came to realize by yourself, adding more rotation to the wrist would increase the issue of non tensionned and over tensionned fingers with full wrist rotation.
      The spring tensioner solves that issue pretty well in my case. When setting tension for the tendons, the springs should stay at rest (not stretched out) other wise they won’t have the desired effect.
      The springs are there to give freedom to the length of the tendons when the wrist rotates.
      I hope its clear enough…

  16. Profile photo of Yeong Jun Yoon

    Hi Gael. Nice to meet you.

    I am Paul in Korean

    I wonder why scale of Robpart3,4 and Robpart2,5 are diffrent.

    when I use a 3D printer, I don’t change the scale of robparts but it is printed differently for size.

    I want to send you picture of my printed part. So could you tell me your e-mail address ?

    if you can solve my problem, just post comment.

    Thank you.

  17. Profile photo of Daniel Rütimann

    Hi Gael

    Is there a detailed description of how to mount the tensioner? I have printed TensionerRightV1.stl and would like to screw it to the servo bed but just can’t see from the picture where exactly I have to put it. Do I have to screw it through the small hole on the servo bed above the opening that looks like a small house?


  18. Profile photo of Doris

    Hi Gael!
    I’m a student at University of California, San Diego and we are working with faculty adviser to build a functional prosthesis for a boy and we want to build a human hand first to do our testing. My question about the InMoov hand is that, what was the goal and philosophy behind your design? For example, did you look to simulate the movement and joints of a human hand or was there a specific functional purpose?
    Thank you!


    • Profile photo of Gael Langevin

      Hi Doris,
      Initialy I designed the prosthetic hand for a commercial campaign in 2011. Because the job didn’t happen, I designed it to look the best way but still behing mechanicaly simple looking and mainly easy to 3D print for everyone. I wanted the joints to be rather accurate situated compared to a human hand. Before releasing the files on the Internet in January 2012, I modified them to add motors and mainly to have independant finger motion using an innovative technic of double actuation through the servo rotation. The philosophy was to create a simple product, easy to 3D print without support, for anyone that was in need to have prosthetic hand.

  19. Profile photo of pedro

    Can someone help me understand at which position should the right wrist servo should be when is attached to the forearm? In the middle of movement? So it moves for both sides or is it already at max ? And only moves towards inside? Thanks in advance :)

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