Introduction: Hummingbird

Epilog Challenge 9

This is an entry in the
Epilog Challenge 9

Hummingbird is a hummingbird themed automata I designed for my wife, who smiles from ear to ear while feeding and watching the gathering hummingbirds at our home. Hopefully it will bring smiles to many more faces.

Hummingbird consists of 97 3D printed parts (38 unique parts) and, as I discovered, requires plenty of time and patience to print, assemble and tune. Along with the 3D printed parts, Hummingbird also requires a "uxcell 16mm DC 6V 60RPM Speed Torque Gear Box Electric Motor for Robot" (available from a variety of sources), a 6vdc power source, and four 1/4" or thicker stick on felt or rubber pads (for the base).

The file "" contains all cad images and photographs included in this Instructable.

As usual, I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make mistakes in plenty.

Designed using Autodesk Fusion 360, sliced using Cura 3.2.1 and printed in PLA on both an Ultimaker 2+ Extended and an Ultimaker 3 Extended.

Step 1: Print the Parts

I've included file "Hummingbird" which contains the parts list and print parameters I used to print Hummingbird.

I've also included the file "" which includes all the parts in stl format.

Hummingbird is a high precision print and build. Prior to starting assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on the colors you chose and your printer settings, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate to make absolutely sure that all build plate "ooze" is removed and that all edges are smooth. I used small jewelers files and plenty of patience to perform this step.

Hummingbird uses threaded assembly, so a 6mm by 1 tap and die may be needed to clean the threads.

And finally, I used petroleum jelly judisiously on the gear train and between the rotating contact surfaces.

Step 2: Assemble the Base

Press "Gear Motor.stl" onto the motor, then press the assembly into "Base.stl".

Assemble "Gear Compound (60, 20 Teeth).stl", "Axle Gear Compound 60, 20.stl" and "Spacer Axle Gear Compound.stl" as shown, then lace the assembly into the base and secure with two "Bolt 6mm, 8mm head, 4mm shoulder.stl" as shown.

Assemble one "Wheel Base.stl, "Axle Wheel Base.stl", "Bolt Wheel Base.stl" and "Bushing Axle Gear Base Long.stl" as shown. Position "Gear Wheel Base (60 Teeth).stl" in the base as shown, then slide the assembly through the Base, Gear Wheel Base (60 Teeth) and the Base as shown. Insert "Bushing Axle Gear Base Short.stl" onto the free end of the Axle Wheel Base, followed by the remaining "Wheel Base", then secure with the remaining Bolt Wheel Base.stl.

Finally, apply four 1/4" or thicker stick on pads to the bottom of the base, one in each corner.

Step 3: Assemble the Transmission

The first image shows (left to right) "Bolt 6mm, 12mm head, 23 mm shoulder.stl", "Arm Body Front.stl", "Arm Base Right.stl", "Spacer 8.2mm.stl", "Spur Gear (30 teeth).stl", "Arm Body Front.stl", "Arm Base Left.stl" and "Bolt 6mm, 12mm head, 23 mm shoulder.stl".

Position "Arm Body Front.stl" and "Arm Base Right.stl" as shown, then slide "Bolt 6mm, 12mm head, 23mm shoulder.stl" and secure loosely in place with "Spacer 8.2mm.stl" as shown.

Position "Spur Gear (30 teeth).stl" onto the spacer.

Complete the assembly with the remaining components as shown.

Step 4: Assemble the Body

Securely attach nine "Spacer 8.2mm.stl" to "Body Right.stl" using nine "Bolt 6mm, 8mm head, 4mm shoulder.stl".

Assemble "Bolt Wheel Body.stl", "Wheel Body", "Bushing Wheel Body.stl" and "Axle Wheel Body.stl" then position on "Body Right.stl" as shown.

Place three "Spur Gear (30 teeth).stl" onto the assembly as shown, then secure "Body Left.stl" to the assembly using nine "Bolt 6mm, 8mm head, 4mm shoulder.stl".

Finally, attach the remaining "Bolt Wheel Body.stl", "Wheel Body" and "Bushing Wheel Body.stl" parts to the assembly as shown.

When complete, the gears must rotate easily.

Step 5: Assemble the Wings

Position "Pivot Wing.stl" onto "Pivot Shoulder.stl" and secure in place with "Bolt Pivot Wing.stl" as shown. The shoulder pivot and bolt must rotate easily in the wing pivot.

Position "Wing Right.stl" onto "Pivot Wing.stl" as shown, then secure firmly in place with "Bolt 6mm, 10mm head, 4mm shoulder.stl" as shown.

Snap the small end of "Rod Connecting 6.3mm Hole.stl" onto the ball on "Pivot Wing.stl" as shown.

Position the assembly on "Body Right.stl" as shown, then secure in place with "Bolt Pivot Shoulder.stl" as shown.

Snap the large end of "Rod Connecting 6.3mm Hole.stl" onto the ball of the right body wheel as shown.

Repeat the assembly process for the left wing, then attach the left wing assembly to "Body Left.stl" as was the right wing.

Step 6: Attach the Transmission to the Base

Slide "Spacer 8.2mm.stl" into "Spur Gear (30 teeth).stl", then position the assembly into the base as shown.

Position the transmission assembly on the base, then secure in place with two "Bolt 6mm, 12mm head, 8mm shoulder.stl" as shown.

Position the right and left base arms on the base wheels as shown, then secure in place with two "Bolt 6mm, 10mm head, 4mm shoulder.stl" as shown.

To test the assembly, remove the motor and make sure the gears turn and the transmission pivots freely. Reinstall the motor, and attach a 6vdc power source to the motor such that the right "Wheel Base.stl" rotates clockwise as viewed from the arm side of the wheel.

Step 7: Attach the Body to the Transmission

Attach the two "Arm Body Rear.stl" to the base assembly using two "Bolt 6mm, 12mm head, 8mm shoulder.stl" as shown.

Slide one "Spacer 8.2mm.stl" into "Tail.stl" as shown the position the assembly into the body assembly as shown.

Slide one "Spacer 8.2mm.stl" into one "Spur Gear (30 teeth).stl" as shown, the position the assembly into the body as shown.

Lower the body onto the front and rear body arms an secure loosely in place using four "Bolt 6mm, 12mm head, 8mm shoulder.stl" as shown.

Step 8: Attach the Stem and Flower to the Base

Press "Flower.stl" onto "Stem.stl" as shown, the press the assembly into the base assembly as shown.

Hope you enjoy Hummingbird!



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    10 Questions


    Spacer Axle Gear Compound.stl it's the same as Axle Gear Compound 60, 20.stl

    I like your design, it's a great project and I'm currently printing it with my home built Mendelmax 1.5.

    I have one question, I can't print the flower, every attempt results in the flower tossed off the print bed. I use a heated (70C) print bed covered with kapton. I tried inserting a raft layer but without much success still tossed after just a few layers printed. Can you post the design file or can you add a pedestal that we can snap off after printing, so as to have a solid area on the print bed? Or can you share the design file or any other trick to help me print it?

    Thanks for all that work in this project, it's very impressive.

    Thanks in advance, Rolland..

    I loved your design, however I don't have (and I don't want to buy) the exact type of DC motor you used. So I was wondering if you are soo brother to share the original CAD files of the base in order to make easier to adapt to a different type of DC motor. Can you? Thanks in advance.

    It is truely amazing!

    Do you know any website/book/something which I can start learn this kind of mechanics from?

    Hi EshRobotics,

    First, well, I'm old and have seen a lot of things, taken a lot of pictures and made a lot of notes over the years.

    However, I recommend websites that show gears and automata. For example, if you use Autodesk Fusion 360, then search for "Fusion 360 gears" and watch the videos. Also search for "mechanisms", "automata mechanisms", "wooden mechanisms" or the like and you'll find a lot of images, videos and "how to's".

    Best of luck!


    Hi. I am attempting to print this project. I printed some starter parts with no problem (100% infill) , but when it came to the base and the 20% infill, it turned out too fragile, like a semi-stiff foam. It took a long time for the base to print, and will be even longer if the infill is increased to something like 60% but I think thats what it will take. Also even though I had support checked in Cura, it didn't print with support which is very strange but it still printed. Just wanted your experience and thoughts on this. Thanks.


    I’m sincerely sorry for the difficulties you’ve experienced with this model.

    Could you please provide the version number of the Cura slicer you are using and your printer model?

    I used Cura 3.2.1 and printed on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.

    Again, I am trying sorry for the difficulties you’re experiencing.



    Fantastic work! I am curious, did you do the motion/animation in fusion as well? Seems like it would be a heck of a task to get all of those joints working properly, but I can't imagine how you'd design it without doing that.

    thank you very much, I’m glad you liked it!

    Yes, I did animate the gears and joints, mostly to check my math to make sure the body didn’t exceed the calculated limits and run into he base gears. However, I never was able to figure out how to model the wing pivot, so I built a small test version.

    Thanks again!



    Great Instructable and stunning work!! Well done!!

    Thank you very much!


    That is one of the coolest projects I've seen on instructables. The movements are so graceful and accurate. Amazing project!

    Thank you so very much, I’m glad you liked it!


    Really impressive. Would be good present. I voted for the challenge!

    Thank you very much, and thanks for your vote!

    This project is AMAZING!


    Thank you, and thanks for your vote!


    As always you've made an amazing project! The video is really impressive, the movements of the hummingbird look so real!

    Thank you very much, I'm still trying to amaze and bring smiles.

    Thanks again,