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May 12

Wrong piece shipped?


The piece I have that connects the two shoulders (https://youtu.be/B8N2KAf8p28?t=34) have two holes on either side of the wood, not two and three like in the part photo in the assembly instructions (see below). That makes it shorter and not long enough to reach. If I got the wrong size shipped, how do I get right size?

two holes on either side




two holes on one side, three on the other


May 12Edited: Sep 12

No, it’s not a wrong piece. The 3-hole shoulder connector in picture was an older version. I made it symmetric to reduce confusion. The way you put up the shoulder group is wrong. The side with servo’s shaft should face up.

But the pieces that hold the servos at the end don't match your video. The wood with the battery on it is too narrow for the piece it gets attached to. See photos.

the bottom holes on this one are big enough for the piece that holds the battery




The servos should be pushed into the dents on y1 to lock all the pieces.

BTW, you are inserting the servos in the opposite direction. The shafts should be on the lower side.

It’s a puzzle. Observe the animation to find where the pink piece (the special shoulder piece) should go.

The animation is different from the video of you putting it together. Are there instructors for the pieces that match the set I was sent? The videos I've seen don't include where the wires should go.

The difference between the two videos are just the pink shoulder piece and the number of holes on y1. Neither of them would affect assembling. The video with my instruction shows where the wires go.

Jun 4

Im having similar issues not sure how to make it fit just right. Can't push the servos all the way in and the y pieces don't feel locked in. Here is a picture for reference


Please help me I'm stuck!



Use the servos to lock one side(front/back) then push the Y pieces towards the other side. Lock left/right side then lock the other side. Pay attention to the wires of shoulder servos. Don’t let them go into the dents on Y.

Jun 4

Do you have an example photo you could post of how the connection should look with the symmetric shoulder piece?

@Rongzhong Li I have the same problem, the pieces do not fit and both the animation and the tutorial use the old one.Please, help

@Donato Rimenti Hi, the difference between the old and new y1 pieces are the number/location of screw holes. The key dimensions, i.e. the distance between the dents on y1 are the same.


Could you take a picture of your current building progress? The structure is designed a little tight and will need some push to lock.


Sorry for my late response. I'm on a trip and the Internet is bad.

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Y1 should enter the flat slot on the shoulder piece, not the tilted slot.

My bad, that was the problem, thanks! And thank you for your awesome work!


Is there any way I could buy another ring piece to fix the one that broke?

Could you take a picture of the broken pieces? I usually try to fix something before buying replacement. I may have some solutions.

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