I ran into exactly same problem as Arduino Braccio Robot Arm Trouble Assembling which is closed without solution shared unfortunately. M6 motor cannot fit into the tight chamber, seemingly wrong dimension used in 3D printed parts of Braccio/Tinkerkit robotic arm.
Hi @qiaoshen. I'm apologize for the problem with the kit. I recommend contacting the customer service of the seller you purchased it from.
If you purchased from Arduino Store, you can use the contact form here:
https://www.arduino.cc/en/contact-us
In the meantime, the forum helpers are of course welcome to suggest solutions.
Two separate problems were reported there, so it is possible the situation would be a bit unclear to other readers. Just to be sure, is the problem you are encountering the one shown in this post?:
which we may compare against the successful assembly shown here:
I found using hobby knife to scrape away a little bit on the inside of the chamber made it motor plugged in easily. Thanks getting back to me so quickly.
Great news! Thanks for taking the time to post an update with your solution.
Regards, Per
Yea that one basically the motor case blocking it so I hand to sand it then it fit