Rotor orange piece slipping

Help & Support Robot Parts
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1

Hello,
I’m kind of new to this and I don’t know where else to turn to, but I bought the Arduino Braccio Robotic Arm (orange one) and I have an issue. The base servo that rotates the whole arm has a small house shaped orange piece (don’t know the name of it) that is screwed in the rotor. It seems like that piece is worn out and has no friction left, as the rotor spins while it stays in place. I have tried gluing it to the rotor so it spins with it but it’s not working. Is there a way to order the piece only or even a new rotor that comes with this orange piece? It’s my senior project and I need to finish it to graduate.

Thank you.

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2

Hello @Phalafelz and welcome to the RobotShop forum,

Arduino actually sells a “Tinkerkit Braccio Rescue Kit” which includes:

  • A big servo Motor SR431 used on the based of the Braccio
  • A servo motor SR311 used for the legs
  • Lots of small parts, plastics, nuts and bolts for recovery your damaged kit

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Or you could also try 3D printing the piece.

3

That’s amazing thank you! Is there a place where I can get the specs for that orange piece if I were to print it?

4

I looked for it but couldn’t find it. However, you could try contacting Arduino to see if they can share the 3D file for that piece.

Or since you already have the piece and seems to be fairly simple you could measure it and make the design yourself. This tool is very easy to use so you could give that a try.

5

HI, i have the exact same issue. I looked over the internet and it seems that the Tinkerkit Braccio Rescue Kit is no longer manufactured. Is there any good alternative of the SR431 motor that could fit on the braccio ?

6

Hi @Eleve2 ,

I think the best replacement would be MG996R:

The size is almost identical and it has the same spline. It doesn’t have the second shaft, but if you don’t need that second shaft, it should be fine.

Here is a comparison:

Feature SR431 (Original) MG996R (Alternative)
Size 41.3×20.7×40 mm 40.7×19.7×42.9 mm
Voltage 4.8V–6.0V 4.8V–7.2V
Torque (@6V) 14.5 kg-cm 11.0 kg-cm
Gears Metal Metal
Type Analog Digital (Works with Braccio Shield)

I hope this helps.

7

thanks a lot !!