Let's Make Robots!

Miniature servo magnetic clutches

Miniature servos are great for robotics, they are small and cheap. Unfortunately they have very small plastic gears that strip easily so they always need replacing....  or do they?  Not any more!!!

DAGU is now producing magnetic servo clutches to suit 8g and 9g miniature servos. Because these clutches use magnetic fields to lock there is nothing to break and they are configurable to suit different needs. These clutches replace the standard servo horn and only sit 3mm taller than a standard horn.

The mounting plate comes in 3 different shapes to suit different needs. Two drive plates are included as 8g and 9g servos have different sized splines on their output shaft. These two plates should fit most brands of miniature servo.

3 different configurations!
The servo clutch can be re-configured to suit different applications by changing the polarity of the magnets. For a standard servo configuration, the clutch is hard locked into position under a normal load. The magnets are attracted to each other when the clutch is locked but begin to repel each other when you force the clutch out of position causing it to try and spring back into locked position.

Continuous rotation servo configurations:
There are two clutch settings that are ideal for continuous rotation servos. The first configuration hard locks every 90°. In this configuration the magnets are always attracted to each other.

The second configuration for continuous rotation is with all magnets repelling each other. This is called soft lock because it gives a soft, spring like response which is ideal for protecting your servos in situations such as driving a wheel over rough terrain. In this configuration the clutch protects agains sudden shock better than hard lock.

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Looks good. I will probably buy a few if they are on the market.


Are you using standard N35 magnets?

The magnets are neodymium but they had to be kept small so the clutch holding torque is only about half of what the factories claim. Not recommended for walkers unless they are feather weight. These clutches work best for servos that are normally lightly loaded but might come under attack from pets and children.

Sign me up for x8!

Hi, was wondering when is this product going to be available


They should be on the market very soon, the first batch had a defect from the molding process and had to be re-made.

Great idea

I will definitely be on the lookout for these.

Wow! These are beautiful for robotics! I have so many servos with stripped gears, I just wish I could find these clutches for larger servos too, say for mini (15-18g) servos (9g servos are considered micro) like this one: http://www.hobbyking.com/hobbyking/store/__8499__Turnigy_S3101S_Servo_17g_2_5kg_14sec.html

We started out with this size because it suits our pan / tilt kit and QuadBot chassis. If it proves popular then we will make molds for other sized servos.

I designed these so my son can play with a quadbot puppy robot without breaking it.... too easily :(


Questions:  How much are they amd where can I get them?