Mechanical Facehugger build

[innerbreed]

Overall performance calculation.

To determine if the 24 servos in our Generation 8 Robotic Facehugger System can provide sufficient torque, we need to calculate the torque requirements for each finger, considering the distribution of weight and the lengths of the distal and proximal phalanges.

Here’s a step-by-step breakdown:

Weight Distribution:
Total weight: 1.5 kg
Weight of each finger: 85 g (0.085 kg)
Number of fingers: 8
Total weight of fingers: 8 × 0.085kg = 0.68kg
Weight of the body: 1.5kg − 0.68 kg = 0.82kg

Weight Per Servo:
Each finger has 3 servos, so each servo supports a portion of the finger’s weight and the force applied due to the finger’s movement.
Weight per finger segment: 0.085kg
Force due to gravity for each finger: F = 0.085kg × 9.81 m/s2 = 0.83385nf

Torque Calculation for Each finger Segment:
Distal phalange length: 153mm (0.153 m)
Proximal phalange length: 104mm (0.104 m)

Torque for Each Servo in the finger:
Distal Phalange Servo Torque Calculation:
The torque τ required by the distal phalange servo:
τdistal = F × distal = 0.83385n × 0.153m = 0.12758Nm = 1.30 kg/cm

Proximal Phalange Servo Torque Calculation:
The torque τ required by the proximal phalange servo:
τproximal = F × proximal = 0.83385n × 0.104m = 0.08672Nm = 0.88 kg/cm

Comparing with Servo Capability
Each servo can provide 3.5 kg/cm of torque.
Required torque for the distal phalange servo: 1.30 kg/cm
Required torque for the proximal phalange servo: 0.88 kg/cm

Conclusion
Distal Phalange Servos:
The required torque of 1.30 kg/cm is less than the 3.5 kg/cm that each servo can provide.

Proximal Phalange Servos:
The required torque of 0.88 kg/cm is also less than the 3.5 kg/cm that each servo can provide.

Therefore, each servo in the finger can handle the required torque, and the servos should be sufficient for the Generation 8 Robotic Facehugger System.

[dialfonzo]

@innerbreed

The required torque of 1.30 kg/cm is less than the 3.5 kg/cm that each servo can provide

Hurray…!!! That’s good news

[innerbreed]

I wanted to support this thread with a little update as well as let you know i havent fallen of the radar with it.

I have been busy with redecorating and a couple of trips abroad, of which has taking me away from updating you guys with the progress.

With this said i have been working in the background and making small changes to further improve the project.
These changes have been vital and have grown from mistakes iv previously made in past iterations.
I am now on the 3rd body production as the changes i made were significant enough to mean i had to reprint the body along with all the fingers.

Previous designs:

Originally i was using universal joints in the knuckle however at various angles these joints would lock up and inhibited the full range of movement.

I then designed my own type of joint, similar to a universal joint but worked with a small ball in the centre rather than a cube in a conventional universal joint.
This also showed signs of locking up at certain angles.

I have now created a full radial gimbal at the knuckle and these prints are at the factory being produced .

I hold hope this new knuckle design will work out and ill post an update on that soon.

[innerbreed]

Below are some of the vital information put together to help visualise the overall design. These parameters help work out the important factors when programming the robot.

[dialfonzo]

Intense CAD drawing there

[innerbreed]

all makes sense right?

[dialfonzo]

You say it like there is an easter egg… humm