# 181 - Claw
Claw is at the end of the Grabber arm.
The purpose of the claw is to:
- provide snappy grab/ungrab to the support rail
- provide a safe, lockable grab
- provide passive suspension against wobbliness of the support rail, relative to main rail
- provide linear bearing against the support rail, with speeds up to 11,1m/s (40 km/h)
While providing those things, the claw is likely the most high-tech area in the Kotka design, material-wise, needing to be both:
- strong
- light
- quiet in operation
# Requirements
These are discussed at the Grabber arm level, also for the claw design.
# MVP 0.2
Goals
- [ ] Get a physical (3D printed) prototype for learning about snappiness, required control motors, noise, suitability of suspension etc.
# MVP later
Goals
- [ ] Producing a claw capable of track operations (probably made of metal)
- [ ] Showing it in action
# Metrics
- [ ] Grab/ungrab noise; dB peak
- [ ] Grab/ungrab speed (between "prepared" and "grabbed" states); ms with distribution
- [ ] Grab/ungrab impact; N·s peak; J overall
- [ ] Failures per 100M grabs/ungrabs (with support rail wobbling in relative distance, within parameters)
# Open issues
- The amount of wobbliness needed to be prepared for is not known. Tests on track will give guidance.
# Requirements to/from other parts
| Towards part | Req id | |
|---|---|---|
| #180 Grabber arm | Providing placement, control and power for the motors |
| From part | Req id |
|---|