What does Forward/direct kinematics entail?
describesTCS in terms ofthe joint variables
What does Inverse kinematics entail?
Calculate the joint variables, given the TCS
What is a jig, and what is a fixture?
• A jig is a workpiece locating and holding device that positions and guides or controls a cutting tool
• A fixture is a workpiece locating and holding device
.• A fixture does not control the position of the tool or instrument that is being used.
Elements in a fixture?
• Locators (Pickup)– Establish and maintain position of a part by constraining the movement of the part. Can be adjustable.
• Clamps– A force-acting mechanism of a fixture to hold a part securely in the fixture
• Supports– To counteract any displacement/ deflection due to process forces or if the part itself deflects due to its weight
• Fixture Body (Fixture structure)– The major structural element(s) to maintain the spatial relationship between the fixturing elements above.
Flags– The unit that goes in between the Structure and Locator– Is larger than a Pickup
• Pickup (Locator)– A pickup holds the workpiecein accurate position during the manufacturing process
3-2-1 principle (6-point contact solution)?
The principle says that a workpiece will be completely confined when banked against three points in one plane, two points in another plane, and one point in a third plane if the plates are perpendicular to each other.
a) three fixed points for supporting the first surface, b) two fixed points for the second surface, c) and one fixed point for the third surface;
Drawbacks of dedicated fixtures?
- Long lead time
- Req. long experience
Benefits of modular fixtures?
- With reduced time-to-market and smaller batch size, the use of dedicated fixtures has been steadily replaced with reusable modular fixtures.
- Modular fixtures take shorter time to configure and assemble, reduce inventory holding, and offer good repeatabilityand accuracy.
- They are invaluable in prototypingand proof-of-conceptdesigns of new products.
- They simplifies computerizationin design, analysis and assembly.
Drawbacks of modudlar fixtures?
- Cost a lot of money to machine precise parts
- Pays for machined features that you don’t use
- Most modular systems on the market are aluminium based, which are not suited for heavy industry applications and large assemblies
Drawbacks of reconfigurable fixtures?
- Existing solutions has limited flexibility
- Very expensive unit prices
- Require expensive support structures
- Expensive control systems
What is flexapods and what do it entail?
- A Flexapod is a configurable Flag that goes in between the Fixture Structure and the Locator (Pickup)
- A Flexapod is a configurable tooling unit that does not have any built in servos or encoders.
- Flexapods rely on a metrology systemto achieve setup accuracy.
- Flexapods can be configured by hand or by the use of a robot manipulato