The Robot Calibrator is a measurement system

new-video-robot-calibration-with-the-faro-gage-P34339The Robot Calibrator is a measurement system that includes three string-encoders mounted to a metal base plate and used to measure the position of a robot in three space. Combining the three string ends and attaching them to a robot arm provides an inexpensive and relatively accurate position sensor with respect to the calibrator base. Using a quick-change plate attached to the three string ends, the robot can attach to the plate, maneuver the plate through a calibration routine, and replace the plate completing an in-situ calibration during manufacturing. Errors that can build during repetitive robot motions are thereby compared to the Robot Calibrator measurements and canceled out. String encoders or potentiometers can be used to provide relatively accurate length measurements with respect to their housings and combined as in the Robot Calibrator to triangulate the position of their combined lengths. Since the string-encoders allow only perpendicular string-extension/retraction, steel toriods were machined and attached to the string-encoder housings allowing the string to exit at angles within a hemisphere, as needed for a robot arm.

Here, the robot tested was a 7-axis arm that ran through a series of tests to “calibrate” the calibrator. Calibration included the simultaneous use of a laser tracker with the calibrator providing a direct calibration of three-space points for this robot.

a. Calibrator attached to the robot arm
b, d, e, f. Laser tracker (black object to the right) tracking the robot position simultaneously with the Robot Calibrator.
c. Close-up of the retro-reflector (laser tracker) and strings (Robot Calibrator) attached to the robot.
g. h. Center stand for the calibrator attachment plate with attached strings. The strings attached to the robot attachment plate such that the robot could quick-change to it and replace it on the stand.

Graymark’s Scooter Model 601A

scooterHere’s an inexpensive kit from Graymark to help you learn motor theory, transistor switching and R/C time constant circuits. Comes with an excellent instruction book of lessons, schematics and troubleshooting guide. Scooter changes direction when you clap your hands or when it hits an object. See KrisTech’s independent First-Person, First-Robot Review — $16.95 Continue reading

RT-12 rotary positioning table

rt12The RT-12 rotary positioning table is designed using ourunique, cost- effective philosophy. The RT-12 can be used to position a varietyof payloads such as cameras, lasers or test fixtures. The 12″ diameter aluminumtop plate has 24 tapped holes to attach your application.

An endless variety of configurations can be created by attaching a linearpositioning table such as our Z-2 or X-9 to the RT-12. The RT-12 can be driven with the MD-2a motion control system and can also be used with a PR23-3 pulley reducer for greater performance.

Pricing and Specifications:

Model # RT-12
Price $300.00 US
Maximum Payload 10 pounds
Accuracy .1 degree
Resolution .15 degrees per .9 degree step
Repeatability .1 degree
Maximum Speed 45 degrees per second
Shipping Weight 8 pounds
Shipping Cost $6.00 US

3-Axis Robotic Workcells

* Automate Repetitive Tasks
* Dispensing
* Pick and Place
* Automated Testing
* Easy to Program
* Very cost effective

rws

Now’s the time to automate those tasks currently being performed manually. By
combining our MD-2 Step Motor Systems with our XY positioning table and a gantry
stand, a complete robotic workcell can be created. Our Z-2 Positioning Table is
added to create a third axis of motion.

In many cases, an XYZ robotic workcell can replace a very elaborate robotic
system at a fraction of the cost. Just connect to your personal computer, attach
a tool, and your system is complete.

Robotic workcell packages come complete with motor control systems, positioning
tables, hardware and an accessory kit which includes cables, cable mounting
hardware, and a tools.

You will:
Supply a personal computer.
Mount the components together (instructions provided).
Route cables from motors to MD-2 drivers (hardware included).
Attach your tool (may require custom made hardware).
Load the MD-2 software.
Set motor parameters.
Program the desired motion.

Increase Performance with a PR23 Pulley Reducer
Add two PR23-2.5 pulley reducers for the X and Y axis of your robotic workcell
to achieve faster speeds, more torque, and a resolution of .002" per step.

Pricing and Specifications
RW-9b 3-Axis Robotic Workcell 9"x9"x2"

Includes:
XY-9 9" x 9" Positioning Table
Z-2 2" Positioning Table
MD-2b Dual Stepper Motor Control System
MD-2a Dual Stepper Motor Control System
ST-9 Gantry Stand
BR-2 Right-Angle Bracket for mounting the Z axis
Accessory package, cables, parallel port, tools, etc.

 

Model

RW-9b

Price

$3,200.00 US

Travel

9" x 9" x 2"

Maximum Payload

5 pounds

Accuracy

+/-.010" per foot

Resolution

.005" per .9 degree step

Repeatability

.005"

Maximum Speed

6" per second

 

 

RW-18b   3-Axis Robotic Workcell 18"x18"x2"

 

Includes:
      XY-18 18" x 18" Positioning Table
      Z-2 2" Positioning Table
      MD-2b Dual Stepper Motor Control System
      MD-2a Dual Stepper Motor Control System
      ST-18 Gantry Stand
      BR-2 Right-Angle Bracket for mounting the Z axis
      Accessory package, cables, parallel port, tools, etc.
 

 

 

Model

RW-18b

Price

$3,300.00 US

Travel

18" x 18" x 2"

Maximum Payload

5 pounds

Accuracy

+/-.010" per foot

Resolution

.005" per .9 degree step

Repeatability

.005"

Maximum Speed

6" per second

Startup Power Sags Can Confuse Your ‘Bot

Here we are starting a new topics Designing robot power supplies, PCB Design Software, Robot Art, Practical Robot Design . You finally set your ‘bot on the floor for its first test run, hit the switch, and the computer starts acting all weird. A real bummer, especially since the robot works great propped up on struts on your workbench.

Chances are the problem lies with your power system. When motors start up, they require much more current than they use once they’re running. The battery will try its best to satisfy this bigger power requirement, but something has to give. In many cases, that “something” is the battery’s output voltage, which can sag so low that the robot’s MCU resets itself. Even worse, the MCU sometimes doesn’t reset cleanly, and “runs away,” executing garbage data from your EPROM. Continue reading