TeleToyland Sandbox How It Works: Step 8
Step 8: Conclusions, Notes, Room for Improvement
That's about it. For TeleToyland, we used some PHP scripts to command the servos via an Internet to serial connection to the SSC-32 board, which the servos plugged right in to. If there is enough interest, we may do a separate Instructible on that setup.Both axes have issues with not quite centering due to the potentiometers - causing the the digital servos to whine a lot at rest. We'll see how long they last in continuous operation for the online site - for occasional use, it's probably fine. We may get a digital servo programmer to see if narrowing the dead band will help. Higher quality potentiometers may help, but we may also be reaching a practical resolution limit in this approach.
Other Uses
This is an interesting approach, and might make an excellent arm configuration for a mobile robot. The Leaf project members are interested in arms, and this could be used for part of it. You could even add a counterweight on the belt opposite the end effector so that the arm would balance automatically - as the hand moves out, the counter-weight would move back. Adding a second linear system behind it would allow the weight of the object picked up to be balanced too.
The following sites provided some of the inspiration for this project
[http://www.instructables.com/member/Tom+McWire/ Easy to Build Desk Top 3 Axis CNC Milling Machine Tom McWire] [http://www.geology.smu.edu/~dpa-www/robo/servo/servohac.htm Improving Servo Positioning Accuracy David P. Anderson] [http://www.servocity.com/html/servo_power_gearboxes.html ServoCity Servo Power Gearboxes]
We didn't use this, but it looks interesting - [http://www.lynxmotion.com/Product.aspx?productID=332&CategoryID=75 a timing belt pulley for MXL belts (0.08" pitch) for Hitec servos]
We found this after building ours - uses gears in a similar way, and the drawer glides are similar: [http://www.instructables.com/id/Autonomous-Foosball-Table/ Autonomous Foosball Table]
Intro | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8