Day #43 – 2/14/15 – One Robot Later

Lab Opening Time: 9:00 AM

The front team number plate which is placed on the face of the elevator.
The team number plate placed on the face of the elevator.

In the early hours of the morning (as in 12 AM – 2 AM), the team accomplished attaching and wiring the intakes while also driving for the first time. The first demonstration (as seen below) was taken slowly, but by the end of it all, Jack (the driver) was running around like we had some powder coat to scrape off.

This morning, the team continued to work. The brake for the elevator was installed, the team numbers were placed all around the robot (excluding the back), the forks along with the ejector piston were cut, programmed for milling, milled, installed, wired up, and chained.

The elevator team number plate.
The elevator team number plate.

 

The programming team continued to debug code along with work with new components of the robot throughout the day.
The programming team continued to debug code along with work with new components of the robot throughout the day.
Cable-actuated disc brake mechanism.
Cable-actuated disc brake mechanism.
Other sub-teams continue work outside the affairs of the robot.
Other sub-teams continue work outside the affairs of the robot.

In tomorrow’s horoscope, the flaps for the elevator forks need to be made while work on the autocanners continues.

We tested the elevator with various numbers of totes and to our dismay we found that the Banebots RS-550 motors are producing less power than expected, and we’re losing more efficiency in the VersaPlanetary gearboxes than we expected.  The elevator runs slower than anticipated, and stalls when lifting any more than 4 totes.  Another contributing factor is the weight of the moving parts of elevator mechanism itself, which amounts to approximately 8 pounds.  Furthermore, we noticed the VersaPlanetary gearboxes themselves become very hot during operation, and we’re wondering if the viscosity of the Mobile moly grease we used is a contributing factor.

The 15 lb constant force spring is an absolute necessity to remove some of the load off the motors.  We also plan to swap the RS550 motors for RS775-18V motors which have significantly more torque.  If that is still not enough, we can gear the VersaPlanetaries to 16:1 for another 33% increase in torque.

One interesting note is that we’ve found when running brand new BaneBots motors in brand new VersaPlanetaries, during the first minute of full speed operation under no load, the speed seems to significantly increase (approximately 50%) as indicated by the sound it emits.  We speculate the motor brushes may be seating against the commutator and the planetaries are wearing in and reducing friction.  It would be interesting to monitor the current on it.

Plenty of work left to do tomorrow, errr, today!

Lab Closing Time: (2:30 AM on 2/15/15)