2009:Mechanical 2.14.2009

1.29.2009

Start time:6:00

End time:9:15

Members present:Alex Wolf, Mike Wolf, Mike M, Cuyler McChesney, Tom Kanzler, Tom Cavaliere, Tony Delsonto, Josh Gannon

Tasks Completed:   Made round belts for back of robot each row has 4 belts, two rows total of 8 belts.

Ref notes:  The 1/4" round belt in the aluminum pulleys measures 2.935" over the OD, therefore the belt pitch diameter is 2.935 - .250 = 2.685"

                 The circumfrence = (Pi) x (dia) = 2.685 x 3.14159 = 8.44" which is the belt length around the pulley.

                 The rear shaft center line, shaft to shaft is 15" nominal, so (15 x 2) + 8.44 = 38.44" which is the pitch line length of the belt in position on pulleys.

                 We want to try 10% stretch, so Initial length x 10% = 38.44;  Solve for initial length = 34.95"

                 We allow for .250" melt loss during joining, so cut length of belt cord should be 34.95 + .250 = 35.2"   (35 3/16")

        The basic process to join ends using a block fixture (takes two people):

                 Using torch on med flame, heat both ends of the belt (1/2" of each end) at the same time, until they start to burn (about 5 to 7 seconds)

                 Quickly place both ends together in the lower block half, second person quickly places top half on the lower block. and tightens "C" clamp.

                 The first person continues to press the joint together for about 2 minutes.  Continue to let the clamped belt cool for another 10 to 15 minutes.

                 Unclamp and clean block fixture, continue to let the belt cool.

          We also made / repaired double long rear belts.  Cut length is 62 1/16" which has a free state pulley center to center distance of 26 3/4"

                 This will provide approximately 10% stretch when put over pulleys with shafts 30" apart on center.

          Robot cart shelf was fitted mounted (thanks Josh) and mounted (Alex and Tom C.)

                 Ideal for Batteries, layed down with the terminals facing up is the safest way load and transport. 

                 May want to line bottom with thin lexan to insure no metal contact in the event terminal tape wears away or some thing else pokes through the tape.

           Belt alignment continued through most of the morning, day and evening.  Started preliminary thoughts on outside panels to contain balls.

                

Tasks In Progress:

Tasks to Complete:   Eight (8) belts were made for the standard rear positions.

                               Four (4) double long belts were made / repaired for the 26 3/4" puylley center to center free state distance