All posts by Luke Burbidge

Oh, it seems you'd like to know something about me. How amusing. Well, since you're so interested, I guess I should get to boring you to death. I'm pretty much your run-of-the-mill socially awkward teenager who happens to enjoy tinkering around with electronics. In addition, I also seem to have an affinity towards writing in a somewhat-sarcastc/sassy tone (in case you haven't noticed already). Bored yet? Well, that's quite sad; I guess I didn't really do my job well. Anyhow, enjoy my (moderately) glorious creation known as the 2014 build blog.

Day #10 – 1/13/2014 – The Start of Prototype Electronics Mounting: Quite a Shocking Introduction

Continuing from the prior day’s work, the mechanical team mounted the bumper brackets onto the prototype. While doing so, they trimmed down the frame to 29 inches wide by 26 inches long to fit the mechanisms while remaining within the 112 inch frame perimeter.

Bumper

Afterwards, pickup mechanism brackets were also mounted, thus leaving the pickup itself ready to be installed at a moment’s notice.

Finally, the trigger system for the shooter was also worked on, and electronics mounting is underway.

ZOE_0002

Meanwhile in the Programming department…

Veteran members of the team have been teaching rookies how to program, and most importantly: debug. To put them to the test, rookies are instructed to code a (rather barebones) drive system for robots of years’ past.

In terms of forward-progressing productivity, experienced members of the programming division have been experimenting with several methods of programming this year’s robot, and to be as prepared as possible for when the mechanical team comes out with a finished product.

 

 

Day #9 – 1/12/2014

 

Lab opening time: 1:00 PM

Mr. Black got off to a slow start today trying to fix the finicky Dimension SST 768 printer.  It has a software glitch where it gets itself into a loop of never attempting to load material.  After several reboots and maintenance procedures, he was finally able to get material loaded, so it should now be ready to print.

The manufacturing of sprockets is nearly complete.  Hex broaching is in process, and will resume tomorrow.  After sprockets, next up will be wheel axles, then gearbox plates.

IMAG0264

The design team decided upon 29″ wide by 26″ long to be the optimal dimensions after determining the width that the ball needs to pass through between the arms which hold the intake roller.   We considered the arms to be constructed from 1″ wide box tubing, and held in a clevis with 1/4″ thickness on the walls, and a shoulder bolt with a 5/16″ thick head.  So, overall, a width of 29 inches provides a space between the intake arms of 25.875 inches, which should allow for manufacturing tolerance and ball over-inflation.  Work will proceed with the 29×26 overall dimensions unless any major issues arise.

We tested the launcher with the ball positioned more toward the rear.  This causes the ball to shoot more upward, and less outward.  We also tried shortening the limiting straps, which causes the ball to not launch as far.  Finally, we are imagining that the pivot point of the launcher will need to be raised a few inches to fit things such as the battery underneath.

For resetting and releasing the launcher, the current plan is to use two 1.75″ bore x 6″ stroke pneumatic cylinders, with McMaster p/n 62135K14 quick-exhaust valves.  While we do not yet have experience with valves of this type, our understanding is that this should allow the pneumatic cylinder to compress very quickly when pressure is removed, without having to push all the air back to and through the solenoid valve.  On the launcher, we have approximately a 5:1 lever ratio, with 20 inches from the pivot to the furthest point in contact with the ball, and 4 inches from the pivot to where the springs attach.  At the end of the long side, we measured approximately 38 pounds of force needed to keep the launcher down.  With the 5:1 ratio, this would be about 190 lbs of force at the short end.  The two 1.75″ bore cylinders will provide 288 lbs of force at 60 PSI, which should provide sufficient margin to counteract the spring force to reset the mechanism.  We decided on 1.75″ bore over 2″ bore cylinders to reduce the amount of air used.  This robot will need A LOT of air tanks.  We hope the compressor will be able to keep up.

The mechanical team reconfigured the prototype chassis and drive-train to match the 29″ wide by 26″ long dimensions. In addition, members of said team worked on prototyping an intake system.

What’s interesting about this prototype, however, is the implementation of 3D-printed parts into the mechanism. The printed parts are for testing purposes only, and–consequently, will not show up in the finished product. Despite that, this interesting use of MakerBot-printed parts comes to show the level of creativity these new machines grant us.

ZOE_0002
The prototype feeder mechanism, with the 3D-printed part (on the left).

 

Lab Closing time: 7:30 PM

Cleanup score: 100% (Nice work guys!)