The mechanical team has been hard at work testing the launcher trajectory with different adjustment devices and methods. What we’ve determined so far is that we seem to sail the ball right into the goal, from 18 feet away to 4 feet away, with the launcher as-designed, Choo-Choo forward about 2 inches to allow more travel on the mechanism toward the end of the range of motion, and urethane over the back round bar of the launcher. We are making the shots with a fair consistency, with some variability due to wind when testing outdoors. So far, we have not had any serious mechanical issues with the design other than shoulder bolts unscrewing themselves over time.
As of this posting, the limit switch mount design is still pending. We’re having difficulty coming with something rigid enough that interfaces with existing mounting holes. The limit switch needs to be rigidly mounted on the Choo-Choo to ensure repeatable and safe operation.
The fabrication team decided that the intake would perform better with a rework of the wheel arrangement, which required removing, cutting, and facing off the VexPro Versaplanetary gearboxes. After completing the rework and testing, we are pleased with the results, and see a noticeable improvement in intake performance. A picture of the reworked intake wheel arrangement is shown below.
We also took the opportunity to do some lab maintenance items including organizing drill bits into our new Huot dispenser drawers. They’re quite nice.
Also, our plumbing department installed a 6-stage reverse osmosis and deionizing filter system to our sink area, to prepare ultra-clean water for our HAAS CNC machining center. We still need to work out some minor leaks.
Finally, the photography and graphics crew finished the vinyl logos and set up to do the robot photo shoot on the seamless backdrop. This ended up taking much longer than expected, but we think the end result will be worth it. A picture of the photoshoot setup is shown below.
We weighed the robot on a large accurate digital scale, and it weighed in at 124.3 lbs with all parts including Odroid computer and cameras. Oops. We debated for 10 minutes on ways to remove the weight, then ultimately decided to just pull out two of the six CIM motors in the drive system. The robot will still be plenty fast with 4 CIMs and 2 speeds, and this puts us comfortably 1.3 lbs under the maximum weight limit. As a bonus, it took only about 1 minute to pull them on both robots.
We got all the pneumatic hoses finished up and side funnels mounted. During the pressure test, the robot leaked like a sieve due to several hoses not being properly installed. After correcting all the leaks at 11:25 PM, the robot held pressure just fine. We got it down to the testing area, and tested the function of all mechanisms as much as we could. Everything seemed to work, but brake mode is set on the Talons, causing the robot to abruptly come to a halt from high speed, causing it to topple over on its face. It should be better with bumpers on, but it’s still somewhat concerning. we were not expecting the CG to be as high as it appears to be.
We bagged at 11:56 PM, with 4 minutes to spare. Here a photo of the robot from about 10 minutes before bagging.
And here’s a picture of it in the bag. Note the time on the clock on the wall.
We assembled and installed the drive and choo-choo gearboxes. We had to rework the gearbox bearing block by putting it back in the HAAS and taking off about .004″ around it, to fit in the hole in the frame. The powder coat was thicker than expected in this area.
We made chains, which installed very nicely without issue.
The gearbox JUST BARELY fit into the cutout in the baseplate. Had to bang it in. All I can say is that if it ever has to come out, “not it.”
We tested the launcher under power and going full speed. It rewinds in about 0.6 seconds as expected. With no ball, it launches so violently the battery jumps out of the battery box and unplugs itself. Also, the breakout boards on top of the cRio modules unplug themselves. Good limiting straps are a definite must, and we should “dry fire” as infrequently as possible.
On the trajectory, the ball was peaking at about 12 feet high, and 12 feet away. It needs to fly further and not as high (flatter).
Here’s a picture of the robot from 1:00 AM on 2/17/14
Today, we unpacked the parts we got back from anodizing and began assembly. We completed one full launcher, as shown below. Plenty more assembly still ahead. Glorious.
Our team’s vice president decided to create a spreadsheet that logged all progress made by the team. It’s only editable by a select few (mainly mentors and division leaders), but it serves as an excellent method of logging what needs to be done while promoting efficiency.
Members of the mechanical team cut some shafts, and made a few standoffs on the lathe.
In addition, they mounted pistons and remade parts for the practice bot. Members also decided to grease and construct some of the VEX planetary gearboxes.
In terms of wiring, members…
Routed PWM’s (Half-way done with on main bot, done with on practice bot)
Routed encoders (Half-way done on practice bot, done on the actual bot)
The ribbon cable for CRIO to sidecar done on both bots.
Although today was not a scheduled student meeting day, work still progressed during class and into the evening. We assembled bearings and standoffs to the Choo-Choo gearbox plates, machined the Choo-Choo output shafts, and cut stock for the launcher shafts (enough for 4 complete launchers).
Over at our sponsor shop Daveco Industries, work proceeded until 11:00 PM where we finished facing off, turning down, and drilling and tapping all 12 launcher shafts. Polishing is now in process, as shown below, and will be finished tomorrow afternoon.
We also checked on the status of the gearbox output shafts at another sponsor shop. They’re coming along quite nicely, and we hope they’ll be done before Friday afternoon. A current picture of the gearbox output shaft in-progress is shown below.
Today we took parts to anodize and took a look at all shafts on the robot. We modified the intake shaft to properly interface with the bearing blocks. We produced print drawings and cut stock for all shafts except for the catapult. We machined the full quantities of the first and second choo-choo gearbox shafts. Tomorrow, we’ll try to machine the remainder of the shafts.
We welded the front funnel assemblies and took all the welded parts including 4 H frames, 3 intakes, 2 front funnels, and 4 side funnels to powder coat. Powder coat will be done on Wednesday. On the way back from the Powder Coat shop, we stopped and picked up the launcher plates from our waterjet sponsor. We drilled, deburred, and scuffed them to prep for anodizing. Also, we machined the choo-choo link bars, and cut the big launcher tubes in preparation for anodizing. The launcher solid rods didn’t make it in time for anodizing, so those will have to get polished.
We put in a McMaster order totaling about $1,000 that should include the majority of the remaining fasteners and pneumatic cylinders for both robots.