4 down… 0 to go!
Well that didn’t really go as planned. The main goal was to have a complete robot up and running by the end of week 4.
Week 3 and 4 were a little rough and chaotic. We’ve never had such an amazing, enthusiastic group of team members who all want to work and participate in the build season. (Usually it was around 20 and this year we’re having 35-50 on a team evening)
Due to this it was a challenge to keep everyone on board and the same page. For example;
people would enter the shop, start working with a couple members on a prototype, send a couple video’s on Slack and then leave. (Making decisions along the way that impact software for example and not telling them about it)
So for the next weeks we’re going to start every team evening with a quick stand up meeting: every subteam lead will have to give a short update. And after every team evening a quick summary has to be given on Slack to inform all the other subteams on the current progression.
Before I officially start on actual updates… firstly:
ACCIDENTAL FUN WITH SHEETMETAL:
Metric version of #118 - Everybot 2020
We’ve decided to put our AM14U chassis to good use after our prototyping is done, by building an Everybot. A group of team members has started on re-designing the Everybot in metric units so we can build it here. A good exercise and we’ll end up with a competitive practice robot for driver practice.
Week 4 - Wheel of Doom
We’ve been testing a little more with the no pockets on an angle solution.
This worked relatively good and quite simple. We’ve decided to move onto different storage concepts and see how our week 1 robot will preform. Based on its performance and that of other teams we’ll make adjustments for Detroit.
Limelight + Turret test
We’re going for a static 2 angle shooter as our first concept but maybe we’ll need a turret for worlds. Since the Wheel of Doom was set aside, we’ve had some parts laying around for a nice testrig.
Two students hijacked this together and got it up and running within an hour. (We were all quite amazed)
(Not so amazed by the amazing video recording skills of Joost tho…)
Current Turret plan of approach:
The turret auto-aligns using the error angle given by the limelight. This error is then put into a simple kP controller that calculates the output for the turret motor. We ideally want the turret to be completely self-controlled, so once we get out of range of the target we want the turret to be pointing at roughly the direction of the target, so the limelight can pick it up more easily once we’re in range again. To accomplish this we use an encoder on the turret motor, and a gyro sensor, the encoder and gyro will be zeroed continuously when the limelight detects a target and the turret is inside of a certain error range of that target. Once the limelight loses the target, the gyro will detect rotation of the robot, and using the encoder we can account for this rotation, and roughly align the turret.
They’ll continue working on the turret and then we can decide if we want to swap the current shooter for a turreted shooter.
Software autonomous update
They’ve been working on some auto code. It will be most likely be a combination of motion profiling and limelight for final positioning.
Week 4 - Sheetmetal storage
Some small mistakes were made in the designing so it was a little hacked together but worked quite well.
As other teams might have noticed the powercells stick to everything hence the improvised lexan covering over the wheels. And not to forget duct-tape:
To fully test this concept we’d need the shooter intake wheel to feed out the powercells from the storage into the shooter. This wasn’t designed and build yet but testing this concept gave us enough confidence to keep on working.
Week 4 - Intake
Powercells stick to pretty much everything. Test below was bare PVC on first roller and hockey stick grip tape on the second roller:
Video below used the same Linerless Rubber Splicing Tape as #118 used with the Everybot. (No pipe insulation, just PVC and tape)
The side plates of the intake were aluminium in this version since we don’t have as much lexan and sheetmetal is a lot cheaper for us. Final version will be sheetmetal and lexan for the arms so that it can take a beating on the field.
Tape + PVC + 1 x 775pro + Driving
Dual 775pro #1
Dual 775pro #2
Dual 775pro #3
We experienced that the powercells bounces back on the top roller. Adding cartboard, sheetmetal, lexan will hopefully resolve those issues. A lot of wobly wobly on this prototype, we’re designing a new version of it for next week.
To make sure the powercells won’t exit the storage hopper while yeeting across the field. It will be tucked in 90 degrees at the start of the match.
After it’s first actuation it will lock off the last 10 degrees so that the next time pulling it back in it only reaches to 80 degrees.
Same as #118 Everybot. (Shown here.)
Our current implementation is as followed:
Week 4 - Shooter Update
To test the powercell path from the 4" storage wheel into the kickerdrum and shooter wheel we designed a new prototype revision. This didn’t have an external flywheel; we could add mass to the shooteraxle.
Shots were a little inconsistent due to being a little to wide internally. I think there was about 5mm, 0.2" clearance on the inside width. Adding cartboard to make it a little more of a snug fit for the powercell helped centering the powercell better.
Our earlier prototype had a flat hood and this one shot with 2 arcs. We felt that shooter with a flat hood was more reliable than the arcs. So for the upgraded design we went back to flat hood and enclosed sides of the exit.
Week 4 - Climber update
We’ve decided that driving on the climbing rung is probably not needed for week 1 but we wanted to proceed on finishing the current proto.
Moving climber horizontal
Moving climber on angle
Climber for now will stick to the 3 stage linear tubes with constant force springs.
3D SOLIDWORKS UPDATE
The CAD team has made good progression after a long extensive CADathon! The main goal was to have the final drivetrain and storage by Sunday evening and the other sub systems done for 90%.
That way the drivetrain and storage can be manufactured on Monday, Tuesday and start assembly on Wednesday. Then the other subsystems had time until Wednesday evening to make sure all subsystems work properly together in CAD and be ready for manufacturing. We’ll be sending out the parts on Wednesday evening so we can start assembly on Friday and hopefully have a robot up and running by Saturday afternoon.
Specifications for the subsystems haven’t changed much between this update and the last update. So here are just some screenshots of the current status.
(They’ve had to wait a little until the storage was finished so they’re not as far yet. It will be little less bulky eventually )
Complete Assembly (Missing Control Panel, Storage walls and Intake currently)
WEEK 5 PLAN
Monday & Tuesday = Production DT and Storage + Finalize CAD from other subsystems
Wednesday = Assembly DT and Storage + Finale check subsystems and start production
Thursday = Production subsystems
Friday & Saturday = Assemble 1 complete robot and DT + Storage for our second robot. Start testing of the complete robot cycle & drive around.
To be continued…