DEWBOT VII Build
From DEW Robotics
Build season is the heart of the FRC year. It is the 45 days during which the team's students and mentors put their hearts, minds and hands into designing and building a great robot. Paradoxically, the time seems both far too short and much too long.
This page contains a day by day breakdown of what we did. Dates hyper-links go to the corresponding photo gallery.
See also: DEWBOT VII Competition Kit List and DEWBOT VII Competition Checklists
Contents
Kickoff
- On Saturday, January 8th, team 1640 students, parents and mentors drove to Upper Darby High School on to watch the events from Dean Kamen’s home in New Hampshire, see the objectives of the 2011 game revealed, examine a mock-up of this year’s play pieces up close, and pick up our kit of parts.
- We attended seminars immediately following the Logomotion Kickoff.
- The Team returned to DRC following Kickoff for a read-through of Logomotion's rules.
Week One (1/9-1/15)
Sunday 9-January - Brainstorming
- Siri Maley & Heather McKown inventoried the Kit-of-Parts (nothing missing) - KOP parts laid out for brainstorm "touch & feel".
- Siri Maley, Heather McKown & Clem McKown set up a 1/7th-scale mock-up field including scale robots, bonus towers & game pieces
- Strategy Brainstorm - well attended by 18 students and 14 mentors - we:
- developed a large number of game-play ideas;
- focus on what, not how;
- consolidated, synthesized and built on ideas as teams;
- presented team ideas;
- simulated the game on the game table (mock-up field) - multiple iterations; and
- consolidated , synthesized & built on ideas as a complete team
Monday 10-January (no photos to speak of)
- FIRSTchoice parts ordered (FTC Kit, Solenoid Kit & Pressure Relief Valve)
- Made key strategic decisions for DEWBOT VII
Tuesday 11-January - Meeting canceled due to snow storm
- Assembled Functions list - started to assign specifications
- Arm analysis - started on arm design concepts
- Started building the first scoring Tower
- Started cutting Al for Pivots Sides
- Welcome to new mentor, Juan Posada
- First Pivot sideplate has been machined - a thing of beauty!
- Finished cutting Al stock for Pivot sides & tops
- Continued practice field construction
- Started prototyping and testing the claw
- Started work on the Minibot
- Defined teams and lead mentors for these teams
- We have Internet!
- Web-based colaboration file sharing initiated for CAD team
- Functions and Specifications largely complete
- Continued claw prototyping
- Cut stock for Pivot Tubes & Transfer axles
- Continued to build field pieces
- Started to play with Tetrix parts for Minibot
- Specified belts & pulleys for drive-train
- Started putting 4-linkage arm into Inventor
- Organized shop & storage
Week Two (1/16-1/21)
- We worked through & articulated our sensor strategy & requirements
- Which required clearly articulating our autonomous strategy
- Also provisionally worked through our motor needs
- Final Pivot Drive stock cut
- Cut a plane work area on the mill bed
- 4-bar arm entered into CAD (Molly)
- Pivot drive pulleys & belts ordered
- More arm prototype testing
- Have a reasonable Minibot concept to develop
- Siri's analysis of the 2-joint arm points out the need to manipulate the attitude of the Logo Piece - a strong argument for the 4-bar linkage arm
- Prototyped the 4-bar linkage arm. It seems we should be able to score on the high targets. On the lower targets, however, we will need to approach the target grid at an angle to stay in the safe zone.
- During prototyping, conceptualized a lighter variation on the 4-bar arm. Will test Wednesday.
- Developed the 4-bar linkage arm in CAD
- Chassis frame is developing in CAD
- Minibot launch design started
- Started improved jaw prototype
- Started machining Pivot spacers on lathe
- Building bonus tower
- Establish material needs for bumpers
- Finished first bonus tower
- Completed Pivot spacers
- Started broaching keyways into miter gears and 9T sprockets
- Finished broaching keyways into the miter gears
- Put together our first Minibot (certainly not our last) - did not take it for a vertical walk
- Atarted cutting custom polycarbonate wheels on lathe
- Chassis frame has been (somewhat) completed in CAD
- CAD collaboration software is working - Andrew has Inventor 2011 running and is therefore in the running
- Made significant progress on arm/claw
Week Three (1/23-1/29)
- Finished polycarbonate wheels with concave profile for the Minibot
- 1st Minibot test
- Chassis designed
- Cut chassis frame pieces (not done)
- Bored steering drive pulleys using lathe (done)
- Bored steering driven pulleys using lathe (incomplete)
- Tested improved claw with pneumatics
- Finally finished boring drive-train pulleys
- Pivot Module top & bottom plates complete
- Drive-train Model has been adapted to the Minibot pole race. Some sample results are available. Light minibots rule, but there are additional (and more nuanced) lessons.
- Help! My magnetic minibot has fallen off the pole and can't get up! What do I do? Find out here & (esp. for the geeks among us) do the math
- Minibot gets up the pole now
- We used the mill to cut lightening holes into the chassis longituninals - both accurate & efficient (not to mention cool)
- FRP pultursion arrived. We plan to use for the arm.
- We are, officially, in the groove!
- The minibot climbs the pole with battery on-board in 4.5+ seconds - but not every time
- Almost all chassis frame pieces are cut; weight reduction holes drilled & chamfered
- Weight reduction holes are drilled in the wheel sprockets (all 8 at a time in the mill)
- Wood cut for 2nd bonus tower
- Snow Storm - No Robotics tonight!
- But designing continues
Thursday 27-January - No meeting - DRC parking lot not yet plowed
- Assembled test Pivot tube/top using thermal interference. Need to reduce interference to 0.0025". Tortured this test assembly (successful!)
- Assembled first Pivot tube/top assembly
- Milled circular keyways in driven steering pulleys (3/16" round in 1" ID)
- Broached keyways in 56T driven pulleys
- Cut more frame pieces
- Started work on frame assembly jig
- Assembled all Pivot tubes/tops (thermal interference)
- Lubricated all BainBot P60 gearboxes, assembled with RS-540 motors onto the Pivot Module bottom plates
- Assembled all Coaxial drive shafts/miter gears
- Assembled all transfer axles
- Transfer axle bearings pressed into sideplates
- Pressed first 1" bearing into a Pivot Module bottom plate
- Milled frame front/back welding template and cut alignment holes in frame pieces
- Made a faster minibot - still under development
- Arm design complete - ready to start fabrication
- Have video feed working
Week Four (1/30-2/5)
- Started welding frame. A slow start. Siri Maley, Matt & Clem McKown took turns practicing and welding the chassis front (2nd robot).
- We made a lot of progress on the pivot modules, with one (provisionally) assembled module by dinner.
- The programming team demonstrated live video from the robot. Very impressive! This is great work.
- The arm design is complete (Maley)
- The 2nd bonus tower is complete
- We've got a faster minibot working
- The mill ran all day to keep up with demand!
- Minibot development is going well; front roller works well; climb time down to ~3 sec!
- ordering Tetrix motors and buying 3, 4 & 5 amp fuses
- Revisited minibot analysis & modeling (McKown)
- Deaver & team assembled pivots (more work pending)
- Ordered cRIO and analog & pneumatic breakouts
- Set up next wellding job
- Intended this to be a big welding night, but the feed tube needs replacement. Will purchase a feed tube and get back to work tomorrow.
- Assembled pivots and pivot modules. (4) pivots are now mounted on modules with steering belts installed.
- Settled on solenoids for purchase
- Repaired welder (replaced feed tube)
- Side & Pivot welding templates fabricated.
- Welded rear and sides of the 2nd robot chassis. The practice is serving us well.
- The pivot braces are done, sxcluding countersinking.
- Scissor Minibot tested for the first time.
- All pivots are assembled to module bottom plates. All steering belts in place.
- Completed welding the 2nd robot's chassis frame (the chassis for the 2nd robot is welded first to provide practice for our welder).
- Started welding DEWBOT VII's chassis (robot prime).
- Douglas cut a concave pc minibot wheel on the lathe for the scissor minibot
- Started building a 12"3 for minibot inspection
- A productive welding night. Chassis prime is almost complete
- Continued pivot module assembly
- Punchlist
- Chassis frame welding completed
- Pivot module assembly completed excluding sensor mounts
- Sensor mount screw holes drilled and screws mounted
- Pivot modules mounted on chassis frames
- Electrical panels cut
- Pultrusion cut for arm
- Obtained accutate mass measurements for pultrusion, pivot modules & chassis
- 4 pcs x 1½" x 1½" x 1/8" wall x 5' pultrusion pieces weigh 10.6 lbm
- 4 pcs x 1" x 1" x 1/8" wall x 5' pultrusion pieces weigh 6.7 lbm
- The pivot module weighs 9.1 lbm
- The welded chassis frame of robot prime weighs 14.1 lbm
- Chassis prime with drivetrain weighs 50.8 lbm
- Chassis deux with drivetrain weighs 52.3 lbm
Week Five (2/6-2/12)
- Punchlist
- Drilled arm column anchor holes in both chassis
- Designed angle sensor mounts allowing for easy zeroing at DRC)
- Electrical Panel robot deux
- drilled and tapped mounting holes
- laid out all electrical components and specified bolt hole pattern in panel
- drilled bolt holes in panel
- mounted all major electrical components on panel
- wired major electrical components
- mounted electrical panel on robot
- chassis, drivetrain & electroncs weighs 67.4 lbm (electronics panel weighs 15.2 lbm).
- Continued work on arm and claw fabrication
- Fabricated 20 wheel treads
- Punchlist
- Pivot angle sensor mounts (mostly) fabricated.
- Mounted the first two pivot angle sensors
- Reenforced the remaining pultrusion (excluding 2 pieces which need to be recut)
- Drilled mounting holes for main disconnect
- Continued wiring robot deux
- Punchlist
- All pivot angle sensors are installed
- Robot deux was turned on for the first time
- Wheel treads are on robot deux
- Replacement pultrusions cut & reinforced
- started laying out field markings
- Arm motor mount designed
- Robot deux went for its first drive today. Drive-train & drive control performance were absolutely wonderful! The robot clearly outperforms DEWBOT VI in this regard, and does so without teething problems. Unlike DEWBOT VI, the new drive-train appears to drive straight lines accurately. Kudos to the programming, electrical and mechanical subteams whose uncompromising efforts led to this result. The value of our post-season analysis and value engineering also shows.
- Minibot Design Meeting
- A deployment means was proposed by the Minibot team. This is accepted, but needs to be converted into a design ASAP. Rich Kulik responsible to CAD the systems and define parts to be ordered.
- The X-bot morphed to a V-bot. Action is to build and test a light-weight V-bot immediately to demonstrate (or not) feasibility of design. Parts are to be taken from the angle-beam-bot to support this test. The V-bot is believed to have deployment advantages over the angle-beam-bot.
- The angle-beam-bot has not demonstrated reliable performance. Reason uncertain, but the variability of the magnet mount geometry is a good guess.
- The composite Electronics Panel for robot prime was laid-up and left to cure overnight.
- cRIO and Compressor were liberated from DEWBOT V.
- Punchlist
- Installed arm on prime. This entailed quite a bit of fab work in cutting spacers, cutting, drilling and tapping shafts, etc.
- Unbagged and rough-trimmed the composite electronics panel (very cool)
- Cut Al for Arm Motor Mounts
- Trimmed and finished composite electronics panel for prime (4 lbm)
- Battery box designed
- Polycarbonate cut for battery boxes
- Electronics panel laid out, with learnings from deux incorporated
- Drilled mounting holes in prime electronics panel
- V-bot built using polycarbonate square tubes in lieu of Tetrix Al
- Deployment design getting close to an executable state
- Performed most of the machining on the Arm Motor Mount Al plates; cut polycarbonate for bearing block
- Resolved an oscillation problem on the left-front pivot of deux. Cause appears to have been flexure the nylon standoffs securing the Vishay angle sensor. Replacing this with steel hex standoffs stopped the oscillation (which was the original intent). Will make this change for all standoffs.
- Installed Electronics on prime's Electronics Planel and mounted the panel onto prime. Mass of Electronics Panel (including cRIO, Jaguars, PDU, Digital Sidecar, Battery Box, Spikes & photodetectors) is 16.7 lbm.
- Refined design of Claw (Maley), adding detail, strength and reducing mass.
- Based on claw design analysis, we determined to produce the critical claw bar (aka triangle) using composite materials. This part requires high strength & rigidity and low mass.
- V-box finished but needs better wheels. Molly designed lightweight wheels which will grip around the pole.
- Fabricated Battery Boxes
- Finished machining Arm Motor Mounts.
- Programming team tested dead-reckoning autonomous (inconsistent - we need sensors).
- Started fab of Minibot deployment scissors.
Week Six (2/13-2/19)
- Punchlist
- Assembled and mounted Arm Motor on prime
- Fabricated composite claw bars (aka triangles)
- Fabricated Claw
- Mounted Claw on robot - we need to do some refinement (but it's a good start)
- Designed Pivot Covers
- Designed drilling templates for IR sensor mounting
- V-bot development made good progress
- Prime's mass is now 95.7 lbm - including compressor, Clippard air storage tank, solenoids, Claw (w/ actuator cylinders) and a 0.4 lbm screwdriver used to prop the robot on the scale - excluding any minibot deployment equipment
- V-bot's operating mass (w/ battery) is 4.9 lbm
- Punchlist
- Installed "Molly Wheels" on V-bot and started testing. Rubber band treads won't work (fall off). V-bot climbs and does not fall off pole, but wheels slip a lot and speed is low. Working on the tread problem.
- Replaced 2000mm arm drive belt with 500mm. The long belt was too bouncy.
- Drilled holed for IR sensor mounting on prime.
- Moved claw to deux for development. Finished assembling arm on deux
- Installed coupling for arm angle sensor both robots
- Arm sensor mount designed.
- Started taping playing field.
- Punchlist
- Tapped mounting holes, mounted and wired IR sensors on prime
- Drilled IR sensor mounting holes on deux
- Fabricated Arm Angle Sensor Mounts (but center hole is a smidge small)
- Started Bumper Fabrication
- Worked on claw (on deux)
- Worked on V-bot
- Continued part fab on deployment system
- Punchlist
- Prime is driving and in the hands of Programming. Pivots calibrated.
- Claw is looking good and deployment seems worked out. Now we need pneumatics!
- latex tubing seems to make an effective arm balance
- Molly supervised the production of the first batch of pivot belt guards
- Most of field is now taped
- Parts being produced for the deployment system
- Bumpers are in the works
- V-bot seems to work satisfactorily
- Punchlist
- Alex, who has driven deux extensively, reports that prime drives noticeably better.
- IR sensors mounted & wired on deux
- Arm angle sensor mounted on deux
- Deployment system in assembly
- Pneumatic system being installed into deux
- All belt guards are complete (waiting on mushroom-head dots for installation)
- Low field walls built
- Punchlist
- Deployment mount specified
- CIMs reoriented to avoid bumper mount wingnuts
- Pneumatics installed in deux
- First claw test (under pneumatic power) - encouraging - some mods needed
- First line-following tests with prime - also encouraging - refinement needed
- Line following sensors mounted in deux (deux is all sensored up)
- Fanny-pad added to V-bot to prevent damage upon descent
- Bumpers in process
- Punchlist
- Field taped for practice
- Low walls in place on field
- Drivers stations set behind scoring grid
- Line following is working more reliably - and faster
- Keyways cut and keys installed in prime & deux arm joints
- Calibrated deux arm - 90° is arm straight out in front of robot (lower arm parallel with grade)
Final Daze (2/20-2/21)
- Punchlist
- Ice Cream Breakfast! Is this day upside-down?
- Change of plans! - in testing we assess the reliability of the intended minibot deployment system as low. This system is redesigned and built in one day. Constraint: we can only use what we've got.
- Claw completed, installed on prime
- A very, very nearly complete prime weighs 110.6 lbm, including a 1.8 lbm hammer used to prop up the arm.
- Sponsor panels cut.
- Pancake, bacon & eggs dinner - Yes, this is an upside-down day.
- New deployment system satisfactorily tested (with satisfactory results)
- Strategic decision: the camera is not needed to help hang logo pieces. The camera is needed to pick logo pieces off the floor and to align the robot with the pole for minibot deployment.
- Camera positioned accordingly
