January 9, 2017
The "Everybot Will” list was created after careful consideration, in order to determine the most effective aspects of a competitive robot.
2017 Everybot Will...
Score in the low boiler
Have an active mechanism to pick up ball off the ground
Receive balls from hopper/player station
Have autonomous to score a gear
There are two types of volumes of which you can build a robot: short (36” by 40” by 24”tall) and tall (30” by 32” by 36” tall). Everybot will be building their robot to the tall volume. Because of the rules that state that the bumpers have to be inside the volume, 3” are subtracted from each side. The Everybot subsystem chose a modified wide chassis option from the AndyMark Base Kit and the Everybot frame perimeter ended up 24” by 26”, with wheels being on the 24” side.
The Everybot subsystem decided to receive gears passively from the human player station. A pocket on the back of the robot was implemented to allow the robot to drive up to the chute and let the bumpers square off on the wall. Various heights and distances from the wall were tested by dropping a gear from the chute into our pocket to determine the proper position of the pocket. The best position was about an inch up from the top of the base frame and 3 ¼ inch back from the frame perimeter.
A 2x4 was used as the base of the pocket. A 2x4 was cut diagonally (see picture) and placed along the back edge to push the gear towards the front of the pocket (see pictures). Two pieces of wood on either side of the pocket at 45 degree angles were attached (see pictures) to drive the gear into the pocket and center it (see video). There are 6” between the angled pieces. A large backboard and short front wall were attached to complete the pocket. The pocket is 3 ¾ inches wide to allow room for the peg to penetrate the gear spoke area.
Because the Everybot subsystem is not pursuing the option to pick up gears off of the floor, the plan is to go and retrieve a gear from the human player station and then deliver it in tele-op mode. Additionally, the Everybot subsystem strives towards performing tasks in autonomous mode, one of which is to deliver the gear and then back away. The current design requires the pilot to lift the gear out of the pocket. The front wall could be actuated with a servo to allow the robot to deliver a gear without the pilot lifting it out.
Ball Intake and Scoring
The Everybot subsystem brainstormed possibilities to collect and score balls.
The robot can collect balls from the hopper by backing into the release mechanism or accumulating the balls from the floor by using a motorized rolling shaft (see picture). The robot can score balls into the low boiler by passively dumping balls or by using a raised rolling shaft.
Collecting Balls from a Hopper on the Side of the Field
The hopper lip is 25” off the floor. As the robot backs up into the hopper’s release mechanism, 50 balls will empty into a container on the robot. Therefore, the container walls’ height should be close to 25” in order to collect and store the balls.
To score passively, the container on the robot must be at least 18” off the ground (the height of the low boiler) and have a sloped bottom to successfully be able to pour the balls into the opening. In order to control the flow of balls into the low boiler, a robot could have a servo actuated gate mechanism.
Another option is having this dump truck container on a pivot point so when the robot drives into the low boiler goal, the load will passively dump.
Collecting Balls Off the Floor
Everybot is collecting balls off of the floor. To achieve this, there will be 2 motorized rolling shafts in the robot. The first shaft will intake balls and the second shaft will serve as an agitator to stir up the balls so that they do not jam up while entering the container. (This intake method has since been updated. See January 25 or the Intake tab for the current roller configuration).
January 16, 2017
In terms of ball intake, two roller prototypes were also developed . To create this, the Everybot subsystem placed a 3” foam pool noodle onto a shaft and attached it to a motor to create rotation. In the future, Eagle tubing can be used to create a pulley system between the rollers to bring the balls into the hopper through an elevator.
The Everybot subsystem had to understand which of these two rollers would be attached to a motor. To do this, we attached the shaft support mounts with the hex bearings that were installed into the base.
The white shaft pulley is a prototype of how Eagle tubing can be used on the shaft to bring up the balls into the hopper through an internal alley way inside of the robot.
Also note the shaft support mount (with hex bearing installed) attached to base.
As previously stated, this mounting is a prototyping effort to determine which way the ball intake shaft might be driven by a motor.
Another viable approach for the ball intake-shaft mounting can be observed from last year's Everybot - SEE the 2016 StrongHold link, the sixth photo down. The height of the ball relative to the desired intake shaft height must be determined, when using this method.
In the above picture, the Everybot subsystem is using a bag motor to drive the ball intake shaft. The center of the hex shaft was drilled out to allow for the small motor collar to emerge. In this case, metric bolts for the motor mount holes must be used. This is just one option the team is looking at to drive the shaft. As with anything, the Everybot subsystem is attempting methods to secure the motor more tightly.
During the prototyping phase, it is important to be able to adjust mechanisms to new heights in order to acquire the most effective mounting height. To do this, the Everybot subsystem aimed towards making the whole shaft assembly adjustable (i.e. capable of moving the shaft vertically during the testing stages).
As depicted, the Everybot subsystem brainstormed several methods to mount the motor. One method can be found in last year's Everybot (the sixth photo down).
In the picture above, the Everybot subsystem drilled out the end of a hex shaft to allow for a collar that would fit over the end of the motor shaft. This was held in place by a set screw. The set screw hole was drilled and tapped for this.
January 18, 2017
The picture above depicts what the shaft-to-motor connection looks like. To achieve this, the Everybot subsystem took a piece of rectangle tubing and drilled it straight through for motor-shaft alignment. Afterwards, the members drilled through one side to receive the hex bearing and the other to mount the motor. This bearing opening was used to have access to the bolt holes for the motor with an Allen wrench. The end result of these steps provided the necessary room for the rectangle tubing to be mounted to the base.
For other alternatives, take a glance through last year's 2016 EveryBot for another intake shaft-to-base mounting connection.
Depicted above is another angle of this process.
High to Low-Fidelity Airship
In terms of building the field, The Robonauts’ hard-working family members and additional personnel took the high-fidelity plans and built a low-fidelity airship platform.
The bottom portion of the airship was built in two pieces. Constructors used conduit pipes, wooden pieces, as well as angle brackets to create the railing. The exact dimensions for the creation of this airship were modeled after the 2017 Field Components PDF (https://firstfrc.blob.core.windows.net/frc2017/Drawings/2017FieldComponents.pdf).
January 21, 2017
The Everybot subsystem encountered an issue with the homemade Ethernet cable. The wires were placed in an incorrect order according to color. On one side, the colors were in the correct order: white-stripe orange, orange, white-stripe green, blue, white-stripe blue, green, white-stripe brown, brown. On the opposite side the order was: brown, white-stripe brown, green, white-stripe blue, blue, white-stripe green, orange, white-stripe orange. Simply put, the correct side complied with TIA/EIA-568-B.1-2001 standards, while the opposite side was made backwards. This meant that the radio was not able to properly communicate with the robot and its systems. The solution to the problem was to cut off the incorrect end and re-make it correctly. While Store bought Ethernet cables will almost always be made correctly and to a standard, teams that decide to make their own Ethernet cables should be careful to follow the internationally recognized standards for cat5 Ethernet cable. More information can be found at https://en.wikipedia.org/wiki/Category_5_cable
The Everybot subsystem also updated the firmware on the RoboRio and PDP, re-imaged the RoboRio.
January 23 2017
The mounting method described on January 18, 2017 had proven insufficient as it was discovered too tight on January 23, 2017. The screw holes are located too closely to the wheels, making it both inconvenient and difficult to take the motor on and off. The motor was also emerging beyond the frame perimeter.
In the photo below, the Everybot subsystem prototypes a vertical elevator system that transfers the balls up into the low boiler.
For a more in-depth description of this prototype,continue to the Hopper tab.
The Everybot subsystem had to rework the intake motor mount in order to make it easily removable. A piece of rectangle tubing was marked for the motor mounting screw holes.
According to these markings, pilot holes were drilled through the material.
In the picture below, a step drill bit was utilized to widen one side of the holes, to allow the screw head and tool to go through.
Afterwards, members deburred the holes in order to improve the quality of the piece.
Following this step, members drilled and tapped 10-32 screws to the surface of the base support in order to mount the intake motor mount.
These two holes were drilled out in the rectangle tubing. The through holes were on one side, while the step-drilled holes were on the other to accommodate the screw heads and tool.
A new Eagle tubing belt was also created. Note the new motor mount depicted, as well.
The picture below shows another ball intake prototype.
In this same photo, the motor being installed onto the mount can be seen on the lower right-hand corner. The two small holes behind the tool being used are for the screw mounting to the base.
January 25, 2017
The Everybot subsystem concentrated its efforts towards perfecting the ball intake. The objective for this mechanism was to intake the balls straight from the floor. To do this, four 18.5” metal shafts were wrapped in magic tap to achieve the friction necessary. Two of these wrapped rolling shafts were positioned 5” a part, raised 2” from the bottom of the robot. The remaining two wrapped rolling shafts were placed aside to be positioned 22” from the floor, 3” a part. However, the Everybot subsystem is yet to achieve this task. The overarching idea behind the ball intake system is that balls will be collected from the floor and brought upwards through a vertical elevator system to the “shooting” device (a wrapped axle attached to a bag motor) which will score the balls into the low boiler.
A major dilemma that the Everybot system has to overcome throughout this entire process was the limited amount of motors available. Only seven motors could be used, and four were being utilized for each of the wheels in the base. It was thus decided that the remaining three motors were going to be used on:
The ball intake system (four wrapped axles)
The “shooting” axle
A door located on the back of the robot (This device will be further elaborated on in the January 27, 2017 section of the Daily Blog)
Therefore, all of these seemingly separate axles in the ball intake system had to coincide and use the same bag motor for all of its motion. To do this, the Everybot subsystem utilized eight sections of Eagle tubing. On January 25, 2017, the subsystem did not complete this entire process of wrapping the Eagle tubing between the aforementioned four axles.
A more detailed description of the current intake mechanism can be found under the Intake tab.
January 27, 2017
On this day, the Everybot subsystem dedicated its time towards developing the door. The idea behind this mechanism is to trap the balls collected from the hopper. Once balls are received from the hopper and into the robot’s container, this motorized door moves upwards and prevents any of the balls from falling out of the robot’s control.
A 23.5” x 10.25” (l x w) piece of thin wood was cut to create this door. On the right side of the back of the robot, a 17.5” AndyMark vertical slide was placed. On the left side, a channel was attached parallel to this vertical slide using countersunk screws. The rectangular piece of wood fit directly in between the vertical slide and channel. The movement was initiated by an attached belt, powered by a bag motor. In the future, this bag motor may be exchanged with an AndyMark motor, and was only utilized initially because of convenience.
In addition to this, improvements were also made on the ball intake system. The initial framework for this ball intake system (that supported the four axles) were constructed out of flat steel metal sheets. However, this specific material bent under the pressure of the Eagle tubing. Therefore, the Everybot subsystem decided to exchange this steel metal to angled aluminum beams. These angled aluminum beams supported the ball intake system much better and met the needs necessary.
January 28, 2017
On January 28, 2017, the Everybot subsystem developed both the door mechanism and the ball intake system towards a higher standard. The Everybot subsystem also improved the shooter device. Members did this by wrapping a metal axle in magic tape. This axle was mounted to a height, parallel to the low boiler. A bag motor was attached to this axle which allowed the rolling shaft to rotate. Once, a ball would be collected from the floor, brought up through the vertical elevator system, and through the rotating axle shooter, the rotating force would push the ball outwards and into the low boiler.
January 30, 2017
On January 30, 2017, the Everybot subsystem encountered an issue. As mentioned previously, the structural supports for the ball intake system bent under the tension that the Eagle tubing had caused.
The term “tension” encapsulates the pulling force of the Eagle tubing between the rotating axles. Tension can be found with the equation: T= mg+ma, and is recorded in Newtons. Therefore, the greater amount of tension equates to a greater amount of force that is being applied to these structural supports. The flat steel plates bent under this pressure and were incapable of withstanding the force applied. Because of this, we planned on replacing this with angled brackets. These brackets would provide more support in order to endure the exact amount of tension exerted through the Eagle tubing.
This day was dedicated to switching these steel plates with aluminum “L” brackets. It is important to note that the exact same mounting method was utilized with these new supports as with the steel plates. One 17 ¼” angled aluminum bracket was placed on both of the sides, parallel to one another. These supports were mounted to the robot in this fashion:
Attach a bearing to both sides of the most-front rotating axle (wrapped in magic tape)
Outside of this bearing on both sides, attach a mounting plate (this plate should have holes already drilled in it. If not, drill one hole into each of the mounting plates.)
Drill one 10-32 hole ½” from the end with a 7 clear drill bit. (the size of this hole can be altered according to preference, but must correspond with the hole drilled in the mounting plate, as noted in 2.)
Flip the bracket, and drill one 10-32 hole ½” into the other end.
There should now be two holes drilled into this 17 ¼” aluminum bracket.
Bolt one end of the angled aluminum bracket to this mounting plate (that is attached to the wrapped rotating axle). Complete this task on both sides of the axle, making the robot symmetrical.
These structural supports should now be mounted to the axles, but must be connected through a horizontal metal beam at the top, that holds the upper two rotating axles. (This step will be expanded on in the the following blog posts, as it is yet to be accomplished).
This entire ball reservoir system is at an angle, creating a direct slope between the height of the hopper (24”) and the low boiler (18”).
When creating measurements for your own competitive robot, please take note that we utilized the game objects to guide our dimensions. For example, the height of the most front-forward rotating axle from the ground was derived from the ball’s height (minus ½”). In addition to this, the distance between the two lower rotating axles was derived from the ball’s width (minus ½”).
As a brief update, the motorized door is still going to be pursued, in order to trap the balls once retrieved from the hopper. The rotating axle ball intake is also the direction we are going for this year’s Everybot. Lastly, the magic tape-wrapped axle is also the current outline for the “shooter” system. As mentioned in previous blog posts, this shaft does not necessarily shoot the balls, but rather it disgorges or expels the balls into the low boiler.
February 1, 2017
Today, the Everybot subsystem spent time re-shafting the top rollers. These top rollers were a part of the ball intake system, but were evidently an issue. We encountered a problem when trying to manipulate the roller.
Terminology: The inner shaft (inside of the roller) is called the axle.
The axle was too short and therefore was difficult to remove and put back into the shaft. To fix this issue, we removed the axle and inserted a longer axle. Once this was accomplished, we placed a stopper on either side of it to prevent slipping. This basically allowed us to easily manipulate the entire shaft/roller.
Once this task was completed, we also focused on adding another Talon motor controller to the control panel. This was added to accommodate for the climbing system that we plan on adding later (which will require a motor).
As a tip, the Everybot subsystem connects everything from 0-9, reading left to right. To elaborate on this thought, on the Robo Rio, there is a control panel that connects to motors, reading 0-9. Just to make things simple for our software and controls systems, all of our motor controllers are linked to the Robo Rio and PDP (Power Distribution Panel) by growing in number from left to right (i.e. Motor 0 is on the most-left side, and the hypothetical Motor 9 would be on the most-right side).
Lastly, the Everybot subsystem also developed new ideas on picking up the gear. We prototyped a new method in which we would have a passive “gear grabber” that would pull the gear from a horizontal position to a vertical position, onto a Plexi-glass plate. This Plexi-glass plate would then be driven upwards through a vertical lift, and thus into scoring position. We spoke about integrating this linear slide system with the same device used for the motorized door.
The Everybot subsystem created this “gear grabber” out of ¼” Lexan sheets. We cut two 8x1” Lexan pieces (as the fingers of this mechanism) and one 3.5x1” piece (to connect these fingers). To create this exact grabber prototype, follow these steps:
- Cut the aforementioned Lexan pieces with a band saw or a jigsaw (with a fine blade). You should now have three pieces in total.
- Bolt one end of the 8x1” piece to one end of the 3.5x1” connector piece. This should resemble an “L” formation.
- Take the second 8x1” piece and bolt it to the other end of the 3.5x1” piece. This should resemble a “U” formation. Bolt size does not matter, but we used two 10-32 bolts and nuts, drilling the holes with a size 7 clear drill bit.
- Bolt one 1.5” bolt onto the end of one of the long Lexan pieces. Repeat this step for the other long Lexan piece. There should now be two long bolts emerging from both of these Lexan pieces; parallel to one another.
- Attach rubber grommets (through the use of nuts) to the end of these bolts.
At a later date, we will elaborate on the vertical lift system, and how efficient this gear prototype becomes.
February 4, 2017
On February 4, 2017, the Everybot subsystem found an error within the code for the drive train. The left side of this code had a break whereas the right did not. With this issue, the right side of the robot continued to move even when the joystick was not being touched. We fixed this issue by troubleshooting the code and fixing some values. Next time, we will be more conscientious of the code.
In addition to this, the gear intake was improved upon. A new vertical belt, running from the top axle to the bottom axle, was implemented. This belt, attached to the gear intake, was measured to fit the intake’s vertical length. The belt was attached using heat shrink.
Lastly, we worked on the hopper ball intake. We discovered that the space on the top of the hopper between the two top intake axles was too small. In order to fix this problem, we took the hopper intake off of the robot by unscrewing the bolts (that attached the intake to the robot.) Then, the Everybot subsystem measured how much space was necessary. We then reattached the intake to the robot. After this was done, we also discovered that the intake needed more Eagle tubing between the two front top and bottom axles. To accommodate this issue, we added 5 extra Eagle tubing rings around our robot. The intake worked in a much more efficient manner, afterwards. We twisted the Eagle tubing (that was attaching the top front axle to the motor) into an 8-shape.
February 10, 2017
Today, we spent the entire work session replacing the wooden frame with aluminum supports. This provides a more realistic design, making the entire robot more structural and robust. To do this, follow the same directions as before when constructing the frame.
February 15, 2017
We are pleased to say that the Everybot is close to completion. Here are the updates we have made since February 10, 2017.
First, we changed the wooden structure to aluminum. Four 1” aluminum tubing pieces from the Kit of Parts were used to transition from the prototyping phase to the flight robot stage in building.
Side-length Lexan pieces were also added to enclose the balls. These were attached by Velcro to the aluminum posts on the side. We may exchange this method of attachment from Velcro to zip-ties, depending on the force that the balls exert on the Lexan.
Once this was accomplished, we focused on completing the gear pickup mechanism. The Everybot subsystem added a ¼” polypropylene 24 ½” x 20” rectangular door to the elevator system. Remember, this door is going to be both utilized 1) for the gear pickup system to move the gear from the floor to the appropriate height for scoring, and 2) for ensuring that all of the balls from the hopper (in the frame of the robot) do not escape while driving. This belt system ensures that when we need to get balls from the hopper, the door will go down, and when we need to drive away and score these balls, the door will go up.
It is important to note that we had to support this polypropylene door. To do this,we attached the polypropylene rectangle to two wooden blocks (one on either side). These wooden blocks were then attached to the outer wooden frame. (Right now, this gear pickup system is all detached from the robot and is yet to be integrated. That is why there is a wooden frame mentioned, instead of an aluminum frame). A right triangle Versabracket was also added for support.
We then worked on the physical mechanism that picked up the gears from the floor and transitioned them to scoring position. To do this, we made two fingers out of Lexan, and a connector piece, that made it resemble a straight “U” shape. We bolted 1” pieces of surgical tubing (wrapped in friction tape) to the ends of these fingers. We bolted this mechanism (from the connector piece) to an angle Versa gusset piece. We then attached this Versa gusset to a long scrap piece of aluminum that connected to the motor. This motor is responsible for pushing the finger device inwards and outwards so it can latch onto the gear. Note: this motor comes in the Kit of Parts. However, we modified it to accommodate our needs. We took the gear (that was originally inside of it) out and used a grooved out aluminum bar to achieve the same purpose (as the gear).
Through this method:
The fingers pick the gear up in the triangular plane of space in a horizontal position.
The belt system moves upwards.
The gear hits a piece of Lexan, and transitions from a horizontal state to a vertical position.
The belt system continues to move upwards until reaching the optimal scoring height.
The driver moves the robot forwards and scores the gear.
The Everybot subsystem changed the Eagle tubing to a chain and sprocket drive because the Eagle tubing continued to “chew up” the Magic tape (that wrapped the rotating shafts). The Eagle tubing also contributed to issues with the motor. The chain and sprocket connects to the upper shaft of the intake (also known as the back half of the intake system). The front half of the intake is driven by the back half through a twisted piece of Eagle tubing (on the opposite side of the sprocket drive: the Eagle tubing is on the left-hand side, while the sprocket drive is on the right-hand side). This twisted piece of Eagle tubing, however, is inefficient as it keeps stopping. As a short-term fix, we plan on continuing to put a “band-aid” on the problem and just add more Eagle tubing.
We are elated to say that we added a climbing mechanism! Now, an aluminum hex shaft runs in between the two front aluminum frame posts, about 4” above the shooting device. Note: that we try to avoid aluminum as it easily bends. A steel shaft is a better alternative, and we plan on either replacing the aluminum hex shaft with this or reinforcing it. Next, we milled this aluminum hex shaft. This allowed for the flat surface necessary for bolting two split hex shafts that would rotate, grapple the rope, and pull the robot upwards. However, the fact that we milled the aluminum shaft down even more made it less sturdy and more prone to bending.
The motor that controls this rotating motion is a Mini-SIM adapter that connects from the Mini-SIM Vex Gearbox, purchased from AndyMark.
February 17, 2017
One of the students came up with a way to pick up the gears from the ground, instead of relying on the team player-fed method. Today, we started work on creating a "picker-upper." We will rename this later, when we finish it. Below are two videos of our progress of said "picker-upper."
February 20, 2017
Today we finished attaching the aforementioned gear intake door to the Everybot. After we accomplished this goal, we also began creating a low boiler ball shooting autonomous.