2013-14 VEX Toss Up Engineering Notebook

Engineering Notebook VEX Team 8756
McCallum High School 2013‐14

Date: 09‐05‐2013 Start Time: 4:15 End Time: 5:30
Recorded By: Dexter Snacks: Chips/Fruit Leather Page:

TASKS REFLECTIONS
Figure out which tournaments we will be
participating in this season. Since there are
quite a lot this year that are happening in
Texas, we have a lot of options and will
probably be attending a decent amount.
We have decided on specific competitions to
attend in the Austin area, and one in Houston,
there are some other possibilities in the
Houston, Dallas, and Austin areas. There is a
larger competition that is qualify‐only later in
February, so if we qualify, we will attend. The
overall goal of course is getting to worlds.
Consider ideas for recruiting new team
members, both upper and lower classmen.
Lower classmen are preferred since all of
the current members are seniors.
So far Dexter has gotten one possible new
member who can attend some of the
meetings. In the long run, we want new
members who are in lower grade levels so
that there is still a team next year when the
current seniors leave.

Tournament Possibilities:
 Scrimmages before any official competition
 Houston Regional Competition
 Austin VEX Competition
 Killeen Regional Competition
 Possible: South Texas Regional Competition

Recruiting Ideas:
 Sponsor will talk to underclassmen in her various CAD and engineering classes
 Convince friends to create a B‐Team
 Signage in the halls
 Morning announcements


Date: 9/10/2013 Start Time: 4:15 End Time: 5:30
Recorded By: Dexter Snacks: Chips Page:

TASKS REFLECTIONS
Brief the new recruits for the B‐team on the
goings‐on and rules of Vex in general and
the new competition in specific
The new team has begun assembling the VEX
proto‐bot to teach them the ways of robot
building. So far they seem pretty interested
in the prospect of making the robot and
competing in the regional Austin
tournament.
Remove the linear multistage slide lift (1103‐
style) since it was too big for the robot and
not very convenient for our purposes
Now we need to come up with an idea for the
intake and a method for hanging the robot,
hopefully high hanging. We’ll be making
plans for the intake between this and the
next meeting.
Oversee the new team, make sure they are
going strong, and working diligently,
meanwhile discussing intake ideas for our
robot.
They are working fine, and our discussions..
well they devolved a bit into discussing
school, and other non‐VEXian topics.
Remove the plate that the brain sits on so we
can replace the metal with aluminum and
move the brain to a different location
The new location for the brain will help save
space for things such as the intake and
hanging mechanism.


Recorded By: Dexter Snacks: Girl Scout Cookies Page:

TASKS REFLECTIONS
Discuss intake/linkage designs for the robot We have decided to have an “NZ” style intake,
with horizontal rollers on the sides of the
intake. We had an idea to move the basket
separately, but we will make the rollers go
along with the robot.
Discuss food   We need food for every robotics meeting,
hungry kids=no progress
Remount the brain towards the back of the
robot, for looks and ease of access.
This will be helpful for making the brain easy
to access, and also make more room for
linkage/intake/and more.


Recorded By: Dexter Snacks: none Page:

TASKS REFLECTIONS
Brief a new senior member of the robotics
team on the goings‐on of our robot and the
contest. He’ll be on our team since he is a
senior, and wouldn’t be much use on the
freshman team.
Dexter and Jake will begin working on an
intake soon, and JT and Aidan will work on a
lift method.
Remount the brain It works now, and we can put batteries in the
slot we made, which is useful.
Discuss intake/lift methods Basically our best idea is to create a horizontal
roller mechanism, but we’re still not sure
about the basket part. The lift is going to
have to reach about 40 inches, in order to
hang.


Recorded By: Dexter Snacks: Pirate’s Booty Page:

TASKS REFLECTIONS
Work on the intake, strengthening it in order
to attach the motors and the roller that will
actually intake the buckyballs
Since the intake basket was initially made out
of 1x25’s, it’s very difficult to strengthen it,
since we basically have to take it apart and
rethink it completely.
Work on a linkage design that will go in
between the treads of our robot and also
stay under the 12” height limit we have set
for ourselves. We will not be using any sort
of reverse linkage and currently are leaning
on the idea of a 6‐bar.
After Aidan stared at metal long enough, he
came up with a standard 6‐bar linkage
design we can use that stays under the 12”
height limitation if we cut the extra ends off
some of the pieces, and also reaches over
40” into the air, perfect for high hanging.
Sort screws, metal, and all of the loose junk on
our worktable.
This is just an ongoing process that will
probably never end until we spend multiple
hours just organizing, sorting, and finally
everything will be clean.


Recorded By: Dexter Snacks: Fruit snacks‐Chips Page:

TASKS REFLECTIONS
Work on an intake that focuses simply on
collecting the bucky‐balls.
This has gone smoothly, we have decided,
finally, to use a horizontal roller with a
chain attached to a powered gear in the
center of the roller.
Create an 8‐bar linkage that stays under the
12” barrier we have set for ourselves when
fully retracted and then extends at least
35”‐38” in height to reach the hanging bar.
It looks good; there currently aren’t any visible
issues with it. But the one thing we don’t
know for sure is how stable it will be.
Cut aluminum c‐channels on the linkage to fit
under the height limit, as the pieces that
need to be cut are excess.
This worked, we needed a jigsaw, but Aidan’s
dad has one, so we were able to easily cut
through the aluminum like butter.
Replace some steel parts on the drive base
with pieces of aluminum to lighten the load
on the back of the robot.
The aluminum has helped make the robot
lighter overall, and has also improved the
center of gravity extremely, now there isn’t
as much of a back tipping issue.
Build a gearbox for the linkage. Gearbox looks solid, it was built so there are
no axles with unsupported areas, so there
won’t be an axle twisting issue. But
stripping might turn out to be a problem.
Build a motor mount and mount the motors
for the intake mechanism.
The motors don’t seem super stabilized, but
since all they are doing is powering the
rotating ball intake, it shouldn’t be that big
of an issue.


The roller is on a swinging arm that is stopped so it’s high enough at the end to fit a ball



Retracted (12 inches tall)

Extended (41 inches tall)



Gearbox (top); All of the –current‐ disassembled parts (bottom)


Recorded By: Dexter Snacks: Cheese squared Page:

TASKS REFLECTIONS
Attach the intake to the arm This went well, we don’t have the intake at the
highest point on the arm since it’s not
necessary, so there is a little horn‐looking
peak on our arm.
Wire up the motors on the robot Went slow at first since some of the motor
controllers were hidden behind motors
which had to be unscrewed to get plugged
in, but in the end we got everything plugged
in very easily.
Begin programming the robot Very easy since in a programming sense, our
robot is the same as our Sack Attack Robot,
so the only things that need to change are
the motor numbers.
Figure out where we need to put a hook on
the top of our arm for robot high hanging
purposes.
Using some trigonometry we were able to
easily figure out how our robot fits in the
corner of the field and decide on a position
for our hook.


Recorded By: Dexter Snacks: Pretzels Page:

TASKS REFLECTIONS
Add a program to the tank tread robot and
test the results.
After extensive testing we realized several
problems:
1. Couldn’t get over bump
2. Massive friction
3. Because of the friction, our motors
experienced massive resistance making
them overheat immediately.
4. Really bad derailing on the bottom
5. Tread slips off (clicks) over the
powered sprocket
Completely remove all of the tank tread
mechanisms, except for the motors
themselves as they are in a good, solid spot.
This involved, first and foremost, unscrewing
and removing all of the rubber band
tensioned tread suspension. Then,
removing all of the miscellaneous odds and
ends that were involved with attaching the
tread to the robot.
Come up with a new idea for our drive train. We have decided to go for a localized motor
design, using the top wide c‐channel as the
supports for each motor. There will be a
total of 6 wheels, each with one motor to
prevent friction, and to get our robot over
the bump.
Begin the assembly of the new drive train. So far, no progress has been made on the
drive, but we should have it done by
Thursday of next week, the day when we
begin packing for Houston.

Critical Deadline: October 24, 2013 – Need to have robot finished



Completely disassembled robot


Date: 10/19/2013 Start Time: 9:00 a.m End Time: 4:15 p.m
Recorded By: Dexter Snacks: Whataburger Lunch Page:

TASKS REFLECTIONS
Create a wheeled drive train for our robot.
 Six wheels powered by six motors (1
motor per wheel)
 Decide on a method for mounting the
motors (direct drive vs. a motor block
at the back end of the robot)
 Figure out how to attach each wheel to
the motors
We decided to use the largest wheels
provided by VEX, they are just standard
wheels, not omni or mecanum. We decided to
go for a motor mounting solution with 2
groups of 3 motors on the back right and left
sides of the robot. We attached the motors
like so:
 1 small sprocket chained to another on
the inner‐outside edge of the wheel
base.
 The axle attached to the chained
sprocket powers a long length of high
strength chain that winds around the
wheel base, powering each wheel.
The drawback to having all of the motors
positioned at the back of the robot is that it
could create a backwards tipping problem like
we had before, but so far it seems like our
robot has a sensible center of gravity.
Prevent the high strength chain from slipping
off of the sprockets by using a tensioner.
This was most important for the chain
connecting the motor block to the powered
sprocket, and all we really had to do was
slide in another small sprocket so it spreads
out the chain very slightly, no rubber band
tensioning mechanisms necessary.
Build the framework for the “tower” of our
robot, as well as a mounting solution for
the brain, power expander, and wires. For
the brain and power expander, we are just
hanging it off the back plate of the robot
with 1x25’s. For the rest of the wiring
(motor controllers, sensors, etc..) we are
tucking all of the wiring in the space
between the two 5x25 c‐channels.
Our tower is not even a normal “tower”, there
are really only two 5x10 c‐channels that
make up the entirety of the tower, this is
where our arm’s gearbox will be exclusively,
making it quite difficult to compact it
enough. The wiring will be pretty
straightforward and tidy, but possibly
difficult to access.

Gearing



One side of the wheel base

The wheel base motor block/gearbox



The completed (and new) wheel base

The new wheel base and “tower” with the arm in place (not attached)


Recorded By: Dexter Snacks: none  Page:

TASKS REFLECTIONS
Design and build a gearbox for the arm. Our
gearbox is very condensed, using high
strength gears, no chain, and one motor per
arm.
This gearbox looks like it will work very well,
there are not that many gears, and the lack
of chain makes it very rigid. On the other
hand, there are a couple very small spaces
between some of the gears, so there’s the
possibility for the gears to touch during a
heated match in competition.
Wire the robot – hook up all of the drive
motors and arm motors to motor
controllers and plug 2 drive motors from
each side of the robot into the power
expander.
This took a lot of 5 cent zip ties to complete,
which is unfortunate both financially and in
terms of usability, because a lot of the wires
are completely wrenched down on the back
5x25’s, making them both hard to reach and
hard to work with.
Begin thinking about adding the hook This didn’t go very far…
Organize a box of parts that can be taken to a
competition and has only the necessary
parts for a competition, that way we don’t
need to bring as much, and only have the
absolutely necessary parts for our robot.
Aidan seemed to be doing well with this task,
and found a lot of low‐strength gears which
were consequently unsorted into a plastic
bag.

New Gearbox – 15:1 ratio Robot Wiring


Recorded By: Dexter Snacks: Cookies Page:

TASKS REFLECTIONS
Finalize the wiring on the robot; basically all
that needs to be done today is connect the
rest of the wires to the cortex.
This went really fast, there wasn’t much that
needed to be completed for the wiring.
Then Dexter made a diagram for Aidan
depicting all of the motor numbers and the
ports where they are plugged into on the
cortex.
Remove the middle wheel on each side of the
robot and reconfigure the chain a little bit
so there was no stopping between the front
and back wheels.
This will actually help us go over the bump
much easier, because the 5x35 c‐channel is
actually about 2.5 inches above the ground,
so after the leading wheel clears the bump,
our robot can straddle the bump. One issue
that might come up is that we have a long
stretch of completely exposed high strength
chain which may get caught up in another
robot’s arm or other mechanism which
would be very bad.
Begin programming the robot. Going slowly, Dexter’s diagram for the motors
and ports seems to be mildly useful, but the
way he wired the robot is pretty confusing
since the ports and motor numbers don’t
line up.

Now there is simply a chain running from the powered wheel to the front


Recorded By: Dexter Snacks: Fruit leather Page:

TASKS REFLECTIONS
Replace the two arm motors and one of the
driver motors, its internal gears were
completely stripped out, then rewire those
three motors.
This wasn’t too hard of a task even though all
of the wires are zip tied down to the robot,
and it is very helpful since working motors
that aren’t stripped help things.
Attach potentiometers to the arm axles and
possibly optical shaft encoders to the drive,
but we aren’t sure about those.
This will help us install the arm‐stabilization
program to the robot so our arm won’t go
below the wheel base (making it pop up)
and keep it from dropping on its own.
Add the basic drive and lift program to our
robot and test for any possibly friction
points.
So far it seems like this new drive will serve us
very well, there isn’t much friction in the
sprockets and the wheels can very easily go
over the bump. The arm motors,
unfortunately, are not strong enough to lift
our robot and hang.
Dexter will work on finalizing the engineering
notebook, polishing past pages he’s done.
This went well; the only thing that really
needed changing was the times on each
page, and adding in some photos for the
more recent pages.


Date:10/26/2013 Start Time: 7:30a.m End Time: 5:00p.m
Recorded By: Dexter   Snacks: BBQ Sandwich Page:

TASKS REFLECTIONS
Compete in the Houston Regional robotics
competition – we had 5 matches in total,
we won the first 2 matches and lost the last
2, we had no ally in our last match so it was
a pretty easy win for the other alliance.
Our robot was semi‐decent overall, pretty
much all of the elements of our robot will
be changed – wheel base, motor mounting,
wheel type, intake type, and more, we will
be keeping Aidan’s linkage since it is
probably the most unique and strong
linkage we’ve built in a long time.
Fix ongoing problems that occurred during
matches and during practice. One of the
major problems that kept popping up was
that the chain connecting the 3 motors to
the wheel chain would break over and over
again. Another issue that came up was that
our intake mechanism would drag along the
ground, so we added a simple float
mechanism (standoff) to get it off the
ground a little. The last major problem,
which ultimately led to the demise of our
robot, was that our wheels were incredibly
grippy making it nearly impossible for our
robot to turn in place. During one of our
driver skills challenges our robot actually
sheared off screws on the tower due to the
immense torque being applied to the robot
because of the wheel grip.
On our next robot we will resolve any chain
problems by using gears wherever possible
and likely by using direct drive on our wheel
base – motors on the inside of the chassis,
and wheels on the inside. We have decided
that we will probably be using omni wheels
for our drive base because they allow our
robot to turn in place very easily. We will
stick with a 4‐wheel drive since 6 wheels
aren’t really necessary and would require
extra power that we have decided to
devote to the lift (4 motor lift geared down
at 15:1). Our robot’s construction was also
not particularly splendid; we used way too
many standoffs in very important places on
our robot which we will be changing on
future robots of ours.
We weren’t picked for finals, but we still
watched all of the finals matches for fun
and to see if won the Excellence award,
which we didn’t.
We were actually happy we didn’t get picked
for finals, because our robot would not
make our alliance member very happy,
finals requires a robot with longevity,
something our robot clearly, and
unfortunately lacked.


Date:10/26/2013 Start Time: 7:30a.m End Time: 5:00p.m
Recorded By: Dexter Snacks: BBQ Sandwich Page:


Recorded By: Dexter Snacks: Cheese Squared Page:

TASKS REFLECTIONS
Discuss new possible robot designs and
solutions to problems that arose during the
Houston regional competition.
Problems with the old robot:
 Wheels are too grippy for turning and
maneuverability.
 Chain connecting the drive motors to
the wheels keeps breaking.
 The 6‐motor drive isn’t really necessary
when it could be dedicated to the lift.
 Our drive base is much longer than
other robot’s, so in order to fit in with
the crowd and in order to get over the
bump easier we’ll use a shorter base.
 Our top‐roller intake design proved to
be quite ineffective compared to the
side rollers used by other teams.
We have decided to fix the problems that have
arisen by using a short (20‐25 long) drive base
using only 4 wheels and powered directly (one
motor per wheel) so we have 2 extras for the
lift. 4 motors on the drive is plenty for 1:1 and
4 motors on the lift using the same gear ratio
(15:1) will enable us to lift and score extra
points. In addition we will reduce chain usage
and standoff usage to strengthen the robot
and prevent breakage.

Doug will begin disassembling our robot to
give us maximum time before the Austin
Regional Competition to design and build
the robot.
Doug’s disassembly proved to be immensely
useful, because we were able to finalize our
ideas and divide up labor for the next
iteration of our robot. Plus, as a bonus,
Doug organized all of the parts as he
disassembled something none of us would
have done.
MECANUM DRIVE We will be using a mecanum drive in all of its
strafing glory, because while an omni drive
would allow us to turn easily, we could very
easily be pushed sideways across the field
which would be very bad for us. Strafing will
also allow us to accomplish some desired
tasks.


Recorded By: Dexter Snacks: Cheese Squared Page:


Recorded By: Dexter Snacks: cookies Page:

TASKS REFLECTIONS
Aidan made the decision to use direct motor‐>
axle‐>wheel with the mecanums being
flanked by aluminum c‐channel that are
both 25‐long, so our wheel base has
changed in three ways – new wheels, new
size, new motor mounting, and this time
with 100% less chain!!!
The shorter wheel base means the wheels
have to stick out a little past the edges of
the c‐channel which means they will
undoubtedly hit the bump first, therefore
less momentum will be lost, second the
smaller drive means the wheels are closer
together, meaning it’s harder for our robot
to get caught on the bump. Lastly, and most
obvious, is that the mecanum drive will
prove to be quite useful, or at least more so
than sack attack, because there is a lot
more maneuvering that can be done when
avoiding or picking up balls.
J.T began working on an intake design, but
didn’t get very far since intakes are one of
the weirder, more obscure things to design.
J.T has some interesting ideas for the intake
that may or may not prove to be useful, or
even buildable, it’s difficult for him because
we have a very tight, but vague size
restraint – it must fit between the lift arms,
but we’re currently not even sure how wide
that is.
Misc tasks: Dexter cut 3 full length aluminum
c‐channels down to 25 units long, Aidan
helped Doug teach the M‐team some basic
programming to get their robot up and
running, and Dexter copied what Aidan had
done for one side of the drive.
Cutting the aluminum with a jigsaw is easy, M‐
team seems to be doing good work, they
already have their own tank drive nearly
finished and programmed, now they will
have to begin thinking about lifts, and by
the sounds of them talking about linkage
concepts, they are well on their way.



TASKS REFLECTIONS
JT worked on the intake some more, deciding
it would be the best idea to use the largest
sprocket for the intaking part and attaching
the motor to the same side of the c‐channel
that the roller is on, just spacing them
enough so none of the flaps get caught on
the powered chain or the motor.
This intake design should work very well, or at
least from what we’ve seen at competition
it will work very well, we will have chain
with flaps attached for intaking the bucky
balls and on the top of the axle, a smaller
intake mechanism for the big balls.
Aidan had to rethink the wheel mounting
solution we were using, because the old
one was scaring us with its insecurity and
plastic qualities. The new one utilizes cut
1x25 pieces, bearing blocks, and standoffs
and seems pretty secure for being relatively
dumb.
The new mounting solution is more effective
than the plastic pieces we were using
before, and although its construction is
dubious, it is surprisingly sturdy.
Unfortunately, we don’t have a good place
for the front motors currently which
presents a problem for the arm and intake.
Other tasks: the tower was slightly modified in
order to get it more secure and more
efficient, Aidan and Dexter spent a good
deal of the time thinking about a new
method for mounting the front motors so
it’s out of the way of the intake mechanism.
The motor mounting problem is going to be
the biggest issue when moving forward with
our robot, so before we attach the tower
we are going to have to slowly move
through the process of making a new
mounting system for the front, most likely
attaching the motor to the inside of the
drive base and then connecting that to the
wheel via chain that runs along the outer‐
inner edge of the wheel base.

The current selection of mechanisms of our robot



A close‐up of the current wheel mounting mechanism


Date: 11/1 – 11/3 Start Time: 12:00 End Time: 5:30
Recorded By: Dexter Snacks: CHZ2
Page:

TASKS REFLECTIONS
Rethink the drive base power system – this
involved moving the motors inwards, so
they are both right next to each other and
connected via chain to the mecanum
wheels. The motors are also now located
above the c‐channel that attaches the
wheels.
This is much better solution to what we had,
because now the front motor is out of the
way and still just as easy to remove as it
was when we had direct motor to wheel
power with no chain involved. We tested
the drive and it seems to be working fairly
flawlessly, if we had the robot fully
assembled and the weight properly
balanced, we think it will work perfectly
fine.
`Think up a solution for the arm, since the
wheels require a wider drive base, there is
less room between the two sides of the
drive base to have an intake, but since we
want to intake large balls, we have to have
a wide enough intake for them, so in the
end our arm has to clear the wheels but
also start at a lower height.
The lowered starting height and need to clear
our drive base has driven us to make a 10‐
bar linkage, which we have officially dubbed
ham‐bone. Aidan will begin working on the
linkage as soon as we have the 15‐long c‐
channel pieces required for it.
Create the gearbox for the arm and attach two
motors per side to provide sufficient power
for lifting.
This required a little bit of interesting gear‐
work, but not too much, it was basically
getting a 15:1 gear ratio and have two
motors powering each arm.
Make minor modifications to the intake
mechanism including perfecting some of
the attachment methods, tightening
screws, and compressing the whole thing
into a 10 unit long mechanism that is
attached onto a 15‐long c‐channel.
Having the mechanism about 5 units shorter
than the c‐channel it is attached to allows
us some free space for creating a
mechanism that allows the rollers to either
fold upwards or inwards, something
required for our robot to be in dimension.
Make the whole chassis of the robot sturdier –
adding cross braces and eliminating
standoffs wherever possible.
This helps our robot during competition
because the screws won’t loosen as much,
and none of the mechanisms we have built
have a chance of becoming detached,
something that happened at Houston. By
having a more rigid robot we ensure that if
our robot makes it to finals, we will be able
to endure the stress that finals puts on
robots.


Page:

Front of the robot with new drive motor mounts and arms motors attached

Close up of the drive motor mechanism (motor to sprocket to chain to sprocket to wheel)


Page:

Close up of the arm gearbox with the two motors visible to the left

Intake mechanism – bucky roller underneath, large ball roller above (not attached currently)


and Candy Corn Page:

TASKS REFLECTIONS
Now that we got a shipment of 35‐long
aluminum c‐channel we can begin
constructing our linkage arm. Aidan began
assembling it without any prior planning
and got a pretty efficient 8‐bar linkage that
reaches over the wheels and hits the
ground at the end.
We are all very glad that the linkage didn’t
turn out to be very bad, an 8‐bar is
completely tolerable, although there is an
issue of it not reaching 40 inches, currently
it only reaches 32 inches high so hanging
might be an issue if we don’t figure
something out before the competition this
Saturday.
We tested the gearbox for the arm, currently a
15:1 powered by two motors on each arm,
and we were able to begin warping the
aluminum chassis before the arm would
budge when we held it down – this was
only with a stubby little arm section that
would start the linkage, so it’ll become
more difficult for the robot once we have
the full arm on.
The gearing and motor system we have
working currently will be extremely
effective for lifting, plus we have taken
steps to get our robot as light as possible –
almost no 5 wide c‐channel, and a very
small number of large pieces, and no steel
parts, all of this makes for a much lighter
robot which will help for speed and ease of
lifting.
Configure the motors for a fully functioning
mecanum drive – involved Aidan writing a
simple mecanum program then flipping a
couple motors to perfect the system.
The mecanum drive, after testing it, seems a
little slow, for sure slower than the 5.5”
wheel base we had, but that just comes
with the smaller wheel size, but seeing the
robot strafe for the first time made us all
realize that a mecanum drive is a very good
idea.

Linkage in progress – only one more bar to go until it hits the ground!


Recorded By: Dexter Snacks: 1 Butterfinger/person Page:

TASKS REFLECTIONS
Quickly alter the linkage a little bit to ensure
that it reaches the ground to an ample
degree as well as clears the drive base
easily. Aidan took a little longer than
expected on this, so it slowed down
progress on the intake mechanism a little.
The final linkage will reach about 35 inches, so
we need the hook to reach a little higher
than the top of the arm – we will be lifting
with the end of the arm, not the top of the
intake mechanism like we saw some teams
doing. Plus the linkage looks a little crazy –
a lot of bars in a small amount of space.
Begin thinking about an idea for mounting the
intake rollers onto a basket sort of thing to
hold up to 3 bucky balls.
The intake rollers will flip down at the
beginning of the match, so there has to be
enough room for them to do this (no
obstructions for the flaps) and they have to
connect to the actual mechanism we will
use to contain the bucky balls.
Mount the brain and power expander Our brain will be mounted sideways towards
the back of our robot, a suggestion from
Anderson High School’s robotics team
(2158m). We also got a new power
expander since our old one had a faulty
battery wire and would get unpowered
during matches and while driving.
Mount the batteries The batteries are in the middle of the robot, to
balance it out – the batteries are primarily
what we will use to balance the robot for
our mecanum drive, but currently they are
just secured on small plates and strapped in
with the battery zip‐ties.

Competition is this Saturday, so we have very little time for finishing our robot and finally
testing it on a field – which we have acquired. This Saturday’s competition is at Anderson High
School, very near to McCallum which is fortunate because we won’t have to drive far to get
there, and no hotels necessary. Luckily all we have to do in order to finish is build the intake
basket which will probably happen tomorrow and testing on Friday.


Recorded By: Dexter Snacks: 1 Butterfinger/person Page:

Battery, cortex, and power expander mounting Display of the up/down linkage positions


Date: 11/9/13 Start Time: 2:45pm(Fri) End Time: 12:00am(Sat)
Recorded By: Dexter Snacks: Pizza, Torchy’s Tacos Page:

TASKS REFLECTIONS
Friday – work on the robot, adding finishing
touches to the drive base, linkage, and any
other various mechanisms that need
tweaking.
Most of the work that wasn’t related to the
intake was tightening screws or adding little
pieces of metal to certain parts to
strengthen the robot or make it more
usable.
Friday – Change the intake mechanism so it
flips down after starting within the 18”
length requirement and hinges outwards so
it envelopes the bucky balls. This took an
incredibly long time to assemble due to its
increased complexity and strange
attachment location on the robot’s linkage
and intake trough.
The ability for our intake to hinge in and out
will be very useful because it both helps
keep the bucky balls in the basket we made,
and also seems to work better than a
normal intake mechanism because of its
dual intaking action – the rollers and the
pulling in of the entire rotating mechanism
itself. Unfortunately we didn’t really design
our arm and intake with this plan in mind so
it was mounted completely too insecurely
and needs to be thought about more for
our next robot redesign.
Friday – we had worked late into the night at
Aidan’s house where a field was setup and
we worked on finishing the actual physical
robot, Aidan put a program on the robot to
test the mecanum drive, the arm, and the
two intake mechanisms. Something
happened with the intake mechanisms that
made it so they spun weird, and Aidan was
able to pinpoint the area in the code that
made that happen. He also made a very
slight outline for an autonomous we could
use to knock the two big balls on the 12”
barrier over.
The outline for the autonomous helped
enormously for getting a finalized intake
working for the competition, an
autonomous that would inevitably score a
total of 10 points for our alliance and
generally help us win the autonomous
bonus on multiple different occasions. In
addition, the general programming of our
robot’s driver control mode went smoothly,
Aidan is very used to programming now, so
he’s able to whip up something like a
mecanum code very easily, plus the motors
were logically laid out this time making
programming a whole lot easier.
Saturday – compete in qualifications for the
Austin VEX Competition, we had a total of 5
matches with alliance members varying
from a couple push‐bots to an ally like the
world‐renowned Discobots, in fact we were
able to make a little friendship with
Discobots that would help us greatly in
finals, because during alliance selection we
were in 15th
place and when they got
picked by 1366, they suggested our team as
Overall, one of the biggest things we’ve taken
away from this competition is our team’s
friendship with the Discobots which will
help us greatly in future competitions such
as San Antonio and the South Texas
Regional which we have now qualified for.
We played good matches with Disco, them
being the scoring team and us being great
defenders, helping fend off teams like
4252a and 2158m, both teams that


Date: 11/9/13 Start Time: 2:45pm(Fri) End Time: 12:00am(Sat)
Recorded By: Dexter Snacks: Pizza, Torchy’s Tacos Page:

a second pick and we did, in fact, get picked
by 1366 to be allied with Discobots in the
finals. We advanced through the
quarterfinals and semifinals pretty easily
and once we reached the finals we found
ourselves against 9090a, 9090c, and
another team, but 9090 or T.Vex was the
real competition on their alliance. The first
match our robot’s arm got caught on the
arm float we had constructed that day
upsetting us greatly, then the next two
matches which our alliance won was played
by 1366 and 2587z. They were both very
close and T.Vex put up a huge competition
to us, leaving us with a 1‐point advantage in
the final match. In the end we won the
competition on the backs of the far
superior team: 2587z.
performed incredibly well at the World
competition last year during Sack Attack.
Another very positive benefit of this
competition is the improvement of Dexter’s
driving, he went from barely being able to
navigate the field at Conroe to being able to
score the maximum number of bucky balls
in one swift go, something not many other
robots and drivers can do so soon. We have
also walked away with some plans for our
next robot and nearly a month to perfect it
which will be very good since then we’ll
have time to build, test, and refine,
something we have only been able to do on
a very small scale at competition.
We also had the pleasure of receiving the
Design award at the Austin VEX
Competition, another South Texas Regional
qualifying award.
Dexter was extremely pleased that the team
received this award, because he has been
working extremely hard on the engineering
notebook, reflecting on nearly anything he
can, and putting in pictures wherever
possible, except this page, funny enough
since it’s about the competition where we
won the award for our notebook.



Robot pieces
TASKS REFLECTIONS
Disassemble our old, award winning robot
from the Austin competition. This didn’t
involve much time or effort, because there
really wasn’t much to disassemble, so we
mostly conversed at Aidan’s house while
disassembling the robot.
When we finished disassembling the robot we
realized just how many bearing blocks and
half‐inch screws we ended up using on the
robot, quite amazing really, but weirdly we
had an incredibly small amount of metal
that we actually used on the robot. By
disassembling the robot early, we were able
to begin working on the robot itself sooner.
Discuss ideas for the robot;
1. Omni‐wheel, 6 motor drive to help
with the robot’s speed, since we could
possibly gear the robot up.
2. 7:1 gear ratio on the arm for faster
lifting, unfortunately this makes it
harder for us to hang, even when we
couldn’t before making this change.
3. Possible piston‐assisted lift, but we just
saw Pastoral Invasion using a 7:1 gear
ratio and 4 motors on the arm lifting
their robot, so we might transition to
something like that since it would be
much simpler.
Omni wheels will allow us to use tank drive for
more precise movement of the robot,
especially when scoring and maneuvering
around obstacles like other robots and big
balls. In addition, the omni‐wheels will help
our robot go a little bit faster which is
something we seemed to be lacking in our
previous robot. On the note of faster
movement, a 7:1 lift is very necessary for
lifting, because it will allow our robot to
score quickly and not make us wait for the
arm to fully lift before we can do anything,
something that Dexter noticed at Austin as
something holding us back a little.
Dexter began working on the drive base a little
bit. The goal is making the drive base about
5 units wide so we would fit an entire large
ball in between the wheel base.
The 5 unit width is a challenge, because there
has to be a one inch wheel, a sprocket, and
no interference with chain or metal
touching the wheel, so it may not be
possible to get it under the 5 unit goal.


Recorded By: Dexter Snacks: Chz Squared Page:

TASKS REFLECTIONS
Work on building the drive base, the 5 unit
goal is becoming quite an issue, and Dexter
has gotten it as narrow as possible using a
variety of spacers and axle locks to get the
spacing just right for the sprocket and
wheel, but nothing seems to work.
We are starting to rethink the 6 motor drive
idea, because Aidan built a mock‐up arm
using one motor on a 7:1 gear ratio and it
seems incredibly weak for our purposes, so
we will inevitably need a second pair of
motors on the arm. Not only that, but the
width requirement of the drive base is
making it difficult to include a sprocket in
the “equation.”
Revert our drive base from the sprocket
method to direct drive – one motor to one
wheel, using only 4 motors and adding the
other 2 leftover motors back to the arm.
This incredibly simple design will hopefully
help our robot hang easier since there
won’t be very many metal parts and
connections being made.
This will make each side of the drive base
incredibly narrow, and will help us fit the
arm between each side, giving us a lot more
freedom with the arm. In addition, not
having a motor block on the robot means a
simpler mechanism for powering the
wheels, and thus, less weight, something
that is becoming increasingly crucial to our
robot.
Aidan mocked up an arm using one motor for
power and a 7:1 gear ratio like we want, he
also mounted it on a 5‐wide c‐channel to
simulate the drive base we’ll be building.
The 7:1 gear ratio means the arm is much
weaker than on our previous two robots,
with an increase in speed as the benefit to
this speed increase. But as we’ve seen in
competition, Toss‐Up seems to be a game
of speed and efficiency rather than blocking
and defense – whoever scores the most,
the quickest, and the soonest will often win.
Unfortunately the gear ratio means we will
have to strengthen the arm somehow and
make our robot super lightweight in order
to hang.



Early build of the Omni‐Drive

Aidan’s simple mock‐up of an arm with a 7:1 ratio



TASKS REFLECTIONS
Dexter worked on the drive base some more,
making it so that the entire base uses no
chain or sprockets in its construction, and
the motors attach directly to the omni
wheels. The new design is 2.5 inches wide,
not including the motor which is attached
right on the outside of the 2.5 inch wide
base. The new design grants us a lot of
freedom with our arm and intake which will
fit inside the drive base. J.T also helped
Dexter by replicating the other side of the
drive base, ultimately finishing it during this
meeting.
The motor mounting system we are using isn’t
easily removable like we’ve done in the past
– using standoffs to mount a small 5‐long
1x25 pieces that are attached to the motor,
we have used this sort of method a lot in
the past, but since we only have one motor
per wheel with no chain and complicated
mechanisms, detaching the motors if any
problems arise won’t be an issue.
Additionally the increased freedom with our
arm will help us focus on creating an arm
that isn’t super complicated and an intake
that can manipulate the large balls.
Aidan worked on a pneumatic mechanism that
would assist our arm with hanging since
we’re really unsure about our robot’s ability
to hang even with 4 motors since it’s on a
7:1 gear ratio. The hang assist would shut
off the pistons from the air tank so they
could move freely until activated, and then
contracted and expanded via the controller
once activated.
Aidan is very unsure about the hang assist
since it would be very strange to attach the
one directional piston to the rotating
linkage arm and also be able to utilize the
piston’s power to actually translate to lifting
the robot. We’re hoping that we won’t have
to use the piston assist and only motors,
but we’ll have to build a really simple robot
that doesn’t weigh very much at all.

The Drive base in its current configuration


Date: 11/22 and 11/25 Start Time: 3:30 End Time: 5:30

TASKS REFLECTIONS
Create and attach a very light weight but
mildly rigid tower to the base of the robot.
We ended up using 2, 2‐wide c‐channel for
each side of the tower and we have two
connected, large, low strength gears to act
like a high strength for our 7:1 gear ratio.
We reinforced the tower from the front and
the back with aluminum L‐channel that is
also connecting the two sides of the drive
base.
Our design for the tower is sufficient for the
gearbox we are creating and since it uses
such a small amount of metal, it furthers
our goal of making the robot incredibly
lightweight. In addition, using the L‐channel
in front of and behind the tower provides
support in both directions, something we
usually don’t have, or we have it but it’s not
a very good system. This one is screwed in
on 3 planes, adding a greater level of
rigidity to the tower and thus, the arm.
Design a linkage arm for the robot that lowers
in between the two sides of the drive base,
this gives us a lot of flexibility for the actual
linkage design.
Our linkage will most likely stay with the usual
8‐bar design, or even be reduced to a 6‐bar
linkage. The only clearance requirement we
have is a motor at the front of the robot
which should be really easy to overcome
since our drive base is only a measly 13”
long, so there is even room in front of the
motor for our arm to drop down to the
ground. We may still create the piston
assisted lift, because we have the drive base
area to mount the mechanism and it would
almost certainly guarantee hanging.
Aidan prototyped the arm early in the
meeting, creating a linkage that only makes
our robot 15” long and the design we used
was an 8‐bar. Hopefully, we will be
attaching the hanging mechanism on the
back of our intake instead of the arm,
because then we would need to have the
hook extend above the intake area of the
arm and could impede large ball intaking
like our last robot.
Our linkage design will allow our robot to have
a roller mechanism that can outstretch 3
inches in front of the robot, but since the
space in between each arm is so small, it
might be challenging to create a mechanism
that can manipulate the large balls and one
that flips up and down before the match,
because we can’t create the whole
mechanism in this small 3” space we have
allotted ourselves, what it does is make the
whole design process a bit easier since we
now have space to work.
Attach the brain, power expander, and the
two batteries to the robot.
We tried attaching the batteries in a way that
wouldn’t affect its center of gravity.



C‐Channel tower with the gearbox installed The arm, fully contracted

Brain and power
expander mounting



The arm, fully extended Closeup of our arm float – a simple 1
inch screw, spacers, and a nylock.


Date: 11/30 – 12/4 Start Time: n/a End Time: n/a

Linkage Arm
TASKS REFLECTIONS
Work on tightening the 2” axles that are
connecting all of the linkage pieces.
This will help our linkage be more stable and
not wobble during operation. One of the big
benefits for this is just general structural
endurance of the robot during operation.
Add an arm stop that is directly attached to
certain pieces of the linkage. One piece stood
off on small (1/2”) standoffs at the end of the
linkage and one closer to the point of rotation
that is stood off a little more (1”plus a little).
This type of system will help our linkage keep
its shape when the arm is fully extended –
during tests the arm would collapse in on
itself when fully extended which made the
lifting very inconsistent and we couldn’t
predict where the arm would rest at its max
position, it also just looked bad. This new
system is very simple and works very well.
Test our arm’s and our robot’s ability to lift
itself on the hang bar. We had to re‐
program the robot a little, doubling the
motor code lines because we think the
robot wasn’t utilizing all of the motors, this
was confirmed when we saw that only two
of the wheels were actually spinning.
With the motor code doubled, our arm was
able to lift our robot, but not fully and of
course it won’t stick in the up position. The
lift is a little weird; the robot’s arm doesn’t
fully contract so building some variety of
stop mechanism won’t be easy.
Build an arm stop/catch that will keep the
robot suspended on the bar – it can be
passive or active, using pneumatic pistons.
The piston method we initially tried is directly
attaching the pistons on the arm like a sort
of lift assist we were thinking of using
before testing the current robot build, but
there doesn’t seem to be any good place to
put the pistons, unfortunately. The passive
method seems like it would be simple and
easy to do (hooking the arm to the drive
base when the arm lowers as it hangs).



Arm fully extended, with arm stops installed

Arm fully contracted, ready for intaking



Intake (“NZ‐style)
TASKS REFLECTIONS
Build an intake using the very common “NZ‐
design” and add the extra, smaller wheel at
the top of the axle that connects the motor to
the main intake spinner.
This design is really effective for picking up the
bucky balls, but not necessarily best for the big
balls, but currently it’s the easiest, lightest,
and most effective method we have tested
and come up with. The unfortunate thing
about this competition is that basically every
team has the exact same intake design and
robot design.
Test different orientations for the motor that
does two different things:
1. Keep any non‐moving parts out of the
way of the big ball from being took in
(our last robot had that big time, there
was a large metal piece obstructing the
big ball and the motor was mounted
on top of the intake mechanism which
also obstructed the big ball)
2. Have enough clearance off of the
ground so that none of the intake
pieces drag against the ground.
In addition to those things we need to have
the intake tensioned inwards using a hinge as
the rotational joint, and tensioned down so
the intake flips down at the beginning of the
match.
The biggest problem with our last robot when
it came to the intake was not being able to
manipulate the large balls, this new one does
very well, we used a rubber band covered
roller for the large ball mechanism and once
we “capture” the big ball, all we have to do is
spin the intake and the big ball gets sucked in.
As for the small balls, this mechanism works as
well as the last robot: very well. This intake
mechanism used a lot of bearing blocks and an
extra little mount for a chain and two
sprockets since we have the motor at the base
of the intake and the roller at the other end.
As a result of all the bearing blocks (and ½”
screws and nuts) the robot has become
incredibly unbalanced, proving a huge
challenge for us just before the competition.
Lighten the intake by simplifying it a lot – we
basically took a 10‐long aluminum c‐channel,
attached the motor at the bottom of the c‐
channel (closer to the ground, so there is very
little clearance) and have the intake rollers
extend up on the other side of the c‐channel.
By doing this and moving the batteries to the
back of the robot as opposed to the middle
where we had them, we minimized the weight
imbalance we had, but it still is a slight
problem since our drive base is so short and
easily tipped over.



Here the entire intake mechanism can be seen, with the large ball and bucky ball rollers
installed – the large ball rollers may change to use VEX mesh in the future

In this picture, the intake’s hinge, shaft (for vertical rotation), and inward tension rubber bands



Other Changes from Thanksgiving
TASKS REFLECTIONS
Wire the robot in order to test all of components
we’ve added, like the arm, intake, and to see if the
robot hangs‐ which it did.
The wiring went well, there was a little issue with
the arm wiring since Dexter wired the arm, and
since it moves so much and has so many different
areas for wires to get damaged, and he ended up
not doing a very good job, ending with a broken
motor controller.
Add a hang lock mechanism using pistons to latch
a small 5‐long aluminum c‐channel onto one of the
vertical members of the arm, it will be extended
upwards at the end of the match so the 5‐long flips
up (it will be up‐tensioned) and then the piston
will be retracted and lock the arm in place.
This mechanism is relatively simple, and as long as
the arm works how we think it will, it will work.
The only problem is that if we extend the arm and
the lock flips up, we have to hope the arm will
push it back down again and not get stuck or
impeded by the mechanism.
We moved the batteries to the back of the robot
and only had them attached via the battery zip‐
ties, and they snapped during operation. So we
devised a new method of securing them using
1x25 pieces as a sort of holster for them.
The method we devised is much more effective at
holding them, and it is still very easy to put them
in place. Unfortunately, this just adds more weight
to the base of the robot which is something we
don’t necessarily want at this point.

Here the battery mount can be seen using 1x25 steel


Date: 12/7/13 Start Time: 6:30 am End Time: 9:00 pm
Recorded By: Dexter Snacks: Pluckers and
Concessions
Page:

Killeen Toss Up Competition
TASKS REFLECTIONS
The night prior to the competition, JT and
Dexter worked on a hang lock mechanism
for roughly nine hours, modifying the
mechanism over and over again. In the end
the mechanism would have worked, but it
made the robot too heavy and, when
attached, the robot could not lift itself up
anymore, so we decided to take it off and
not utilize the hang during competition.
It was really unfortunate to find out that the
one mechanism that would allow our robot
to hang made it impossible to hang in its
current build state, the gear ratio we are
using (7:1) doesn’t supply enough torque to
lift up the robot. After looking at Anderson
High School’s (2158M) robot, we have
begun to think that just attaching the piston
to the arm and base will be enough to assist
and lock the robot in place. We tried this
method before, but decided not to use the
idea since the range of motion of the piston
might not be enough for the arm to lift the
intake the full 24 inches to stash bucky
balls.
Compete in the Killeen Toss Up Competition Reflection on the competition will be
below/on the next page.
We were the runners‐up in the finals of the
competition with Pastoral Invasion (4252A)
and the AustinCans (2158M). The alliance
we lost to was led by Team Floyd 2 (400x).
Pastoral Invasion competed the entire time
during finals and we switched out with the
AustinCans. It seemed like our major
downfall was our robot’s inability to hang as
well as our lack of a good autonomous for
this competition. We did, impressively, win
the autonomous section for almost every
match, except for a couple against the Floyd
alliance. But we won’t be completely
rebuilding our robot before the San Antonio
Competition so there will be more time to
practice and program an autonomous for
our robot, this will help level the playing
field at a competition that will be as fierce
as San Antonio is shaping up to be.
Planned Changes: located underneath the
competition reflection.
We saw a couple of ideas we would like to
work off of and some changes we already
knew we would make, even without going
to the competition.


Concessions
Page:

Killeen Toss Up Competition Reflection

We went into this competition knowing our robot was inferior to some of the robots
that would be there such as the AustinCans senior team and Pastoral Invasion. But we also
knew the competition was pretty low level and that it wouldn’t be super competitive so we
were pretty sure there was a good chance of getting to finals. Our original strategy was to be
fairly competitive, but try to stay out of the top 8 because the AustinCans, Pastoral Invasion,
and our team have forged an out of competition alliance via online social networking and
friendships formed at previous competitions.
Our actual performance went something like this: at first we did well, there was little to
no competition because most of the competition was push bots. Then we began making small
changes to the robot like upward tension on the arm since we didn’t have to hang, but
magically this made our robot tip forward really easily so after tripping through a match we
scrapped the idea. During another match, against our B‐team, one of the gears powering our
arm slipped out of place, this disabled our arm for the entire match, meaning we were a
glorified push bot against our own school’s team. Then towards the end of the competition we
picked it back up, reverting any changes we made so our robot simply picked up and stashed
bucky balls and large balls. In addition, Dexter, the robot’s driver, relaxed a bit and was able to
easily score balls and defend against opponents. In another match we were up against both the
AustinCans and Pastoral Invasion and our robot was partially non‐functional due to the upward
tension we added to arm prior to the match, so we didn’t do well at all during that match. In
the end we placed 12th
with a record of 3 wins, 2 losses. The finals were just a simple 4‐alliance
semi‐finals then finals, so a total of 12 teams. We were approached by 400x twice with them
asking us how well we competed and what our robot could do. But in the end our team got
picked by Pastoral Invasion in addition to the AustinCans. We advanced quickly through the
semi‐finals, easily beating our opponents during driver control and autonomous. In the finals,
400x and their alliance proved to be a very good opponent, 400x has come leaps and bounds
since last year, especially in their driving abilities. We lost the first match between Pastoral and
AustinCans vs. Floyd and 2880A. Then when we were up, we flattened Floyd and their alliance
partner. In the third match, a repeat of the first one, we lost mainly due to some rough play
from 400x, in other words, they were pinning Pastoral’s robot against a large ball for over 10
seconds and never backed up more than 3 inches when called on it. This leads me to my next
point about the competition, the organization, judging, and reffing of it.
The downside about this competition was the competition itself. Starting with the
organization of it, due to ice that never formed, it was delayed 1 hour, then the competition
itself didn’t start until 2 hours after the planned start time. Between the first few matches there
was about a 20‐30 minute delay due to technical troubles and slow counting by the referees. In
addition, the referees didn’t seem well trained and didn’t know the rules of the competition,
even something as simple as putting a bucky ball back into the field if it went over the barrier
slipped the ref’s mind. The finals match I described above was another great example of the
referee’s inability to recognize simple rules that were being broken really badly. Early in the


Concessions
Page:

competition the AustinCans went up against our M‐team (8756M) and M‐team got called for
pinning and instead of just deactivating their robot for the match, the match official disabled
every robot on the field. Besides the poor officiating and refereeing, the judging and award
giving was done relatively poorly, at every competition we’ve been at the wealth of awards is
evenly distributed amongst teams, so Excellence goes to one team and Design to another.
However this competition was different, Pastoral Invasion (4252A) was awarded the Excellence
and Design award. Overall this competition was relatively inadequate on the scale of normal,
good competitions we’ve been to, overall the lack of good competition and the bad refereeing
and organization made this competition less than satisfactory.

Planned Robot Changes:
1. More stable drive base
a. Possibly lengthen the base or add a anti‐tipping mechanism on the front
2. Redesign the intake mechanism a little so the big ball intake and the bucky balls
a. Offset intake rollers so the big ball roller is in front of and wider out than the
bucky ball roller (see attached illustrations).
3. Paint the robot black
4. Make sure the robot hangs by adding pneumatic lift assist.
a. Lift and lock – may require a linkage redesign
5. Multiple autonomous programs for both sides of the bump
6. Possibly meth motor the intake
7. More nylocks, fix and tighten certain elements of the robot, and improve other areas
8. Help the other 2 teams complete their robots before the San Antonio Competition.
9. Practice and test the robot thoroughly.


Recorded By: Dexter Snacks: Provided lunch Page:

TASKS REFLECTIONS
Compete in the San Antonio VEX competition
sponsored by the U.S army. During the
competition Dexter took decent amount of
pictures of robots at the competition, but
none of the competitions that our team
competed in, since he drives the robot.
This competition was one of the better ones
we attended, the competition was good,
meaning the other teams that were in
attendance were either really skilled or had
some interesting robots. Teams that were
there included 9090 (T‐Vex), 2587
(DiscoBots), 4252 (Pastoral Invasion), 2158
(AustinCans), 400X (Team Xtreme), and two
really high achieving driver skills scores
from 6966 (GonBotz).
The competition was arranged into two
separate divisions, the RECF Division and
the US army division, we were placed in the
US Army division which we quickly realized
was the far more inferior division. US army,
besides us had 400X whereas the RECF
division had 2587, some 2158’s, 4252,
9090, and more teams. We knew that in the
finals, the winner of the RECF division
(which happened to be 2587Z and 9090C)
would win the competition. As far as our
team went, we got first pick by the 8th
seed
alliance, but were about to be the 1st
seed’s
second pick, in other words we would have
ended up being finalists.
We were slightly bummed about our
performance in this competition, because
we went into it thinking we had a good
chance of doing well. Based on our
friendship with the DiscoBots, it was
entirely possible to be their second pick had
there been no division play, we also have
built up a strong friendship with Pastoral
Invasion. The main reason we were hoping
to do as well as we could at this
competition was because it was a really
good way of judging our level of
competitiveness in a competition similar to
what the South Texas Regional will be like.
Of course 9090C won’t be there, so
DiscoBots will have to choose someone else
for their alliance.
We figured out several problems with our
robot ranging from communications issues
like we’ve had at every past competition
(the controller and cortex disconnect for a
second then have to reconnect fully before
continuing the match). Aside from that, we
had the same front tipping issues we had at
Killeen since the drive base wasn’t changed
at all, we also had problems that we
noticed while scrimmaging with 2158M the
night before, with our intake: it seems to
fling the bucky balls out in a rather irregular
We really have no way to fix the
communications issues that have been
plaguing our team the entire season, aside
from getting new VEX keys (which are
expensive and touch‐and‐go on whether or
not they work out of the box) we don’t
know any way to fix the problem. Solving
the tipping problem will be as simple as
making the drive out of a full length 35‐long
c‐channel, and so far the best intake idea is
the one we were using at the beginning of
the year, but just modified a little bit for



pattern which means our scoring ability is
hindered. Dexter also noticed that the
robot was much slower than all of the other
robots on the field, which put our team at a
bit of a disadvantage.
optimal bucky ball picking up. The big ball
intaking was also a little rough, but that’s
just because of obstructions on the intake
structure itself, so rebuilding it will help a
fair amount.

Pre‐match preparation

Army Division Fields ready for play!



Our finals alliance captain 400X high hanging with large ball

US Army Division Finals


Date: 1/7q/2014 Start Time: 2:40 End Time: 5:30

TASKS REFLECTIONS
Dexter started building the new drive base for
the robot using pieces of 35‐long aluminum
C‐channel instead of the old configuration
we used that had 25‐long C‐channels.
This new design that obviously isn’t the most
revolutionary, will help drastically reduce
the tipping problem our robot has been
having in competition. The problem that
tipping has presented for the team, and
especially Dexter, the driver, is that he has
to focus more on not tipping the robot than
actually driving and picking up bucky balls.
Hopefully the new design will help him
drive better than he has been.
Aidan worked on reinforcing the tower of the
robot with nylocks, by doing this we can
ensure less work on the robot – tightening
loose screws – and more time practicing
and focusing on competition‐oriented
tasks.
Using nylocks more often will help improve
the robot’s endurance in a competition
setting where the robot is constantly being
driven and carried around, in addition, help
make connections more rigid.
The idea of gearing the drive motors on our
robot for speed rather than torque was
discussed because we’ve realized that there
aren’t many pushing matches going on,
rather there is an emphasis on getting to
the tube quickly and efficiently to score
bucky balls. We agreed that a 4 motor
speed drive would be feasible and we
would do this once the drive base is
finished.
Having a speedy robot can help us be more
defensive and offensive at the same time,
offensive because we can quickly transport
buckys across the field and defensively
because we can get to the tube and block it
from the opposing robot faster. Overall,
speed has become the apparent deciding
factor in a good robot, with 400X being the
glaring exception because it is only heavy,
strong and slow.
Dexter has been discussing and formulating
tactics for the South Texas Regional that is
coming up at the end of February by
compiling a list of teams going to the south
and north texas regional, currently only 5
teams have qualified for the north
competition, and 22 for the south
competition. We are unsure whether we
can go to the north or the south since our
team is located in central Texas. Dexter also
talked to 4252A, Pastoral Invasion who was
crossed by DiscoBots at the San Antonio
competition and now wants revenge.
Our team has been establishing a close
friendship with 4252A, Pastoral Invasion, so
there is a great possibility of being with
their team at the South Texas Regional, the
problem is that, combined, we may not be
good enough to beat out alliances with
teams like 400X or 2587Z (Disco). If we had
the opportunity to go to the North Texas
Regional, Pastoral has a really good
connection to 9090C (T‐vex) so they could
be together with our team as a second pick,
but that’s only if we can go there. Overall
qualifications are really confusing.


Date: 1/7q/2014 Start Time: 2:40 End Time: 5:30

The tower and arm without a drive base

The tower and arm with the new 35‐long drive base



TASKS REFLECTIONS
Continue working on the drive base design,
today Dexter finished the other side of the
drive base he started during the last
meeting, this meant screwing both sides
together with standoffs then attaching the
base assembly to the tower. No motor
mount solution has been discuss
Our new design for the drive base will help
significantly lower the problem we have
had with tipping at past competitions. The
unfortunate part about this design is that
we have to adjust the motor mount for the
front wheels, because having a direct drive
isn’t possible due to the linkage terminating
right where the motor would be, previously
we designed the linkage to float over the
motors. We think internal chain will be
necessary to power the front wheels, so the
two drive base sides will need to be
widened to accommodate the sprockets
and chain.
Dexter thought about how to improve the
tower design of the robot. More
specifically, how to mount the motors on
the outside of the tower frame. It will be
difficult because our motor mount method
uses standoffs and a 1x25 to attach the
motor, that way it is much more modular
than straight attaching the motor to the
tower. But unfortunately the spacing of the
screws for the motor mount combined with
the spacing for the gearbox axles makes the
bearing blocks very difficult to place and
choosing where to attach them and what to
attach them with will be difficult.
The method of attaching the motors on the
outside of the tower frame will make it
easier for us to maintain the structural
integrity of the gearbox. In addition, the
way we previously attached the motors
meant that two motors were facing back to
back (literally touching each other) which
meant they were possibly overheating, or
could have overheated faster. But mostly,
the previous mounting method was easy,
but was not efficient for performing normal
maintenance on the gearbox motors,
mostly tightening them (and the ones on
the inside of the gearbox loosened
incredibly quickly).
Dexter took the linkage off of the robot to
make working on the gearbox and drive
base much easier, this was also inevitable
since we would have to redo the linkage
anyways. Aidan started taking apart the
entire linkage and intake (which will also be
changed quite significantly).
The linkage will hopefully not be too difficult
to redesign, and if we get everything done
quickly (the drive base and gearbox) Aidan
can focus on making a really good linkage,
which again will probably be an 8‐bar like
we’ve had on every robot so far.



Bare Bones Robot Empty Gearbox

Intake being taken apart



TASKS REFLECTIONS
Dexter removed much of the pieces involved
in the gearbox, including the motor
mounts, some of the bearing blocks and the
potentiometer on each side. This provided
a good space to work on redesigning the
gearbox. Then the spacing for each axle was
figured out, 3” between the two powered
axles that are connected to metal pinions
(12‐tooth) and an axle right between those
two pinions (1.5” away) for the 84‐tooth
gear. This creates the 7:1 gear ratio we’ve
had on many iterations of the robot.
The new gearbox is required because of
having the two motors attached on the
outside of the tower frame, because they
are separate from each other, requiring two
12 tooth pinion gears, one for each motor,
to power the 84 tooth gear. This will also
help us troubleshoot any issues we have
with the lift, seeing if one of the motors
isn’t working or is spinning the wrong
direction, our last design relied on one axle
going through both motors.
Once Dexter finished the new gearbox, Aidan
copied it on the other side of the robot.
Two people working on the robot seems ideal,
because one person can copy what the
other did, often times having three people
working leaves the third doing nothing the
whole time.
Aidan began designing a way to power the
drive base, especially the front wheels since
the rear wheels will likely be direct drive
with no chain. What he found after minimal
investigation about our current design is
that the drive base needs to be widened
slightly in order to accommodate a chain
and sprocket powering method for the
front wheels.
We ended on this note, so during the next
meeting we will have to make some
modifications to the drive base, widening
the frame that supports the motors and
wheels. Unfortunately this is relatively
difficult at this point because most of the
attachments we have to change use
nylocks, so it’ll be a huge pain to change
anything.



Right hand perspective of the left gearbox Left hand view of the left gearbox



TASKS REFLECTIONS
Before school ended Dexter finished widening
the base of the robot which included
changing out the standoffs on the
unfinished side of the drive base to 3 inch
standoffs and then moving the 1 inch
standoffs on the rear cross beam inwards
by a unit to account for the widened base.
Doing anything related to the drive base is
painful because most of the connections we
are using are either extremely tight or we
used a nylock, so this widening process took
a while. But fortunately the wider base will
allow us to add a sprocket‐chain system to
power the front wheels.
Dexter also figured out a method for mounting
the motor and connecting the front wheel
to the motor via a sprocket and chain. This
involved, for one thing, taking out the front
set of standoffs that hold the drive base
together, so once the whole robot has been
completed, including the arm and intake,
we’ll figure out a method for connecting
the two sides again, preferably with a 35‐
long cross beam that spans both sides of
the drive base to not only hold the two
sides together, but to make the entire drive
base more rigid.
Once Dexter figured out how to mount the
motors for the front drive, he attached the
motor, then let Aidan finish working with
the chain system, spacing for the wheel,
and general attachment of all the related
parts. Dexter will finish attaching all of the
motor and wheel related parts tomorrow,
since it’s a very simple process, but we ran
out of time and weren’t able to finish
everything for the drive base.
The idea of starting the linkage designing
process was brought up by Dexter, but
nothing really got going since we need to
have the drive base complete and wheels
attached.
Aidan is the linkage designing champ on our
team, so he really does have the sole
responsibility for designing and building at
least one side of the linkage, the other side
can be easily replicated by someone else on
our team.

Sprocket and Chain Mechanism for the front wheels


Date:  1/15/14 Start Time: 2:45 p.m End Time:  5:30 p.m
Recorded By:  Dexter Snacks: Page:

TASKS REFLECTIONS
Finally finish building the drive base by re‐
gearing all of the motors in exchange for
speed rather than torque. Then test the
speed of the robot once all of re‐gearing is
finished, but with our newly decided wiring
configuration.
Aidan re‐geared the motors since he is really
the only person on the team that knows
how to do this, it went pretty fast, and all of
the motors got reattached to the robot for
testing later on during the meeting.
Undo most of the wires on the robot,
including sensors, motor controllers, and
motors that were directly connected to the
cortex (through ports 1 and 10). Then
remove the power expander in favor of less
weight and lower battery power. Dexter did
this then wired up the drive base to test it.
Removing the power expander was the main
goal of rewiring the robot, without a power
expander the robot won’t be able to draw
as much power as it did before, but since
this competition seems like a relatively low
stress one for the batteries, we decided to
opt for a low‐weight solution using only one
battery connected to the cortex.
Once Dexter got all the wires plugged into the
cortex, he tested it out with the leftover
program from the San Antonio
Competition. It seemed to be a bit faster,
but its drive‐path was slightly curved and
we found out that once of the motors
hadn’t been switched out for a speed
motor, in addition we found that some sort
of ghost value was left on the motors after
driving in a direction, making them more
difficult to hand spin (when the robot was
on) in only one direction. To change this,
Aidan began to figure out a programming
fix to this problem, but didn’t want to start
during this meeting due to time constraints
as well as weird RobotC errors that started
occurring.
After changing out the motor, we didn’t get to
retest the robot’s drive, because we wanted
to get right to work on fixing the
programming issue that cropped up. But it
does seem like the motor we used for the
“slow” wheel that was geared for torque is
a rebuilt one (we have rebuilt many of our
motors due to various damages, sound
issues, and circuitry issues, but this motor in
particular seems to have a large amount of
friction internally, which could be a
contributing factor to the lowered speed on
that side of the drive. The programming on
the other hand probably won’t have too
much effect on how the robot drives,
except possibly making it a little more
responsive since it won’t be saving ghost
values like it was.


Date: 1/15/14 Start Time: 2:45 p.m End Time: 5:30 p.m
Recorded By: Dexter Snacks: Page:

Back of the robot with the new wiring configuration (no power expander)

Finished drive base, with speed geared motors

2013-14 VEX Toss Up Engineering Notebook

2013-14 VEX Toss Up Engineering Notebook

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