Nov 30th weekly update

This past week was a short week due to Thanksgiving break however, we
accomplished much. On Monday and Tuesday this week we finished the
manufacturing and assembly for our most critical module. The manufacturing
included drilling holes in the side braces for the axles, cutting the belt
to the needed length and fastening the two ends together, cutting the motor
mount and attaching it to the side braces, and attaching the scoops to the
belt. The two ends of the belt are fastened together using staples, a
simple method that appears to be holding well enough for the purposes of
this project. The motor mount was made out of 1/16” thick steel and was
cut using the ban saw and then bent to a 90 degree angle using the metal
bender. The scoops are attached to the belt using epoxy and electrical
tape, another simple method that appears to be holding extremely well.

One of the important tasks that we accomplished this past week was the
mounting and coupling of the motor. The planetary gear box motor is mounted
near the top axle of the conveyor belt and is coupled to the axle using
3/8”OD and 1/4"ID plastic tubing. One of the problems we are encountering
with our motor is that one of the planetary gears inside the gear box is
too small. We will have to replace the gear in order to prevent jamming
during the competition.

For both aesthetics and the regulations of the competition, we wrapped both
of the side brackets with black electrical tape. The tape helps distinguish
the metal of the brackets from the other metal of the conveyor belt as well
as keeps the conveyor belt from scratching the inside of the slot on the
arena. Since a scratch on the arena leads to an immediate disqualification,
this was a very important step to take.

On Wednesday, we demonstrated our most critical module to our GSI. We
showed our module and its movement in the arena and consequently we feel
the presentation went very well.

Also this week we cut the wood for the conveyor’s support box. The rough
shapes of the bottom, sides, front and back of the box are all cut out and
are ready for further manufacturing. Since we need to make a few small,
exact cuts on both the bottom and front of the box, we have held off on
assembling the box until we have access to the laser cutter to make these
cuts. Once the cuts are made with the laser cutter, the box can be
assembled (we will use wood glue to assemble most of the box and some small
nails where appropriate).

This week we will try to finish all of our manufacturing. We have yet to
laser cut and assemble the support box, cut the sides of the chute, and
couple the second motor to the conveyor belt and attach it to the inside of
the support box. After the final machine is assembled, testing can begin.
We plan to test the machine as much as possible so we will know when small
adjustments need to be made. Also, like we said in last week’s blog, we
will need to continue to take photographs and videos of our progress to
include in the one minute long introduction video that will be played at
the competition.

Nov 22nd weekly update

This past week we focused on the manufacturing of three parts for our most
critical module for the Mile Stone 7 assignment that was due this past
Friday. The three parts that we manufactured were the pulleys for our
conveyor belt, the side bars/braces for the conveyor belt, and the axle for
the conveyor belt.

To manufacture the pulleys, multiple processes were used. Last week we
decided that we wanted to manufacture our own pulleys rather than spending
$60 on pulleys we had found on the McMaster-Carr website. To accomplish
this we used the water jet to cut two circles of 1/16" aluminum and then
used sand paper to sand down the sides of the polypropylene wheels that
were provided in the kit. Then using a drill, a center punch, a center
drill, a step drill and a size I drill bit, we were able to make the holes
for the axle in the 1/16" aluminum circles. These parts put together on the
axle make a pulley that can be used in our most critical module design.

To manufacture the side bars/braces, we used the 1/4" aluminum plate that
was provided in the kit. We used the ban saw to cut this plate into four
equal width braces. These will be welded together to make two 2ft long
braces to support the conveyor belt.

The last part to manufacture was the axle. For this part we used the 3/8"
aluminum rod that was provided in the kit. The aluminum rod was lathed down
to the appropriate diameter and length.

Another part that we made last week for our most critical module was the
scoops that will attach to the conveyor belt and pick up the ping pong
balls. To manufacture the scoops we cut on the water jet 6 strips of
aluminum (1/16" thick). These 6 strips were bent slowly, using the metal
bender in the machine shop, into a curved shape. Unfortunately, due to the
nature of the metal bender, each scoop could not be made into a perfectly
curved shape, nor could each scoop be made the same. This irregularity will
simply allow for some scoops to work better than others, and if we have
time during the testing period, if we find one particular scoop is working
much better than the others, we can alter them the best we can.

One of our other accomplishments this past week was ordering the belt for
the conveyor. We ordered 5 feet of belt, knowing that we will only need
about 4 feet, and we will have to cut the belt to size and then fasten the
ends together, most likely using the Kevlar string that is provided in the
kit.

Since we have to demonstrate our working most critical module this
Wednesday, there is much we still have to finish. We have to cut the holes
for the axles in the side braces of the conveyor belt, attach the motor
mount to the side of one of the support braces, connect the two ends of the
belt, put the belt on the pulleys, and then attach the scoops to the belt.

The last thing we should also begin working on this week is our 1 minute
film that has to be shown during the competition. We plan on bringing a
video camera to the shop so we can get some video of us working on
constructing the most critical module.

Nov 15th. weekly update

The main focus for this past week was to finish the motor lab
assignment. One of the main things we noticed while completing our motor
lab is that one of the sun gears in our planetary gear box set does not
rotate well with the other gears (meaning, that it gets stuck very easily).
If we were to use the 400:1 gear ratio in our module, we would have to
trade one of our planetary gear sets with another team who would be using
the 25:1 gear ratio for their machine. Since we will be needing two motors
for our design (one to rotate the conveyor belt, one to move the conveyor
belt up and down) we will be needing the dual gear box motors as well (most
likely only one of them). In preparation for needing the dual gear box
motors and gear boxes we exchanged the motors that came with the gear boxes
with the ones the GSI's were providing for us during section.
This last week, we also decided on some small changes to our design.
During our most critical module discussion with our GSI, we discussed the
possibility of manufacturing our own pulley for the conveyor belt rather
than purchasing them from the McMaster-Carr website, since the ones we were
looking into buying cost $32 apiece. We have since decided that we will be
manufacturing our own pulleys since we do not wish to spend so much money
on this project, we would rather use the materials that have already been
provided.
During one of our team meetings, we also set a time line for this
upcoming weeks manufacturing processes. During Monday's section time, we
plan to make the path file for the water jet to cut our 1/16" thick
aluminum plate into the appropriate parts we will be needing. Wednesday is
when we plan on doing most of our manufacturing, as well as the water jet
(we are signed up for a time slot on Wednesday to use the water jet).

Nov 8th. weekly update

This past week we presented our most critical module. We compiled the bill
of materials, the manufacturing plan, as well as the engineering drawings
we will need to show the shop before we can begin manufacturing. We also
made some modifications to our CAD solid model, due to some suggestions at
the Design Review.

During our meeting with our GSI one of the main things we discussed was the
tolerances we had indicated on our engineering drawings (on the order of
0.001). The instructor suggested that although tolerances that small are
definitely possible, she does not believe they need to be so small for our
purposes.

This week, we will begin the manufacturing on 3 parts for our next
milestone assignment. The manufacturing of these 3 parts must include the
use of 3 different manufacturing processes and 2 different materials. We
are uncertain which 3 pieces we will choose to manufacture yet because of
the assignment restrictions (2 materials etc), we will most likely not
follow the steps of our manufacturing plan.