A few more upcoming dates

Here are a few more dates we need to keep in mind besides the machining days.


Tuesday Dec 7 - We will all get together in the evening to make the team video. It must be uploaded to the blog and ctools by the next morning.

Thursday Dec 9, 1:40-3:00 - Slotbots competition

Sunday Dec 12 - We will finish our final team documentation and upload it to the blog. The individual reflections are also due the next morning (Monday 9AM).

Upcoming Due dates and Machining

I hope you guys are having a fantastic Thanksigiving Break.

Here are the upcoming due dates and our parts that we need to machine out.

December 6th - MS 9 is due - Demonstrate working machine
December 8th - MS 10 is due - Finalization of the machine and the machine is locked until the expo

In order to catch up on our due date, we need to get machining!!

So, after Thanksgiving, we should try to machine at least four times for next week so that we are confident in our machine. Here's the schedule that I think would be nice:

Monday November 29th - getting started on the base and the back block of our machine
Tuesday November 30th - Continuation of our base and the back block and if this is done, front arm
Wednesday December 1st - Contination of the front arm and getting started on the angled guide and the motor support
Thursday December 2nd - working on the front left axle and the Rack and pinion axle.
Friday December 3rd - Checking on all of our machined parts and get them together so that we are ready for Monday.

The Newest Update

On Wednesday, November 17th, in class, we decided that we need more aluminum in order to continue our machining. We figured out the exact dimension that we need so that we could purchase at Alro's.

On Thursday, November 18th, we went to the Alro's and bought two 6160 Aluminum parts that we will use to make our machine. During our regular lecture time, we were able to use the shop and we cut out small parts from the aluminum parts that we have bought to make several needed chunks.

On Friday, November 19th, we were able to use the shop from 4 ~ 6 and we managed to get our rack screwed into our solid metal piece. There were some risks in chance of drilling through the rack with the mill but with the maximum precision, we were able to be successful.

On Monday, November 22nd, it was the due date for our three completed parts of our machine and we showed it to Mark. We received 17/20 on our drawings. We decided to meet back at the shop from 6:30 ~ 8:30 in order to keep working on our machine. During our shop time, we used milling to drill all the holes into our motor mounts and the rotating mounts and we were able to screw in our parts together.

On Tuesday, November 23rd, we decided to meet from 4 to 6 in order for the due date the next day to show Mark our final MCM (MS8). We checked back on our parts and looked carefully at the things that we have might have missed in our final MCM and polished our work so that we felt comfortable to show Mark the next day.

On Wednesday, November 24th, it was the due date for our final MCM as an MS8 with all of our rest of the engineering parts completed. During class time, Mark met with us and we recieved 58/60 on our MS8.
Happy Thanksgiving to everyone!

Machining Started

We machined several parts over the past week and are going to show Mark 3 of them on Monday for MS7. We were scheduled to use the mill and lathe on Thursday from 4-8:30 but the shop was closed at 5, which set us back a little bit. We were still able to do the machining on Friday though. Here's a picture we took of us milling one of the motor mounts.


Something we overlooked in our design was the weight of the rotating arm. It was originally going to be 28"x2"x1" but we realized that would be too heavy for the small motor to power. However, we can just mill out the back of the arm into a "U" shape to decrease the weight.

Pic of front arm

Here's a picture of the aforementioned change to the front flipper-blocking arm.

Blocking arm

We've come up with a better idea for the front blocking arm that will hold the flipper. It was initially going to be a simple arm extending down at an angle from the robot, but we realized it probably will make the machine too large. We were then considering coupling the arm to the front axle so that it flips down into the slot at the beginning but we've decided on something better. We will still couple the arm to the front axle, but instead of flipping and rotating downwards, the arm will slide through an angled slot in the bottom of the chassis and into the flipper.

First parts manufactured

Today we used the mill to make two of the components of the MCM. These parts were the track for the main arm and the base used to mount the rack. Bob was very helpful in getting us started on the mill and making sure we made our part efficiently and accurately. We'll be using the lathe and waterjet in addition to the mill next week and we'll hopefully finish or come close to finishing our MCM.

Motor lab

We'll be doing the motor lab in class in a few days. Our machine will be powered by 3 different motors, so hopefully the lab will make us more familiar with them. I expect that after the lab we will be able to apply some of the concepts and tricks we learn to our design, such as decreasing the radial load on the motor and choosing the optimal gear speed for each motor depending on its task.

Machine possibly too large

A few days ago we noticed that our machine may not fit into the 24x12x12 box with the long extension arm out in front. We will need to fully dimension the whole machine to see if this is indeed the case. If we need to, we could possibly couple the extending front arm to the front axle so that when the machine first drives forward into the slot, the extending arm will flip down into the slot. This way, the machine will initially fit into the box but still allows the front arm to block the flipper.

MCM ready to be manufactured

Here's a picture of our solidworks model of our MCM. Now that we've fully designed the MCM, it's ready to be manufactured. We're going to buy the aluminum we need for the module from ALRO some time in the next few days so we can get started working on it in the lab. ALRO sells aluminum 6160 stock for approximately $0.44/in^3 and is located in Ann Arbor which is the main reason we decided to buy from them.

More design changes

After putting some more thought into our design, we've made a few more minor changes. We are now attaching the nylon rack to our machine by screwing it into a thin slab of aluminum which will then screw into the main arm. This is the method that was described in the manufacturing and assembly guide on ctools. We're also tinkering around with how we want to couple the rotating mounts to the track, which is proving to be more difficult than we imagined given the thin walls of the track.

Small design changes to MCM

Today we had a team meeting to discuss MS6. We decided on making several small design changes to our MCM. One of these changes that was brought up by Mark was to add another bearing on the other side of the pinion for more support against a radial load.

We also made another small change to the track that the main arm follows because the old design would be very difficult to manufacture given our tools and machine access. Basically, instead of making the track from a single piece of aluminum, we are going to cut 3 pieces and then screw them together.