Tilt Assembly (tentative assembly)

We have put together the pieces of the tilt assembly. Overall the build quality is better than expected. The links match up to the CAD model orientation and angles. It can be balanced to stay static which is surprising. See Figure 1 and 2. We also received shaft collars so we will be able to assemble it tomorrow to further revise its operation. Once the waterjet cutter is used to cut the platform plates that hold the scissor lift together we can assemble that together with the tilt assembly.

Figure 1

Figure 2

The next challenge is to incorporate the motor into the tilt assembly. The Mechatronics team will need to work closely with us to get a solution completed by Maker Faire.

Week 7 (March 15 - March 22)

After calling a couple places to order metal for the links we found a local place. We learned about it when calling Coast Aluminium and they recommended Gorilla Metals. Gorilla Metals carries flat stock aluminium in the size we wanted to get, so we used it to make the links. We did not get the metal for the tilt cradle. This week we will get the metal for the tilt cradle and start working on that.

The tilt links are made out of aluminium 6061. They are a 1/4 inch thick by 1 inch wide. These are test pieces used to verify operation and motion path. If binding becomes an issue then they can be replaced by links designed to be used with flanged ball bearings for smoother operation.  

We completed the bars for the scissor lift. We cut the square tubing to size. These wont take much time to make as they just need to be cut and drilled. 

The links were supposed to made with waterjet cutting. However, in the interest of time and money we decided to make them by cutting and drilling flat stock instead. 

Week 6 (3/8-3/15) Current Build Progress

We have made the follower beam last week. (see figure 1) We used 1x1 inch square tubing to make it. The gauge of the tubing was thin. When we tried to weld it there would be areas that either melted or flash rusted. A couple factors can be traced to the argon gas feed for the MIG welder. The regulator for gas feed could have been broken. Since the material is inexpensive it would be better to remake it. It needs to have solid welds since it will be holding the entire assembly. We can use a thicker gauge of 1x1 square tubing so that it will be stronger and easy to weld. In addition, we can use a different MIG welder to prevent flash rusting while welding.

Figure 1 : Follower Beam

This week we will check with Campbell Metal Supply to see if they have the flat stock that we want to use in our build. Once we get that we can finish the links for the tilt mechanism and the mechanical suspension. Already have the square tubing for the lift mechanism. We need to weld together the tilt mechanism cradle piece as well. 

Week 5 (March 1 - March 8)

The first presentation of the spring semester for the Active Suspension team

Week 4 (Feb 22 - Mar 1)

This past week we have been checking our calculations in order to submit the AS application. Another update is that after reviewing the motors that will be used in propulsion is that we have come to the conclusion that their motor will be able to power our tilt mechanism. This does not mean that the motor will be used for both applications. We made this decision since the motor that propulsion will use is cheaper than the motor that we were quoted for by Groschopp. The differences are that their motor is cheaper, less torque at similar rpm, and less amperage draw. All these are advantages rather than disadvantages. The cheaper price will help us make our budget smaller and cost effective. The motor produces 150 in lbs less torque at a similar rpm. This is fine because we don't need to move our tilt assembly at 15.5 rpm. We can move it at a lower rpm, which according to the motor spec sheet, the motor will be able to meet our torque requirements at the lower rpm. The lower amperage draw is less load on the power supply.

PM -8014 : Motor Spec Sheet

Week 3 (Feb 15 - Feb 22)

Spent this week double checking our BOM calculations. Then after we were absolutely sure that we knew how much material was needed for our project we went to get quotes. Campbell Metal Supplies has a large selection of Aluminum. The quote we got for the needed quantity of Aluminium 6061 was high. It was $404.61. This high price is most likely due to the weight and dimensions of the piece we need. We found a substitute over at Sims metal management. They do not have 6061 Aluminium on hand but they do have steel metal plate. By choosing the steel over the aluminum we would save $181.89. This is a better choice as the money can be used for extra materials or motors and since this is a prototype it's better to budget on certain aspects. The design has a large safety factor to account for the extra weight of the steel.

Week 2 (Feb 9 - Feb 15)

Our team is delayed on our Gantt chart. However, this is a good opportunity to revise our BOM so we can get it approved. One of the items that we will need is a DC motor that can produce enough torque to move our Tilt mechanism. Oriental Motor has motors that can supply the torque, however they are limited in their offerings from what we have seen. Groschopp is another company that manufacturers motors and they are able to supply us with a motor with a high range of customizability and torque.

We have calculated that the needed continuous torque needed to move the tilt mechanism was 644 in lbs. They are able to supply a motor that can operate at 650 in lbs at 15.8 RPM. This would be more than acceptable considering that the tilt mechanism would slowly tilt to keep the cabin stable.

 

Figure 1: Motor Specifications for Tilt Mechanism 

As we look at the graph we can also see that operating the motor at this speed and torque would give us a high motor efficiency. It would be close to 75-77 percent. 

Week 1 (Feb 1 - Feb8)

We are currently waiting to get out bill of materials approved in order to start building our design.

Week 15 (Nov 30 - Dec 7)

For slide 5, here is representation of it moving - https://gfycat.com/UntidyCandidBats


For slide 6, here is representation of it moving - https://gfycat.com/EquatorialGraveAustraliansilkyterrier#?speed=0.5

Week 14 (Nov 24 - Nov 30)

We have begun simulating the mechanism with the cabin model made by a previous team at Spartan Superway. Minor changes were made to the Cabin Model. It needed to be scaled down to half-scale. After that it was possible to reuse the mounting plate to attach it to the suspension assembly. We would have liked to connect it to the Bogie system as well but there were issues with that in SolidWorks. However, we will keep trying to integrate everything into the simulation.

Figure 1 : Pod Car with Active Suspension

Week 13 (Nov 17 - Nov 23)

We have started working on presentations. My teammate and I are also reviewing our calculations for the force analysis on the four-bar tilt mechanism. We have also begun making designs for a mounting system for the cabin. We believe this is needed to properly simulate the suspension system with the cabin. Hopefully, this will show any issues or design constraints that need to be revised.

Week 12 (Nov 9 - Nov 16)

For this week we saw another instructor to talk about how to solve for different forces in a moving system. We want to make sure we did the right calculations before we start using FEA on our whole system, so that we would be on track according to our Gantt Chart.

Week 11 (Nov 2 - Nov 9)

 Here is the Active Suspension's Presentation 2




In addition, we also started 3D printing some of our parts, which can be seen below.

Week 10 (Oct 26 - Nov 2)

For this week as a team we are preparing for our presentation, making sure that we have everything covered. We also want to make sure that are calculations are correct by consulting different professors and going over what we did and plan to do.

Week 9 (Oct 19 - Oct 26)

For this week as a team we are working on our presentation. Making sure that we cover everything that is required, such as updating our current design, make sure the calculations are correct, etc.

Week 8 (10/12 - 10/19)

For the week of October 12 to October 19, we are in the process of figuring out how to combine each system. See pictures below for sketches of what we plan to do.

 Figure 1: Sketch of tilt mechanism

Figure 1 is a rough sketch of the four bar mechanism we want to use based on previous CAD work. 

 Figure 2: How we plan to attach tilt mechanism to bogie

Figure 2 is a possible configuration to support the tilt mechanism and the self-leveling mechanism. The idea in this sketch was to support the tilt mechanism rigidly and then support the self-leveling mechanism at 4 points. The self-leveling mechanism is a square so we would make 4 tilt mechanisms that would connect at each corner.

Figure 3: How we plan to attach tilt mechanism to the self-leveling system

Figure 3 shows this idea with one tilt mechanism connected at one corner. 

Week 7 (10/5 - 10/12)

As a team we are continuing to do the CAD drawings using Solid Works. We are also utilizing Grab Cad so that we can see how our design fits with all the other designs. Once we get that finished and the whole system looks like it can all work together then we can start to 3D print our system to get a prototype to test even more before the final design.

Week 6 (9/28 - 10/5)

Week 5 (9/21-9/28)

For the week of September 21 - September 28 we basically worked on our presentation. Since this is our first presentation of the year we want to make sure we do everything right and spend a lot of time on it. This includes doing more research, the calculations, and any drawings we want to put on the presentation.

Active Suspension Week 4

We have updated our Gant Chart to include presentations, so we can start preparing for them.

In addition we observed a video of  an active suspension of a formula 1 racing car, which we modeled our current design after it. The video can be seen here:
 https://www.youtube.com/watch?v=hd2qhmx6hvI

We are also in the process of constructing the free body diagram for our system to determine the equation of motion.