Daniel's Spartan Superway Project

For the past week, the team have modified the current rail and the current pick up mechanism. The figure above represent last year design. the figure above is the latest design The figure on the right is the mechanism that will make contact with the electric current rail. the legs (L-shaped) are design to fit the the width of the overall Guideway track. 

The carbon brushes we intended to  use are the Helwig Carbon products (fig.1). They are electric current collectors. It is important to anticipate how current behaves as load is applied against it. previously we have mentioned we need 50 N contact force. However, applying unnecessary load is not ideal because it  creates friction which adds additional friction for the bogie to overcome. Additionally, the brushes wear at a faster rate. working with Tynan, it was important to find how the current behaves with increasing load to find the ideal load and the performance of the current collector. the figures above represent the T shaped current rail sitting on an insulator.  We tested our analysis multiples weights as shown below Mass added on top of the current rail the results shows that adding more weight does not necessarily mean more current. For the graph above, testing for 2.5 V supplied the current collected by the carbon brush starts behaving uniformly aft

The current pick up mechanism will be attached to the slave bogie. It was noted visually that the mechanism will be best attached near the rear wheels on the strut channel. It will experience  the least rotational inertia because it is being pulled by the front. After taking all measurements of the slave bogie and the best possible location to attached the current pick up mechanism, the following design has been accomplished.  The top view on the left reflect the position how far the pick up mechanism will extend. more  analysis and calculations are coming for the last presentation This prototype help us visualize the  some assumption that were not clear at first. In SolidWorks one can easily mate parts but in reality we have to account for clearance, tolerances, machinability of parts, simplicity/complexity. After analyzing with the team, some changes are in the works. another aspect is running FEA on some components. The most weakest part is the middle section

This week is spent 3D printing all the parts for the prototype. The CAD is coming along however  3D printing takes longer because we depend Makerspace availability. This is the 3D printed part that will be attached to the body of the slave.  The plans is to secured, fixed (bolted) one side on the torsion spring (the outside) and  apply a force on middle legs. this will counteract  the force applied and create the 50N we expect. It was important to design a housing for the spring so we can attached to the spring and to legs. We are making iterations as we continue receive all printed parts. One important factor was how to hold on to the leg.  the next figures show the the changes.  These two figures are parts of the mechanism that will house the legs on the middle section. as we continue with these models we realized many iterations that have to made and  prototyping provide the opportunity to see that. the two figure will replace  the middle sections housing.

For this week, we are pushing for rapid prototype of the Supercapacitors and the mechanism  to pick up the current. This prototype will have  will consist of (right  and  left winding) torsion springs  each of them will housed to rotate the spring accordingly. This torsion springs were particularly chosen for their great Torque (44.in-lb). we hope they can exert the required force. This is part of the whole mechanism we plan to put in place some of the parts are already 3D printed on Makerspace and we plan to have the complete the following week There is more work to be done  and we hope that by next week to have a small scale prototype to be able to test our components and our ideas.

For the second presentation, we mentioned about adding a torsion spring to generate a counterbalanced to secure we have a 50N contact between the current carrier tthe carbon shoe pad. Now adding torsion spring is very complicated as of now. However, I am working a prototype to  fit the torsion spring on the mechanism first,  torsion spring the prototype will include a two springs right and left winding direction  already ordered from the link below https://www.mcmaster.com/9271k643 s pring design result 120 degrees torsion spring parameter units inner diameter 0.832 in torsional moment 45 in-lbs outer diameter 1.102 in tensile strenght 216396 number of coils 7 max% allowed tensile 80 deflection in degress 120 bending stress 188092 wire diameter 0.135 stress limit 173117 wind direction right