Hi guys!! So we got till next Friday, 26 July, until our rolling frame is due!!
So far, we may be behind time as we wanted to send our parts for waterjetting today, but weren’t able to make it by the 4pm deadline..
In any case, we will continue to refine and CAD out remaining parts such as the seat, the brake and the rear wheel assembly. Then, we plan to waterjet everything next Tuesday, so that we can assemble on Friday!
On another random topic, in order to improve our steering system, we approximated for Ackerman steering geometry. This did not need to involve any crunching of numbers, but we simply adjusted the dimensions of our steering parts, by checking our angles on Solidworks and using general rules-of-thumb. Once accounted for, the inner tire will turn a greater angle than the outer tire, which minimizes the sideways slip of tires when our vehicle makes a turn.
A general rule of thumb is that the lines from the steering kingpins to the steering pivot points on each side, when projected, will intersect at the centre of the rear axle. Something that we achieved with our steering, give and take one degree.
Another thing we could do is to draw concentric circles which imitate the path of our vehicle as it turns. We then check that the inner and outer wheels are turning at the appropriate angle; tangent to its corresponding circular path!
Enough with the steering. Next up we have our seat. We are planning to make one out of wood, and it will be adjustable! More updates soon.. Stay tuned! =)
CADing the different components and systems
CAD of our initial frame
CADing our frame in Solidworks helped us to better visualize our vehicle, which resulted in us making some changes to the frame and connectors. It helped us to improve upon the structural integrity of the frame, and create connectors that optimize the amount of aluminium plate given to us.
CAD of the steering system
We also split the CAD work among the three of us, as the Solidworks workload was quite heavy, and this way we could all gain some experience in Solidworks as well. We CADed the steering system separately, before assembling this together with the frame.
Our final CAD of the frame and steering system combined
CADing was a good way for us to confirm the dimensions of our frame and other parts, knowing that they will be properly aligned. CADing was also essential in helping us know what parts to order. We ordered more specialised parts such as shoulder screws for our front wheel axles.
All’s good at IDC
The laser-cut connectors and rail
We then put the parts together to form…
A laser cut prototype of our frame – we even laser cut the extruded rails
Guan Yang and Zijian evaluating our frame prototype
A prototype of the seat that we will be mounting onto our vehicle!
Budgeting: What’s there left to purchase?
We now have a total of around $65 left to purchase remaining components for the brake and throttle system, belt and sprocket, seat and electrical system. $65 is not alot, thus we will have to carefully plan for the remainder of our budget! Hopefully it will be enough, otherwise we may have to beg, borrow