If your winter season is somewhat similar to my neck of the woods, I suspect those plans may remain in the drawer for some time yet. For me, this is a slow time of the year for project work (no heat in the garage). So I've kept indoors and had the time to revisit some of my posts, and it occurred to me that, I didn't really explain why I incorporated features such as hub-centered wheels with special front hubs. Or, why I chose to use swingarms instead of front wish bones.
So, I decided to try my hand at Google Slides to graphically illustrate some of those design decisions.
Here it is.
After being told about it, I downloaded a "screen recorder" and did a "take 2" on the slide show. The message is the same, but the sticky slides are gone and background music is added. Here it is again.
WOWSER, Howser. That, sir, is impressive design & engineering. Those wheels are exciting. I'm beginning the 1st round design & build of what I hope is 1st of a few (or more) streamliners.Since becoming an AZ member I have become familiar with some of the builds in "Discuss Your Project". I must say, this site is a real gem for a DIYer. I am impressed by the know-how, knowledge and the support expressed by members of this community, as well as DannyC's humour.
This project is now in its 14th year of numerous failures, many so-so results, and a few successes. Over the years I experimented with all sorts of tilting, steering, and wheel designs. Even the vehicle's layout has morphed from a tadpole into a quad, and now into this delta-quad switch-over model which my wife claims is evidence that I will never truly complete the project.
I'll begin by describing the design, build, and assembly of the two-part main frame and six swingarms. The following images show two full-size dimensional drawings and how the notched, bent, then welded, aluminum tubes match a drawing. A left or right swingarm is made by simply flipping the fabricated part over, as every part is built on one plane without the need for welding jigs. I required four dimensional drawings - two for the main frame, one for the front 4 swingarms and one for the 2 rear swingarms.
Three spindles are fastened to the main frame with brackets and hose clamps. Yes, standard hose clamps). They worked surprisingly well for fastening round-tubed items onto my previous models while offering the flexibility of quick removal for the all-too-frequent redesign/rebuild sequence. For high stress locations I used T-Bolt clamps which are similar to fuel-injection hose clamps, but larger.
2-part Main Frame with Spindles
The spindles are shown with machined nylon bushings, but during actual assembly, the bushings are inserted into the swingarms and then pushed onto the spindles. Bolts with nylon washers are fastened into the spindle ends to hold the swingarms in place. Blue cardboard hides the distracting un-insulated wall of my garage and helps to make the aluminum tubing more visible than if it were just against the concrete flooring.
4 Front Swingarms
The front swingarms are likely overbuild and somewhat grotesque looking. I experimented with dual wishbones and found that swingarms perform better due to their "plane of inclination" suspension travel which minimizes tire-scrub in depressions, bumps, and when tilting in corners. Plus, the switch-over to a delta is quick since a single-sided swingarm is simply placed onto the upper front spindle.
I considered using smaller diameter tubes similar to the structure of the dual wishbones on the Tripendo Trike. While fabricating would have been more complicated and likely require welding jigs, the result would have been more visually appealing as well as lighter in weight.
As things are seldom ideal every step of the way, I eventually settled on what you see. Thankfully, the more ugly central section of the swingarms (next to the frame) will be hidden by the velo's cabin section.
The rear swingarms are more complex and heavier than those generally found on free-tilters. I'm not sure if these are overbuilt, but they will need to take the stresses generated by the tilting apparatus.
4 Wheels Nesting
Four shallow-dished fiberglass wheels with flange and brake routers attached are shown here before being installed onto the swingarms.
The vehicle (weighing 9.7 kg) is now ready to roll.
In the next post I will focus on the tilting mechanisms and suspension.