Category: Prototyping

LEGOs for prototyping

LEGOs are a great way to prototype something mechanical. But what if you don’t have enough of the right kind of LEGOs? Well that’s where the LEGO Digital Designer software comes in very handy. It’s basically CAD for block heads. Here I’ve rendered how my front end could work were it built out of LEGOs. I really think like I’m getting very close to where I can proceed to the next stage of prototyping: a functional small-scale model.

Two for one

I had a fun realization yesterday. As part of my prototype roadmap, I plan to build a smaller version of Project Streetliner using bicycle components. This was originally intended to be a test platform just for steering/leaning geometry, suspension, and handling characteristics. I hadn’t even made up my mind as to whether or not to go to the full trouble of actually making it pedal powered. In general, I imagined that I’d just sort of slop something together as a proof of concept. But upon deeper consideration, I’m re-evaluating this prototype step for the better in two key ways. First, I’d gain a ton of valuable experience by going ahead and building a streamliner shell for that bicycle prototype. Not only would it be the place to perfect my fiberglass construction skills, it would force me to solve a lot of control linkage, entrance and exit issues, and other problems on a simpler vehicle before tackling the more complex road version. But what’s even more awesome than the learning value is that if I take the time to build this prototype to a good level of quality, I’ll actually have my very own tilting Velomobile — something that to my knowledge doesn’t exist in the marketplace right now. When all was said and done and Project Streetliner was on the road, I’d have two fantastic alternative vehicles. One perfect for commuting and errands on the open road, the other perfect for cruising the bike paths of the twin cities (and possibly being a perfectly viable commuting vehicle all its own depending on where I’m headed). That’s very exciting. I’ve even thought of a name: the Pathliner.

Shape Study #3

This is Project Streetliner Concept #3. After watching Gizmag’s fantastic video on narrow and single track vehicles, I wanted to explore a form that was as narrow as possible. More specifically, I also wanted to explore what the original kernel of my idea would look like. That is, if I took a Piaggio MP3, stretched it into a recumbent form factor, then built an aerodynamic body shell around it, what would I have? Well, I’d have this. It’s very trim and very shapely and definitely pays good homage to its Velomobile roots. Of my concepts so far, it would stand to reason that this one would be the most efficient in terms of aerodynamics, but I’m ambivalent about something so narrow. This is mainly because of low-speed stability and the need to put a foot down or not. Riding a normal MP3 is really no different than riding a standard 2-wheeler except that under just the right circumstances, you can lock the tilt at stop lights and things like that. That works for those situations, but there are times when you need to unexpectedly stop and catch the bike with your feet. If you’re already leaned over, locking the tilt isn’t going to keep you from falling over. However, if the front wheels were a bit further apart (like Concept #2), I’m optimistic that an on-demand tilt lock would keep the vehicle from tipping over in a sudden stop situation, even if the vehicle is fairly well leaned over.

As much as possible, I want to avoid having to Fred Flintstone this vehicle (that is, have my feet hanging out the bottom), including when I need to back up. But that’s a separate problem.

All in all, having shaped Concept #3 I think that I’m getting closer and closer to a final idea and that this idea will ultimately be somewhere in between Concept #3 and Concept #2. It’ll be restricted to half the width of a conventional car, but that’s still quite a bit wider than the Piaggio MP3’s current wheel span. Perhaps that’ll indeed be the sweet spot.

Shape Study #2

This is my Concept #2 Streetliner. As I sculpted Concept #1 in clay and later in birch, I realized that making a body style like that tilt and lean into turns was going to be pretty difficult without perhaps having the mechanics under the body shell lean independently of it. As much as I love those european curves, that’s a level of complexity I can do without. So for Concept #2 I knew I wanted to try a nearly open wheel design. Inspired by a modernist 1930s era kid car on display at the Minneapolis Institute of Art, the initial sketches have taken shape. I’ve loving it! The single headlight up front gives it a feel one part airplane, one part streamliner locomotive. This is the front-runner aesthetic so far.