Skateboard Nearing A Good Place

In order to get the Skateboard (Facebreaker) a little less rough I’ve worked on a few things over the last couple weeks. Build process previously documented here and here.

Painted the frame to keep it from continuing to rust, and for STYLE, obviously.

Added these 1/16″ thick HDPE strips to the middle bottom of the frame to reduce metal scraping when it bottoms out over curbs and stuff (long wheelbase, low clearance, it happens)

Cut out and attached a full-size solid deck out of this crappy shipping-crate plywood

Then stained it to reduce the show-uppiness of shoe marks, to the state in the first picture. I also reworked some of the component mounting strategy, extended and tidied the potbox-controller wire and adjusted the potbox lever. I have ordered a 4QD VTX40-24 controller to replace the Curtis 1208C, for the sake of being able to adjust the acceleration/deceleration ramp rates. Unfortunately that controller will not drop right in with the potbox setup, so I will have to set something up to make it work. I would like some sort of neat-o pistol grip style controller but I’ll probably just slap something together for now.

I have largely realized the concept I started out with. Pretty nicely indeed, if I say so myself.

The question I’m thinking about now is really where I need to take the concept- I don’t think what it is now is really there. I need to pick a direction for the project, and see if I can get something that really makes sense. In short, I don’t really like riding this thing. Sure, I’ve probably only put in maybe 20 minutes of “board time”, and I’m not a skateboarder by nature or history, but for me the design doesn’t really feel quite “there” or “right”.

This line of thinking can be expanded to address the state of “stand-up” personal vehicles in general.

• Scooters
• Skateboards
• Self-balancing 2-wheel Scooters (Segway-style)

Both Segways and Scooters have handlebars. Segways go 12mph, (non-seated) Scooters usually top out around 10-30mph, some of the electric skateboards on the market can hit speeds above 20. My machine doesn’t manage more than a tepid 6-8mph (estimated, limited by the voltage and gearing of wheelchair transaxle). Fast jogging speed. It steers like a skateboard but has a form-factor unlike any electric skateboard I am aware of. It’s taller, longer, wider. I think it could feel secure and stable at 15-25 mph. Not sure if I’ll be able to test that assertion with this motor transaxle I’m running now. It’s got more than enough power but is geared wrong. I really can’t put any bigger wheels on it.

Benefits of stand-up vehicles:

• Can be awesome
• Good visibility in traffic
• Hop-on, Hop-0ffness
• Generally reasonably compact, efficient nature

Downsides of stand-up vehicles

• High likelihood of falling on your ass
• Practically limited top speed

I don’t think you can safely go much faster than 25 or 30 mph on something without Butt-Support. The Segway is freaky enough at 12, not to mention the ever present “if this thing pukes I am going to be on my ass, hard” factor.

Despite the issues with this prototype, and stand-up vehicles in general, my concept has some things going for it.

• Big pneumatic wheels soak up little bumps pretty well
• Big enough deck for two people (untested, I won’t be the one testing it), or stuff
• Massive undercarriage- you could put enough battery to go 40-80 miles on a charge in it, easily

That’s assuming you are comfortable enough riding it to want to go 80 miles on it. So far, for me, I don’t think that’s so much the case. It’s a pretty good ankle/knee workout.

The other big benefit of my concept in its scale/implementation is its nearly boundless versatility with permutations of design. Some big possibilities that have come up:

• Put toe hooks/clips onboard for better steering and stability leverage- this was independantly suggested by two skateboard afficianados who rode it.
• Put a handlebar on the (non-tiling) axle assembly- would take much of the trickiness and uncertainty out of riding it.
• Put a bucket seat on it. Particularly if you had your hands free I think you could generate plenty of tilting force to ride it sitting down

I’ve got an idea for a more elegant, reliable and adjustable axle-pivot/damper setup, and indeed it would be a good idea to get a powertrain setup that allows for more speed. These transaxle motors are built sturdily, and could be run over-volt, maybe even double voltage at the expense of brush life. I don’t think the windings themselves are at great risk of frying given the light weight of the vehicle. I haven’t monitored the cruising current draw of my motor at 24v, I suspect it is quite low.

I don’t envision trying to produce these things, or have them built. I think that I may just work on a second prototype to develop the things I just mentioned, then I might just make documentation and plans available. That would suit the flexibility of this design well, so that anyone can build it the way they would like it.

So- there is still potential and promise here, as well as a few issues keeping me from hopping on and cruising around town more. I’m still scared of the super-quick accel/decel from the current motor controller after getting pitched off of it. I’m still just not comfortable with the stability of the board (I think that’s more my problem rather than an issue with the machine). The top speed is boring. Also, while in some road situations it’s clear where to ride a thing like this, be it the bike lane, or in the street- on other streets it’s a bit more difficult to work out. I’m not sure how a vehicle like this is supposed to be allowed or prohibited. It’s too wide and slow to really play that nicely on bike paths or sidewalks, it shouldn’t be duking it out with cars on bigger roads though.

Indeed, my most imminent job is just to get it out and ride it more. I tend to avoid opportunities to hurt myself. Suppose that’s why this is not really such a good project for me… but I’m this far into it already, right?

If you are in the bay area and are interested in riding this thing and telling me what you think I would appreciate your input. Drop me a line.