We finished The Wizard of Oz as our bedtime story and have started on The Marvelous Land of Oz. I've never read any of the other Oz books--in fact, I'd never read the first until last time we read it. The movie is the next item on my Q, but it might be too scary (or boring) for the Numbers.
Still have not distilled the mead but we did at least assemble the "still", including having to go back to Home Depot for the right PVC cement.
Number Two is now 5, which makes him eligible for a library card. I took him on Saturday and he was pretty excited about it. He carried the card around all weekend, often asking "Can you believe I got this card??" and so forth. He's been very interested in optical illusions recently, so I brought him back to the library on Sunday so he could check out some books. I also found a huge tome containing (tiny reproductions of) all of Escher's work, which he thought was awesome.
This book is surprisingly helpful. It has a lot of good general engineering information, obviously aimed specifically at Lego. For instance, most of an entire chapter is spent in discussing how to drive straight, with both software and hardware solutions. And it doesn't hold your hand too much--there are some pictures of the general idea and then you are left to build it yourself. Which is hard, when you excel more at following meticulously detailed and well-designed construction instructions than actual design skill.
I spent a lot of the weekend trying to build a straight-driving robot using a differential gear and semi-failed. That is, the wheels all turned the right way and everything but the gearing(?) was wrong and so the motors couldn't drive it. The biggest problem is that if you hold the differential stationary (which you need to do while driving straight) then the axles on either side rotate in opposite directions. So you have to go through 2 or 3 gears to reverse that, plus a couple more to move the axle axis back in line with the other one (probably not strictly necessary, but nice). All those gears really eat up the power.
Maybe I should use both motors to drive forwards and a ratchet system to control the differential.
Made less progress than hoped on the 3D graph at work. I keep being stopped by design issues that the user (i.e. me, up until now) doesn't even notice (unless they are done wrong). For instance, choosing how many tickmarks to show when you zoom in. You have to detect how zoomed in you are, have a system for making all levels of zoom look about the same, etc. The non-trivialest part is making sure my code works the same way as the existing code for uniformity. Also, how does 3D UI interaction work? When I drag my mouse on a 3D graph, around what axis should it rotate? An axis perpendicular to the movement of the mouse, sure, but what Z component (into the plane of the screen) does that axis have?
|< All your rights are belong to us | BBC White season: 'Rivers of Blood' >|