rbandrews: (Default)
I finished putting lights on the quadcopter. Image album!

This involved making little feet to raise the whole thing up 30 mm, and making a little power supply board for them (since they want 12 volts and the batteries might provide anywhere from 11 to 14, depending on battery size). It means I can fly the copter at night, because I can see it. Cassie thinks it looks like a UFO and she's totally right. I'll have to get her to take a video of it next time.

The little yard-space in front of my apartment is big enough to hover in, although not as roomy as the field behind my office. I plan to fly there plenty. :)

Next step is making the lights controllable with a switch on the radio. I'm pretty sure I know how to do that, although the last time I thought that, on Sunday, I started a small fire.

Today I:

Jan. 25th, 2014 06:52 pm
rbandrews: (Default)
Today I:

- Went to EPO and spent about seventy bucks. I needed some parts for something I'm doing to the quadcopter, putting lights on it. Got 12V voltage regulators (Radio Shack supposedly sells them but they were out), LEDs (I actually already had these but I found better ones), perfboard, wires (better wires for this purpose than what I already had), stuff to make connectors, and some random odds and ends. I forgot to get a switch, which is a little annoying.

The goal here is to have red lights on the back arms of the copter and white lights on the front arms. This way I can see how it's facing in the dark, so I can fly it later in the evening, so I can fly it more often. One of the sort of annoying things about flying something like this is that it's easy to lose track of how it's oriented, since it's square and spends most of its time hovering in place.

- Cleaned my room. Cleaned off my desk, cleaned the work table, put things in boxes and in the closet. I hadn't done this since, oh, October sometime? And in that time I've built several small projects, one big project, added a tool (the cutter), spent two weeks sick, et cetera. My desk was actually buried. Like, the level of crap covered up the bottom of the monitor.

- Put the Commando 23 set on a keyboard. This was a group buy for some keycaps that I got in on a while back, and last week they were delivered. They were the final straw for junk piled on my desk. They look pretty all right on a keyboard though.
rbandrews: (Default)
I've had a piece of cardstock stuck to the cutting mat, ready to be fed through the cutter, for over a month. Tonight I finally got around to doing that, and now I have a little custom deck of Werewolf cards. They're not too fancy but they're definitely a proof that I can make cards. I'll post pictures tomorrow.

Part of the problem is that I am about at maximum table capacity: I had to run a USB cable across the room to reach the cutter, and I'll have to move the whole thing when I want to solder anything again. I can't wait to get into a house and have a room I can line with 6-foot tables.

Cards came out pretty well though. I need to do two things: one, figure out how to do the classic WarGames-like monoline font thing (looks like this). Since it's a cutter, it thinks it's cutting the outline of something, it can't shade in solid shapes. I need to teach it to be a plotter.

Two, I want a better way to remove the cards from the mat than "peel them off individually with a spatula." It's kind of annoying, especially if I want to make multiple cardsheets.

I also got a servo working on an Arduino, and got my print on with a little mount for a laser module. I can now send commands to aim a laser (although only on one axis; I haven't finished the whole assembly yet).
rbandrews: (Default)
My transmitter module came on Friday, so today I went to the field behind my office to fly. Mike, my friend who ran the class for building them, came too.

Hovering inside is more or less easy. Holding a constant altitude is tough, the throttle is really sensitive, making it pretty much like every other RC helicopter I've ever flown.

Flying outside is a bit harder. I don't have to care as much how high I am, so it's easier in that respect, but then there's wind. Holding it steady in the wind (even a fairly light breeze) isn't easy. I did figure out how to recover from an imminent crash: cut the throttle, so I start falling, then gun it right before I hit the ground to soften the landing. I saved the thing from being carried away by the wind a few times by doing that.

We found out that there's an RC hobby place about 15 minutes from work, and although they don't have replacement rotors, they do have tools, servos, radio stuff, batteries, et cetera. I bought some tiny screws and a hot air gun (for something else I'm building).

I also found that some (expensive, carbon fiber) propellers can be had from Amazon for about $16. This is more expensive than the $4 / set prop sets from the Chinese site Hobbyking, but they also don't take three weeks to be shipped.

Why do I care about props all of a sudden? Because, naturally, I managed to flip it over (I blame the wind) and break a prop in half. So, it'll be Wednesday before I can fly it again.
rbandrews: (Default)
A few months ago, Tina told me that Mike was running a class at the hackerspace on building remote-control quadcopters, so I signed up. The class was last weekend.

The class cost $250 or so, which included a bunch of quadcopter parts. It didn't include all the parts, though, because some stuff (a radio, batteries and a charger, etc) would already be owned by someone who was into RC stuff, so I had to buy those separately, another $200 or so. Which wasn't really a problem.

First day, I come in a little late, and we start assembling things. I brought my own soldering iron and some other tools, because I was kinda worried that the hackerspace would have crummy tools, and I wasn't disappointed: their iron was pretty low quality and the soldering we had to do was actually fairly hard (really giant wires, to pass really giant currents to motors) so I busted out mine. The guy I was sitting next to, Michael, was really cool and we helped each other out a lot.

First problem I had was that apparently my transmitter module was dead. The receiver works because it worked with Michael's (identical) transmitter, but I can't transmit. Still, I'm able to get everything built by borrowing his transmitter to test it. Solder on some wires, assemble the frame, attach components to the frame, use a laptop to set up the firmware and calibrate the sensors, balance the props, configure the RC controller, it took pretty much all day. But I had the hardware done!

Second day, we get to test them. Everyone took their copter out to a warehouse in the back of the building and we flew them around some. I lagged behind a little bit because I was trying to set up the firmware again on my laptop (I had used Michael's on Saturday) but I eventually get out there, borrow Michael's transmitter again, and fire it up.

The thing flies perfectly. It's completely stable, because the controller board is smart enough to sense whether it's level and adjust it. I can pretty easily hover it at about chest high, move it around, land it without letting it drop too far. Way easier to fly than my other (little bitty) one.

Of course, after flying it for a bit, I discover that the battery charger I ordered was also DOA. Argh.

So, now I have a nice quadcopter sitting on my bed that I can't do anything with. I bought another battery charger from a hobby store locally, and I ordered another transmitter but until I get it in I can't fly it. It's pretty annoying.

On the other hand, after this class, I have a pretty good idea how to build RC things. I think I want to build a little RC robot next, like a tanklike thing (maybe not a tank, maybe wheels, I dunno) with a turret I can aim. I think I can print most of it and I know enough electronics to make it.
rbandrews: (Default)
...is love, sweet love.

Well, no.

If you take an average sea creature and measure the elements it's made of, you find that it (like everything else) is mostly carbon. But there are also some larger elements in trace amounts, that are in a higher concentration in the creature than in the surrounding environment.

The element that is most over-concentrated like this happens to be phosphorus. Phosphorus is the limiting factor of life: given a source of extra phosphorus, life could find everything else it needs to exist in plenty.

So I would say, what the world needs now is phosphorus. That's the only thing there's just too little of.
rbandrews: (Default)
It sort of makes sense: before yesterday I didn't have the energy to post about how I was sick, so right after I did I start feeling better. I don't want to jinx it but you know how there's a sort of intangible switch that gets flipped where you go from "sick" to "tired and hungry but not sick?" That happened last night I think. I was able to eat something, and now I'm still hungry.

I'm also a little stir crazy. I am thinking about maybe going out to a bookstore or something this evening and pretending I have christmas money and spending it. :)
rbandrews: (Default)
On the 13th or so, I started coughing, a lot. I coughed up white stuff, then yellow stuff, then brown stuff. Then I stopped coughing up stuff, but I didn't feel any better: I still had a fever, I was dizzy and light-headed, and I couldn't eat anything. And I kept feeling like this. I took off the entire week before I was supposed to go on vacation, then stayed in bed the entire time I was on vacation. My fever stopped a few days ago, but I've still been light-headed and crappy. I alternate between lying in bed reading and sitting up watching Parks and Recreation on Netflix.

So I have had a kind of shitty christmas. I spent all day either in bed or on the couch, watching the Doctor Who special and Indiana Jones and the Last Crusade. I ate a couple of ginger snaps and Cassie's leftovers from going to the Cleburne Cafeteria. Finally got Cassie to go on christmas day, and I couldn't ever go with her!

Hopefully I'll start to feel better now. I can do stuff I had planned to do over the past two weeks, like mailing out christmas presents.
rbandrews: Jeb from Kerbal Space Program (Kerbal)
In my last Kerbal post, I had gotten Jeb (and his assistants, Bill and Bob) to Duna. They landed, they walked around some, they took off again. Then they were out of fuel and hung out in orbit for a couple weeks.

Tonight, I rescued them!

The first attempt was to just get them some fuel. I built a little robotic probe with a big fuel tank and flew it over there. Unfortunately, it took most of the fuel in it to get it there... I'm not good at interplanetary flight yet. So that was a bust. That was about a week ago.

Tonight I tried again though. I built a probe with a larger tank and a nuclear engine. I was able to get it into orbit really easily (I discovered a foolproof way to build launch vehicles), and then flew it over to Duna. I'm getting better, slowly, at interplanetary transfers. The hard part isn't getting to the planet, it's getting to a decent orbit once you're there. You have to spend a huge amount of delta v to get into orbit at all, and unless you make correction burns way before the encounter your orbit is going to be crazy tilted and really high. Like, the first Jeb mission ended up in a polar orbit around Duna.

So, okay, got there. Rendezvoused and docked with the stranded ship. Now for the second part of my plan: the ship that I first sent there had four small landing rockets on it. These are great for landings but they use way too much fuel for interplanetary flight. The nuclear engines are the exact opposite: low thrust but extremely low fuel usage. The same tank that had maybe 2000 m/s delta v gave me over 5000 with a nuclear engine.

Which meant that after I got to Duna, normalized my orbit, rendezvoused, and docked, it made sense to just throw away most of the original ship and carry the crew capsule home with the probe. Which I had about twice the delta v I needed to do. I burned back home, made a correction burn (getting decent at those by now), and got back into Kerbin orbit. I could have made a really fast reentry there, but I figured what the hell, and actually took a couple orbits to slow myself down. I managed to actually stay out of the red zone on the G meter during reentry.

Next task: rescue the guys I left stuck on Duna's moon. That'll be tough because they can't even take off, they're so out of fuel.
rbandrews: (chicken dog)
Silk Soymilk "Seasonal Nog" is not only not terrible, it's actually good.

I had low expectations, I'll admit...


Dec. 7th, 2013 04:43 pm
rbandrews: Mississippi Queen piece (printing)
On Black Friday, I got an email from a website I go to sometimes, Inventables. They were having a sale on this thing called a Silhouette Cameo. I don't buy much there because they're somewhat overpriced, but this was a normally $300 machine for $220, so I went for it.

What it is, essentially, is a plotter. Sort of. It's a cartesian robot, like a 3d printer, in that it has a print head that it can position anywhere over a piece of paper (or other thin material). The print head can hold a pen, making it exactly a plotter, or a knife, making it a sort of poor-man's die cutter.

Back in the before-times, there was a thing like this sold in hobby stores called the Cricut. Like the Cameo, it was designed for crafting, cutting shapes out of cardstock and so on. I wanted one the moment I saw it, but in order (presumably) to keep from cutting into their industrial sales they nerfed the thing: you had to buy cartridges that had shapes on them, so you'd buy a cartridge with a bunch of butterfly patterns or whatever. I didn't want to cut out butterflies, so I didn't get one.

The Cameo has no such restrictions. It's pretty clearly a hobbyist machine at heart, despite the cutesy craftiness of the box. You can draw whatever you want to cut with it, put it on an SD card and plug it in, just like the Makerbot. They have a "Pro" version of their software for $50 that will import SVG, but the basic version will import DXF (from CAD programs) so I don't know why anyone would bother.

Already I've seen people cutting out stencils for surface-mount soldering with it, and papercraft things. I've cut out a little cardstock gear (as a test) and I drew a little pattern of lines. One thing I want to do with it: since I have the pens, I could make several files, for "red," "black," "blue," and "cut," say. Run the same sheet of cardstock through several times, to draw red lines, black lines, blue lines, and then cut out cards. So I could manufacture card games this way.

Which was actually most of why I bought it; I had just come home from BGG.con and I was thinking about making games. I think maybe my first big project with this thing may be a copy of Sail to India.
rbandrews: Jeb from Kerbal Space Program (Kerbal)
I've been playing on the "career mode" where you start with a few simple parts and have to do experiments in space to get science points to research more. So, last night I tried to make a rocket out of very basic parts to get to Minmus.

I got there, and got into orbit, but when it was time to go home I didn't have enough delta-v. I was able to escape Minmus but my Kerbin perigee was still about 1200 km.

I know that stage separators push the stages apart with some force, so I aimed myself right and separated my last stage. That got me down to 900 km.

Then it hit me: I still had one source of propulsion left. I had Jeb go on EVA, wedged him up against the capsule and fired his jetpack. One full load of jetpack fuel.

That did it, the last 30 m/s or so of delta V I needed.

So, at one point in the history of my glorious space program, yes, I had an astronaut get out and push.
rbandrews: Jeb from Kerbal Space Program (Kerbal)
What's this?

Just Jeb & company, in their new lander, aerobraking high over the south pole of Duna.

You can't tell from this picture but at 30 km up, they're in enough atmosphere to lower their orbit. A couple more trips through and I'll be going slowly enough to make a cheap landing burn.

(Duna, by the way, is the Kerbal equivalent of Mars).
rbandrews: Jeb from Kerbal Space Program (Kerbal)
Look at this. It may be my new wallpaper.

Jeb, with his shiny new-model lander, on the plateaus of Minmus, with a crescent Kerbin behind.

Minmus is Kerbin's outer moon, much smaller and with lower gravity. This same lander can actually land on the Mun unassisted, but it needs a refuel to get home. I should be able to return from Minmus easily though, since it takes so much less fuel to land there.
rbandrews: Jeb from Kerbal Space Program (Kerbal)
With my new landing technique, it's a lot easier to actually do precision landings: I took Jeb & company back to a place they had landed before on the Mun as proof of concept.

I had some trouble on the final descent stage but I ended up about four km away, at the far edge of jetpack radius.

Unrelatedly, I am basically over my cold. I'm not stopped up at all any more. I bet if I hadn't been tired / hungry / stressed / whatever from the con, I wouldn't even have had symptoms from this. I got better almost immediately after getting home and having a good night's sleep in my own bed.


Nov. 24th, 2013 02:19 am
rbandrews: (Default)
I am far too keyed-up to sleep right now, so I'll make a post and try to pack some things, then go to bed.

BGG.con was pretty awesome. I am definitely coming back next year, and I think it'll probably replace Origins for me.

The good:

- It's in Texas, so I get to drive, and no plane tickets, no packing, no flight departures determining my schedule. Basically I block out an entire day for air travel, and driving here is a simple four hours.

- No kids. It's hard to explain, but it makes it better. It's a subtle difference. Their policy is no one under 18 without an escort, and no one under 12 period. I saw a couple babies in carriers but that doesn't really count and they weren't obnoxious anyway. It's the pre-teens that usually make Origins annoying.

- Serious games. Origins has a lot of nice crunchy Euro games too, don't get me wrong, but there's also a lot of Ameritrash. BGG.con is all about the Euro games, the new stuff from Essen, the big strategy games. You won't find any gamers who don't want to play a nice 1-2 hour game, because that's why they're here.

- The library. This is amazing, and it puts the Origins Board Room to shame. There's, basically, every game there. They have them all. I wish I had been able to get a panoramic picture of it. And I mean they have everything, rare stuff, old stuff, new stuff, everything. It really makes for a hell of a party when you can sit around talking with gamers about games, and then decide to play one and you can be certain it's right there, available.

- The people. Origins has a good crowd too, of course. I haven't seen Rachel and Mark in forever and that sucks. But aside from Joe Cochran and his group of friends (who are all really fun to play with) the crowd in general is good. Even if you know no one, you can wander the main hall looking for a "players needed" flag, introduce yourself to someone nice, and sit down and play a game. I played so many new things that way. You can be confident that, whoever you sit down with, they're also a crunchy-Euro-game fan.

The bad:

- The location is not so awesome. It's not walkable at all, there's nothing around to go to. Origins is in the middle of a nice downtown area; here you're pretty much limited to the hotel restaurant, which is a hotel restaurant. There's a free shuttle to other places but it takes a couple hours so I never went; there's no equivalent to "let's run down and grab food to go from North Market."

The neutral:

- The dealers room. It's smaller. A lot smaller. Not the awe-inspiring majesty of the Origins dealers room at all. But, on the other hand, practically everything I would want was there: all the big strategy game companies are there, what you're missing is a lot of fluffy stuff. So I'm kind of okay with that. I mean, I should be, I spent a lot of money there (and not all of it on myself).

Anyway, I had a hell of a good time. I played more games this weekend than I think I have in the entire last year. It's definitely not a "show up and go to panels" con, or a "show up and play in tournaments" con, or a "show up and buy things" con. It's about playing. All. The. Games.

And now, of course, I'm exhausted, and I think I caught a cold, and I may have to drive through an ice storm tomorrow to get home.
rbandrews: (Default)
Maybe too many? I don't even know. I'll post a full list when I get back.


Nov. 18th, 2013 10:46 pm
rbandrews: Jeb from Kerbal Space Program (Kerbal)
Ladies and gentlemen, the Cricket lander.

This is what I was talking about before: three modules, an orbiter, a descent stage, and a command module. Launched in two parts (the bottom descent stage on one booster, the orbiter and command module on another). A little intricate docking dance in low Kerbin orbit to arrange them (orbiter docked to the bottom of the lander, command module on top like you see here), then fly them to the Mun.

What went right: it did actually work, obviously. The launches went off perfectly, the rendezvous was easy, the landing was perfect (more on that later).

What went wrong: The thing is absolutely a beast to handle in space. The orbiter is an enormous fuel tank with a not-rigid-enough connection to the lander. The lander has its mass spread out in those four tanks, so it really does not want to rotate. If you throttle up the orbiter enough, it actually rips the entire spacecraft apart. Docking was slow and frustrating, and I ran dry of RCS fuel long before I landed. So it works but it's tricky to fly. It was not designed with Wookiees in mind.

The landing was perfect though, thanks to a Youtube tutorial I watched. It changed the way I do that in a small but important way:

I used to make a deorbit burn that would have me intersecting with the ground, so that when I landed, my velocity vector would be pointing diagonally forward and down. I'd need to kill that velocity before I landed, but in such a way that I killed the forward velocity first, so that I was heading straight down over where I wanted to land. And, I had to do this while picking a nice flat landing spot. Lots of things that had to be done all at once that were very touchy, and if I didn't do them right I'd either crash or end up hovering over a hill.

The new way is much easier: make the deorbit burn not quite enough to actually hit the ground. Then, you'll fly low over the landing area totally horizontally (maybe 5 km up, going about 600 m/s). When you pass over a good spot, kill all your forward velocity. You don't need to worry about the downward velocity because you don't have much. Then just slowly descend, throttling the engines to make sure that you land softly. Much easier.

Edit: And I just brought it back to Kerbin, and landed within sight of the space center where I launched. Landing in a particular place is the next thing I want to get good at, so I can build up bases and such.


Nov. 18th, 2013 10:39 pm
rbandrews: (Default)
Tomorrow, I'm leaving here to drive to Dallas for BGG.con.

Today, my copy of The World's End on Blu-Ray shipped from Fort Worth, to be delivered tomorrow evening.

We'll each arrive at the other's starting point within a few hours of each other.

Actually doubly ironic: if it's here when I get home from work tomorrow, I plan to take it with me to watch in the hotel tomorrow night. So it's going to rush overnight delivery and then I'll immediately drive it back to where it came from.

(I didn't do this on purpose; it comes out tomorrow and I preordered it a couple months ago)
rbandrews: Jeb from Kerbal Space Program (Kerbal)
Kerbin has two moons. One, the Mun, I've landed on multiple times and while I'm still trying to perfect it, it's not super challenging. The other is much farther out, in a slanted and eccentric orbit, and is called Minmus. I just landed Jeb and his pals there.

I had a plan for a nice lander. I built a few and tossed them at the Mun; they look like this. The idea is that my old lander designs tended to fall over on landing, because they were too narrow. This thing, which I've been calling the Cricket, can land on very slanted ground and not fall down. The problem is that rockets carrying them are top-heavy and wobbly, and it's hard to launch one (although the lander handles well once it's in space). So, after trying for two hours yesterday, I eventually decided to throw up the lander on one rocket, the ascent stage center part on another, and an orbital maneuvering rocket on a third (not visible here, it's still in orbit). This Minmus lander was to be the ascent stage, but I decided to go ahead and throw it at Minmus without a lander to get a closer look, sort of a flyby. Then, once I got there, I had plenty of fuel left so I decided to land. Then I realized that that lander is total overkill because Minmus has such low gravity.