April 8th, 2013
|01:55 pm - Oops.|
So, after a couple of server crashes I realized my pronoun patch for TinyMUSH 3.2 had a nasty memory leak. What can I say...my C skills are a bit rusty. Here's version 2, which hopefully won't crash your server.
Current Mood: chastened
February 23rd, 2013
|11:13 pm - Pronouns and Passwords|
I recently wrote a couple of TinyMUSH patches, and I thought they might be of interest to other people.
Backstory: I run a small TinyMUSH world, as an online place for friends of myself and my wife to hang out. It has a rather long history, originally having started as a TinyMUX 1.6 world in 1998, and it's moved around to various Linux and FreeBSD hosts over the years. Because of TinyMUSH's simplistic use of the crypt() function, the result was a database with three different password hash formats in it. I'd patched TinyMUX to cope with that, and when we recently upgraded to TinyMUSH 3.2, I had to write a new patch.
I also wanted the ability to set custom pronouns. Some of my friends get creative with pronouns for non-binary genders, and unlike MUCKs, MUSHes have only a few hard-coded gender pronoun options. The patch I wrote allows using custom ones just by setting attributes on your character.
The patch is written against TinyMUSH 3.2. I don't think the code I modified has changed much in a while, so it may apply cleanly against other versions, too. I also wrote up a quick description of how to configure custom pronouns; I suggest putting it in the news.txt file, e.g. as "news pronouns".
EDIT: That patch had a nasty memory leak. Guess my C programming is rustier than I thought. I've replaced it with a version that hopefully WON'T crash your server.
October 15th, 2012
|12:23 pm - Mechanic tips: Crush washers|
Crush washers are maybe the most misused kind of seal in automotive work. They're commonly found any time a threaded fastener has to seal in a liquid; the most common example is the crush washer under the oil drain plug of most cars. Tighten the plug, the soft copper washer deforms to fill any gaps, making a liquid-tight seal.
What makes them misused is these are supposed to be one-time-use items. You can maybe get away with reusing them once, if you're careful; but after that, the washer gets work hardened and doesn't deform anymore. The usual response to this is to crank down on whatever it's sealing to try to stop the leak. In the case of the oil drain plug, this usually results in stripping out the threads in the oil pan.
Most parts stores have a rack of oil pan crush washers of various sizes; they're cheap, and should be replaced with every oil change. But what if you have an odd size? I was faced with this on Saturday, when I needed to replace the two crush washers that sealed a banjo fitting on the hydraulic pump for the Mercedes. They were an odd size and none of my local shops stocked anything like them.
It turns out there's a trick to re-using these things -- but only if they're copper. (If it's aluminum, you're out of luck, but copper is more common.) You have to anneal the metal to counteract the work-hardening and make it soft again. Hold the washer in a pair of pliers and heat it with a torch until it glows cherry-red. (An ordinary plumber's torch will do.) Once it cools, take a file and file down any ridges or burrs until the washer is smooth again. Now you can reuse it and it won't leak.
One more note -- you don't have to reef down on these things to get them to seal. That just risks stripped threads. With a good crush washer, tightening about a quarter turn past where you start to feel resistance will usually do the job.
September 8th, 2012
|07:17 pm - Car stuff!|
Today I replaced the rear sway bar* end links on the Mercedes. These are well-known among Mercedes owners for making a distinctive and really irritating rattle going over bumps when they get play in them, and these had a lot of play. The right one was, I think, original to the car; the left one was a replacement. Why someone chose to only replace one, I don't know; they're only $10 each and about the easiest part to replace on the whole car. Just another one of those puzzles.
Tire wear is much improved since I replaced the rear subframe mount. The rear tires are no longer wearing rapidly on the inner edges. The previous owner had warned me this car "ate rear tires" and, looking at his receipts, he replaced them repeatedly; apparently none of the tire shops ever wondered why the rear alignment was so out of whack, or thought to notice the bent mount throwing everything out of line.
I also finally fixed the windshield washers, which had been an irritation for a while. The check valve had disintegrated and the pieces had clogged the nozzles. New nozzles were cheap enough that the most sensible thing was just to replace both of them and the check valve, together.
* For any Brits reading: "anti-roll bar"
August 16th, 2012
|12:57 pm - Basic care of long hair|
I've noticed a lot of people who have long hair don't really know how to take care of it. Guys, in particular, generally aren't taught anything about it when they're kids. I thought it might be helpful to give a few very basic tips.
- Wash the roots, condition the tips.
Consider how hair works. The actual strand of hair is dead. If you have oily hair, the oil you're trying to wash out all comes from your scalp. When you wash your hair, apply the shampoo mostly to your scalp. Similarly, when you condition it, apply the conditioner mostly to the tips, which don't get the benefit of the natural oils from your scalp.
Do NOT gather your long hair all into a big pile on your head to wash it. This contributes to tangles and breakage. Let it hang straight down while you wash it, either down your back or in front of you, whichever is more convenient. (Personally, I tilt my head forward and drape it all in front, because I find it easier to reach that way.)
- Use a conditioner.
No, a "shampoo and conditioner in one" product is not going to work. You need an actual, separate conditioner. Apply it after washing your hair, and leave it in for a minute or two before you rinse it out. It'll make your hair less dry and frizzy, and greatly reduce the tangles you have to deal with when you brush it.
Note, too, that not everyone does best washing their hair every day. If your hair tends to be dry, experiment with skipping a day or two; you may like the results.
- Brush (or comb) gently.
Some hair types do better with a brush, others with a comb. In either case, don't yank on tangles. If your hair wants to tangle, brush or comb the tips first, then slowly work your way upward until you've worked out all the knots. Tugging too hard will break your hair. If your hair is thick and you use a comb, use one with widely spaced teeth. Trying to force a fine-toothed comb through long hair is a recipe for tangles.
- Blow dry with care.
It's best to let your hair dry naturally. If time constraints require you to blow dry it, don't dry it until it's bone dry; leave it a little damp. This will avoid making it dry and frizzy.
- Get it trimmed now and then.
Even if your goal is to grow your hair out longer, you should have a little trimmed off the ends now and then. This will even it out and get rid of split ends. A good stylist can also give you individual advice on how to take care of your hair and present it to best effect. Yes, it costs a bit, but if you have long hair in a simple style you probably won't be going more than a few times a year.
- Use good hair ties.
If you pull your hair back into a ponytail, buy only fabric-covered hair ties, and use ones with a little thickness to them. I'm not saying you have to wear a scrunchie, but the slightly thicker ties result in a lot less breakage than the skinny ones. Avoid ties with metal crimps that can catch and break hair.
May 28th, 2012
Fixed the parking brake on the Mercedes today. It wasn't so much broken as it was massively out of adjustment -- the pedal would go straight to the floor without affecting the rear wheels at all.
First step was to make an adjustment at each rear wheel. This car has rear disc brakes, but the parking brake is independent and works like a miniature drum brake -- when you press on the parking brake pedal, shoes move outward against the inside of the rotor hub. Like most drum brakes, adjustment is done with a star-shaped wheel inside each hub. You remove one lug bolt and turn the wheel until the star wheel aligns with the lug hole, then you turn it with a screwdriver. (It's edge-on to the hole, so you can turn it by prying on the points with the screwdriver tip.) This is about as much of a pain in the butt as it sounds; you can't really see what you're doing, and it's hard to figure out which way to turn things except by trial and error. After a considerable amount of fiddling and a few false starts, I tightened them until they locked the wheels, then backed off a bit until the wheels turned freely again. So much for that adjustment.
Testing showed the parking brake now kinda, sorta held, but still went to the floor. So I dove under the car and tightened the adjustment under there, which effectively shortens the brake cable. It took quite a few turns -- I suspect no one had ever adjusted it, and the cable stretches over time -- but eventually the brake started to take after only a few clicks, and was fully on before the pedal hit the floor.
As a side benefit, while I was under there I finally found a loose exhaust mount that had been causing an annoying rattle for...well, pretty much since I got the car.
May 12th, 2012
|04:06 pm - Automotive misc.|
Took on a couple minor things on the Mercedes that were non-critical, but had been annoying me.
First was the climate control system. The car has automatic climate control, and it worked, after a fashion, but it was always overshooting in cool weather -- it would heat for too long, then blow cold air for too long. From reading other people's comments on the system, it seemed the problem was likely to be a foam hose that goes to a vent on the dash that samples the air temperature. When it fails, the system samples the temperature inside the dashboard instead of the temperature in the car. I took out the glove box to access it and, sure enough, the 30-year-old foam hose was rotted out. As luck would have it, I'd bought some foam pipe insulation a while back to stuff a costume tail with, and the leftover length turned out to be precisely the right size. I won't get a chance to test the fix until this evening, most likely, when things cool off -- the A/C hasn't worked since God was a boy, so it's really only the heater that I'm hoping will function more smoothly.
Secondly, I went through and troubleshot the central locking system. On this car it's vacuum-operated and of the typical European "all the doors mimic the driver's door lock" style. The vacuum line to the whole system had been plugged off, which is usually a sure sign of a massive leak somewhere that someone didn't want to deal with. There are five vacuum elements that operate the locks -- one in each door (except for the driver's door, which has the control valve), one in the rear hatch, and one for the fuel filler flap. This system has a reputation for being tough to troubleshoot, but it's pretty easy if you have a MightyVac or some other hand-operated vacuum pump; just take apart the tee connectors under the carpet and test each part of the system individually. Three elements turned out to be bad, but two of them were bad only on the unlock side. So, by selectively plugging off hoses, I now can lock everything except the rear hatch from the driver's door, and unlock the passenger door and fuel flap. Eventually I may replace the bad parts to get the whole system working, but at the moment it's not worth the $75 or so in parts it will cost to do that.
March 29th, 2012
|06:54 pm - I smell like 90-weight|
Hm, never did post about the automotive work I did this weekend, although I did tweet about it.
The Mercedes needed a new left driveaxle. One of the CV boots had gone and steadily increasing driveline vibration told me it wasn't going to last much longer. I'd been putting it off a bit because the job is a messy pain in the ass; unlike more modern cars where you can just unbolt the CV joint from the drive flange on the diff, on this one the differential has to be opened to remove a circlip that retains the axle's splined shaft inside the diff.
All things considered it went fairly smoothly. The fill plug in the diff turned out to be stuck — very stuck, I'm guessing, since someone had managed to mostly strip the 17mm internal hex. I ended up refilling the diff through an air vent on the top. This worked but was slow, and I ended up wearing some of the gear oil on my arm because I had to keep lifting the hose out to let the air out as I added oil. If you've never experienced the smell of hypoid gear oil, let me just say it is not quickly forgotten. It has a strongly sulfurous smell, a bit like someone startled a skunk while it was bathing in used motor oil. By the time I was done I smelled like it, the garage smelled like it, and the hallway outside the garage smelled like it...
The hardest part of the job was actually getting the circlip back on the axle. It was far too big for my circlip pliers, and in too restricted a spot to really get to with circlip pliers anyway, so I had to resort to tapping it back into place with a punch. Every time I got it crooked it popped back out and landed five feet behind the car. It took about two hours, but eventually my persistence won out.
I had already planned to replace the diff mount, which also serves as the rear subframe support, because it has to come out to do this job anyway. I'm glad I had a replacement on hand; the old mount turned out to be bent. Not sure how they managed that...maybe by jacking the car up by it with a very heavy load in the back? Anyway, this probably explains my uneven rear tire wear.
Tip: When you have to support something like a differential or engine while removing/reinstalling a mount, use a scissor jack instead of a hydraulic jack. It gives you much finer up/down control and it won't slowly sink under load.
February 20th, 2012
The timing belt change on the Honda is done (along with all the other stuff I decided to do while I was at it.) This is the first modern car I've done a job this extensive on -- modern, that is, in that it's not a chassis designed in the 1970s. Some of the changes are interesting. For example, there seem to be very few flat gaskets; the water pump gasket and even the valve cover gasket are O-ring type seals that fit into machined grooves. There are also some interesting design touches that are obviously meant to facilitate automated assembly -- for example, some of the engine mount studs taper to points, so they can act as locator pins when the engine is lifted into place from below. Likewise, the water pump has sleeves around two of the bolt holes to make it self-centering when it's pushed into place
I actually don't have a lot of major complaints about this job, except that some of the timing cover bolts are very tricky to access. (Perhaps it would be easier if I had smaller hands.) Also, the alternator belt is a pain to adjust. They gave me nice little jack-screws for adjusting the tension on the power steering and A/C belts; why couldn't they give me one for the alternator, too, instead of making me use a pry bar?
February 18th, 2012
The thing about doing a big car maintenance job like a timing belt change is it tends to expand due to "while I'm in there" syndrome. It starts with, "while I'm in there, I might as well replace the water pump too." And then, "while I have the valve cover off, I might as well set the valve clearances." And then you notice the spark plugs you took out look kinda worn, and maybe a new valve cover gasket would be a good idea, and oh yeah the rubber in that engine mount you took off to get to the timing belt looks pretty hashed...