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More an electrical failure, But ive got a dead 2006 mac pro on my desk at the moment. Whats felled it? $15 worth of capacitors on the Nvidia 7300GT, out of the 10 caps on the board, 9 are bulged. loving capacitor rot...
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Apr 13, 2014 04:40
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Ferremit posted:More an electrical failure, But ive got a dead 2006 mac pro on my desk at the moment. Whats felled it? $15 worth of capacitors on the Nvidia 7300GT, out of the 10 caps on the board, 9 are bulged. Oh, but they fixed that! It's no longer a problem! (so the component manufacturers keep saying, and so we all keep finding out is a load of crap - guess it's time to blame it on counterfeits again)
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Apr 13, 2014 04:44
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This, among many other reasons, is why I don't use aluminum electrolytics in ECM designs. Ever. Tantalum or niobium oxide? Sure. MLC? Sure. Aluminum electrolytics? FUUUUUCK no.
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Apr 13, 2014 04:46
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Nidhg00670000 posted:I'm sorry for this everyone. Nice gif. FWIW modern diesels don't inject at TDC, they have multiple injection events. They have 'pilot' injection, which is a small injection long before TDC which starts the flame front initially. Then when the main injection event happens, it can start expanding and making power immediately instead of having to ignite the air first. This plus ridiculous turbo setups is why CRDI engines have such insane power compared to their mechanical brethren.
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Apr 13, 2014 04:55
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Ferremit posted:More an electrical failure, But ive got a dead 2006 mac pro on my desk at the moment. Whats felled it? $15 worth of capacitors on the Nvidia 7300GT, out of the 10 caps on the board, 9 are bulged. At least you can chuck another graphics card in it - I think you can even get 10.9 running if you get the right model.
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Apr 13, 2014 04:58
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Slavvy posted:FWIW modern diesels don't inject at TDC, they have multiple injection events. They have 'pilot' injection, which is a small injection long before TDC which starts the flame front initially. Then when the main injection event happens, it can start expanding and making power immediately instead of having to ignite the air first. This plus ridiculous turbo setups is why CRDI engines have such insane power compared to their mechanical brethren. Yeah, IIRC correctly BMW started bragging a couple of years ago about having five (!) injections per stroke or something. The injection pressures and injection times of the latest common rails are insane!
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Apr 13, 2014 05:00
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kastein posted:Tantalum or niobium oxide? Sure. MLC? Sure. Aluminum electrolytics? FUUUUUCK no. Works great until your low-cost manufacturer/integrator starts bitching about BOM cost.
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Apr 13, 2014 05:02
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Nidhg00670000 posted:Yeah, IIRC correctly BMW started bragging a couple of years ago about having five (!) injections per stroke or something. The injection pressures and injection times of the latest common rails are insane! Five is reasonably common nowadays, though most of them are for emissions/NVH. Usually there's a pilot, one main and one immediately following the main, then two post-injections for emissions. Toyota 1KD's have a (harmless) problem where the most commonly used part of the RPM range is also very knocky and makes customers complain. Toyota's crdi system also happens to suck balls. The solution? Move the entire torque curve a couple of hundred RPM up the range. The noise shifts to higher in the rev range and you lose some power, but the complaints go away.
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Apr 13, 2014 05:27
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I am supposed to be some kind of mechanical engineer but I can't wrap my head around that casting... how do you get the cavity inside of the ring races? Does it have something to do with that little hole you can see in the cut face? Do they just
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Apr 13, 2014 08:12
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Pretty much. Also note the steel expansion rings.
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Apr 13, 2014 08:30
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Two halves (upper and lower) are cast and are friction-welded together, the combined unit is then machined. You can see three remaining fringes from the friction weld remaining on the finished product.
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Apr 13, 2014 08:33
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Tsuru posted:Two halves (upper and lower) are cast and are friction-welded together, the combined unit is then machined. Didn't know this, awesome!
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Apr 13, 2014 08:34
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The breather hole is just that, a breather hole to allow the cavity to be ventilated by the sump and prevent corrosion since the kind of plants where steel friction welding is done don't have a controlled environment. Also, they provide pressure relief. Fun fact: they also use friction welding to create the upper and lower surfaces of the A380's wings, since nobody in the world can reliably cast single slabs of aluminium alloy large enough.
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Apr 13, 2014 08:47
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Tsuru posted:Two halves (upper and lower) are cast and are friction-welded together, the combined unit is then machined. AH-HA! Was wondering what they were. Cool beans, friction and explosive welds are the coolest welds.
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Apr 13, 2014 09:18
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dissss posted:At least you can chuck another graphics card in it - I think you can even get 10.9 running if you get the right model. Its great IF its got a running version of OSX on it- You can just hoik any PC graphics card into it (as long as it doesnt draw more than 300w thru the aux power connectors) and it will work, you just loose your boot screens. This came with no HD's. So no OS. So I need to resurect the 7300GT to get an OS on it. Its getting turned into a media server with 4x4TB drives in it anyway, so graphics arent really of high importance. So Kastein- If i needed 1500uf, 6.3v 105degC, 470uf 6.3v 105degc, some 330uf, 16v, 1200uf 4v and a pair of SMD ones that only say "67 47 6A" on them, Wheres the best type to replace them and where would I find them that can ship to Aus for a reasonable price?
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Apr 13, 2014 10:44
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SlapActionJackson posted:Works great until your low-cost manufacturer/integrator starts bitching about BOM cost. Yeah, fortunately that isn't an issue here. Production run is pretty limited, not sure exactly how many but it's over 100 and definitely under 1000. The vehicle I work on is NOT a mass market vehicle, that's for sure. Tsuru posted:Two halves (upper and lower) are cast and are friction-welded together, the combined unit is then machined. Beat me to it. Those pistons were cast/forged as separate parts, then spun and jammed together forcefully, producing a perfect weld with 100% penetration, no inclusions, no flux, no warping (because the parts were heated evenly around their entire perimeter at exactly the same time), and no filler metal required: https://www.youtube.com/watch?v=-NIVUnk2kyw Ferremit posted:So Kastein- If i needed 1500uf, 6.3v 105degC, 470uf 6.3v 105degc, some 330uf, 16v, 1200uf 4v and a pair of SMD ones that only say "67 47 6A" on them, Wheres the best type to replace them and where would I find them that can ship to Aus for a reasonable price? Need more specs - diameter, height, and pin to pin spacing on the through-hole ones, and height/width/length on the SMD ones. A pic would help too if you don't mind. kastein fucked around with this message at 11:17 on Apr 13, 2014 |
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Apr 13, 2014 11:13
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OK but what's with the 2-stroke piston ports?
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Apr 13, 2014 15:06
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13 INCH DICK posted:Customer states vehicle was making a noice and died in our parking lot. Technician was unable to start the vehicle. gently caress that lovely poo poo engine. This is what I do to them https://www.youtube.com/watch?v=C_ewkJDV88c
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Apr 13, 2014 15:18
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CVH motor? One of my first roommates had an old Ford Escort wagon with that motor (probably a smaller version than the 2.0) and all I really remember is that he'd flat-foot it from every stoplight and it had MR2 three slot wheels on it.
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Apr 13, 2014 16:00
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All I know about it is its the "split port" 2.0. I guess it tends to drop a valve seat or something. The new engine we put in that car did the same thing like 2 months later. gently caress that car. Ive never heard anything bad about the 1.9 and the 1.8 BP is actually kind of nice.
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Apr 13, 2014 16:08
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Rev. Dr. Moses P. Lester posted:OK but what's with the 2-stroke piston ports?
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Apr 13, 2014 16:56
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Rev. Dr. Moses P. Lester posted:OK but what's with the 2-stroke piston ports? Those aren't 2-stroke ports, notice that they don't affect the combustion chamber. I'm not 100% sure what the purpose of those is, but I'm going to assume they are there to reduce the weight or allow some kind of squirter to hit the wrist pin.
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Apr 13, 2014 16:59
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Horrible mechanic/DIY failure. Did control arm/ball joint replacement on my MK4 golf this weekend. Noticed the passenger side looked different from what I took out, so I grabbed the driver's side I had already done. Both the old joints were identical, while the new one leans the opposite way. Some complete moron put 2 driver side balljoints on my car.
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Apr 13, 2014 17:04
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Nidhg00670000 posted:I'm sorry for this everyone. e:wait I think I got the numbers wrong 
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Apr 13, 2014 18:47
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quote:Friction welding chat My favorite video, possibly on the entire internet. (Which says terrible things about me...) http://youtu.be/5JbnDXw-0pM
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Apr 13, 2014 19:40
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Not a direct failure, but definitely something that could turn into a failure. https://www.youtube.com/watch?v=Nyk4PWGVQgw Some Yamaha XT660 owners have had troubles with a persistent rattle, especially on earlier models. That particular nut that he points out and unscrews by hand is supposed to be tightened to 100Nm, yet despite a lock washer with folding tabs, it sometimes vibrates loose. As it's sitting on the end of the crankshaft, if it's gone the engine will basically rattle itself apart. Even partially undone, the gears with munch themselves, possibly taking the water pump along with them. The fix seems to be to use locktite and overtighten by 20-30%. I can't believe a fuckup like that made it through testing.
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Apr 13, 2014 22:01
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KozmoNaut posted:Not a direct failure, but definitely something that could turn into a failure. Doesn't every KLR suffer from something similar?
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Apr 13, 2014 22:09
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A Melted Tarp posted:Doesn't every KLR suffer from something similar? Yes, the infamous "doohickey". It's not 100% the same issue, in the KLR's case it's the cam chain tensioner. Due to a design flaw, it tends to snap and mess up the timing chain. It took Kawasaki 20 years to fix it 
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Apr 13, 2014 22:14
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Well, this is a new one for me. Magnetron cooked itself when I wasn't paying close attention, and overcooked some cheap microwave popcorn. Why it decided self-immolation was the solution to this, I have no idea.
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Apr 14, 2014 00:59
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Speaking of long-running, stupidly unfixed problems in kawasaki engines, here are some pictures of horrible mechanical failures! There is an awful lot of oil under this exmark...  Wait, what is this thing?  Oh! Ohhhhhhh.....  Took a nice chunk of steel with it, along with a couple of studs  I had four mowers with variations of this same kawasaki c420v 1-cylinder, and three of them had the same issue. "What happened to the fourth one" you ask? The newest, nicest, and by far most expensive of the bunch?  You may notice that there is no tire on that solidly welded axle at the bottom of the screen. Two of my guys failed to properly secure the ramps in the back of one of the trucks, and dropped it four feet onto the pavement, snapping the axle where it met the frame.  It would have cost half as much to fix as to buy a new one, and that engine in the pictures had just poo poo its pants, so I scavenged what I could from the various broken mowers to make two working ones, and fired the crew that broke the scag... Also, gently caress this pulley, and gently caress the small engine mechanic. He broke off the hex end of this set screw when I had him adjust something or other, and never told me. It was wedged between the pulley and frame, so I couldn't really get a drill or anything in there, so I said "gently caress it" and got out the reciprocating saw. 
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Apr 14, 2014 05:13
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BLARGHLE posted:Two of my guys Right there is why we got our of mowing and landscaping years ago. The quality of help you end up getting for the wages that can be paid is shockingly bad. If they even bother to get themselves to work up you end with poo poo like this. Or minor issues they they are too lazy to fix, so they just tell you a machine is down and you end up playing road mechanic between your crews all day long. Everything was better when it was just two of us, but you just can't make decent money that way.
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Apr 14, 2014 15:41
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God dammit. I did the rear brakes on my son's '96 Mustang this weekend because they started making a hell of a grinding noise. Pulled the left rear to find the caliper slides completely locked up sentencing one pad to death by maximum grindage. I KNEW I should have taken pictures as soon as I logged on the SA and remembered this thread.
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Apr 14, 2014 15:50
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ncumbered_by_idgits posted:God dammit. I did the rear brakes on my son's '96 Mustang this weekend because they started making a hell of a grinding noise. Pulled the left rear to find the caliper slides completely locked up sentencing one pad to death by maximum grindage. I KNEW I should have taken pictures as soon as I logged on the SA and remembered this thread. Probably from power braking it to make large clouds of tire smoke
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Apr 14, 2014 17:42
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If he was doing peg leg burnouts, it'd be the right rear. 
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Apr 14, 2014 17:50
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Farking Bastage posted:Probably from power braking it to make large clouds of tire smoke Uh nope.....he's only had it a week. The amount of rust that was in the sockets was far more than I would ever have imagined would fit, both boots were cracked and broken pretty bad. It has a lot of little things wrong with it but nothing major and for the price I couldn't say no. I paid $1600, it needs a paint job but it has almost new American Racing wheels, brand new tires and a three-year-old convertible top. For that price I can put a little bit into it for stuff like brakes.
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Apr 14, 2014 18:01
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Tsuru posted:Weight saving, most probably. You still need the bottom of the piston to stop it from rocking or even tumbling, but everything in between which is not required for strength is dead weight. And since they went to all the aforementioned trouble to create the cavity in the top I'm going to guess that's what it's for. That makes sense but why not just use a slipper skirt like high performance gas engines do?
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Apr 14, 2014 19:04
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Motronic posted:Right there is why we got our of mowing and landscaping years ago. This pretty accurately reflects my experiences as well. Things were going great when I just had one crew and could keep on their asses about stuff, but once I got the second crew going everything suddenly broke at once. They would just run poo poo to death, and not even care. Hell, even my supposed business partner ran the nice truck for an extra 3000 miles after the change oil notification came up before finally getting it taken care of. They also ran an old but otherwise functional mower so far out of oil that it completely siezed up. I got it going again with a breaker bar and some transmission fluid, but it was unsurprisingly the next one to lose a chunk out of the back. Hiring good help really is the hardest part of running any business, otherwise you just stagnate doing whatever you can supervise directly, or everything goes to poo poo when you try to expand. I also have some pictures of the lovely secondary truck around here somewhere...I still owe the PO some retribution for that debaucle...
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Apr 14, 2014 20:38
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Year old car, happily driving about :  
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Apr 14, 2014 21:19
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Hard to tell from the picture, but it looks like that's a chunk out of a hubcap, no?
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Apr 14, 2014 21:26
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drat, I was convinced they were alloys but you may be right. Some wheel trims are pretty convincing now. Edit: Yup, those style wheels are trims on steels, I'm I'm an idiot! stump fucked around with this message at 21:34 on Apr 14, 2014 |
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Apr 14, 2014 21:30
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