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It looks like a carbon steel bit, those get pretty twisty if you get them stuck in a hunk aluminum.
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Jun 28, 2019 17:18
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MrOnBicycle posted:Lol the best thing about that dude failing at jacking his car is that he maintains that it was the jacks fault and that his hockey pucks slipped. Even bought new jack and jack stands because of his "bad" jack". Yeah keep telling yourself that mate. he's unrepentant about how stupid he is, just look at the comments and his replies to them.
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Jun 28, 2019 17:52
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um excuse me posted:It looks like a carbon steel bit, those get pretty twisty if you get them stuck in a hunk aluminum. 
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Jun 28, 2019 19:00
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Here's one I've been meaning to post for a while...
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Jun 28, 2019 19:46
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BraveUlysses posted:he's unrepentant about how stupid he is, just look at the comments and his replies to them. Never read the comments.
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Jun 28, 2019 20:33
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wesleywillis posted:Here's one I've been meaning to post for a while... Okay this one confuses me. Titanium nitride is silly hard.
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Jun 28, 2019 20:55
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um excuse me posted:Okay this one confuses me. Titanium nitride is silly hard. It's only coated with TiN.
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Jun 28, 2019 21:13
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Well, the Drill Master brand from HF does let some QA slip through the cracks.
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Jun 28, 2019 21:16
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C-Bangin' it 
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I have one of those tooSagebrush posted:oh nice i can repost this thing i found in one of the drill presses a couple years ago
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Jun 28, 2019 21:48
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Oh we're playing that game again? God dang it Jamie
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Jun 28, 2019 22:20
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big crush on Chad OMG posted:Imagine being that stupid and still posting the video the real tragedy is his haircut
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Jun 28, 2019 22:30
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sandoz posted:ah, an ambidextrous bit Looks like a piece of wrought iron
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Jun 29, 2019 21:50
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oh and just btw ambidextrous bits are a real thing They are meant for use in routers, on woods that are prone to tear-out -- you set the height so that the up-cut portion of the bit is below the material and the down-cut portion is above, so the cutting forces on both sides are into the middle of the part. That lets you clean up the edge while avoiding the little splinters you get if the cutting forces go from the inside out. Obviously this does real wacky things with chip ejection so you have to be careful about your cut geometry and give lots of clearance. Plunging with one of these or doing a full-width slot can be really sketchy
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Jun 29, 2019 22:03
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  gently caress M62TU exhaust cam sprockets are apparently torqued to 4 million fuckin foot pounds, still not sure where the rest of the T55 bit went
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Jun 30, 2019 01:40
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hitze posted:
 Now that's fuckin' impressive Do the cams have flats or pins for locking? I'd be afraid of snapping a cam, BMW's cams are infamously delicate (at least on the M/S 5x motors)
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Jun 30, 2019 03:36
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probably reverse thread, lol I've lost many a T55 to ford box bolts. What a stupid loving design, limiting the size of your tool to T55. At least with a bolt you can get a thicker wall socket. Ain't no way to add material to a torx bit.
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Jun 30, 2019 03:51
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Sagebrush posted:oh and just btw ambidextrous bits are a real thing You awakened a need to find tool porn videos of different router bits in super slow motion.
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Jun 30, 2019 09:47
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  My dad's car decided to do an expensive thing. that must've been an experience.
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Jun 30, 2019 12:28
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Drove over a piece of metal in a most unfortunate fashion? I had a Scion xB long ago which got opened like a can of tuna by something similar. The construction company which had left the metal plates on the road ended up paying for the repairs, so that was good, but it was pretty unsettling - it could’ve easily taken my foot off if it happened slightly differently.
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Jun 30, 2019 20:23
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Krakkles posted:Drove over a piece of metal in a most unfortunate fashion? That piece of metal is usually an integral part of the steering
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Jun 30, 2019 20:54
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 The guy is on fire. Check the heat distortion coming off the car and driver. Methanol produces an invisible flame. um excuse me fucked around with this message at 04:04 on Jul 2, 2019 |
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Jul 2, 2019 04:02
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um excuse me posted:
btw that's Parnelli Jones in the 1964 Indy 500. He was fine afterwards.
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Jul 2, 2019 04:17
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um excuse me posted:
https://www.youtube.com/watch?v=Ku7TdLeEGsQ
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Jul 3, 2019 17:58
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Thought I'd post something I came across on the job yesterday. Some of you know I'm in the bearing business... and have been for going on 27 years now. I see a fair amount in my day to day business but it isn't that often that I see an absolute textbook case of something that isn't super-duper, everyday common and have a chance to share it. Client has a small electric motor... probably 5-7.5HP and they were suffering from bearing failure. The millwright who was working on it had a good idea what was wrong and he asked me to take a look at the bearing for my opinion. His opinion was bang on. Bearing with the outer race cut apart  Close up:  This is a textbook example of Electrical Fluting. Basically the electrical current is trying to find ground and it's going through the bearings to do it. Not terribly common on small HP motors like this, but the chances of it significantly go up with the addition of using a VFD to control the motor. Here is a good article about it. https://www.ecmweb.com/motors/diagnosing-understanding-motor-bearing-currents Just thought I'd post because I suspect a fair amount of people have not seen this type of failure before as it's relegated to electrical equipment by definition.
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Jul 5, 2019 19:14
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Love the fact that you actually cut it apart and analysed the failure mode, happens less and less these days.
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Jul 5, 2019 19:53
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Chris Knight posted:All the same we take our chances plus tire change plus c'est la même chose
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Jul 5, 2019 19:54
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How do you prevent that bearing failure mode? Is there an electrical malfunction going unnoticed that can be corrected? Ceramic bearing?
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Jul 6, 2019 06:41
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EightBit posted:How do you prevent that bearing failure mode? Is there an electrical malfunction going unnoticed that can be corrected? Ceramic bearing? The first one. Current has to go somewhere and will seek the path of least resistance, which in this case is through the bearing.
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Jul 6, 2019 07:19
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Jul 6, 2019 07:30
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That must have been one hell of a "oh poo poo" moment for his poo to come out fast enough to singe the seat.
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Jul 6, 2019 07:34
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EightBit posted:How do you prevent that bearing failure mode? Is there an electrical malfunction going unnoticed that can be corrected? Ceramic bearing? They also make grounding rings for the motor shaft's. The body of the motor is grounded so induced voltages on the shaft (from ugly waveforms with lots of high frequency components like the choppy stuff you'd see coming from a VFD) have no where to go unless they arc through the bearings and produce that sort of flutting. Grounding rings give a path for the pixies to escape without having to go through your nice bearing surface. That damage is more typical on larger motors due to the currents involved but can happen on smaller stuff too. VFD waveform has a lot to do with it so a cheaper VFD that's only 3 levels (high, zero, low) will be worst for this than something with a fancier switching circuit that can do 6 or 12 pulse switching (output looks more sinusoidal and has less high frequency components) output filtering can help considerably as well but again that costs $$ and on the smaller stuff you'll hardly ever see it, at least in hvac applications. Nicer VFD's have some filtering built in. On small stuff I've only ever seen it on 600/575V equipment. 600V is essentially a non tariff trade barrier and because Canada isn't that huge of a market most companies just tweak their 480V design and call it a day rather than design their products with 600V in mind. They don't always do a good job and when you add in that 600V can be quite "dirty" power, particularly in remote northern communities that have generator power plants, you'll see a higher rate of failure in those areas.
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Jul 6, 2019 13:20
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https://i.imgur.com/W6L1yMp.mp4
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Jul 6, 2019 13:54
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It's a problem on boats too, shaft grounding brushes are pretty common.
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Jul 6, 2019 15:37
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loving Taco Bell!!
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Jul 6, 2019 15:41
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EightBit posted:How do you prevent that bearing failure mode? Is there an electrical malfunction going unnoticed that can be corrected? Ceramic bearing? Bajaha posted:They also make grounding rings for the motor shaft's. Look like this  Ceramic/coated bearings are certainly a thing too and an option. Pure ceramics are big money and, not made in every size/style and are not really the panacea they are cracked up to be. They also have a different characteristics vs carbon steel (and not always for the better). Coated bearings are a more realistic, cost effective option for many sizes but it is super easy to scratch the coating on install (or mishandling) as it's only a micron or so thick, which make it worthless. Since bearings are normally pressed into a housing, you really have no way of knowing if you scratched it on install either.
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Jul 6, 2019 16:14
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Midjack posted:loving Taco Bell!! For real, i ate at taco bell for the first and last time in over a decade yesterday and i don't understand why taco bell still exists. Who eats that poo poo and says "yeah, i want more of that disgusting mushy poo poo in a flavourless tortilla, or some of those unseasoned fries covered in viscous white and orange liquids. I love how it gives me quality time with my toilet." I think i judge people who enjoy taco bell as harshly as i judge people who buy mitsubishis at this point. As for the bearings, i was thinking "if only we could harness those forces to cut metal" and that's pretty much what electrical discharge machining is isn't it.
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Jul 6, 2019 17:21
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slidebite posted:Thought I'd post something I came across on the job yesterday. This is also believed to be relevant to a number of spacecraft failures. These spacecraft all had reaction wheel failures that correlate with various space weather incidents, and it's believed that the bearings in the reaction wheels had current arc through them and cause damage as a result. illectro did a video about it a little while back: https://www.youtube.com/watch?v=KibT-PEMHUU
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Jul 6, 2019 19:52
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Some mechanical engineer tell me why you cannot just put an insulating spacer around the outer race of the bearing, or between the inner race and motor shaft.
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Jul 6, 2019 20:32
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slidebite posted:<snip> This is super interesting. I never would have thought of this as a failure mode, but when you're in the hundreds-of-volts VFD motors...
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Jul 6, 2019 20:56
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MRC48B posted:Some mechanical engineer tell me why you cannot just put an insulating spacer around the outer race of the bearing, or between the inner race and motor shaft. Deformation, most likely. [IaNaME]
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Jul 6, 2019 21:01
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