#homecmos IRC log for Wednesday, 2011-06-22

B0101Azonenberg: Did you fix your mask problem?13:25
azonenbergLol, i keep missing B010118:27
azonenbergSo I just got some tungsten wire18:42
azonenbergplanning to make probe tips from it18:42
azonenbergAnybody have ideas on cutting it?18:43
azonenbergIn any case, it will be sharpened by electrochemical etching19:22
bart416uhm, how clean of an edge do you need?20:42
bart416btw azonenberg, uploading that book20:43
azonenbergbart416: thx20:43
azonenbergAnd not very clean20:43
azonenbergi just tried metal shears20:43
bart416Just use a wire cutter then :|20:43
azonenbergThey'll be electropolished after20:43
azonenbergAnd i didnt want to use my normal wire cutters as they arnet meant for hard stuff20:44
bart416Those knipex cutters are perfect for this sort of thing20:44
bart416do you have cutting plates from a metal working machine like a lathe or mill?20:44
bart416azonenberg, http://dl.dropbox.com/u/27788352/Ingalls.ATM.book3.pdf20:51
bart416Say when you finished so I can delete it again20:51
azonenbergbart416: I do not, but one of the labs at my school has a lathe and a mill20:51
azonenbergSo i can use them for building instruments if need be20:51
azonenbergSeveral of each, actually20:51
bart416Well, the cutting plate of most mills and lathes are made out of high speed steel20:51
azonenbergAnd file is downloaded20:52
bart416Fairly strong material20:52
bart416Anybody else want it?20:52
bart416just don't use a new cutting plate for it though20:52
bart416But HSS sort of contains tungsten20:53
bart416+ it's hardened20:53
bart416So if you use an old cutting plate you should get through it just fine20:53
azonenbergThe wire is only 400 microns diameter20:53
azonenbergMy shears worked fine20:53
bart416But heayh, should give a clean cut without damaging it20:54
bart416They're designed to go through high carbon steel :P20:54
bart416At the speed of a few meter / second20:55
bart416So they're fairly resilient :P20:55
bart416My back is killing me21:06
bart416And so are my shoulders and so are my arms and hands21:07
bart416Exam analog circuit design!21:07
bart416Actually not cause of that21:07
bart416Had to "remove" 16.2 square meter of tiles in our backyard21:07
azonenbergOh lol21:08
bart416issue, they're sort of in a concrete-ish substance21:08
bart41615-20 cm thick21:08
bart416So had to use a heavy duty breaker21:08
azonenbergReminds me of ripping out concrete at home21:08
azonenbergcracked landing midway up the front steps21:08
bart416You know, Hilti, 1.8kW, 15kg21:08
bart416That sort of thing21:08
azonenbergLol, i see21:08
bart416"Active Shock Reduction System" my ass :|21:08
azonenbergIn our case we managed to yank the entire slab loose21:08
azonenbergThen blast it with a sledgehammer21:08
bart416Heh, the tiles would splinter if you used a sledgehammer21:09
azonenbergand pour a new piece21:09
bart416ceramics flying around at high speed = bad idea21:09
azonenbergThis was 4+ inch concrete21:09
azonenbergAnd we put a heavy tarp over it to catch shrapnel21:09
bart416Heh, our house used to be owned by a person that worked at a concrete plant21:09
bart416So he had free access to concrete and other building materials...21:09
bart416We noticed it when trying to demolish a small wall21:09
bart416Ever saw a high end diamond cutting blade break due to the material it was encountering?21:10
azonenbergNo, then again i've never used them21:10
azonenbergMy only diamond cutters are for scoring silicon21:10
bart416Well yeah, diamond blades on angle grinders = fun21:10
bart416Goes through everything21:10
bart416Except that wall >_>21:10
bart416Eventually we use the breaker21:11
bart416And then rammed it a few times with a friend's landrover defender >_>21:11
bart416The wall came down in a single piece...21:11
bart416We had to cut it up with a breaker21:11
bart416And cut through the steel wires (yes tensioned concrete :| )...21:12
azonenbergthis was a dinky little retaining wall21:12
bart416We simply threw it in the back of a van and disposed it like that21:12
azonenbergmade of prestressed reinforced concrete?21:12
bart416Dunno what the guy did21:12
bart416I think that wall was nuclear bunker worthy21:12
azonenbergProbably :P21:12
bart416Never saw that much rebar in my life ever before21:13
bart416We decided to just leave the walls the way they were after that21:13
bart416Should have pictures of it here somewhere21:13
bart416Oh one thing got through, a rotary hammer...21:14
bart416But those go through anything really21:14
azonenbergI dont usually do heavy industry type stuff, personally...21:14
azonenbergI prefer extreme precision at tiny scales21:14
bart416Should have asked my father to bring a tank (he's an officer in the army :P )21:14
bart416Leopard tank vs Wall would have been funny21:15
bart416Sad reality is that the wall had a high chance of winning21:15
azonenbergWell, the problem is that use of the main gun wouldnt be feasible given proximity to civilians and your house21:15
bart416The thing with these tools is, they're actually fairly precise21:15
azonenbergI'll bet that 120mm APFSDS will go through that concrete no problem lol21:15
bart416Uhm, the wall was 40 cm thick...21:16
bart416Reinforced tensioned concrete...21:16
bart416With a sand layer21:16
azonenberg40cm? Shoudlnt be that bad *looks up penetration stats*21:16
bart41620cm of that would have been steel though...21:16
bart416And my father wants to break down a shed the guy built (also in concrete) :|21:17
azonenbergQuick googling suggests that current russian APFSDS rounds have penetration equivalent to 65cm of rolled homogeneous steel armor21:17
bart416I'm going to go and ask for a crane + wrecking ball21:17
azonenbergI dont know how much easier/harder concrete is, but my guess is you'd get most of the way through if not all the way21:18
bart416But doubt there'd be much damage after the wall considering how thick it is21:18
azonenbergYeah, you'd be punching a hole through21:18
bart416but keep in mind this wasn't even a support wall of the house...21:18
azonenbergAPFSDS does most of its damage from pyrophoricity on the inside21:18
bart416I wonder what the support walls look like21:19
bart416Should borrow an ultrasound from college lab for a day :P21:19
azonenbergground penetrating radar?21:19
bart416dunno, don't have access to that21:20
bart416+ an ultrasound I actually know how to use :P21:20
bart416ground penetrating radar I do not21:20
bart416Too bad you can't just take a piece of a wall out and use a MRI scanner, those are horribly easy to control o_O21:21
bart416Really it's a joke with the new software21:21
bart416A 5 year old could do it21:21
azonenbergI dont think mri would work well on concrete anyway21:21
azonenbergAnd i'm not too familiar with any penetrating imaging methods21:21
bart416I'm more worried about the steel inside of it :P21:21
azonenbergI mostly do optical and some electron microscopy21:21
azonenbergAh, forgot it had rebar21:22
azonenbergAnd the guy who trained me on the SEM in our cleanroom says that he's taught 14-year-olds how to use similar models lol21:22
bart416If a small none support wall already has rebar...21:22
bart416most of these devices aren't really hard21:22
bart416Anybody can work with a MRI, just don't bring anything magnetic close to it and you'll be fine21:22
bart416Well, a modern one at least21:23
bart416body part, patient position on table (depending on how the table is arranged really), algorithm (you can sometimes choose), single frames, 3D, record over time, ...21:24
bart416All nice options in the menus, lol21:24
bart416And afterwards it'll ask where to send it if it hasn't been pre configured21:24
berndjbart416, you into amateur telescopes or why're you pasting the ingalls link?21:24
bart416Even contains the nice option to burn one of those annoying CDs with those crappy viewers21:24
azonenbergberndj: They have a part on sputtering21:25
bart416Well, they mention some articles about it21:25
bart416+ also about other methods of coating21:25
bart416And vacuum systems in general21:25
bart416And I sort of am actually21:25
bart416But I bought my telescope21:25
bart416But the mirror has its best time :(21:26
bart416You into amateur telescopes berndj ?21:27
Action: azonenberg has done a decent amount of astro stuff but never built his own scope21:27
bart416I'm probably going to sell mine21:27
bart416Too much light polution anyway21:27
bart416When I move to a desolated part of Vietnam in about 30-40 years I'll pick it up again21:28
berndjyes, i am into amateur telescopes21:28
berndjjust haven't worked on mine for a few months21:28
bart416The cost is prohibitive sadly21:28
berndji don't recall any mention of sputtering, but then again book 3 is the one i don't have21:28
bart416Want me to upload it again?21:29
berndjwhat i did see was evaporation21:29
bart416That's also covered21:29
berndjnah, it's okay21:29
berndjyou might've had better luck with a thermal lance vs that wall21:29
azonenbergI was actually gonna suggest that lol21:29
bart416berndj, next time I'm cutting to the rebar and I'm pulling out a plasma cutter21:30
bart416Lets see how it likes that >_>21:30
berndjoh, azonenberg, what was that about cutting tungsten wire?  for what purpose?21:30
bart416he wants to make probes21:30
berndjthat desktop STM project i may have mentioned (some dude at uni the year before me built one) had probes made from incandescent bulb filaments just pulled apart21:31
azonenbergberndj: I have two six-foot pieces of 400 micron tungsten wire from amazon21:31
azonenbergonly a few dollars each21:31
bart416Heh, STM is on my to do list21:31
berndjturns out you don't need great precision in forming the tip - almost any chunk of tungsten will have *some* part of it that forms an adequate tip21:31
bart416STMs are fairly easy21:31
azonenbergI plan to use the STM technique (electrochemical etching) to sharpen them21:31
azonenbergBuilding a STM and later a SEM is on my todo list too21:32
azonenbergBut i need more workbench space21:32
berndjoh, for probing a chip?21:32
azonenbergmy lab is growing :P21:32
azonenbergberndj: Yes21:32
bart416What you really need is a good electron microscope so you can see the current flow in future prototypes :P21:32
azonenbergI have a wentworth labs probing station that i got used on ebay and am in the process of fixing up (needs some vacuum hoses replaced and a good cleaning but is otherwise in decnet shape)21:32
berndjbut not an actual STM?21:32
azonenbergAnd an actual STM would be nice too21:32
azonenbergBut is a bit further out21:33
bart416The best part is that you can just take apart a buzzer to get the piezo electrode21:33
bart416But don't have a scope so it's hard to build this sort of thing anyway21:34
bart416So instead it's going to be the more insane project21:36
bart416Try to put an ARM Cortex A8 on a double sided board21:36
azonenbergHave fun21:37
Action: azonenberg is equally insane but wants to do 4 layers on a xilinx BGA fpga21:37
bart416How much pins is it21:37
bart416Mine is 400 or 500 or something like that21:37
bart416Also where do you get 4 layers?21:38
azonenbergbart416: ExpressPCB is what i've been using but i'm leaving21:45
azonenbergProbably 4pcb 6 layer is what i'll end up using21:45
bart416That costs close to $200...21:47
bart416My total budget for my entire project is less than that21:47
azonenbergI'm not paying for it :P21:49
azonenbergMy advisor will be21:49
bart416If you can get a good powerplane + ground plane it's a lot easier21:52
azonenbergI need >1 power plane lol21:53
azonenbergat least a 2.5 and an 1.2v, maybe a 3.3 as well21:53
azonenbergplus ground21:53
azonenbergthen two to three signal layers21:53
azonenbergit will end up being a six or eight layer board i think21:54
azonenbergXC6SLX75 is the plan21:54
azonenbergplus some sdram, flash, and other fun stuff21:54
azonenbergand maybe an MCU for stuff i dont want to waste fpga gates on21:54
bart416It's the same league21:55
bart416Difference is, I'll have to do it at home with a toaster oven >_>21:56
Action: azonenberg will be having the board fabbed professionally but hopes to assemble it in a toaster oven here21:56
azonenberg256-FTBGA package lol21:56
bart416oh that's easy :|21:56
azonenbergIts 1mm pitch21:56
azonenbergShouldnt be nearly as bad as the 0.8 i was thinking of doing earlier21:57
bart416AM3715CBP100 is what I'm doing >_>21:57
azonenberg515 FCBGA?21:57
azonenbergHave fun21:58
azonenbergwhats the pitch on that monster21:58
bart416Haven't dared to look yet21:58
bart416http://focus.ti.com/lit/ds/symlink/am3715.pdf is the datasheet21:59
azonenberg_labTime to have some fun23:40
azonenberg_labTungsten probe making23:40
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