#emc | Logs for 2008-04-14

[01:56:17] <jmkasunich> I gotta say I'm pretty happy with the "Tormach Tooling System" - 30 to 35 seconds chip-to-chip isn't bad for a totally manual toolchange
[01:57:19] <jmkasunich> of course I'm getting lots of practice - three changes per part, and I just finished part 13 of a run of 18
[02:27:15] <SkullWorks_PGAB> 3 tool changes per part - JMK your getting off easy - I run out of tool space with a 32 tool ATC... But then the parts I do have like 6 different threads on them.
[02:28:26] <jmkasunich> you don't do them in your basement either
[02:28:48] <SkullWorks_PGAB> ah true that
[02:29:06] <jmkasunich> heh, your collection of toolholders probably cost more than my machine
[02:29:37] <SkullWorks_PGAB> water table is only 11 ft down here - basements are rare in my neighborhood - wish I had one.
[02:30:06] <jmkasunich> the only problem with basements is that you can't get heavy stuff into (and out of) them
[02:31:20] <SkullWorks_PGAB> guy I know here made a stairway hoist to move machine tools and heavy things into his basement
[02:32:30] <SkullWorks_PGAB> he put 1.5" pipe on each edge of the stairway and had a refrig dolly with grooves wheels that fit the pipes
[02:33:13] <SkullWorks_PGAB> used a cheap 12V winch to lower the stuff down the track.
[02:33:30] <jmkasunich> hmm, interesting idea
[02:33:54] <jmkasunich> I've used a block and tackle to slide things down the step before
[02:34:00] <jmkasunich> but the rails thing is clever
[02:35:07] <SkullWorks_PGAB> he worked for FED-x - help build there first package tracking network - think he retired and went to FL
[02:36:34] <SkullWorks_PGAB> he used to come by to raid our scrap pile - we had a great collection for one off parts.
[03:55:40] <K`zan> which would make a better leadscrew? 3/8-24 or 1/4-20?
[03:56:00] <K`zan> 3/8-24 it would seem but I see a lot of preference to the 1/4-20?!?
[03:58:35] <SkullWorks_PGAB> if space allows 1/2-20
[03:59:38] <SkullWorks_PGAB> or better 3/4-10
[03:59:51] <K`zan> Noy sure I can go that big, but will check.
[03:59:53] <K`zan> Thanks
[04:00:22] <SkullWorks_PGAB> bigger will reduce whip during rapids
[04:03:10] <K`zan> Considering this will be a pico mill with floppy steppers, I am not sure, beyond a certain point, that would help :).
[04:03:51] <K`zan> But, it should be educational and perhaps not cost me much over $100.
[04:04:19] <K`zan> Ok for smallish stuff, wood, plastic, foam...
[04:04:47] <K`zan> At least I can do something while I contemplate what (if anything) to do with the HF Micro Mill...
[04:10:26] <SkullWorks_PGAB> go with 3/8-24 - make your nut from brass. - small steppers can run fast but lack much torque so the finer thread works for you
[04:11:15] <SkullWorks_PGAB> If you were using Nema 23's then you want the larger/corse type thread.
[04:38:14] <K`zan> Thanks! IIRC, the steppers are ?NEMA 17? Would have to look again.
[04:39:37] <K`zan> http://www.kaitodenshi.com/english/product/motor2.htm
[04:39:45] <K`zan> the -29 one on line 9
[04:41:29] <K`zan> Looking for the original link I have to the supplier.
[06:52:05] <K`zan> Night all.
[09:16:18] <sweeper> http://en.wikipedia.org/wiki/Mosfet#MOSFET_structure_and_channel_formation <-- when this article says current flows from source to drain, are they using classical + to - flow refernce, or electron flow (- to +)?
[09:47:03] <Vq^> current flows from + to -
[09:47:26] <archivist> electrons flow from - to +
[09:48:26] <archivist> it is anoying that theory still messes with "conventional" current flow
[09:50:41] <sweeper> mkay
[09:50:58] <sweeper> * sweeper keeps working on trying to get the arduino to drive his mosfets
[13:04:31] <tomp> sweeper: maybe this is of use from pbs http://www.pbs.org/transistor/science/info/transmodernex.html
[13:05:28] <tomp> oh, and physics jokes too http://www.pbs.org/transistor/album1/fun/index.html
[13:13:41] <sweeper> :D
[13:45:38] <alex_joni> heh
[13:45:41] <alex_joni> bbl
[13:52:08] <sweeper> I think I got it sorted tho
[13:52:44] <sweeper> except, either the datasheet is backwards, or I've got some weird mosfets, current flows seem to be opposite of what the datashee indicates
[14:07:50] <jepler> sweeper: I believe this page is accurate. http://www.physics.udel.edu/~watson/scen103/mos4.html -- also matches http://www.armory.com/~rstevew/Public/Motors/H-Bridges/Blanchard/nch-brdg-sch.htm
[18:04:00] <tomp2> I need a N.American supplier for hi-current co-axial cable like this http://imagebin.ca/view/EPUlyTb.html used in EDM for 3.3kHZ to 500kHZ. Lo freq used at 300A peak, higher freq at 32A peak.
[18:04:32] <tomp2> Any ideas where to look? it doesnt fit any RG-xxx descriptions with 4mm core & shield.
[19:03:05] <SWPLinux> tomp2: if it's not a standard cable, just try emailing the major wire companies with the description
[19:03:22] <SWPLinux> Belden, Alpha, Champlain Cable (local to me :) )
[19:04:00] <SWPLinux> unless you only need 6 feet, in which case you should invest in a pair of bolt cutters and visit the nearest EDM shop ;)
[19:06:53] <tomp2> a bit less than 1000 ft for 2 machine :) wiil try emailing the photo as you suggest , thx0
[19:07:22] <tomp2> each has 4 runs of near 32 ft, but i buy xtra
[19:46:58] <Tekrad> anyone have an Hardinge HLV-H?
[21:18:17] <jymm> SWPLinux: ping
[21:18:27] <SWPLinux> pong
[21:18:36] <Tekrad> hello
[21:18:42] <SWPLinux> hi
[21:19:20] <jymm> SWPLinux: I'm going to pick up some things - I have no damn poendant now, as it's no longer running on the laptop.
[21:19:32] <SWPLinux> ?
[21:19:55] <jymm> SWPLinux: gonna plagerize bigjohns idea on a usb gamepad
[21:20:15] <jymm> only $20
[21:20:20] <SWPLinux> ok - I didn't get the laptop reference. no USB on the desktop machine?
[21:20:34] <jymm> yes usb on desktop
[21:20:48] <jymm> laptop was using a IBM 10Key pad
[21:20:52] <jymm> as pendant
[21:20:58] <jymm> under tcnc
[21:21:01] <SWPLinux> ah
[21:21:31] <jymm> SWPLinux: hows the driver board coming along?
[21:21:31] <SWPLinux> I still don't follow then. can't you plug the keypad into the desktop and use it?
[21:21:42] <jymm> SWPLinux: no, laptop only
[21:21:43] <SWPLinux> it's on my list :)
[21:21:54] <SWPLinux> you have the soldering iron, remember? ;)
[21:22:07] <jymm> SWPLinux: email me the drawing
[21:22:16] <SWPLinux> once I draw it :)
[21:22:54] <jymm> SWPLinux: that what I thought you were working on today so I can find a place to put the thing.
[21:23:10] <SWPLinux> yes, it is/will be
[21:23:21] <jymm> SWPLinux: I dont believe you
[21:23:36] <SWPLinux> of course not, considering my past performance ;)
[21:25:04] <jymm> SWPLinux: do you have driver board parts?
[21:25:13] <SWPLinux> not at the moment
[21:25:26] <jymm> I thought you said you were going to pick them up, but I could be mistaken.
[21:25:26] <SWPLinux> I haven't gotten out to get the car or to RS yet
[21:25:33] <SWPLinux> yes, but I haven't yet
[21:25:33] <jymm> ah
[21:25:43] <SWPLinux> it's only 2:25 - plenty of time
[21:25:50] <SWPLinux> well, sort of anyway
[21:26:16] <jymm> what was the spacing?
[21:26:20] <SWPLinux> I still need to talk to them about getting the machine into the room (and when that can happen)
[21:26:30] <SWPLinux> and also find out about your pass
[21:26:30] <jymm> .100" ???
[21:26:45] <SWPLinux> the board holes are 0.1, the terminals are 0.2
[21:26:54] <jymm> .200"
[21:26:57] <SWPLinux> the IC is 0.3 wide
[21:26:59] <SWPLinux> ys
[21:27:01] <SWPLinux> yes
[21:27:06] <jymm> what UOM ?
[21:27:11] <SWPLinux> inches
[21:27:13] <jymm> k
[21:27:26] <jymm> laters
[21:27:29] <SWPLinux> yep
[21:27:47] <Tekrad> anyone familiar with Hardinge HLV-H lathe?
[21:28:16] <jymm> SWPLinux: mA rating the regulator? and voltage?
[21:28:17] <SWPLinux> not me. there are some folks who have done conversions on HNC and CHNC models
[21:28:25] <SWPLinux> I don't know how close those are
[21:28:46] <SWPLinux> regulator maybe 100 mA to be safe, 5V output, they more or less all go to 35V input
[21:29:11] <SWPLinux> if you have any (7805 or similar), let me know, or I can get them at RS
[21:33:18] <alex_joni> good night all
[21:33:28] <SWPLinux> see you Alex
[21:43:18] <SWPLinux> JymmmEMC: actually, I think we don't need the regulator. the 2803 doesn't need it (it's just a bunch of transistors, not really any logic in there)
[21:43:59] <SWPLinux> so just the chip, some resistors (maybe a SIP if I can find one), and the terminals (plus the parport header, of course)
[22:45:05] <SWPLinux> jymm: are you planning on using the DIN db25 breakout to connect the stepper drives?
[23:06:37] <Jymmmmmm> swp I got vr terms din rail
[23:29:35] <BigJohnT> weeee I got a new computer today