#linuxcnc | Logs for 2013-09-22

[05:44:57] <jthornton> morning guys
[05:49:43] <Jymmm> Morning Gracy
[06:03:07] <jthornton> Jymmm, http://www.dd-wrt.com/wiki/index.php/D-Link_DIR-632
[06:05:58] <Jymmm> jthornton: Cool. Can you live without it if you brick it?
[06:06:49] <jthornton> yea, I kept seeing brick if you do this and that
[06:07:07] <jthornton> well I can buy another one I guess
[06:07:33] <Jymmm> jthornton: I meant you won't be down if you do, will you? You have a spare/backup?
[06:07:37] <jthornton> Tom_itx, had a link to some higher up routers the other day
[06:07:57] <jthornton> not an 8 port just some 4 port routers
[06:08:12] <Jymmm> that's fine, just a CYA thing
[06:09:11] <Jymmm> jthornton: not YOUR router, but the same idea... http://www.linksysinfo.org/index.php?threads/howto-dd-wrt-snmp-mrtg.5132/
[06:11:06] <Jymmm> jthornton: More Info http://www.dd-wrt.com/wiki/index.php/SNMP
[06:15:11] <Jymmm> jthornton: Do realize the SNMP is gawd, and you need to be aware of security issues.
[06:15:38] <Jymmm> s/the/that/
[07:46:28] <jthornton> any one want to play with the mill g code generator http://www.gnipsel.com/shop/files/mill.zip
[11:15:00] <ReadError> hmm my gcode paths stopped showing up
[11:16:22] <archivist_> zoomed out too far or off centre too far
[11:16:39] <ReadError> nope
[11:16:43] <ReadError> i can see the toolpath history
[11:16:55] <ReadError> just when i load a new file it suddenly stopped showing it
[11:16:58] <ReadError> may need to restart it
[12:14:27] <andypugh> I didn't think this was possible with permanent magnets: http://www.youtube.com/watch?v=LyvfDzRLsiU
[12:14:29] <Tecan> (LyvfDzRLsiU) "Amazing Discovery With Magnets" by "Hendrik Ball" is "Tech" - Length: 0:02:41
[12:15:15] <IchGuckLive> hi all
[12:19:48] <archivist_> hmm patently obvious
[12:20:35] <archivist_> hint vectors and angles
[12:21:59] <IchGuckLive> vectors are better then angels
[12:22:15] <IchGuckLive> angles re not good for speed
[12:22:24] <IchGuckLive> are
[12:24:40] <andypugh> archivist_: I thought it had been proven that levitation with only permanemt magnets is impossible. I suppose that that might well still be the case, as that system is stabilised by the table surface.
[12:25:26] <andypugh> Any idea what arrangement of magnets is used in magnetic bearings?
[12:25:47] <archivist_> not looked for a long time
[12:26:42] <archivist_> I can see that the rate of change to the centre magnet is different to the two singles nearest
[12:27:06] <andypugh> The Wikipedia page mentions Earnshaw's Theorem, which is what I was thinking of.
[12:27:32] <archivist_> Laithwaite would be giggling at the moment
[12:29:32] <Jymmm> andypugh: If impossible, then how do all those $20 toys do it?
[12:29:52] <archivist_> I can see the table is the stabilising element there
[12:29:55] <andypugh> Read for yourself: http://en.wikipedia.org/wiki/Earnshaw%27s_theorem
[12:30:21] <Jymmm> andypugh: Sorry, meant to be rhetorical
[12:30:49] <IchGuckLive> andypugh: passiv or acvtiv beraring
[12:31:12] <archivist_> but countless millions will attempt to prove that this is real
[12:31:35] <IchGuckLive> passiv i think you will own the nobel price
[12:33:06] <IchGuckLive> http://www.fz-juelich.de/zea/zea-1//DE/_SharedDocs/Downloads/magnet/0b30_pdf.pdf?__blob=publicationFile
[12:33:10] <Jymmm> andypugh: Do you have any info on the difference on SS grades? 302,304,316,316L
[12:33:12] <IchGuckLive> look at the picturews
[12:33:46] <archivist_> andypugh, spotted a job for your sister https://www.elance.com/r/jobs/cat-engineering-manufacturing/cry-GB/p-1 silversmith
[12:35:10] <IchGuckLive> ok im off its election day in germany
[12:35:21] <andypugh> archivist_: She has mreo work than she can handle already
[12:35:25] <IchGuckLive> and i need to go to the mayors house for BBQ
[12:35:43] <archivist_> andypugh, lucky :)
[12:36:59] <Jymmm> andypugh: do you have samples of her work?
[12:41:31] <andypugh> http://www.doltons-jewellers.co.uk/gallery
[12:43:33] <Jymmm> andypugh: ty
[13:38:26] <CaptHindsight> http://www.kickstarter.com/projects/occipital/structure-sensor-capture-the-world-in-3d?ref=search
[13:39:09] <CaptHindsight> Precision: 1% of measured distance, resolution: 640 x 480
[13:50:55] <Chemeleon> seems odd they dont show any scanned model results on the page
[13:54:51] <ReadError> typically scamstarter
[14:34:29] <kwallace> andypugh, do you have a link to your brushless information handy?
[14:34:47] <andypugh> Which information?
[14:37:28] <kwallace> Anything you might have. I'm dusting off my motor and three phase bridge and looking at getting something working, maybe.
[14:40:17] <kwallace> I'm looking for a cheap way to run the 440 Watt version of this: http://www.wantmotor.com/ProductsView.asp?id=181&pid=81
[15:45:29] <andypugh> kwallace: 48V / 38A is quite an awkward combination.
[15:47:45] <andypugh> (Thinkng of Mesa drivers, it is 8i20 current and 7i39 voltage)
[15:47:55] <kwallace> I think I can get Wantai to wire a set of motors for 90 V or whatever I need.
[15:49:09] <kwallace> Pico's seem too small and the Mesa 8i20 too big.
[15:49:17] <andypugh> Yes.
[15:50:25] <andypugh> The 7i39 is a 250W drive (50V / 5A), so is also too small.
[15:50:38] <andypugh> Do Wantai suply drives too?
[15:51:40] <andypugh> I think Mesa might be working on a smaller version of the 8i20. But I think that will be "smaller" in the sense of current, which isn't what you need.
[15:52:31] <kwallace> The Wantai driver is a speed controller, not four quadrant, if I recall correctly.
[15:54:08] <kwallace> I'd like to find a system that would be appropriate for my Shizuoka or Bridgeport and compete with steppers in cost.
[16:00:26] <andypugh> So, new drivers only? I wonder if AMC have anything?
[16:04:52] <kwallace> BE15A8 at $300, no joy there. http://www.servo2go.com/product.php?ID=100470
[16:05:22] <NickParker> kwallace: I've been considering prototyping a board around SI-7321M. It's a 4 phase unipolar stepper driver IC that can only handle 2A or so, but it exposes the current sense and FET gate pins so you can use it to control arbitrarily large amounts of current with external FETs
[16:06:32] <NickParker> it can do 1/16th steps
[16:07:27] <kwallace> But it's for steppers, or am I missing something?
[16:09:04] <Einar> 38A is a peak value. And below it says you cannot push that much without risking damage. (Demagnetizatioon limit?)
[16:09:40] <kwallace> Oh, if you want to keep the unis on your Shiz. I'm thinking of moving to servos.
[16:12:39] <NickParker> kwallace: ah sorry, joined the channel mid conversation
[16:15:31] <kwallace> I looked at the Gecko 203V http://www.ebay.com/itm/330679897616 , then got to thinking... If I'm going to spend a bunch o money, why not do servos?
[16:16:24] <andypugh> For one-off, I think would buy a 3-axis set of motors and diveres from that eBay seller in South Korea.
[16:49:59] <kengu> andypugh: what set? which seller?
[17:04:10] <andypugh> FA-Parts
[17:05:58] <andypugh> http://stores.ebay.co.uk/FA-PARTS/_i.html?_nkw=3-axis&submit=Search&_sid=542968597
[17:26:30] <CaptHindsight> andypugh: did you see that $100 SLA printer that uses water for the z-axis?
[17:28:07] <andypugh> No, but it sounds like an interesting idea.
[17:29:20] <andypugh> Anyway, time to log off.
[17:50:07] <pcw_home> too late but Gilbert(engineer here) made one of those magnetic levitators
[17:51:10] <pcw_home> fairly amazing to see a magnet suspended mid air with no control system
[17:53:15] <pcw_home> kwallace, the 8I21 will be close for that motor (48V 20A cont 40A peak)
[17:57:22] <kwallace> That sounds like it should work.