#linuxcnc | Logs for 2012-03-01

[00:23:42] <Jymmm> It would be interesting to see emc reunning on one of these and Mesa to create an add-on I/O board for it as a daughter card . Raspberry Pi http://www.element14.com/community/groups/raspberry-pi video demo here http://www.youtube.com/watch?v=6BbufUp_HNs
[01:54:14] <DJ9DJ> moin
[02:44:59] <pjm> good morning
[02:50:45] <DJ9DJ> good morning
[03:16:52] <pjm> ah i guess u have a ham license DJ9DJ !
[03:17:08] <DJ9DJ> yes :)
[03:18:00] <pjm> same here, mine is m0eyt but i'm not active on the tx side
[03:18:21] <DJ9DJ> hehe, same here...
[03:18:29] <pjm> i use my cnc mill mostly for making bits of waveguide and feeds etc
[03:23:23] <DJ9DJ> nice
[03:28:01] <pjm> although last was some nice polycarbonate cutting for my clock http://pjm.dyndns.org/twtr/nixie4.jpg
[03:33:17] <cncbasher> g0jqo
[03:39:22] <DJ9DJ> hui, very nice
[04:08:26] <archivist> an M must be a youngster /me was G8
[04:13:06] <cncbasher> yea although i started young my first was a G6 ,my son has M3EAM
[04:13:43] <cncbasher> he got that on his 14th birthday
[04:28:50] <pjm> lol yeah the M0 is my second call, i had a G7 prior to that
[04:35:00] <archivist> small toy http://www.theatlantic.com/magazine/archive/2012/03/iron-giant/8886/
[04:53:00] <cncbasher> yea thats one hell of a toy
[04:57:45] <archivist> just been trying to find the one that used to be in Sheffield 12000 ton, went to see it in operation
[04:58:15] <Loetmichel> and who made it possible?
[04:58:19] <Loetmichel> ... germans ;-)
[05:04:20] <archivist> http://www.geograph.org.uk/photo/1668885 8000 tone due to a ram fault but 12000 iirc when all rams working
[05:04:31] <archivist> 1912!
[05:04:59] <archivist> I was with chris when that was taken
[05:45:33] <elmo40> archivist: back when they wanted parts made from one piece. Now, they would rather weld strips together and hope to get the same strength.
[05:46:17] <archivist> forging is still being used for certain work
[05:57:24] <archivist> same trip we saw this in operation http://www.geograph.org.uk/photo/1689068
[07:44:42] <A2Sheds> is andypugh off sailing the high seas?
[07:49:10] <archivist> in port http://www.clipperroundtheworld.com/index.php/follow/race-viewer/
[08:21:28] <skunkworks> http://www.cnczone.com/forums/1075406-post134.html
[08:22:14] <skunkworks> I think he has a pretty good understanding how emc works... Right? He makes the the kflop.
[08:40:26] <cncbasher> skunkworks > yea tom's a great guy ,
[08:46:46] <pcw_home> Why would you so a circle in line segments?
[08:47:00] <archivist> crappy cam :)
[08:47:11] <pcw_home> Oh
[08:47:46] <mikegg> BobCAM for solidworks likes to show you an arc in the tool path preview, and then substitute a line in the gcode
[08:47:46] <archivist> and....drawing formats to gcode where the drawing is in segments due to similar crappyness
[08:47:48] <pcw_home> Looks like he still is assuming exact stop mode for LinuxCNC
[08:47:48] <FinboySlick> I was actually tempted to ask "But EMC doesn't do arcs as line segments, does it?".
[08:49:06] <archivist> and stl source will be in segments too
[08:49:11] <pcw_home> or maybe its a general profiling type of thing where arbitrary curve performance is the real question
[08:50:13] <skunkworks> http://www.cnczone.com/forums/1075754-post137.html
[08:50:28] <awallin> g2/3 is actually quite limited, since they are allways in one of the principal planes (xy, xz, yz)
[08:51:33] <skunkworks> awallin: all we need is someone to write a new motion/planner... ;) hint hint. (for me it works just great as is)
[08:52:19] <pcw_home> it would be interesting to do circle experiment
[08:53:24] <skunkworks> Heh. I don't think you would get anywhere near 100ipm with .0003 tolerance with emc... (if .3 mills is .0003)
[08:53:40] <skunkworks> I should boot up the laptop.
[08:53:59] <archivist> skunkworks, I can think of ways :)
[08:54:11] <skunkworks> (with 40in/sec^2 acceleration)
[08:54:28] <archivist> think outside the box and use rotaries
[08:54:34] <skunkworks> heh
[08:55:08] <pcw_home> He not talking about actual machine performance just how fast the trajectory can be generated
[08:56:38] <archivist> he is assuming short segments for accuracy, get the code and machine right for the job and your segments get longer
[09:06:48] <archivist> an example from my helical gear gcode is G1 F4 Y#4 a[0-#5] z#6 which is the entire tooth cut
[09:07:35] <pcw_home> he's also assuming LinuxCNC is in stop mode
[09:07:49] <pcw_home> exact stop mode
[09:11:10] <pcw_home> archivist: because your mechanics do the curve?
[09:13:11] <archivist> yes 4th axis is rotating
[09:18:31] <skunkworks> I get 40ipm...
[09:22:15] <skunkworks__> http://pastebin.com/WkjSv57H
[09:22:29] <skunkworks> that gets me almost 50ipm
[09:23:23] <skunkworks__> g64p.001Q.001
[09:23:26] <skunkworks__> gets me 80
[09:25:39] <skunkworks__> g64p.01Q.01 gets my 180ipm or so..
[09:25:52] <skunkworks__> unless I am doing something wrong
[09:26:41] <cradek> what's your accel in X,Y?
[09:27:40] <skunkworks> 40in/sec^2
[09:28:06] <cradek> 1" radius?
[09:28:08] <skunkworks> if I set the accelleration to 100in/sec^2 I get about 210ish ipm
[09:28:12] <skunkworks> yes
[09:28:56] <skunkworks__> with g64p.01Q.01
[09:28:57] <cradek> ok just wondered - centripetal accel limits you to 379 ipm
[09:29:26] <cradek> if you set you maxvel at 9999 and you do a g3 with radius=1, you'll see that 379
[09:30:24] <skunkworks> heh - http://www.cnczone.com/forums/1075406-post134.html
[09:30:34] <skunkworks> he came up with 379 also.
[09:30:56] <cradek> ah ok
[09:38:00] <skunkworks> yep - circle is 379ipm
[09:38:12] <skunkworks> so - just a limit of line-line blending
[09:39:56] <awallin> how many G1 moves per second does it do for that 222-sided polygon
[09:40:11] <awallin> not close to one G1-move per traj_cycle I guess?
[09:40:46] <cradek> skunkworks: that's nice (I didn't test it, I only did the math)
[09:42:15] <pcw_home> about 5 ms/segment
[09:42:57] <awallin> ok. I guess any improvements on lookahead must get rid of the 1block/traj-cycle limitation also then!
[09:43:22] <cradek> I think the typical config today is 1ms traj cycle (used to be we used 10ms!)
[09:44:27] <pcw_home> skunkworks what is your traj cycle?
[09:44:40] <skunkworks__> 1ms
[09:44:54] <pcw_home> ok
[09:45:02] <skunkworks__> It is sim axis.
[09:45:26] <skunkworks__> I just changed the velocity's to 9 and the acceleration to 40
[09:46:15] <skunkworks__> I increased the tollerence to .1 - it is funny to see. still only reaches around 240ipm
[09:48:52] <skunkworks__> ask me what happens when you do a g64p005 when cutting a part... ;) Meant to type g64p.005
[09:49:17] <cradek> oh ouch
[09:49:18] <pcw_home> 5 inch tolerance?
[09:49:49] <cradek> although I bet that wasn't funny at the time, the thought of it makes me laugh a bit.
[09:50:12] <pcw_home> OK for really really big things
[09:53:45] <cradek> http://timeguy.com/cradek-files/emc/g64p5-splashscreen.png
[09:55:57] <skunkworks> heh
[09:56:24] <skunkworks> Yes - it cut strait though a part that was supposed to have a profile... ;)
[10:51:58] <MrSunshine> hmm, vectric aspire isnt realy parametric or whatever its called is it ?
[10:52:06] <MrSunshine> (so i can move points to a specefic position)
[10:55:02] <MrSunshine> ahh yes, i can use it together with a cad program if i want to :P
[11:08:53] <jdhnc> I use autocad and draftsight with Cut2D
[11:12:18] <jdhnc> do you have aspire?
[11:15:41] <MrSunshine> trying it out
[11:15:58] <MrSunshine> would be real neat if i could use it both for ornamental work and for 3d metal cutting for parts =)
[11:16:04] <MrSunshine> it has a real nice interface
[11:16:45] <Loetmichel> re @ home
[12:29:05] <pcw_home> http://www.mmrc.iss.ac.cn/~xgao/papernc/29-10.pdf
[12:31:56] <archivist> luverly bit of maffs /me wont be implementing
[12:36:56] <archivist> that was something awallin wanted iirc
[12:45:02] <MrSunshine> damn vectric realy is a nice program to work with, maybe not as feature rich as the high end cam packages like mastercam etc but very easy to work with, fast .. and one can import dxf files, alter them the way they need to be and generate the toolpaths realy quick =)
[12:45:10] <MrSunshine> vectric aspire
[13:10:57] <joe9> mikegg: I got it out. went to the Napa machine shop and the person used a press to get it out. had to use the auto puller tool to remove the bearings from the sleeve.
[13:11:07] <joe9> the bearings were too tight on the sleeve.
[13:11:50] <joe9> I do not see any signs of rust. Why would the bearings be so tight on the sleeve? Is that how it is supposed to be? Anyway, just wanted to let you know that I am cool now.
[13:12:32] <mikegg> good deal
[13:12:33] <archivist> joe9, bearings can be bought with clearance designed to close up after pressing on, they are tight then
[13:13:02] <mikegg> yeah, I would expect them to be pretty tight
[13:13:25] <joe9> archivist: i want something that is a bit easier to remove. not something that needs a press or impact wrench.
[13:13:35] <joe9> had to use an impact wrench with the puller.
[13:14:25] <archivist> so they are scrap now even if they were ok
[13:14:52] <joe9> i think they cannot be used.
[13:15:11] <joe9> will buy new ones. need to figure out something that does not bind so hard.
[13:59:05] <iwoj> Hey d00ds. Has anyone here successfully recompiled their own version of EMC2 Linux?
[13:59:40] <archivist> plenty, ask the real question
[14:01:35] <iwoj> This will seems really stupid, but I can't get the damn source code.
[14:01:47] <iwoj> when I call apt-get install linux-source
[14:01:54] <iwoj> it pulls down an empty directory.
[14:02:09] <iwoj> sudo apt-get install linux-source
[14:02:27] <iwoj> (which is apparently what the EMC2 source code is looking for when I try to build that.
[14:03:42] <archivist> http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Installing_EMC2#Resolving_outstanding_build_dependencies
[14:04:45] <archivist> better http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Installing_EMC2#On_Ubuntu_10_04_or_8_04_from_source
[14:05:42] <iwoj> beauty. thanks.
[14:13:04] <joe9> is there anything that I can do before I put the new bearings in, to ensure that it will be smoother to remove them the next time?
[14:13:33] <joe9> I am looking at http://www.mcmaster.com/#6661k104 to replace what I had initially
[14:15:29] <iwoj> Sorry. I actually asked the wrong question. I need to recompile RTAI.
[14:15:33] <iwoj> Has anyone done that?
[14:15:40] <joe9> like putting in a slightly bigger bearing with the sleeve wrapped in teflon oslt.
[14:16:44] <archivist> joe9, taking a sliver off the shaft is what I would do, but requires some setup, lathe and skill
[14:17:07] <joe9> archivist: is that a good idea? will it increase play?
[14:17:41] <archivist> bearings have play by design
[14:17:50] <joe9> even getting the whole drive sleeve assembly (with the bearings) was a pita. Had to go to a shop with press to do that.
[14:18:07] <joe9> I meant runout, sorry.
[14:19:16] <archivist> have you even inspected the internal morse taper yet
[14:19:46] <joe9> archivist: is it a good idea to replace both bearings with a single cylindrical bearing?
[14:19:57] <joe9> archivist: no, I have not inspected it other than visually.
[14:20:09] <joe9> the machine shop person told me that it fell right off.
[14:20:15] <joe9> he did not even charge me for it.
[14:20:38] <joe9> but, I had hit it with a mallet and wooden dowel and I am sure it did not fall right off.
[14:20:59] <joe9> but, I think when using a press, his definition of "falling right off" might be different from mine.
[14:21:00] <archivist> the runout on abused spindles includes internal damage
[14:21:42] <joe9> archivist: the bearings are gone. but, the spindle seems ok. barely a scratch on it.
[14:22:00] <joe9> actually, no scratches.
[14:22:07] <archivist> is it bent
[14:22:11] <joe9> except for the bottom where the pressure was applied.
[14:22:58] <archivist> you should go to a college evening class for machine work
[14:23:16] <joe9> archivist: not that I can see.
[14:23:31] <archivist> do you have a lathe
[14:23:35] <joe9> looks like this. http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman9.jpg
[14:23:42] <joe9> archivist: no, no lathe.
[14:24:08] <archivist> that part up the top we dont care much about
[14:24:35] <joe9> oh, ok.
[14:24:36] <iwoj> Has anyone here compiled their own custom version of RTAI?
[14:25:04] <archivist> iwoj, again wrong question ask the real question
[14:25:04] <joe9> archivist: that is what I am talking about with the scratch and which is proving a bit hard for the bearings to go it.
[14:25:10] <joe9> s/it/in
[14:25:44] <joe9> I used the impact wrench with puller to get from http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman8.jpg to http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman9.jpg
[14:26:17] <joe9> for this, I went to the machine shop: from http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman7.jpg to http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman8.jpg
[14:27:12] <archivist> http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman6.jpg part on the right os the part needing inspection
[14:29:48] <joe9> that i did not do much with it. just removed it and then put the new bearings on it. the bearings came off when I hit it with a rubber mallet.
[14:30:04] <archivist> joe9, you have been messing with the drive not the spindle!
[14:30:11] <joe9> it was pretty easy to remove, actually.
[14:30:25] <iwoj> so i'm recompiling RTAI but it can't find my linux source. But never mind, I just found this page http://wiki.linuxcnc.org/cgi-bin/wiki.pl?RtaiSteps
[14:30:39] <joe9> archivist: the spindle, I changed the bearings on it. Now, I am doing the drive sleeve.
[14:31:39] <archivist> the drive sleeve has/should have no effect on chuck runout at all
[14:32:56] <joe9> oh, ok. I noticed that the pulley was moving around a lot. while I was doing all this, thought might be a good idea to replace those bearings too.
[14:33:03] <joe9> and put some better bearings.
[14:34:21] <joe9> archivist: btw, can I use a little bit of sand paper to increase the diameter of the head in this picture: http://www.machinistblog.com/wp-content/uploads/2010/09/Craftsman7.jpg
[14:34:22] <archivist> because they are close together they may have deliberately put them on tight to reduce bearing clearance
[14:35:30] <joe9> probably, yes.
[14:36:08] <archivist> sandpaper near running bearings is a nono
[14:36:14] <joe9> archivist: is there anything that you would recommend doing other than using a lathe or big tool, to make the bearings go in easier?
[14:36:35] <joe9> archivist: thanks, good to know. I am stupid enough to have done it, if you had not said so.
[14:36:43] <archivist> pressing bearings is normal
[14:40:21] <joe9> archivist: why does it need 2 bearings? why not just one?
[14:41:26] <archivist> to properly distribute the forces (from the belt drive) that bend the drive
[14:45:29] <joe9> mikegg: wondering if you would be interested in removing a sliver off of the drive sleeve and the head, so I could tap the bearings in?
[14:45:49] <joe9> archivist: thanks.
[14:45:58] <archivist> joe9, dont bother, just press as it was designed
[14:46:09] <mikegg> I think that's a better plan
[14:46:23] <joe9> archivist: "Install the drive sleeve assembly into the head.  Put a light coat of oil on the outer bearing race of the drive sleeve bearings and push the drive sleeve assembly into place from the top.  Try pushing it into place manually; if the bearings align correctly you can push or gently tap the assembly into position.  If it won’t go in easily then you can pull it into place using a threaded rod passed through the ...
[14:46:29] <joe9> ... assembly.  Use a scrap of wood or metal below and a washer and nut on top and tighten the nut to pull the assembly down.  You only need to get it in far enough to install the upper circlip.  Do not distort or damage the lower circlip." found this at http://www.machinistblog.com/restoring-a-craftsman-15%E2%80%B3-drill-press/
[14:46:42] <mikegg> the difference between a sliver and "oops this part is trashed" is not very mucb
[14:47:02] <archivist> a nats cock
[14:47:07] <joe9> mikegg: yes, that makes sense.
[14:47:53] <joe9> archivist: what is a "nats cock"? googling up on that word takes me to all porn stuff.
[14:48:03] <joe9> archivist: you mean the instructions are BS.
[14:48:06] <joe9> ?
[14:48:26] <isssy> http://www.youtube.com/watch?v=6BbufUp_HNs
[14:48:34] <mikegg> haha lol
[14:49:21] <mikegg> just put it in the freezer, and put the bearings in the oven on about 200 F
[14:49:38] <mikegg> and be ready to go quick
[14:49:48] <archivist> gnats are small therefore a "gnats cock" is a small amount, common engineering term in the uk
[14:49:54] <joe9> mikegg: good idea. thanks.
[14:52:43] <joe9> Can I take the spindle to a machine shop and ask them to check if it is straight?
[14:53:40] <archivist> ask your friendly machine shop not us
[14:54:41] <joe9> archivist: I just moved to this area. Have no friendly machine shop yet. just wanted to check if it is a big deal or if it is something that they can do easily.
[14:54:48] <archivist> machine a morse taper on a lathe, mount your spindle on that test mandrel then rotate
[14:54:48] <joe9> or, do normally.
[14:55:11] <joe9> archivist: ok, thanks.
[14:55:37] <archivist> get v blocks and a surface table, is the other method
[15:00:50] <joe9> mikegg: I am willing to take the risk of the parts getting damaged. would you still be willing to do that?
[15:01:08] <archivist> also see if any local model engineer groups near you
[15:04:08] <MrSunshine> hmm, i find aspire lacking somewhat in its cutting abilities :(
[15:04:17] <MrSunshine> yeah, great for ornamental work =)
[15:04:23] <MrSunshine> but maybe not for machine part making :P
[15:12:57] <jdhnc> isn't aspire made for artsy stuff?
[15:24:16] <MrSunshine> jdhnc, yeah seems so =)
[15:24:31] <MrSunshine> tho it can be used to cut alot of stuff i guess
[15:24:59] <MrSunshine> as you can import dxf files and generate toolpaths for it =)
[15:25:08] <MrSunshine> but i wanted to use a stl model, slice it (due to the fact that its 33mm thick no endmills i have can cut that) but it didnt work to well =)
[15:27:40] <jdhnc> I thought aspire would slice in any axis
[15:39:24] <MrSunshine> jdhnc, dont know, got it sliced down Z but as i get 3d models only the "3d roughing/finnishing" stuff work, havent learned how to convert stuff into vectors etc yet :P
[15:39:32] <MrSunshine> so i can use the pocket stuff and all that =)
[16:11:37] <raynerd> Just a quick one, you know the new raspberry pi coming out, will it be able to run emc2?
[16:12:31] <djdelorie> it has no parallel port...
[16:13:07] <djdelorie> but it will run the same Fedora as your PC, just with a lightweight desktop. You could hook up the GPIOs I suppose.
[16:13:19] <djdelorie> "same" being at the source level, of course it's not x86...
[16:16:02] <raynerd> humm ok
[16:16:12] <raynerd> not sure what GPIOs mean?
[16:16:19] <Thetawaves> raynerd, there is limited rtai for arm
[16:16:59] <Thetawaves> raynerd, GPIO is general purpose IO and really only exists on SOC (system on chip aka only 1 chip)
[16:17:05] <JT-Shop> Dang! pop a modem into my desktop and the internet starts to work again... but I must be in a time warp as everyone is speaking in tounge
[16:19:39] <DJ9DJ> gn8
[16:20:54] <djdelorie> GPIO: think "it's a parallel port, but without the fancy connector"
[16:26:53] <archivist> Im waiting for a raspberry pi on ebay I see some wag has created a case 290677470826
[16:40:16] <Thetawaves> ...and here i thought parallel port was the fancy connector
[16:54:18] <djdelorie> it's the connector and the protocol, but linuxcnc doesn't use the protocol anyway
[19:40:58] <TSCDan> Hi! I currently have a RepRap Prusa Mendel that I want to use to mill some PCBs. I've already got the spindle design done, but I'm still working on the control mechanics. The reprap uses an Arduino Mega to control the steppers. Has anybody gotten EMC to play well with an Arduino-controlled mill? :-)
[19:57:07] <skunkworks__> TSCDan: probably not.
[19:57:27] <skunkworks__> Linuxcnc would be the motion controller. (not the arduino)
[21:50:02] <mikegg> joe9: I had to step out for a bit. Did you get your drill press sorted out?
[21:52:47] <jdhnc> and if not, I'll sell you mine for $50
[21:57:07] <mikegg> heh
[21:57:27] <mikegg> So I got some good news today. they are going to send me an envelope for my hair sample
[21:57:29] <mikegg> woot
[21:57:46] <mikegg> dodged that bullet
[21:58:22] <jdhnc> heh... that is absurd... what a waste of money.
[21:58:46] <jdhnc> guess signing off on someone elses hair would be an integrity violation.
[21:59:53] <mikegg> well, i'
[22:00:04] <mikegg> ve always had a certain moral flexibility
[22:03:52] <Tom_itx> who takes hair samples for employment?
[22:09:15] <mikegg> lots of folks, apparently. I think all the casinos in vegas do...
[22:22:25] <jdhnc> anyone heard of the SeeMeCNC 3d printer kits work with emc?