#linuxcnc | Logs for 2014-11-28

[00:00:06] <PetefromTn_andro> I think I am making a deeper impression in my bed mattress than normal after thanksgiving dinner and two slabs of cheesecake LOL
[00:01:10] <PetefromTn_andro> But damn it was worth it.
[00:01:32] <PetefromTn_andro> ;)
[00:05:31] <PetefromTn_andro> Somebody poted a 5hp three phase face mount motor on Craig's list nearby
[00:05:52] <PetefromTn_andro> It's a good price for it too
[00:06:25] <PetefromTn_andro> too but I really wanted to get a 7.5 hp motor
[00:06:47] <PetefromTn_andro> Which is what the lathe came with
[00:07:45] <PetefromTn_andro> Not sure what the specific information was on the original motor
[00:08:33] <PetefromTn_andro> Found just a few brochures on it online but nothing else
[00:09:07] <PetefromTn_andro> I would guess it probably had a slower speed motor maybe a 1725 rpm
[00:09:50] <PetefromTn_andro> Because you generally don't run a lathe this size up above more than say 4k or so I would think
[00:11:03] <PetefromTn_andro> If I picked up a 5hp motor the vfd would probably be a little cheaper and the machine came stock with that size
[00:11:38] <PetefromTn_andro> The 7.5 hp larger motor was optional.
[00:14:55] <PetefromTn_andro> Not sure what would be better for low end torque a 1725 rpm motor geared up to double that or a 3450 rpm motor with more like 1-1 ratio
[00:17:11] <PetefromTn_andro> It has a triple vee belt drive on it. There unfortunately is no motor pulley with the boxes of parts that came with it.
[00:18:52] <PetefromTn_andro> I think what I really would want is to get the larger7.5 hp motor and add a timing belt drive to the machine somehow to get the max torque possible
[00:22:45] <PetefromTn_andro> Someone posted a cool 8hp continuous 18hp max brushed dc motor for sale too. Not even sure how I could power it but it said 24-72 vdc
[00:45:53] <tjtr33> isnt the probe value captured during the same period as the trip?
[00:45:53] <tjtr33> so as the thread cycle time diminishes, the trip to capture interval is small, and _approaches_ interrupt speed?
[00:46:14] <tjtr33> and you can repeat the touch probe to prove repeatability
[00:47:33] <tjtr33> Happy Thxgiving all. have nice sleep on all that turkey tryptophane :)
[02:02:18] <Tecan> http://i.imgur.com/JtRkQn4.jpg
[02:29:42] <Deejay> moin
[02:41:44] <Tecan> moin moin
[07:09:05] <The_Ball> I measured the runout on my lathe today, is this as good as I can expect on a chinese import? https://www.youtube.com/watch?v=d02_FN2AsXM
[07:09:09] <The_Ball> It's about 0.01mm
[07:23:43] <_methods> new lathe or used lathe?
[07:24:15] <_methods> a lot of this chinese stuff has to be "tweaked" in when you get it, to run "right"
[07:33:13] <taiden> hey call
[07:33:27] <taiden> trying to share wifi with my linuxcnc computer using a network bridge on windows 7 and an ethernet cable
[07:33:42] <taiden> i was able to do this pretty easily in the past with ubuntu 10, having trouble now on debian wheezy
[07:34:06] <The_Ball> _methods, I bought it new, had it for a few years, seen very little work
[07:34:23] <taiden> it responds to the cable being plugged in but doesn't actually appear to connect to the network
[07:34:37] <taiden> is there something simple I might have overlooked?
[07:35:28] <_methods> yeah with a lot of those chinese machines you may need to take that chuck off and check the spindle runout without the chuck on
[07:35:48] <_methods> all that runout could be in the chuck
[07:35:49] <The_Ball> _methods, that's exactly what I did
[07:35:57] <_methods> ahhh
[07:36:06] <_methods> same rounout in the spindle?
[07:36:31] <The_Ball> I only measured the spindle, 0.01mm on the "cone" and 0.01mm on the backing plate
[07:36:49] <_methods> well you might have to tweak the spindle in then
[07:37:03] <_methods> unless you can live with that runout
[07:37:11] <The_Ball> Does that mean stripping down the machine?
[07:37:22] <_methods> yeah at least the headstock
[07:37:32] <_methods> but i don't know without looking at the schematic
[07:37:48] <_methods> you might be able to loosen up some easy to get to stuff and bring it in
[07:38:00] <The_Ball> hmm, ok
[07:38:01] <_methods> or you might have to rip apart the whole headstock
[07:52:36] <taiden> Lol. two click share internet over ethernet on OS X, works flawlessly
[07:52:48] <taiden> 30 minutes trying to configure Windows 7 to do the same... nothing
[07:58:06] <taiden> go figure
[08:02:20] <SpeedEvil> Deep throat 2014.
[08:02:21] <SpeedEvil> http://www.ebay.co.uk/itm/STARTRITE-316-HEAVY-DUTY-BANDSAW-/301390680020?pt=UK_Hand_Tools_Equipment&hash=item462c48cfd4
[08:04:43] <taiden> good lord that is cheap
[08:05:08] <taiden> so british
[08:06:22] <taiden> so I went to open a debian package for linuxcnc 2.7 wheezy-rt
[08:06:37] <taiden> and it asks me what program i want to use to open the package...?
[08:07:08] <taiden> so I choose Synaptic and it says
[08:07:18] <taiden> "failed to execute child process "synaptic"
[08:07:42] <taiden> lul
[08:09:19] <taiden> how the heck do I install this thing?
[08:09:30] <taiden> on ubuntu you'd just double click on a debian package and wheeeeee off to the races
[08:09:54] <jthornton> I installed it using the iso
[08:10:43] <ssi> time to go pick up my southbend :D
[08:11:04] <taiden> there's a linuxcnc 2.7 iso?
[08:11:21] <jthornton> 2.6
[08:11:33] <taiden> I'm trying to install 2.7
[08:11:37] <jthornton> sorry missed the 7 part
[08:12:11] <jthornton> bleeding edge
[08:12:18] <taiden> any ideas on how to open this debian package on ... debian lol
[08:13:46] * jthornton seems to be having connection issues
[08:22:53] <_methods> http://buildbot.linuxcnc.org/
[08:24:16] <_methods> oh ignore me
[08:24:30] <_methods> my screen was way up
[08:24:56] <Jymmm> /ignore _methods
[08:25:17] <_methods> i'm suprised you didn't have me on /ignore already lol
[08:25:30] <Jymmm> =)
[08:29:36] <taiden> alright got 2.7 on there
[08:29:42] <taiden> tp is a lot faster but now i lose a ton of steps
[08:32:42] <taiden> 2.6 will be used in the shop
[08:37:19] <_methods> hahah apparently we've infected england with our black friday retardation
[08:37:41] <taiden> exporting democracy one made up holiday at a time
[08:37:48] * taiden salutes the flag
[08:38:05] * taiden fondles glock
[08:38:15] * taiden eats turkey
[08:38:41] <_methods> hilarious
[08:38:43] <PetefromTn_> taiden has my respect
[08:39:50] <_methods> wow poor saps have walmarts over there now
[08:39:58] <_methods> asda = walmart
[08:40:51] <PetefromTn_> over where?
[08:42:23] <SpeedEvil> _methods: it's really not
[08:42:38] <SpeedEvil> _methods: it's owned by the same vendor - but it hasn't meaningfully changed since the acquisition
[08:42:45] <SpeedEvil> they do not use the walmart brand at all
[08:48:04] <_methods> interesting
[09:06:29] <archivist_herron> they did have a walmart sign as an addition on the derby asda for a period
[09:23:38] <pcw_home> If you lose steps you probably have the velocity or acceleration set too high
[09:25:15] <pcw_home> new TP, same accel but at higher velocities = lost steps if you were close to the edge with old TP
[09:33:58] <alex_joni> the new TP was tested intensively against limit violations, and if the limits are set ok for your machine there shouldn't ever be lost steps
[09:46:25] <pcw_home> Yeah I suspect think his accel /velocitysettings are just too fast for the drives
[09:50:02] <SpeedEvil> pcw_home: resonances also
[09:51:10] <pcw_home> Yeah the new TP will be tougher on drives because it will run the same back/forth accels at higher speeds than the old TP
[09:54:52] <pcw_home> and since step motors lose torque quickly as speed increases, this
[09:54:53] <pcw_home> is likely to cause missed steps if there is not sufficient margin
[09:55:59] <taiden> my motors aren't running more than 1200 rpm
[09:57:11] <taiden> I think I will have to accept the fate of open loop steppers
[09:57:21] <taiden> and upgrade to closed loop servos later
[09:57:36] <SpeedEvil> taiden: resonance can be a big issue - robbing torque at particular speeds to the point it stalls
[09:57:54] <taiden> SpeedEvil: I wouldn't deny that at all
[09:58:02] <SpeedEvil> adding a fairly massive flywheel to the stepper shaft may actually help
[09:58:07] <taiden> do you think frame vibration will contribute as well?
[09:58:59] <SpeedEvil> possibly, yes
[09:59:09] <taiden> because this steel tube frame is terrible for that
[09:59:35] <SpeedEvil> adding lossy stuff can help
[09:59:45] <pcw_home> 1200 RPM is fast for common step drives (just about where torque drops close to 0)
[09:59:47] <SpeedEvil> stupid stuff like filling tubes with sand can help
[09:59:54] <SpeedEvil> ah
[09:59:57] <SpeedEvil> I missed that
[10:00:39] <SpeedEvil> https://www.youtube.com/watch?v=Mey1z2zRVYQ
[10:00:45] <SpeedEvil> (somewhat related)
[10:02:25] <taiden> OK when a whitepaper says 200 pps
[10:02:31] <taiden> is that 200 full steps per second?
[10:02:43] <taiden> or 200 pulses per second, including microstepping
[10:03:05] <SpeedEvil> full
[10:03:28] <taiden> does microstepping effect graphs using pps on the x axis?
[10:03:35] <taiden> it must
[10:28:03] <PetefromTn_> http://knoxville.craigslist.org/tls/4780654957.html I was not aware Sears sold these 7x bandsaws but that one looks very nice albeit quite overpriced.
[10:45:55] <archivist> taiden, 1200 rpm is fast for a stepper, the loss of torque at speed is very large
[10:48:03] <SpeedEvil> esspecially if you don't have a high voltage driver
[11:00:34] <pcw_home> also hardware step generation will allow some boost in speed
[11:00:36] <pcw_home> (not because of the faster step rate but because of more regular steps at higher speeds)
[11:00:37] <pcw_home> the software stepgen suffers from phase noise caused by beats with the base thread rate
[11:00:39] <pcw_home> when running close to its limits
[11:02:34] <pcw_home> this phase noise can end up at frequencies that excite resonances
[11:11:04] <taiden> thanks for clearing that up pcw_home
[15:55:50] <_methods> anyone in here use the eagle pcg-gcode ulp much?
[15:56:01] <_methods> i can't get it to read stuff on the milling layer for some reason
[15:57:06] <_methods> ahhhhhhh
[15:57:14] <_methods> it's just not reading my arcs
[15:57:21] <_methods> great googly moogly
[15:59:17] <_methods> guess i'll have to bust all the arcs up into line segments
[16:00:29] <PetefromTn_> bust 'em up man!!
[16:00:51] <zeeshan|2> methods what the hell man
[16:00:55] <zeeshan|2> 0.01 mm runout on that chinese lathe
[16:01:00] <zeeshan|2> and youre telling the poor guy to fix that!! :P
[16:01:06] <_methods> heh
[16:01:11] <_methods> i didn't tell him to fix shit
[16:01:23] <zeeshan|2> :)
[16:01:29] <zeeshan|2> perfectionists
[16:01:42] <_methods> i told him if he couldn't live with that runout
[16:02:23] <_methods> yeah i would have left it alone
[16:02:33] <_methods> i don't make any space shuttle parts at the house
[16:03:49] <zeeshan|2> PetefromTn_: having turkey left overs? :D
[16:03:56] <renesis> _methods: that sucks
[16:04:11] <PetefromTn_> LOL yeah for dinner tonight probably
[16:04:29] <PetefromTn_> and cheesecake for desert :D
[16:04:36] <zeeshan|2> nice
[16:04:37] <renesis> omg nom
[16:04:45] <PetefromTn_> and how
[16:06:56] <ssi> hi
[16:07:09] <zeeshan|2> Hi
[16:07:22] <ssi> got my new lathe home :D
[16:07:26] <zeeshan|2> pics
[16:08:35] <ssi> https://pbs.twimg.com/media/B3j0s6ZIQAA_KpF.jpg:large
[16:08:38] <ssi> lol
[16:08:50] <zeeshan|2> nice :D
[16:08:51] <ssi> check out that squat
[16:08:54] <_methods> right on
[16:09:26] <renesis> poorcar
[16:09:29] <ssi> best pic I have as of yet:
[16:09:29] <ssi> https://pbs.twimg.com/media/B3j0undIYAE_r5M.jpg:large
[16:09:43] <ssi> car is a CHAMP
[16:09:52] <ssi> pulls that load better than a v6 pickup would
[16:09:59] <renesis> ha nice
[16:10:01] <ssi> and 37mpg average over 100 miles dragging it home :D
[16:10:10] <renesis> nuh uh
[16:10:12] <renesis> what car
[16:10:21] <ssi> diesel :)
[16:10:27] <ssi> normally I'd get more like 48mpg on that trip
[16:10:31] <ssi> at the same speeds :P
[16:11:01] <renesis> my car consumes all the gas
[16:11:11] <ssi> mine consumes zero gas :D
[16:11:16] <zeeshan|2> hey your manual mill is nice :)
[16:11:25] <ssi> zeeshan|2: yea!
[16:11:26] <ssi> I love it
[16:11:29] <ssi> it was a good deal
[16:11:39] <renesis> i like the cabinet stand
[16:12:06] <ssi> renesis: the old open stands look more traditional, but the cabinet stand is more useful
[16:12:18] <renesis> yeah
[16:12:42] <ssi> http://shanewhitlock.com/photo/d/4047-1/IMG_8234.jpg
[16:12:44] <ssi> that looks awesome
[16:12:45] <renesis> looks cool, too, big louver doors
[16:12:47] <ssi> but it's not as useful :)
[16:13:30] <renesis> thats doesnt look like a real machine it looks like some art gallery interpretation of a real machine
[16:13:58] <renesis> i bet someone spent like 20 minutes arranging those tools on the tray, haha
[16:14:02] <ssi> heheh
[16:14:58] <renesis> omg rain
[16:15:05] <renesis> so much rain is happening i did not expect
[16:15:19] <renesis> laundry gonna suck
[16:22:55] <_methods> anyone got any slick tricks for converting a dxf with arcs to all line segs?
[16:32:11] <Tom_itx> my cad cam will i think
[16:32:32] <_methods> looks like i might have to install acad lol
[16:32:42] <_methods> there are some lisp routines that do it i guess
[16:32:49] <Tom_itx> i've never tried it with acad
[16:33:26] <_methods> haha i've been tryin to save it as iges, stl, whatever to break the arcs up
[16:33:30] <_methods> but no go lol
[16:33:55] <Tom_itx> why do you need line segments?
[16:34:24] <Deejay> gn8
[16:34:41] <_methods> the eagle ulp i'm tryin to use won't read the arcs for some reason
[16:35:09] <Tom_itx> dxf import to eagle?
[16:35:17] <_methods> yeah
[16:35:20] <_methods> i think i got it
[16:35:27] <_methods> i got an stl to come in broken up
[16:36:36] <_methods> it imports the dxf fine
[16:36:48] <_methods> the problem is pcb-gcode wont' read the arcs on the milling layer
[16:37:01] <_methods> i'm trying to make a custom pcb outline
[16:37:47] <_methods> buwhahahah now i brought it in at wrong scale lol
[16:44:30] <_methods> finally
[16:45:23] <_methods> ok so if you ever have to break up a bunch of arcs into lines you can do it by exporting as stl then import back into solidworks and make dxf from that
[16:47:37] <renesis> hahaha
[16:48:20] <renesis> thats neat i guess you can control number of segments by the stl resolution
[16:49:45] <_methods> yeah
[16:49:57] <_methods> talk about goin 'round your elbow
[16:50:18] <_methods> i've had this problem before though and i always forget how i deal with it
[16:51:42] <_methods> i'm always getting files from customers in splines and polylines now i'll just extrude them and save them as sldprt
[16:51:55] <_methods> then export that as stl and reimport