#emc | Logs for 2009-05-14

[00:08:28] <H264> H264 is now known as WalterN
[06:34:52] <Valen> tesssting
[06:35:01] <Valen> thats better
[08:13:23] <archivist> fail
[08:14:05] <alex_joni> archivist: ?
[08:14:25] <archivist> testing above :)
[08:15:33] <archivist> my bot does an auto fail for for people in #mysql
[08:16:05] <alex_joni> for for?
[08:17:06] <archivist> its an unnecessary thing in IRC if you see stuff it works, a fail is success )
[08:18:40] <alex_joni> but a .. failbot?
[08:19:01] <archivist> no
[08:19:19] <archivist> remember less is better than more
[08:20:41] <archivist> unix world uses a light hearted opposite approach
[09:03:06] <piasdom> g'mornin all
[09:18:27] <Valen> what does a fail bot do?
[09:21:46] <archivist> reacts to a user
[09:21:59] <Valen> by doing?
[09:22:14] <archivist> join #cam
[09:42:15] <Valen> heh instant mini mill, just add spindle http://cgi.ebay.com/G29424-Nutec-3-Axis-Positioning-Stage-Controller_W0QQitemZ330319459423QQihZ014QQcategoryZ55826QQcmdZViewItem
[09:45:29] <archivist> no Z some of the scientific positioners are not up to milling
[09:45:39] <Valen> has 3 inches of Z
[09:45:43] <Valen> aparently
[09:46:56] <archivist> I thought it was rotation at first
[09:47:12] <Valen> dunno i was just looking at the description
[09:47:22] <Valen> There seems to be more AC servo motors than dc
[09:47:36] <archivist> I have a small one with micrometers and it rotates
[09:47:44] <Valen> funky
[09:48:27] <archivist> ok for an optical stage but not real work
[09:51:07] <Valen> http://cgi.ebay.com.au/Mitsubishi-AC-Servo-Motor-HA-FE63-Brand-New-Old-Stock_W0QQitemZ200329038238QQcmdZViewItemQQptZAU_B_I_Electrical_Test_Equipment?hash=item200329038238&_trksid=p3286.m20.l1116
[09:51:17] <Valen> little light on info though
[09:53:56] <Valen> what do you like about those scanners archivist?
[09:54:28] <archivist> just works basicly
[09:54:41] <archivist> and fast
[09:54:56] <Valen> yeah the scanner part of them is pretty bullet proof
[09:56:37] <archivist> got it off ebay looks like its could have done 4-5 years work and in good condition, working well
[09:56:58] <archivist> I love stuff with a makers date on it
[09:57:15] <Valen> heh I just wish this lot didn't have "2002" written on it ;->
[09:57:57] <archivist> this has july 2004
[09:58:24] <Valen> wow these must have been worth mega$ when they were made
[09:59:50] <Valen> yours the 16mb ram ones?
[10:00:33] <archivist> dunno what ram is in
[10:14:19] <Guest666> Hey, anyone here?
[10:14:40] <archivist> maybe
[10:18:31] <Guest666> I'm going to build a CNC mill and use EMC2 to control it.
[10:19:40] <Guest666> I was going to make one with a stationary head and moving table but I've decided that it takes up too much space in my room so I'm thinking I'd make one with one or more robot arms instead.
[10:20:10] <Guest666> I was wondering what your thoughts were on havign more than one arm and how much harder it'd be to work with.
[10:21:52] <Guest666> This is going to be a small one mainly for PCB prototyping but I'd like it to be able to do more than that so in my mind robot arm(s) make sense.
[10:22:39] <archivist> gantry router type for pcb's
[10:24:00] <Guest666> Yeah I've used one of those before.
[14:25:53] <als> Tkemc.tcl change suggestion ( 2662 $programfiletext see $activeLine.0 "To 2662 $programfiletext yview $activeLine.0 this keeps the activeLine.0 at the top not the bottom
[14:26:33] <als> so you can see the next line to be acted on
[14:31:19] <EbiDK> EbiDK is now known as EbiDK|AWAY
[14:46:35] <als> bbl
[18:07:44] <xyzee> Hi there: I Am trying to coax a little more speed out of my table router. At the moment the steppers stall at about 15mm per second.
[18:10:13] <cradek> higher voltage!
[18:11:46] <jepler> smaller millimeters!
[18:13:11] <xyzee> At the end of the stepper config wizard it says if the motor locks up decrease max velocity. And if the motors loose steps change the motor timings or check latency. What is the differnce between a motor locking up and a motor missing steps?
[18:14:54] <cradek> a lock up (I call it "stall") means it stops turning until the end of the move, resulting in a gross position loss
[18:15:41] <cradek> a lost step is where the machine is one or two steps off after a while. this can happen for very obscure reasons if the timings are not quite right (usually, a step is taken in the wrong direction by the motor driver.)
[18:16:23] <cradek> I assume you are getting stalls if you go over 15mm/sec. that is NOT a step timing issue.
[18:16:54] <xyzee> When my machine stalls it makes a pretty unplesant noise ....so it is locking up?
[18:16:58] <cradek> stalls at high speed just mean you have run out of power (steppers get weaker the faster they go)
[18:17:25] <cradek> yes in my experience it has a distinctive sound when it stops moving - very easy to detect.
[18:18:02] <cradek> it may be a mechanical resonance problem or a problem of running out of power. sometimes it's hard to tell the difference.
[18:18:38] <xyzee> So the motors are not powerfull enough?
[18:19:03] <cradek> it could be that, or the drivers, or the power supply
[18:19:55] <archivist_attic> higher voltage allows more speed, first thing to change if you can, then half step
[18:20:08] <archivist_attic> then servo
[18:20:16] <cradek> yes top speed is nearly proportional to supply voltage
[18:20:31] <SWPadnos> if you have a chopper drive
[18:20:45] <xyzee> It is quite strange because in the step config wizzard I can get quite high speeds. When I run EMC it stalls much easier
[18:20:50] <SWPadnos> otherwise smoke is proportional to supply voltage
[18:20:56] <archivist_attic> or bigger fatter resisters
[18:21:02] <cradek> then it might be an acceleration problem
[18:21:17] <cradek> in what cases does it stall?
[18:21:26] <SWPadnos> it could be the power supply also, multiple motors is more of a current draw than testing one at at time
[18:21:30] <maddash> n%2==0
[18:22:29] <xyzee> Could it be a latency issue? I have a max jitter of about 37563
[18:23:01] <archivist_attic> nope steppers are not that good
[18:23:42] <cradek> I also doubt it
[18:23:48] <archivist_attic> you have to stay in a steppers operating curve to not stall
[18:24:50] <xyzee> So I need to increase current somehow?
[18:25:30] <archivist_attic> voltage, run at or near max current
[18:25:32] <cradek> you haven't told us anything about the system yet
[18:25:44] <cradek> what are your motors, power supply, and drives rated?
[18:26:14] <xyzee> Thanks for this guys....
[18:26:57] <xyzee> I have
[18:27:23] <xyzee> an MSD%$@ microstepping driver
[18:28:16] <archivist_attic> set to what?
[18:28:49] <xyzee> I am not very technical so you will need to tell me what is relevant
[18:29:26] <cradek> voltage and current ratings, along with the microstep setting
[18:33:04] <xyzee> At the moment each drive is set to 1.4 Peak Current (A) and microstepping set at 16
[18:33:31] <JymmmEMC> 16?!
[18:33:50] <cradek> you might try 2 or 4 microsteps
[18:34:01] <JymmmEMC> 8 or 10 is typical
[18:34:31] <archivist_attic> I would change microstep to a lower number I have seen 2 as being the best for speed and smootheness
[18:35:01] <JymmmEMC> Why would you go to half step? Seems too clunky imo
[18:35:28] <cradek> you should try each setting and measure the performance
[18:35:46] <JymmmEMC> I'd try 8 first.
[18:36:27] <xyzee> I have tried different micro steps with little result. It Is possible to crank peak current up to 5.6 but do not want to damage anything
[18:36:44] <JymmmEMC> What are the motors rated for?
[18:36:50] <archivist_attic> set to the motor current spec
[18:36:56] <cradek> you should set the current to ... yeah what they say
[18:37:07] <JymmmEMC> Yeah, what cradek said
[18:37:14] <cradek> what archivist said
[18:37:23] <archivist_attic> they will get warm to hot, thats ok
[18:37:46] <cradek> I'm still wondering what the voltage and current ratings are on the power supply, drivers, and motors
[18:37:53] <cradek> we know that driver max current = 5.6 amp
[18:38:00] <archivist_attic> yup missing info
[18:38:03] <cradek> now we need 5 more numbers :-)
[18:38:18] <JymmmEMC> 6 more for good measure.... always good to have a spare.
[18:38:18] <cradek> without all six numbers, anything else is just guessing
[18:38:52] <JymmmEMC> Then I can go play the lottery
[18:39:20] <archivist_attic> * archivist_attic has to collect his £10 on the lottery
[18:40:35] <JymmmEMC> Anyone have a Thinkpad T60 by chance?
[18:42:00] <JymmmEMC> archivist range?
[18:42:28] <xyzee> The steppers are FL86STH.. Voltage 3.93V, Current 2.8A, resistance 1.40hm, inductance 3.9mH
[18:42:43] <JymmmEMC> Then set to 2.8A
[18:42:53] <JymmmEMC> what brand?
[18:43:19] <cradek> good steppers, high current low voltage.
[18:43:20] <JymmmEMC> what voltage is your power supply?
[18:43:32] <cradek> I agree set driver current to around 2.8.
[18:44:07] <cradek> ideally you'd be driving these motors with 40-60 volts
[18:44:11] <JymmmEMC> Hmmmm, they can take almost 100V
[18:45:41] <JymmmEMC> What's the FULL part number?
[18:46:53] <xyzee> Power supply is 2 X 42V, 280 watts
[18:47:09] <JymmmEMC> in series or parallel?
[18:47:22] <JymmmEMC> Details man, details!!!
[18:47:28] <cradek> haha
[18:48:03] <xyzee> OOPS I got it wrong the steppers are 5.25V, 4.2 A
[18:48:18] <JymmmEMC> What's the FULL part number?
[18:48:27] <JymmmEMC> What's the FULL part number of the stepper motors?
[18:49:11] <JymmmEMC> IT'll be something like: FL86STH65-2808
[18:49:15] <xyzee> I can't remember if parallel or seriesbut I chose the method that would give faster movement.
[18:49:29] <JymmmEMC> O_o
[18:49:59] <xyzee> Full part no FL86STH156-4208?
[18:52:17] <JymmmEMC> xyzee: What driver are you using?
[18:52:52] <JymmmEMC> and is 280 Watts per power supply, or total?
[18:53:20] <JymmmEMC> are these swtiching or linear power supplys?
[18:54:01] <xyzee> 2 X MSD542 Micro stepping driver @ 280 W per driver
[18:55:08] <xyzee> No idea if switching or linear
[18:55:19] <JymmmEMC> xyzee: are they heavy?
[18:55:35] <JymmmEMC> MAx driver input voltage = 50VFC
[18:55:40] <JymmmEMC> VDC
[18:55:46] <JymmmEMC> @ 4.2A
[18:56:51] <xyzee> Don't think they are heavey, about the size of a small router box
[18:57:01] <JymmmEMC> flat?
[18:57:18] <archivist_attic> they are chopper/switching drives max 50 v http://www.motioncontrolproducts.co.uk/product_info.php?products_id=3
[18:57:54] <JymmmEMC> PDF http://www.cnczone.com/forums/attachment.php?attachmentid=66050&d=1220823475
[18:58:14] <xyzee> Yes that is where I got all this stuff!
[18:59:03] <JymmmEMC> xyzee: Can you hold one of these power supplies using two fingers?
[18:59:39] <JymmmEMC> xyzee: Can you hold one of these power supplies in the air using two fingers?
[19:00:04] <xyzee> Oh Yes (one finger and one thumb)
[19:00:12] <cradek> heh, good test for switching/linear
[19:00:14] <JymmmEMC> ok, switching.
[19:00:55] <JymmmEMC> cradek: I try =)
[19:09:35] <archivist_attic> any road up...voltage ok current can be ok microstepping could choose faster, check acceleration and mass (no idea yet whats being moved)
[19:11:40] <xyzee> Heaviest axis is about 670kg
[19:12:16] <xyzee> oops. heaviest axis is about 70kg
[19:14:36] <archivist_attic> ah heavy
[19:15:20] <archivist_attic> you could well be running out of torque at speed
[19:15:44] <archivist_attic> allow some spare for cutting load