#linuxcnc | Logs for 2013-12-27

[00:01:10] <nsp> lead screws
[00:01:26] <tjb1> Which do you want to know about? ball screws or acme screws?
[00:03:18] <nsp> http://www.mcmaster.com/#general-purpose-acme-rods/=pzgyjk
[00:04:07] <tjb1> Yes, I use 1/2-10 acme on my plasma table
[00:04:37] <nsp> how well does it work?
[00:07:12] <tjb1> In what way do you mean?
[00:07:15] <tjb1> It gets the torch up and down
[00:07:35] <nsp> do you use antibacklash nuts?
[00:07:50] <tjb1> I use 1 anti-backlash nut
[00:07:50] <nsp> or how does the acme rod transfer linear motion to the carraige
[00:08:08] <nsp> what motor size do you use
[00:08:16] <tjb1> http://www.cncrouterparts.com/dumpstercnc-acme-assembly-p-36.html
[00:08:22] <tjb1> nema23
[00:09:07] <nsp> cool me too. im trying to design a setup that uses nema 23- i already have them- and then a lead screw and an antibacklash nut for every axis
[00:09:10] <nsp> trying to make it cheap too
[00:13:05] <nsp> how does your nema couple to the threaded rod without backlash
[00:18:23] <tjb1> oldham coupler
[00:22:18] <nsp> the guy whose designs i am building off of claims to use 11mm threaded rod and i cant find such a thing that exists
[00:23:09] <ReadError> which design?
[00:23:13] <ReadError> threaded rod is bad
[00:25:11] <tjb1> Hello ReadError !
[00:27:36] <nsp> http://www.instructables.com/id/The-AnniRouter-v02body-only/
[00:30:02] <nsp> they use the steppers with the built in lead screws and i dont have those so im gonna use threaded rod and coupler
[00:34:31] <nsp> how much does lead screw diameter matter
[00:35:59] <nsp> how do u spec out the right size of oldham coupler
[00:37:26] <tjb1> Well you find a bore that you like
[00:37:30] <tjb1> thats about all you can spec
[00:44:04] <nsp> what about the bore for the 1/2 inch rod? and for the nema- do you just measure the od with calipers and get close with the bore? is the set screw just enough to hold the motion without backlash
[00:51:14] <tjb1> Well a 1/2 rod is close to .5 in diameter
[00:51:19] <tjb1> but you should turn the end anyway
[00:51:23] <tjb1> to like .375
[00:51:31] <tjb1> with a decent fit into the coupler
[00:52:26] <nsp> gotcha thats smart. so my threaded rods will be approx 3 or so feet whats the best setup in a lathe to turn the ends
[00:52:39] <tjb1> Uh
[00:52:46] <tjb1> Why are you using threaded rods 3 feet long
[00:52:52] <tjb1> What diameter are they
[00:52:56] <nsp> 1/2
[00:52:58] <nsp> inch
[00:53:03] <nsp> for the axis
[00:53:21] <tjb1> Not a good idea, you may get leadscrew whip when the nut isnt near the center
[00:54:04] <nsp> what is whip?
[00:54:28] <nsp> the nut will always be in the center because it will be constrained in the carraige in the center by the two smooth rods on the acis
[00:55:35] <tjb1> I mean the nut being in the center of travel on the leadscrew
[00:55:41] <tjb1> otherwise the screw can whip out from the center
[00:56:37] <nsp> hmm im not getting it
[00:57:09] <tjb1> The centrifrugal force can cause the screw to whip
[00:57:19] <tjb1> No longer being concentric to the axis
[00:57:25] <tjb1> that the screw is on
[00:58:36] <nsp> oh i see. but the force is proportional to angular velocity so that problem would be made worse by high speeds
[00:59:25] <tjb1> yes
[01:00:18] <nsp> so that was how it was in the original design i basing my model off of. - that one looked like it still worked fine enough for carving woods. how do you get around that problem on yours?
[01:00:28] <tjb1> I use rack and pinion
[01:00:32] <tjb1> http://linuxcnc.org/index.php/english/forum/30-cnc-machines/25901-diy-cnc-plasma-table-lots-of-pictures
[01:03:19] <nsp> that thing is awesome
[01:03:56] <nsp> also the whip is proportional to the cantilevered length of the beam, my cnc will be approx 2feet working area by 3 feet so hopefully it wont be super bad
[01:11:16] <nsp> any ideas on that?
[01:12:29] <tjb1> You can try it
[01:20:09] <nsp> whered ya go to college
[01:20:20] <nsp> thats a pretty cool senior project
[01:22:01] <tjb1> Pennsylvania College of Technology
[01:22:20] <nsp> cool
[01:22:35] <nsp> what control board u use for ur plasma
[01:23:00] <tjb1> Gecko G540
[01:23:46] <nsp> cool, whats the control board that those run out of
[01:24:00] <tjb1> What do you mean?
[01:24:27] <nsp> for example i have one setup this is running an arduino mega with some gecko drivers
[01:24:37] <nsp> the arduino is sending signals from the comp realtime
[01:25:04] <tjb1> The Gecko G540 is controller + drivers
[01:28:32] <nsp> oh gotcha
[01:31:53] <nsp> any ideas on how to turn down that rod
[01:32:02] <tjb1> A lathe
[01:34:17] <nsp> wont the cantilevered length be too long
[01:34:35] <tjb1> You only stick out an inch or so
[01:34:42] <tjb1> You will need a way to constrain the end
[01:34:48] <tjb1> or you will have a bent screw
[01:34:57] <nsp> where does the rest go?
[01:35:50] <nsp> stick out an inch from the chuck?
[01:36:02] <tjb1> The end goes through the spindle and comes out the back
[01:37:12] <nsp> i see, so is there a way to support the cantilevered part that hangs through the spindle
[01:37:59] <tjb1> Well you can put a PVC pipe around it and support the PVC
[01:39:38] <nsp> yeah thats a good idea
[01:42:59] <nsp> did u spec out the required torque on the steppers u used for ur plasma?
[01:43:29] <tjb1> No I bought a kit from www.cncrouterparts.com
[01:47:53] <nsp> was the setup hard with lcnc
[01:48:24] <tjb1> Not really hard for the general x-y-z but the torch height control was terrible for me
[01:48:40] <tjb1> I have no experience or knowledge of linuxcnc or linux so it was very difficult
[01:48:51] <tjb1> Everyone here helped me quite a bit with the programming
[01:49:24] <nsp> cool, so howd the end product work out? make some cool stuff?
[01:50:17] <tjb1> Well its been used lightly
[01:50:44] <tjb1> The torch height controller still doesnt work right and the power supply for the logic died so it was down for a while and now I live on my own so it hasnt been used in months
[01:52:05] <nsp> is there any market for making cnc plasma'd parts for people
[01:52:49] <tjb1> JT-Shop_: could tell you more
[01:52:53] <tjb1> If he is really active but I doubt it
[01:53:11] <tjb1> I'm too busy to run it and my dad doesn't know how to use Linux so thats why it sits
[01:53:58] <nsp> u should turn it into a sink edm
[01:54:18] <tjb1> Still no time :)
[01:54:29] <nsp> hahah
[01:55:44] <nsp> hope this cnc works for making electric guitars- carving them out of wood
[01:55:58] <tjb1> Good luck
[02:03:44] <nsp> so the couling's set screws are enough to prevent slip when tightened uo
[02:03:46] <nsp> up
[02:04:08] <tjb1> I have flats on everything
[02:09:26] <nsp> howd u machine the flats?
[02:09:40] <tjb1> file or grinder
[03:02:24] <Deejay> moin
[05:22:22] <sivu> gnnh
[07:09:34] <tom_R2E3> hello
[07:27:15] <archivist> allo allo
[07:54:07] <JT-Shop> howdy
[08:13:38] <cnct> anyone home?
[08:13:43] <archivist> no
[08:13:58] <archivist> in IRC ask the real question :)
[08:14:49] <cnct> I have a 5i25 and 7i77 mesa boards
[08:15:02] <cnct> I am retrofitting a vmc and need more I/O
[08:15:21] <cnct> Can I just add another 7i77?
[08:16:44] <cnct> I am a bit overwhelmed..... I am reading up on the HAL. Hasnt sunk in yet....lol
[08:22:43] <CaptHindsight> cnct: you can add as many boards as you have slots for on your motherboard
[08:23:48] <archivist> that means getting both cards instead of just one extra daughter card
[08:23:52] <CaptHindsight> some of the PCI/e FPGA boards support one IO board, some support 2 or more
[08:24:17] <cnct> The 7i77 is not a slot card
[08:24:30] <CaptHindsight> choose wisely
[08:25:18] <cnct> I allready have a 5i25 and a 7i77, I think I only need extra I/O at this point
[08:25:42] <cnct> So looks like a 7i84, but that needs rs485 card.
[08:28:00] <CaptHindsight> cnct: call Mesa in a few hours or ask PCW, I don't recall which FPGA boards have multiple headers for IO boards
[08:28:31] <CaptHindsight> it's 6:12 am on the west coast right now
[08:28:46] <archivist> 5125 manual states a 2 7177 option
[08:28:49] <cnct> I am reading up on their site now. Rs422, and the 7i77 has two ports I can use so I can add 7i84 which has the I/O required..... cool.
[08:29:48] <cnct> I'll continue researching and run past my idea with PCW to validate.
[08:29:51] <cnct> Thanks guys
[08:30:18] <cnct> I'm going to need a boat load of relays
[08:30:50] <CaptHindsight> I was using the 6i68 with 6 IO connectors and still needed more IO
[08:34:41] <cnct> I have 6 extra motors and a tool changer
[08:36:45] <CaptHindsight> 7 axis + multiple inkjet printheads, laser, motorized zoom microscope, cheese slicer (kidding on the last one)
[08:39:35] <CaptHindsight> cnct: sometimes it helps to add a PLC as well
[08:39:49] <CaptHindsight> http://www.automationdirect.com/adc/Shopping/Catalog/Programmable_Controllers/DirectLogic_Series_PLCs_%28Micro_to_Small,_Brick_-a-_Modular%29
[08:43:10] <pcw_home> you can add one serial I/O card to the 7I77 without extra hardware (just a cable)
[08:44:12] <pcw_home> If you need AC I/O you can use a PLC or use a 7I69 and some OPTO22 I/O racks
[08:49:34] <cnct> I have a DL06 with the extra Z I/O
[08:50:43] <cnct> But whats the point when linuxcnc and mesa boards can do the same thing
[08:51:32] <cnct> Would probably be nice to use it just for the tool changer
[08:52:29] <cnct> Getting way down the road now. If I cant figure out the HAL, this is all mood point
[08:53:54] <cnct> So, I'm thinking a 7i84 connected to the 7i77 to give me extra I/O. Does that work PCW?
[08:55:03] <pcw_home> Thats will give you 32 more 12/24V inputs and 16 more 12/24V outputs
[08:55:58] <pcw_home> plus a couple MPG inputs or analog input if you need them (the 7I77 can do this as well)
[08:56:16] * JT-Shop has used a bunch of DL06's
[08:56:58] <cnct> I use the DL06's for security interlocks. They are great
[08:58:50] <JT-Shop> have you used the Click PLC's yet?
[08:59:44] <cnct> I figure that when there is a tool change required, HAL will send an rs232 message with the tool number, then the DL06 can do all the logic and change the tool and when it is done tell Lcnc it is finished and Lcnc can continue on. Does that scenario work?
[08:59:58] <cnct> no Click PLC
[09:01:19] <cnct> You talking about the CO series?
[09:04:22] <JT-Shop> yes, but you can do all that in LinuxCNC as it has a built in PLC
[09:04:37] <JT-Shop> http://www.automationdirect.com/adc/Shopping/Catalog/Programmable_Controllers/CLICK_Series_PLCs_%28Stackable_Micro_Brick%29
[09:19:04] <tom_R2E3> quick question regarding mesa 7i77 field I/O
[09:19:53] <tom_R2E3> I have applied 24v to field power, which is fine, pncconfig recognises TB7&8
[09:20:17] <tom_R2E3> if I measure between any of the field in pins and ground I have 24v
[09:20:58] <tom_R2E3> to wire in a home switch. From what I understand from the manual, I put the switch in series between field power and one of the field in pins?
[09:21:39] <pcw_home> you probably dont have your 24V ground amd meter ground the same (the 24V I/O is completely isolated from the PC GND)
[09:22:10] <tom_R2E3> ok, I might have got that wrong
[09:22:20] <pcw_home> the inputs should read low relative to field ground
[09:22:31] <tom_R2E3> one sec,
[09:22:32] <pcw_home> (they have 20K pulldowns)
[09:23:23] <tom_R2E3> yep, sorry you're right
[09:24:11] <pcw_home> normal limit switch wiring
[09:24:13] <pcw_home> Fused +24V --> NC limit switch --> 7I77 input
[09:24:41] <tom_R2E3> excellent, thank you
[09:26:16] <pcw_home> and in the hal file you use the input-not pins for limits so open = on limit
[09:27:30] <pcw_home> (and broken wire or short to ground = on limit as well)
[09:29:10] <JT-Shop> tom_R2E3, there is a diagram for I/O at the bottom of this page http://gnipsel.com/linuxcnc/configs/7i77.html
[09:29:30] <tom_R2E3> my home switches are the other way around, closing the switch makes the circuit (opposite to mesa document recommendation)
[09:30:25] <tom_R2E3> thanks JT
[09:32:26] <pcw_home> That will works though its somewhat more likely to fail in a unsafe way
[09:32:26] <pcw_home> work
[09:35:14] <pcw_home> if you are really paranoid you can wire 24V to switch common
[09:35:15] <pcw_home> and bring both NC and NO switch contacts to the 7I77
[09:35:17] <pcw_home> (and fault if you dont have the expected signal inversion between the two)
[09:35:35] <tom_R2E3> yeah I agree. think they are triple throw switches, was just going to get the machine going before I correct them
[09:46:54] <R2E4> tom_R2E3: you converting a R2E3?
[09:51:35] <tom_R2E3> yep
[09:52:06] <tom_R2E3> it's getting there, jogged xy&Z earlier
[09:56:37] <R2E4> boss 9?
[09:59:00] <tom_R2E3> it's a series 1, boss 8
[10:16:52] <tom_R2E3> ah, more following errors :(
[10:19:58] <R2E4> AH, I have a series 1 Boss 9 R2E4
[10:21:12] <R2E4> I ws going to use LinuxCNC andmesa cards. I bought them and when I changed BP to 220 Single phase everything worked so I didnt upgrade. I am drip feeding it now.
[10:23:20] <cradek> ha, it's kind of a curse when the old machine actually works as-is
[10:24:51] <R2E4> ITs kinda cool cause I bought the mesa boards and now I can use them on my VMC
[10:27:07] <tom_R2E3> I converted mine to single phase first too. BOSS worked, but I couldn't be bothered to learn how to use it, thought I may as well just retrofit straight away and learn linuxCNC
[10:27:46] <tom_R2E3> i'm not a machinist, or electrician
[10:28:22] <tom_R2E3> does the drip feed work ok?
[10:30:32] <tom_R2E3> RE: following error. Should I just open the tolerance right up until I can tune the servos?
[10:31:18] <cradek> maybe .1 or .2 inches. if it goes nuts and runs away or oscillates madly it's good if it stops
[10:34:18] <R2E4> Yeah, dripfeed works fine.
[10:34:35] <R2E4> IT would be better if I had linuxCNC, but it is working for now.
[10:35:31] <R2E4> how come there isnpo /etc/inittab?
[10:36:54] <R2E4> Wheres the runlevel kept.
[10:39:14] <jthornton> Tom_itx, I fixed a couple of errors when generating a tapping op in the G code generator http://gnipsel.com/files/g-code-generator/
[11:27:53] <tom_R2E3> what acceleration value can I use?
[11:28:22] <tom_R2E3> 2mm/s^2 as default
[11:28:39] <tom_R2E3> table overshoots my home switch and runs in to the limit
[11:39:22] <sivu> you guys listen to "Push it to the limit" by giorgio moroder when adjusting the machine
[11:42:08] <archivist> listen to the machine shakin' for teh bestest
[11:42:35] <IchGuckLive> hi all B)
[11:43:02] <pcw_home> You should be able to have a much higher acceleration (after tuning)
[11:43:06] <archivist> managed to shake a wheel loose today testing slow speed gearing
[11:44:13] <pcw_home> shake, rattle, and roll?
[11:44:20] <pcw_home> http://gnipsel.com/linuxcnc/tuning/servo.html
[11:44:24] <IchGuckLive> pcw_home: will set up 3 more plasmas tommorrow on 7i76
[11:45:11] <archivist> pcw_home, was testing a stepper through resonance
[11:46:24] <pcw_home> Its fun to put a encoder on a stepper and watch it ring like a bell every time you step :-)
[11:47:54] <archivist> I am turning an encoder with my fingers with linuxcnc in between doing the gearing and a large stepper on half step in a vice, the bench shakes violently
[11:50:39] <pcw_home> this is why u-stepping is a bit nicer
[11:51:22] <archivist> yup, it needs that but on a parallel port that limits the rpm a lot
[11:51:53] <pcw_home> IchGuckLive: do you have torch height control?
[11:52:48] <IchGuckLive> yes
[11:54:30] <pcw_home> archivist: I can send you a proto/blem mesa hardware stepgen card if you like
[11:57:15] <archivist> would be interesting to try :)
[11:57:58] <cradek> like heroin, first one's free
[11:58:22] <pcw_home> (evil laugh)
[11:58:27] <cradek> :-)
[12:04:48] <Loetmichel> bad pcw_home ;-)
[12:06:50] <CaptHindsight> http://rockford.craigslist.org/tls/4236384552.html Bandsaw "Blade runs in reverse (upward)" ??
[12:07:51] <cradek> well that's surprising
[12:07:53] <archivist> fix wiring then it goes the right direction
[12:08:42] <CaptHindsight> so it's not for cutting .... wait for it ...... UP things?
[12:09:05] <skunkworks> or the motor is mounted wrong
[12:09:35] <CaptHindsight> sometimes I call these people just to let them know
[12:12:56] <skunkworks> I don't like that style - it runs the blade around too small of a radious
[12:13:03] <skunkworks> radius
[12:13:44] <archivist> allows a wider throat though
[12:15:52] <skunkworks> sure
[12:16:00] <skunkworks> but so does big wheels.. ;)
[12:37:01] <CaptHindsight> skunkworks: more like this? http://milwaukee.craigslist.org/tls/4242952906.html
[12:39:45] <tom_R2E3> in axis, how do you change the max jog and velocity?
[12:40:11] <tom_R2E3> I mean, how do I set the max and min for the slidy bar?
[12:40:31] <pcw_home> in the .ini file
[12:43:02] <tom_R2E3> thank you
[12:46:53] <IchGuckLive> tom_R2E3: section display
[12:47:30] <IchGuckLive> tom_R2E3: page 14 integretur manual
[13:22:06] <asah> Hey all. I am setting up homing on my machine and running into some cognitive limitations.
[13:22:40] <asah> I have linear glass scales with an index pulse. I want to use the index pulse to set the home reference.
[13:23:19] <asah> I don't have a limit switch really as the limit switch is an estop and depowers everything.
[13:24:04] <asah> so I want to use the index pulse as both the software switch and the index latch so that the homing search sequence will work well.
[13:24:24] <asah> but I cannot seem to figure out how to use this one pin to drive two signals.
[13:24:52] <cradek> you don't need to emulate a home switch. just use index-only homing.
[13:24:55] <asah> I want to make a connection from encoder.00.index-enable to axis.0.inde-enable
[13:25:28] <asah> ok, so do I ignore home_search_vel ?
[13:25:29] <cradek> you will just have to manually position between the correct two index pulses before homing.
[13:25:41] <skunkworks> oh - the scales only have 1 index - that will work..
[13:25:48] <cradek> I don't know - check the homing docs for the exact settings for index-only
[13:25:49] <asah> on these scales there is only 1 pulse.
[13:25:52] <asah> yes
[13:25:54] <cradek> oh excellent
[13:26:05] <pcw_home> there is a index only home option
[13:26:07] <cradek> then index-only is easy as long as the pulse is at one end
[13:26:15] <asah> pulse is at one end.
[13:26:24] <skunkworks> then easy peesy - just setup homing as cradek said
[13:27:31] <asah> ah. ok cool. I see now section 4.3 in the integrators manual has a matrix that shows index only homing.
[13:27:33] <asah> Ill try it out.
[13:28:09] <cradek> I found it here: http://www.linuxcnc.org/docs/html/config/ini_homing.html#_configuration
[13:29:37] <asah> beautiful!!!!
[13:30:33] <skunkworks> asah: have the gearshift comp figured out?
[13:31:37] <asah> nope. I am going to get the rest of the mill up first. I have some manual buttons that allow me to shift the gears for now. Then Ill finish the comp.
[13:32:10] <asah> nearly there. list is now: homing (nearly done!) and then tool changer hydraulics (which may be dead simple)
[13:32:37] <asah> then I am going to cut something! I ran the spiral gcode on tuesday.
[13:32:44] <asah> so I am nearly there.
[13:33:03] <asah> PID tuning on this thing is a pain as the amp allows for very slow control... 100hz!
[13:40:16] <Jymmm> Can thin gauge SS sheet be spot welded?
[13:42:52] <Loetmichel> Jymmm: why not?
[13:42:54] <Loetmichel> sure!
[13:43:09] <Jymmm> Loetmichel: Wasn't sure if any gasses were needed.
[13:43:24] <Loetmichel> spot welding doesent need any gasses
[13:44:01] <Loetmichel> because it happens between two sheets of metal-> nor oxygen there anyways
[13:49:19] <asah> PCW you going into the shop today?
[14:17:42] <asah> ok... homing and tool hydraulics... check!
[14:17:51] <asah> thanks for everyones help.
[15:01:53] <nsp> has anyone every used any of the dremel router bits for more than engraving?
[15:08:27] <cradek> I've stabbed myself with them, and made projectiles out of them
[15:09:00] <cradek> they're really not good for much. they only thing they have going for them is you can find them in crappy hardware stores. but what are you really trying to do?
[15:17:12] <Loetmichel> nsp: i used the 6mm slot bit to level my sacrificial plate on a small router once
[15:17:31] <cradek> that took patience
[15:17:41] <Loetmichel> ...after half the 300*400mmm MDF sheet it got dull :-(
[15:17:51] <cradek> sure, they're not carbide are they?
[15:17:56] <Loetmichel> hSS
[15:18:27] <Loetmichel> maybe not even that
[15:19:20] <Loetmichel> the ONLY Carbide bit for dremel is the "ceramic tiles mortice cleaner bit"
[15:19:43] <cradek> dremels suck
[15:21:11] <Loetmichel> cradek: they're good for making new engraviong bitsout of broken carbide bits ;-)
[15:22:16] <Loetmichel> http://www.cyrom.org/palbum/main.php?g2_itemId=8961
[15:22:39] <Loetmichel> <- after about 20 or 30 i chan do that free hand ;)
[15:23:37] <nsp> im trying to spec out a router that will be able to make guitar necks and bodies
[15:23:44] <nsp> out of 3 inch or so maple blocks
[15:24:02] <Loetmichel> hmmm
[15:24:22] <Loetmichel> an chinsese 6040 should be able to do that
[15:24:39] <nsp> what is that and where do i buy one?
[15:24:46] <Loetmichel> country?
[15:24:58] <nsp> US
[15:25:15] <nsp> keep in mind the router is borline a mini router with a 2 foot by 3.5 foot bed
[15:26:14] <Loetmichel> ah,i thought you wanted a wholemachine
[15:26:34] <Loetmichel> you meant: you are searching for the router bit?
[15:27:06] <Loetmichel> how big your spindle can chuck?
[15:27:33] <Loetmichel> the std 8mm tungsten carbide are MADE for the job of cutting wood
[15:28:43] <Loetmichel> i.e something like this: http://www.ebay.de/itm/35-tlg-Frasersatz-Nutfraser-fur-Oberfrase-Holzfraser-Oberfraser-Fraser-Satz-8mm-/350964032833?pt=Elektrowerkzeug_Zubeh%C3%B6r&hash=item51b7162541
[15:30:13] <nsp> does anyone run a dc motor spindle with a coupler to the bit?
[15:30:26] <nsp> or is there a cheap way to make a collet off of a dc motor spindle
[15:30:42] <Loetmichel> buy one
[15:30:52] <Loetmichel> with a fitting collet
[15:31:33] <Loetmichel> i make it like this: http://www.cyrom.org/palbum/main.php?g2_itemId=12846
[15:32:09] <Loetmichel> (but thats a 8mm shaft from a proxxon FBS230 in the front,i.e dremel like collets up to 3,175)
[15:32:31] <Loetmichel> ... i also have one of these with a 8m cylindrical shaft ER11 collet
[15:32:58] <Loetmichel> http://www.cyrom.org/palbum/main.php?g2_itemId=13221 <-these shafts)
[15:32:58] <nsp> so what is the best for the guitars, ill need an 8mm collet then?
[15:34:05] <Loetmichel> but that is not sufficient for big router bits because the 250W of the DC motor will not be enough to drive a 30mmm slot bit ;-)
[15:35:03] <Loetmichel> i would go for a new chinese Spindle with 1,5kW or 2,2kW and ER16 at least and then use as big router bits as fit the job
[15:38:01] <nsp> http://www.ebay.com/itm/1-5KW-48-63-Hz-WATER-COOLED-MOTOR-SPINDLE-AND-MATCHING-INVERTER-Brand-New-/251409536198?pt=LH_DefaultDomain_0&hash=item3a892d14c6
[15:39:02] <Loetmichel> yeah, something in thalt ballpark
[15:39:05] <Loetmichel> that
[15:39:57] <nsp> those are pretty expensive, wondering if i can just use one of the big dc motors I have
[15:40:33] <Loetmichel> those are pretty cheap
[15:40:51] <Loetmichel> and your ears will thank you to get a water cooled version ;-)
[15:41:12] <Loetmichel> you CAN always use a standard router for the job
[15:41:35] <Loetmichel> like kress FME 1050
[15:41:40] <nsp> yeah that seems like a better idea
[15:42:01] <Loetmichel> but that is MUCH louder and has a life opf less than 500 hrs in the CNC
[15:42:46] <Loetmichel> been there, done that, changed the bearings and brushes regualarry and wore hearing protectiopn all the time
[15:44:01] <nsp> how long do you think it takes to mill out a guitar body
[15:45:26] <Loetmichel> depends on your machine (rigidity and stepper size/torque)
[15:46:06] <nsp> so i have one of these boards- http://www.google.com/imgres?imgurl=&imgrefurl=http%3A%2F%2Freprap.org%2Fwiki%2F4_Axis_TB6560_CNC_Stepper_Motor_Driver_Board_Controller&h=0&w=0&sz=1&tbnid=e9yUXx8rVoKnKM&tbnh=190&tbnw=265&zoom=1&docid=ohia-xeZpMSKvM&ei=JPG9UsmLDae72wXo1ICoAw&ved=0CAIQsCUoAA
[15:46:10] <Loetmichel> i could do a guitar bodi in about an hour or so if not TO complicated contour/ much polising work like beveling every corner and so on)
[15:46:39] <nsp> cool
[15:46:56] <nsp> can the spindle interface be used to power dc motor spindle on board i have
[15:49:31] <Loetmichel> that "interface" is just a ralais
[15:49:33] <Loetmichel> relais
[15:49:52] <Loetmichel> if you are below the Amps that the ralais can do on dc you are fine
[15:51:52] <nsp> ralais?
[15:53:33] <nsp> heres what the spec sheet says
[15:53:34] <nsp> Relay spindle interface - Outputs Max. 36V 7.5A for spindle motors or coolant pump (only one device can be powered by this output!)
[15:58:55] <CaptHindsight> http://www.3ders.org/articles/20131226-apple-files-new-patent-for-an-inkjet-printer-for-printing-on-a-3d-object.html inkjet instead of cutting tool
[16:01:38] <Deejay> gn8
[16:02:37] <tom_R2E3> I have to ask, because it's driving me crazy. How does emc know A: roughly where the tool is when I turn the program on? and B: which direction to travel towards home?
[16:05:23] <tom_R2E3> I just set up a three axis mill with the machine coordinate system as per the diagram in the wiki (home and origin are at the top limit switch of Z)
[16:06:01] <tom_R2E3> tested z direction (jog positive moves the spindle up) all ok
[16:07:01] <tom_R2E3> so with origin at z0, home switch at z0 and a negative travel of -125 positive travel of 0
[16:07:36] <tom_R2E3> turn EMC on and z says -60 or whatever, try to home and it moves in the negative direction?
[16:17:31] <R2E4> Can I add field power 24vdc to the 7i77, without changing jumpers? Just the 5vdc where I need to change the jumpers on the 5i25 and 7i77 correct?
[16:40:20] <tom_R2E3> found it. You change the sign of the search velocity!
[19:29:06] <jm82792> hey I have a LinuxCNC controlled CNC router and I'm about to buy a second one. I'd like to clean things up and standardize them.. So I was thinking about buying a BeagleBone Black.
[19:29:10] <jm82792> But I need 3d back plotting.
[19:29:13] <jm82792> Is that in yet?
[19:29:33] <cradek> I thought all charles's images used AXIS but I have never used them
[19:30:53] <cradek> are you interested in development and bleeding edge? if you're "just an end user" as you said in the other channel, you might want to stick to a real pc for now.
[19:31:26] <jm82792> I"m a tad budgeted and I'd like to ditch a full PC along with I don't mind fiddling to get stuff working.
[19:31:40] <jm82792> But I don't want anything unstable though...
[19:32:04] <jm82792> But I'm just an end user feeding a bunch of generic Gcode.
[19:32:37] <jm82792> Please pardon my somewhat incoherent typing...
[19:33:52] <jm82792> I have been using an older Pentium 4 PC for a few years, and was thinking a small ARM based computer would be the ticket.
[19:33:54] <cradek> last I heard, the beagles had a little trouble running AXIS. They are not fast.
[19:34:18] <cradek> a pentium 4 is a very easy solution and costs about $0
[19:34:32] <jm82792> Yeah that is a bit of a bummer. I'm guessing it will be a year or two before it goes anywhere.
[19:34:47] <cradek> before what goes where?
[19:35:10] <jm82792> I'm trying to watch power consumption since the atom d525's use about 40 watts, the P4's use about 300, and in the end running two smaller CNCs off 15 amps is difficult.
[19:35:50] <jm82792> Before I can easily use LinuxCNC on an ARM based board withiout any effort or considerations, like I would on an x86 system.
[19:35:53] <cradek> do you run them both at the same time?
[19:36:32] <cradek> I have two (er uh, three) interfaces in my linuxcnc pc and I can plug my variety of hardware into it
[19:36:37] <jm82792> I've yet to buy the second one but I am planning on running both at the same time.
[19:36:38] <cradek> two parports and a mesa card
[19:37:02] <cradek> oh ok, then you do need another pc, I guess
[19:37:13] <jm82792> They are just little desktop setups but I want to dedicate one for one thing and oen for another.
[19:37:37] <cradek> you can run many 300 watt PCs on one 15A circuit
[19:37:55] <RyanS> . I'm thinking of this idea, inspired by those simple jigs to help cut straight lines and radii for plasma torches. Except for mig torch. Set the appropriate torch angle attach it to the joint you are trying to make. Slide the torch along the rails of the jig. Even a three axis CNC gantry
[19:38:09] <cradek> (did you measure 300? I'd be pretty surprised.)
[19:38:42] <jm82792> I currently run an 1000 watt router, 400 watt PSU for steppers, then probably 400 for the PC+ lighting for the workshop.
[19:39:16] <jm82792> I think it was about 200- 300 as it's a 8 or so year old computer. I had a D525 but I fried it somehow :/
[19:39:33] <cradek> yeah if that's on one circuit that sounds really tight
[19:39:53] <jm82792> I have a good 6K saved up but 2K for a smaller setup that's identical to what I have sounds best. Then if one goes out I have the other and I can stock up on parts withiout issues.
[19:39:56] <cradek> you may not be able to run two machines simultaneously without better power. the pc is a very small consideration.
[19:40:23] <jm82792> I know, it's just I'd like to have the great latency numbers, the small form factor, and so forth...
[19:40:51] <jm82792> I run the current CNC at 180 IPM at 1/8 stepping and the latency is holding it back some...
[19:41:09] <jm82792> Not to show off but hawaiiwoodart.com shows some of my work :)
[19:41:16] <cradek> 1/8 stepping means a lot of steps. perhaps you need a step generator like a 5i25
[19:42:03] <jm82792> I got about 12K (?) latency for the atom board, but get around 22K for the P4 since it locks up at anything lower.
[19:42:24] <cradek> those are both pretty good numbers
[19:42:30] <jm82792> It's just I've done things so half way for so long that I want that ideal no BS solution.
[19:42:39] <RyanS> ooo http://www.centroidcnc.com/cnc_welder.htm
[19:42:45] <cradek> those are neat. lots and lots of cutting time I bet.
[19:43:14] <jm82792> I get a solid 75 IPM of feedrate for 3d profiling as I get about 60 IPS^2 of acceleration.
[19:43:27] <jm82792> So like one hour for the large island.
[19:43:32] <cradek> the BBB is probably far from no-BS at this stage. you might want to read the forums and list archives.
[19:43:36] <jm82792> Of 3d profiling.
[19:43:54] <cradek> that's nice accel. very helpful.
[19:44:12] <jm82792> I'll do that cradek as I've half done this for so long, and it's been so painful for so long! I mean really I've been though the ringer of learning on this.
[19:44:29] <jm82792> For the past two years. Now I have bussiness but everything I use is ghetto.
[19:44:52] <cradek> making do with what you have is smart business, not ghetto
[19:45:47] <cradek> I have no need for bleeding edge stuff - it just means more work and more money
[19:45:52] <jm82792> It is, I mean I have money, and for being 21 I'm well off. But I know how fast it goes for CNC stuff. But in the end I envision two machines side by side in an enclosure with passive dust collection.
[19:46:14] <jm82792> I have limit switches I've never used, I just hooked up an SSR to turn the router on and off.
[19:46:35] <cradek> good dust collection is smart, especially for exotic woods. some like cocobolo are dangerous
[19:46:44] <jm82792> Crashing on such a small machine isn't a big deal. The only beef I have is I'm getting .0012" or so backlash.
[19:46:58] <jm82792> I've worked with Ipe which is just terrible.
[19:47:00] <cradek> can you even see .0012" in wood??
[19:47:18] <Tom_itx> depends on the wood i would suppose
[19:47:27] <Tom_itx> rather doubtful
[19:47:28] <jm82792> I highly doubt it lol! It's just you get less tool life and stuff.
[19:47:45] <jm82792> I did a lithophane that had 3 million lines oif code and saw some backlash....
[19:48:16] <jm82792> This is coming from one who knew nothing about anyt of this two years ago.
[19:48:49] <jm82792> I did try to hold .013" detail in Brazilian cherry by using a .0625" ballnose bit with 10% stepover withiout any luck...
[19:49:47] <jm82792> I burned through a #35 1/4" 4 flute bit from Precise Bits in only a few hours, I have a dial indicator coming since I think it's runout as I have a few hundred hours of harduse on the router.
[19:50:52] <cradek> for wood I bet you don't want 4 flutes
[19:50:55] <jm82792> In all the time I've been routing things out I've never had a bit last so shortly.
[19:51:01] <cradek> doesn't it get stuck in the flutes?
[19:51:13] <jm82792> Precise bits says it's the way to go..
[19:51:18] <cradek> huh!
[19:51:27] <Tom_itx> i wouldn't think so either
[19:52:03] <jm82792> I get REALLY nice finish with their tapered bits for 3d profiling but past that I don't know much.
[19:53:13] <jm82792> I read two flutes or one flute but that's what they mentioned. I use their collets for the Dewalt 611 I use and the tapered bits for 3d profiling.
[19:54:08] <jm82792> I am trying to rule out bad TIR or backlash for the reason I have had suddenly poor tool life...
[19:54:21] <jm82792> http://img836.imageshack.us/img836/3082/qbqn.jpg
[19:54:27] <jm82792> that's with a 1/8" ballnose bit.
[19:55:12] <Tom_itx> what's the stepover?
[19:55:19] <jm82792> 1/10
[19:55:34] <jm82792> .003" accuracy and like .002" for G64p
[19:55:56] <jm82792> If I'm lucky and the wood isn't too interlocked I use steel wool then that's it.
[19:56:52] <jm82792> http://imageshack.us/a/img571/97/ydbb.jpg http://imageshack.us/a/img843/8021/8wkj.jpg http://imageshack.us/a/img827/1489/xil9.jpg http://imageshack.us/a/img29/3197/0bbi.jpg http://imageshack.us/a/img94/7706/w3y0.jpg
[19:57:27] <jm82792> If you go to .008" stepover and a tighter G64 tolerence along with the third hardest wood in the world you get that :-)
[19:58:11] <jm82792> using a /125" bit
[19:59:46] <jm82792> Anyways if I've sounded a bit impetuous or so forth I apologize. It's been a long time using IRC and usually I can conduct myself better VIA forum posts.