[#emc] "This is the #emc channel - talk related to the Enhanced Machine Controller and general machining. Website: http://www.linuxcnc.org/,
wiki at http://wiki.linuxcnc.org/"
tarzan: these look like collets http://shop.kress-elektrik.ch/browse.php?sid=529001259099882&pos=c136
but i spose many 'hand drill's dont
yay! logs are back
so 1750/13= 134V
might want to keep an eye on these drives also... (usually go pretty cheap for a try)
[22:09:46] <skunkworks_> http://cgi.ebay.com/Advanced-Motion-Control-Servo-Amplifier-BE25A20H-AMC_W0QQitemZ120495808484QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item1c0e1c1fe4
BE is brushless
cheap... reminds me i just got 2 turkeys, and gotta make room in freezer right away. look for 'Deals' in midwest, (like a dollar store) 5$ per turkey, 10-12lbs yep, 5$!
just worried with ebay drives that finding the pinouts for the connectors is difficult and programming the PID-loop and I-limits etc is even more difficult
This drive take +/-10v
BE25A20 is 25a peak 200vmax 14.5a cont.
so where could I get a 1000ppr encoder for the spindle motor? cheap!
aha, but 1000ppr at what speed ( count frequency )?
thats like a kajillion, maybe more
the servo is rated for 3000rpm, and the spindle bearings for 4500 I think
yes, that should be ok for the m5i20
5i20 counts up to 2MHz I think
4000counts/rev * 3000 rpm = 200kHz
awallin i have a surplus heidenhain rod620 quadrature encoder, 1250ppr if its any use
mm, the square wave is only 50kHz, but there are two of them in quadrature, and 200 edges/s
pjm__: does it have A, B, and Index output? any pics?
it says zero pulse ref=1 on the case so i guess thats index
is it 1v p/p or the 11ua for AB and 5ua for Z ( many pre-2000 heids are micro amp)
all the outputs are driven by a 74hc04, its ttl as far as i can see, +5v vcc etc
its pretty much the same as http://stronic.fr/photos/DRJ0016.jpg
except without that multiway connector
rod 260 with ttl? rod270 is ttl http://www.auto-met.com/heidenhain/angularencoders/ROD200.htm
nm: rod 260 is ttl
i'm only guessing due to the o/p IC
plus everything on the case is 5v etc
label shows sqr wave
yeah with UA1/UA2
and a direction arrow
i have another heidenhain encoder, 18000 ppr
but saving that for a rainey day
sornau connectors, plan on soldering your favorite onto cable.
good point... awallin theres how fast you can read it and how fastthe encoder is rated to spin and how fast the encoder electronics can supply the signals ( each has a limit )
i think heidenhain bought out anilam anorad and bei, heidenhain is devouring all the other encoder companies, like geo. fischer ate up so many of the edm companies
Ever look at the Renishaw Resolute encoders? pretty amazing 27 bit absolute encoder capable of 36000 RPM
amazing price also?
They work a little like an optical mouse
Led flash takes snapshot of magic barcode, DSP processes image
(probably just linear image sensor)
Renishae encoders are not horribly expensive, and you can buy direct at http://www.rlsdirect.com/ProductSelection.aspx
PCW: I'm more amazed at the older absolute encoders
the ones that are mostly mecanical inside
one big disc for current rotation, then lots of gearing and smaller discs for rotation counts
(but they dont show the "RESOLUTE" models)
There is a design for a 13 bit absolute encoder with only one track, and the sensors cunningly placed round it.
Doh! stubid snow-leopard "upgrade" has changed the windwo selection behaviour
awallin: take alook at this chip, http://www.rls.si/default.asp?prod=am4096
Alex: Yes, Ive taken some of those mechanical encoders apart. tiny ball bearings and anti-backlash gears
andypugh: running an osx ?
PCW: right.. wonderfull work inside them
Reminds me of some of the old mechanical flight computers
fly by mechanical wire?
is it possible, to build an handjog for emc2 with usb?
check the wiki
joypad or smth
emc reads the wheel in real time to give responsive jogging. you can hook a wheel to a parport or any other realtime digital input you have, or you can use any supported hardware encoder counter
cradek ive just 1 parallel port
no pci ports
USB joypads are easy to set up, even I managed it.
[23:13:33] <andypugh> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Simple_Remote_Pendant
with hm2, is it possible to have PWM-generators in hardware with different PWM rates, say 25kHz for Z and X axes, but 100 kHz for spindle control
that is hm2-driver on m5i20 card I am thinking about
awallin: probably with a special firmware, but PCW will surely set me straight if wrong
I thought hm2 was all about modular firwmare on the fpga?
modular things enabled from an existing firmware
However I am thinking of making a USB jogwheel using one of these chips (which appear as HID devices, so should hook into EMC like the joypad does, but give you 16 digital bits of IO)
[23:16:51] <andypugh> http://www.delcomproducts.com/productdetails.asp?productnum=902770
awallin: take a 12 servo, 4 stepper firmware, then you can mix&match things
say you want 4 encoder counters, 3 pwm gens, 3 stepgens
how fast can emc read pulses from the serial port control lines like DCD or CTS?
alex_joni: ok, I was just thinking about driving the spindle in torque mode, so then I would know in real-time the commanded torque. But maybe I can just drive it in position-mode with step/dir and forget about monitoring spindle torque
no one in there right mind used the serial port
i dont realy want a joypad
s.th like an rotary encoder
archivist_emc: why? the DCD and CTS lines are basically GPIOs
get more parallel ports, or dedicated hardware
numen: Maybe that USB chip then, with a quadrature encoder and hardware quadrature to binary chip reporting wheel position back to EMC on some of the 16 io bits?
andypugh just 1 parallelport avaible
Yes, so use USB
That cypress USB chip I linked to earlier.
this one has no usb...
Or, at the risk of missing some quadrature counts, skip the interface chips and wire the USB IO into a soft quadrature counter in EMC
Eh? You said you had no PCI, but did have USB.
If you have no PCI, no USB, no parallel then you don't have many places to plug in a jogwheel
awallin: With current HM2 firmware, there is only one PWM reference counter so all PWM frequencies are the same
and the driver sets the resolution based on frequency, but if you really needed 25 KHz and 100 KHz and you dont mind
12 bit resolution on 25 KHz versus 10 bit on 100 KHz its possible to hack the driver and get 2 (binary multiple) rates
PCW: ok, I was thinking about a setup with one analog servo axis, your 7i33 is designed for 100kHz, and the other axes would be PWM-drive at 25kHz or so.
andypugh usb i have
Oh NP for 7I33, 7I33 is optimum with PDM and it has its own rate
the chip, you've shown has no usb
numen: which one?
[23:29:57] <numen> http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2508309689
not sure what the best control for a lathe spindle with C-axis capability is. for turning you want high RPMs but for C-axis very slow or standstill
I was wondering.. I want to design my own microcontroller for my 3-axis cnc machien .. what would be the best choice of driver chip to work just fine with EMC2 software ?
PCW: what is PDM?
Engineer: what would your microcontroller do?
Pulse Density Modulation
numen, you use more than one chip to build the interface
PCW: so I could run the 7i33 with 25kHz PWM from the 5i20 and the analog +-10V is still "clean"
controlling the three step motors
and reading a simple feed back
I meant this one: http://www.delcomproducts.com/productdetails.asp?productnum=902770
about the current positions of the motors
awallin: Yes optimum PDM rate ist set to 6 MHZ and PWM is independent of that
Which is digital IO to USB, and then use the quadrature to parallel to link up the rotary switch
Engineer, emc does the position control not external, you just need stepper drivers, step and direction
PCW: ok. do you have 5i20 and 7i34 and 7i33 in stock at the moment?
(optimum for 7I33 you can tradeoff ripple for linearity)
But, as I also mentioned, it isn't too bad if EMC misses pulses on a jog wheel, so you could just wire USB input direct into an EMC encoder counter.
hm I menat 7i37TA
any recomended MC diagram ?archivist
Mesa seem to use highly-trained carrier-snails to deliver to the UK
We are behind with 7I37TAs (maybe a week now) others in stock
(7I47 maigh be a 7I34 alternative if you want RS-422 with terminal blocks)
(better than untrained carrier snails)
I want isolation, differential encoder inputs, and the one analog output
see mid page for setting up stepper systems
Engineer: What do you mean by MC diagram?
7I33 will give you 4 diffen enc niputs and 4 analogs sort of overkill
thanks a lot friend
Engineer, we dont use microcontrollers really
PCW I will need 3 of the encoder inputs. Will not do anything with 3 remaining analog outputs
that was well typed I must say...
then what do u use ?
the pc does the work
and use a stepper driver bought or home made
you connect the stepers directly to the parellel port ? or what ?
very nearly, usually via an opto isolater
You _can_ run steppers directly from the parallel port, but it is silly.
well >> I'm still fresh to the whole CNC stuff
it won't work
Maybe you could try the 7I47-S (new) Its got the 4 encoder inputs plus 1 analog out (unipolar 5-15V you supply reference = isolated pot replacement)
they drain a large amount of current
steppers are silly. use servos, AC ones if you can afford them.
It has been done with very, very, small steppers. I did say it was silly.
PCW: hm, the servo-drive wants +-10V torque command
Engineer, in all cases there is an interface to increase the current
* awallin sleeps
Oh well, no 7I47-S
that's for sure
awallin let me know if u are interested in this encoder, we can do a deal!
archi .. what do you think about this stepper motor : https://secure1.make-a-store.com/cgi-bin/alltronics/Make-a-Store.cgi?category=154&item=28M009&=&quantity=3&<ELEMENT>.qty.x=104&<ELEMENT>.qty.y=15&<ELEMENT>.qty=1
pjm__: where are you (shipping??)
its very light, i can send it to you if u want to muck about with it to test etc
pjm__, did you get the milling head?
ahh finland, i'm up in denmark next week which is closer so could post it then
archivist neggy, it got a bit silly!
could you send me a pic: anders.e.e.wallin at gmail.com
Engineer: Well, it's cheap enough, but a bit tiny.
What size machine are you using?
awallin sure i'll do it tommorow
Engineer, a bit small for real work, a bipolar motor has more power
and what would you recomend Archi .. I need a powerful one
Are you in the US?
I dont know your machine, measure the torque needed
well I had the design in 3d-max form
These Nema 34 steppers look like a serious bargain to me, and he has lots of them.
[23:48:22] <andypugh> http://cgi.ebay.com/G58046-Parker-VS31B-DFFLY-Motor_W0QQitemZ290371630288
pjm__, I was bidding a spectrum analyser near you but that got silly too
I designed it myself
ah right, typical, thats the way of ebay i spose!
although there seems to be a good run of decant priced microstepper drives lately
i bought a couple as 'stock' for my machine
it's quite large so I need a powerful motors .. 3-4 volts and about 4 amp current
If you are in the US, snap up some of those I just linked to.
Engineer, we use much higher voltages to get the steppers to move faster
40 volts ish
is there a website that I can buy the stepper system with their micro-controller from ?
Lots of them. Which country are you in?
geckodrive is popular
[23:52:51] <archivist_emc> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?EMC2_Supported_Hardware
actually I have three geckodrives and NEMA34 motors for sale
what's the current being used with 40 volts ?
You set the drive to the motor rated current
[23:53:19] <awallin> http://picasaweb.google.fi/anders.e.e.wallin/3AxisStepperDriveMotorsForSale#
the drive limits the current
thanks guys .. you're really very helpful
But the voltage is used to overcome the motor inductance, for faster pole-switching and higher speed
I might be the first one in Iraq to design and build a home made CNC mechien LOL
Fastest way to get up and running would be http://www.geckodrive.com/product.aspx?c=3&i=14469
see what others have done http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?EMC2_Supported_Hardware
Though there are much cheaper 4-axis drives out there on eBay.
[23:56:56] <andypugh> http://cgi.ebay.co.uk/New-4-Axis-CNC-Stepper-Motor-TB6560-Driver-Board_W0QQitemZ130345894797
it's hard for me to buy from ebay .. shipping costs too much!
That one I just posted is free shipping...
well this is funny: http://www.freesteel.co.uk/wpblog/2009/11/detecting-shallow-areas-on-bad-triangulations/
(direct from China, so you are closer)
free only inside the US i think
oh really ? from china
yea much closer
Ah, actually, not free to Iraq. But probably worth asking how much extra it is.
I would say about 200$ extra fees