theorb is now known as theorbtwo
anyone use an internet stick with Linux?
hello psha, you have a question?
hello micges_work, you have a question?
I like him ;)
hello jthornton, you have a question?
nope just wanted to see the_wench
* Jymmm lol @ jthornton
/me laffs at jymmm
jthornton: Per your request... http://tinyurl.com/TheWench
take two, they're - err - well just take two
three would be beter
actually, I'm still trying to figure out how to use two at once :)
SWPadnos: the method is for them to use each other, then you join in
I guess you need a spare, in case one gets sick
hmmm. well that could work
SWPadnos: it does
but thats a story for another #
* Valen has made a USB enabled flashing light today
got end mill? http://cgi.ebay.com.au/CoHSS-endmill-slot-dill-50mm-1-threaded-shank-Sutton-/320620249887?pt=LH_DefaultDomain_15&hash=item4aa674c31f#ht_500wt_1156
shell mill? http://www.electronicsam.com/images/KandT/conversion/Shellmill.JPG
Hey - if any of you mill PCB's, what cutting speed would you recommend for a 0.1, 0.2 and 0.3mm V-bit ?
speed of light in a vacuumm ^4
so.. F800? :P
(since that's my machine's limit)
what kind of cut (per "tooth") do you think a 0.1mm bit can handle?
I'd say not much
what do you mean .1 mm V bit? what part of it is .1 mm?
nobody uses 0.1mm dia bits
I'm picturing a V bit that comes to a sharp point. Given the right depth this can leave a .1 mm trough.
when I cut PCBs I cut about .006 in deep and get a trough about .008 in wide
that's with a 60 degree V tool
I use a feed of .001 inch per rev (not sure it makes sense to talk about 'teeth' at that size)
yeah, I assumed that a small V bit like that would be an engraving bit, with one "tooth"
mine actually do have two 'teeth' - they make dust as you cut - it's not just a displacement process
yeah, 60 degree V-bit is what I meant
SWPadnos: it is
no idea what their proper name is :/
finally trying to build a decent machine
trying to fit all parts together using wood first, then ill try to build a steel frame
I have a breakout board with a 78M05 regulator on it. It wants me to apply 9-24v to it and it has an output pin to pass the regulated 5v on to another board or whatever. I (currently) have a 5V supply only. Does anyone know if I feed 5v into the output pin (in order to bypass the regulator) if I will burn it up? Of course the manufacturer of board says never do this, but I am wondering...
...if the chip can handle it. I looked at the Fairchild data sheet but don't see anything useful there about this...
is your 5v regulated?
you could just desolder or snip off the 7805...
grommit: hi, how's your local summit? :)
true, but it would be nice to leave it, if it would survive....
I didn't end up presenting as other talks ran on. I should be able to do it at the next one (next month).
it'll probably be fine - and if not, they're a common part
good point. I can just replace it if it fries...
If your external 5V is a little higher (0 to 300 mV or so) than the 78M05s, output voltage there would be no problem
but if your external 5V is lower the 78M05 will try and power the external 5V supplies load
Oh I didn't see the you want to run it with no unregulated in (safest to put a 1N4001 diode across the 78M05 in this case, anode to 5V cathode to unregulated in)
PCW: Still here?
My 5v supply is regulated. I have it connected to the output of the 78M05 and it seems to be fine. The 78M05 is passing current back through itself, I measure 3.9V on the input pin and it is lighting the input LED (how convenient :-). Nothing has smoked yet.
I think its only a problem if theres a big input capacitor so the 5V charges the input capacitor through the 78M05 backwards and the peak current is too high
is it me, or does flash _really_ suck on 10.04 ?
really suck for me on 64bit
works fine for me
its less bad on this p4 box im on now
cradek: it's not that it isn't working, it's just using 50% more processor and feels a bit more sluggish than on doze
oh, I wouldn't know about that comparison
using 10.1.103.19 on both
* alex_joni has to read into power management as well
the battery I got is ok for about 4h on doze, only 2h on 10.04.1
Is that with RTAI over-riding the power management?
I did change the governor, and that helped a bit
# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
"Anyway, for recent enough Intel CPU, ondemand is the one recommended for power efficiency (over userspace, and even over "powersave") by the Intel's kernel developer Arjan van de Ven"
that is what my laptop defaulted to.
Almost perfect as a spindle encoder ring for a lathe or mlll. (Just add hall sensors)
[18:25:50] <andypugh> http://cgi.ebay.co.uk/Peugeot-BNIB-207-307-407-ABS-ESP-Speed-Sensor-Ring-/270676759555
I didn't know that they used magnetic ring for ABS (I did know they used them for crank position)
anyone know where "TP1" on a Gecko 340X is located? The instructions use this nomenclature for the motor calibration procedure but we can't find TP1 anywhere and none of the Gecko docs seems to show it....
how about: http://www.geckodrive.com/upload/G320TestPoints.pdf
That is the older one, the 320X doesn't look anything like it and we can't find anything that even looks similar....
call them and ask?
I obviously have no clue, but that would be my first choice.
yep, that is what we are doing. thanks.
* mikeggg hums purple rain
* Jymmm invites mikeggg to the 21st Century
party like it's 1999
Prince' limo was purple and wanted his cell antenna to be too. One guy told him it required special paint and that it would cost $700. he paid.
makes sense to me.
andypugh, brilliant idea for a spindle encoder
Aye, nice big hole through the middle.
I am not sure how much the sensors cost.
andypugh, I know Ford calls them "tone rings" for ABS use
a friend had one break on his Escape hybrid
The Ford ones I have seen are toothed wheels. The eBay one is a magnetic ring.
oh hmm. I never actually saw his when it was repaired - the vehicle was under warrantee still :)
I am amused by the name "tone ring", that's very Hammond Organ. http://en.wikipedia.org/wiki/Hammond_Organ
today's xkcd.com is amusing, if you are in to that sort of thing.
I am, and was
* JT-Shop takes a short break from bisecting the tractor
I missed another Wohlhaupter boring head on that eBay.
They seem to go for £200 (and are probably worth every penny)
I have a really neat idea for an electrically controlled boring head.
(They already exist, it is the mode of driving it that I consider clever)
Are you familiar with the automatic boring heads, where you hold a ring to advance them, without stopping the spindle?
I like the way some e-bay add are so misleading "Neise UFB-4 Wohlhaupter Style"
no, I've not seen one
is that for facing only that you do that?
Facing you tend to use an anti-rotation bar. They advance to the stop, then rapid-retract.
For boring you bacj them out, hold the ring for the right number of clicks, then run through the bore again
My idea is to make the ring the stator of a stepper. And also the wheel of a magnetic encoder.
(rotor of a stepper, I mean)
Software simply keeps the stepper and encoder in synch to produce no net ring rotation, but adds or subtracts a bit when you do want relative motion.
(And there goes any hope of patenting the idea now it is in the public domain)
I am semi-serious, I think it is the most patentable idea I have had
I was just laughing about the public domain part
what kind of application do you use that type of boring bar for?
Which type? The existing sort or the hypothetical CNC sort?
the CNC sort
or one off's?
which is mostly what I do but don't need that much precision for the most part for what I make
I use my conventional boring head a lot for bearing housings. And get really bored of stopping the spindle, rotating to where the adjuster is, and tweaking some more
* JT-Shop goes back to tractor disassembly
Some seriously big stuff being made here
[23:06:17] <andypugh> http://www.youtube.com/watch?v=sRXFkH3-iAk
anyone know how to control DC motors with tachometers?
is it common/easy?
It's certainly common
harder than steppers though I assume as it needs to send the tach pulses back to the computer?
Generally speaking the tach only goes to the drive, and the computer is uninvolved
ah, I see, so the computer sends pulses to the driver, like a stepper driver
From what I have heard here and on the mailing list you only bother with tachs (or simulate them in software) to keep velocity-feedback drives happy.
Otherwise you might as well run the drives torque-mode, ignore the tachs, and close the loop in EMC
are drivers expensive or easy to build?
There probably are step/dir drives which close their loop with a tach. You would hope to have both halves in that case
What do you actually have?
what do you mean
If you describe the hardware, we can probably advise how best to make it work.
Oooh! Neat! http://www.youtube.com/watch?v=tu2GFst6Ehs&NR=1
it is a DC motor with + and - leads, and an encoder/tach on top with 4 wires coming out
I don't know that any step/dir drive would use a tach, unless it's a drive that has the option of running in velocity or "smart" position mode
an encoder/tach with 4 wires is most likely just an encoder
i opened it up and it is a disk with slits in it
since an encoder needs power (2 wires) and A and B quadrature outputs
Do you have the matching drive? If not I would ignore the tach
that's an encoder
no i dont have a driver
a gecko drive will work
if you want step/dir
gecko is too expensive for me :P
Or a Pico, or Mesa
also too expensive ;)
if you look on the wiki, you should find some information on a simple H-bridge design
so it is more complicated than a stepper driver or what?
Parport PWM and power Mosfets then
it's not likely to work very well with a small motor, since the response speed of the motor will be pretty quick
Actually, it is elecronically easier than a stepper, and the rest is just sotfware
(ie, the motor bandwidth is high, so the control bandwidth needs to be higher, which requires a faster control loop, which the PC may not be able to handle
Aye, you might need to add a flywheel :-)
yeah, a stepper needs twice the power electronics since it has two coils
but it doesn't need the encoder, so it's often less expensive overall
the motors are Buhler A-3140-0864-1
and there is also "256/95" on the label
is that important
[23:23:52] <SWPadnos> http://mesanet.com/
7i30 plus 7i43 plus 7i47 would give you control for 4 motors with encoder inputs, plus another 24 I/O
the 7i30 is actually the power electronics for 4 motors
3A limit per motor though
You could possibly skip the 7i47, and wire encoders direct to the 7i43
the encoders go to the 7i30, the 7i47 is for isoaltion of other I/O
Ah, OK, I am fuzzy on part numbers
me too. I was looking at the site :)
seriously big machines holding the boring bars
If you skip the isolated IO we just spent $180 of your money.
But saved you months of messing about. And the parts to build your own p-port based system wouldn't be cheap
it's a steal :)
and it wouldn't work for more than 2 motors, due to the need for both input and output for each motor
i only have 2
we use to face the gun mount with a homemade facing bar from a piece of H beam and all thread with a star wheel at the end to move the cutter just a bit each pass about 8' across
Do you want a fun, educational project, or computer controlled motors in a hurry?
ok, you can run 2 motors with the parport, but you need additional hardware
is it possible for emc to control a machine with 2 DC motors and 1 stepper?
well maybe ill look into it
though you're pushing the input capacity of a parallel port with that, since there are only 17 I/Os, and they're in a specific input/output arrangement
I guarantee you can't build stuff good enough cheaper than Mesa will sell it to you for.
andypugh: cool video
you need 6 outputs for 3 motors (step/dir and 2x PWM/dir), you need 4 inputs for the two encoders
But you might well learn a lot about motion control building your own p-port system.
that can be done, but it doesn't leave much room for additional inputs (like limit switches) or outputs (like motor enable)
[23:31:25] <AR_> http://www.ni.com/devzone/advisors/motion/buehler.htm
only way I'd try and build something like that is if I didn't care if it worked and only wanted the education from building it
actually, you'll learn a lot about making a cheap H-bridge, and a little about motion control :)
have fun. bbl
well, Im building a cheap 3 axis cnc
I'll stick to Mesa
i bought some used assemblies on ebay and these motors came with it
i was just wondering if they may be useable for something
certainly can be :)
Servos are better than steppers
PCW_ is now known as PCW
Do you have any steppers, or are these the only motors you have now?
i have steppers
And are they already fitted to the actuators?
Motor already on actuators, and no steppers in the cupboard would be a no-brainer on all levels.
Do you have drivers for yiour steppers?
these motors came with gearheads on them for a timing belt, and one of the leadscrews had a gear on the end too and a belt
andypugh, i dont know
The DC motors are not stellar performers on the torque front (0.35Nm)
[23:37:40] <AR_> http://www.ni.com/devzone/advisors/motion/buehler.htm
i think these specs at the bottom match these motors
Aye, that is where I get the 0.35Nm from
What do you know about your steppers? (frame size, current?)
i run them with 27v
I would guess at about 1.5Nm from them
But that is at 0rpm, steppers fade away very fast with speed
However, I don't _think_ that the DC motors you have will outperform the steppers yiou have
But I am just some guy you have never met on the internet, do your own research
Do you have a stepper driver?
there is quite a bit of info on steppers on the EMC wiki site