[#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/"
some of this http://www.bussert.com/forsale/index.html
arch, just name it... if you are close, you can come over and inspect it
Im in the uk
shame. ups ships.
cradek, any hints on where to look for a rc filter diagram? does it matter if my i/o board is outputting buffered
heh, unknown device :)
hey, there was a LOT of stuff there!
Jessica501: I think that's a rheometer
Bausch & Lomb Spectronic 20 Spectrophotometer hmm, dribble
rheometer? what is that?
used to determine viscosity of fluids
viscosity/other flowing characteristics
i have no idea what this guy was doing with all of this stuff....
wee I already have two items
collecting "stuff" is a valid hobby
satorious blance, and edwards vaccume
need some more -stuff-?
LOL, someone has seen my place LOLOLOL!
I, erm, know about collecting stuff
hey folks, when coupling a shaft to a drive screw, what are your suggestions/ideas/best practices?
a flexible coupling, of some sort
there are many
the cheapest is a hose
do you have a mcmaster PN for connecting 1/4" to 1/4"?
but I'd chose a flexible coupling
hose has caused me no end of problems
Jessica501: I can understand why :)
I made mine for some axis
[16:43:20] <alex_joni> http://www.usdigital.com/products/fc/
I'm using 1/4" fuel line here :).
With the little screw down clamps.
Also, did go with 1/4-20...
Save the old 10-24 for something else (my, ahem, junk collection :-).
$20 each for the flex couplings? ouch!
junk, nevar, it might be useful
Jessica501: 14.20$ at mcmaster
for the cheapest one, probably too small
too small in what dimention?
9845T102 should be 1/4", 3/4"OD
3/4 od sounds about right for my project
around page 1146
do you all hit the set screws with locktite?
(they have a horrible webpage.. can't get you a working link)
depends on the size.. for ones like these I only use a T shaped tool to tighten it hard
on larger ones you have more than one screw to fix it.. so again no loctite needed
i have a flying gantry design and my main axis has two slaved nema-23's. when I drive that axis front and back a couple of times, it's obvious that I'm getting a few lost steps. I think I might be getting slip in my current rigid couplings.
plus, i hear the steppers hicough now and again.
yuck, that sounds bad.. might have too much accel/vel ?
i'll play with it.
Grr, between google and link rot I'm having a hell of a time finding a NEMA 23 mounting template :-(.
Here's some 1/4" couplers. I've ordered belts + molex plugs from these guys a few times and they are fast shipping
[16:56:27] <SkinnYPupp> http://cgi.ebay.com/CNC-stepper-motor-DRIVE-COUPLING-1-4-bores_W0QQitemZ330217136401QQihZ014QQcategoryZ71394QQtcZphotoQQcmdZViewItem
hmmm. I'm looking for flex this time
K`zan: Mounting template?
K`zan: draw one up
K`zan: if you go to www.galilcmc.com and go to their products page and onto the motor datasheet there's a detailed drawing
anonimasu: Thanks, google becomes more useless by the damn day </frustration>
:-(, link rot - goes to: http://earthlink-help.com/main?AddInType=Bdns&Version=1.3.1el&FailureMode=1&ParticipantID=xj6e3468k634hy3945zg3zkhfn7zfgf6&ClientLocation=us&FailedURI=http%3A%2F%2Fwww.galilcmc.com%2F
Thanks though, I guess I'll just have to wait until the steppers get here and measure the damn things, sigh.
K`zan: not really
sorry it's www.galilmc.com
[17:02:34] <anonimasu_> http://www.galilmc.com/catalog/blm_n23.pdf
Ah, thanks much! You do much better than google :)
[17:04:33] <anonimasu_> http://www.google.se/search?hl=sv&q=nema+23+drawing&btnG=Google-s%C3%B6kning&meta=
Jessica501: if you hear the steppers hickup, it's probably your step pulse train that's bad
if you're using emc, are you getting realtime errors?
GOT 99 PROBLEMS BUT RT AIN'T ONE
one is your broken capslock
those microkeratomes are like mini shapers
I'd sure like the binocular microscope and flexy mount from image 2185
and maybe a vacuum pump for my pumpless vacuum table
poor vacuum pump :(
oops! wrong chat window!
* skunkworks_ makes that mistake all the time.. ;)
cradek, I use binocular microscopes on the lathe, exceedingly useful!
zoom ones are nicer
What are you doing that needs a microscope on a lathe, sounds interesting at least!
Heh, with my lathe it would be a waste of time, I think (8x12 minilathe).
cradek and I do clocks and watches, so we work on small stuff
hand turning a balance staff becomes reasonably easy, except for sizing
K`zan: you have the 8x12?
archivist: yeah that's where I'd want to put it
I like it except for refocusing to read top and crossslide dials
I also have one dedicated to cutter centering for small pinions
archivist: Your eyes must be worse than mine :-(, I just use a magnifier :)
my problem is I can't see in a microscope with glasses, and can't see outside it without
cradek: You just need one with adjustable focus on the eyepieces :0 (not cheap).
* K`zan uses bats for seeing eye dogs :)
some of those she has have the correct light as well
I just use a power supply and a halogen light
Yes, got to have good light, got 2KW in the shop (a spare bedroom).
cummins has a 8x12 now?!
Had it for a couple years now
K`zan: how annoying is it to not have a variable speed control?
But I have that one everything, so there is one place life is easy :)
pretty annoying to exceedinly
K`zan: think that is the primary drawback of the 8x12's...
Mine has variable speed...
the ability to change speed mid cut to get a better finish is well worth it
But from the old guys I have talked to, without it you learn more to compensate.
that link you pasted is the 7x12
Oops, sorry, typo :-( <blush>
I know cummins has the 7x12 for long time
Sorry about that.
Looking at making up brackets for the NEMA23s I am getting and wasn't paying enough attention to either :-/.
With everything being built around the steppers, I suppose I should try this patience thing :)
Read the EMC manual, that is going to take a while.
the 8x12 on paper looks like a much nicer lathe
I'm sure they are. Mine seems a bit flimsy to me.
Only other thing I worked with was a 14x60 IIRC.
from the pictures, it looks like that is the lathe I had... I got it when they came by with a Truck
Best price overall and as near as I can tell they all come from the same place with different labels. This one at least came with some accessories.
Has been handy.
not having to wait for it to ship was a really nice plus
Yep and no attitude from UPS either :).
are you using the included 4way tool post?
Allthough if I am careful, it is reasonably easy to move, something that surprised the hell out of me.
No, got a QCTP for it from LMS.
I been able to do 0.060 deep cuts on that thing in steel
nice blue chips and all
Not bad then
[19:47:51] <K`zan> http://wrlabs.shacknet.nu/~vw/MyMachineShop/projects/QCTP-Hack1/index.html
the only remaining problem on there is getting the tail stock to line up and travel straight
I am doing something wrong I think :-(. Either that or the cross slide is still not properly adjusted.
K`zan: did you check to see if your compound and headstock are aligned right?
ds2: Yah, that is a frigging nightmare from hell to do, tried it and I am still not sure it is right on.
ds2: Err, I assume so (heh).
K`zan: Mine wasn't :(
TO be honest I am not sure what you mean.
from the factory, if I faced stuff on there, it would rock
let me put it another way - chuck a 2-3 inch peice, face it, take it out
put it on a surface table or some other known flat surface
Ah, must be close, anything I have done with that doesn't seem to do so.
does it rock?
mine did, had to shim the headstock
Biggest U have done was about an inch, so I probably need to get something bigger.
I worked in a CNC shop, but all they would let me do is draw up the parts and punch out the tapes for the Moogs, never would let me get loose in the shop :-(.
heh.... work in a smaller shop where everyone wears 12398432014823849020923842314 hats
LOL, the place I learned most was a friend who ran a little mom-n-pop and I nagged him until he put me to work :).
Got quite a wall of hats myself. Best kind of shop I think.
Hard to sit here with all these parts waiting for the steppers :-/.
k'zan \Have you turned a length of stock and checked the diameter at each end ?
thats a test you never want to do on a clockmakers lathe SkinnYPupp
top slide is the only method
carriage is bolt down
its a pain in the A
very fast for job changing poor accuracy
yea, chatzilla works for irc
Oh thought it was a 8x12 lathe
SkinnYPupp: Yes, I have, very slight taper.
Much better after working at centering the tailstock, but still off some. Just turn the small end to what you want and then turn it over :).
Let it meet in the middle ha ?
Stuff I have been doing is generall not all that long.
Well, yes :)
My HOURS of tapping and tightening the tailstock resulted in very little gain.
If you've put hours into it you know what ya have then..
Yes, here are some pix I took during that cluster, err, ah, experience: http://wrlabs.shacknet.nu/~vw/tmp/TailstockCentering-1/
Frustrating job, I need to make up something to help, the way that is set up is AWFUL for adjusting.
no camlock mod?
Did the LMS one, not greatly impressed but it works.
Pretty easy to slide the tailstock.
Tighten it up any more and you can't move it manually (larger hammer time).
I made my own version with a single 5" bolt
Just go easy and things are ok.
glad it isn't just my design... I think the bed is not of uniform thickness
Sure is fun trying to get real accurate itsn't it :).
Sheez, no wonder I am starving, bbiab.
I looked at those little lathes at HF. They look surprisingly decent
the basic machine/castings anyway
this should be quite nice with emc: http://www.artlebedev.com/everything/optimus-tactus/
is the tailstock ram not parallel to the spindle, or are you just trying to center it?
The one I saw at h/f must have been a disaster, you could file your fingernails on the ways
yeah the one I saw was not like that at all.
I would have bought it for a project if it weren't like that. I'll check again next time I'm by there been a year or more
I thought it would make a neat little cnc (with new leadscrews and bearings)
wonder how the spindles are though
I see this one has a threading dial, but I don't recall any provision for threading on the one I saw
Little red one ? That cummins looks nicer
to maximize startup torque, i wanna set my accel really slow, right?
what problem are you working to solve?
hiya chris. when my x starts, i'm looking at the end of the stepper shaft, and i see a little jitter go back-n-forth. i dont know the cause. too much drag on something? a software issue? a port issue? so I was trying to max my torque to see if that fixed it.
what do you mean by jitter?
gotta admit, i'm driving my mill with a laptop, so a port issue wouldn't surprise me.
yeah bad quality pulse train can be a real problem with steppers
have you run a latency-test yet?
but if your laptop is bad for realtime, emc will tell you
jitter means that i drew a little dot on the end of the stepper shaft, and as i start up i see a point where the shaft goes a few degrees clockwise, then jitters back a couple of degrees, and the continues forward.
that's a lost step
no latency test so far
what kind of drivers are you using?
alex, yeah a lost step... but due to what? drag? port? software? something else?
what is stepperd?
[20:38:14] <cradek> http://www.probotix.com/stepper_motor_drivers/ProboStep/
something else can be resonance if not accelerating fast enough
yes sometimes very slow acceleration is worse, but if that's the case you probably need to fix the hardware somehow
if you have this microstepping drive you could try the different settings.
what microstepping are you using?
i'm full-stepping to max out torque
don't do that
full stepping doesn't ever work
use half step
Full stepping has issues with resonance
so, my logic was all wrong.
that's why I asked what problem you were working on, instead of answering your question with yes or no :-)
i'm using the probostep driver, btw
read principia steppermotorica
try 1/2 or maybe even 1/4. 8 and 16 are probably no use
ok. any ideas on accel and max speed?
set accel slow. increase vel until you get stalls. reduce vel a bit. increase accel until you get stalls. reduce accel a bit.
you should try step_confg... It has a test program to test axis performance.. (I have not used it yet) where you can set accelleration and speed and see how it performs. *IIRC
yeah, stepconf is very nice
I used stepconf
i'll give it a go and be back in a bit
the documentation suggests a procedure which is pretty similar to what cradek said .. http://linuxcnc.org/docs/html/config_stepconf.html#sec:Finding-Velocity-and
if you change your microsteppin - your going to have to change your scale for that axis fyi
this is the best intro to stepper motor theory i know of: http://finance.groups.yahoo.com/group/geckodrive/files/Gecko
I have had resonance issues with half stepping.. (well - they where some home made drives - so that could have been the issue.)
ok, so before I rtfm, tell me this: I thought torque was inverse of speed. so why does a reall slow accel cause probs?
resonance in the mechanical system
in general you are right though. there is a speed above which torque drops off (fast).
half or microstepping will help you avoid these resonances and you'll end up with pretty constant torque over the useful speed range
so is fixing a resonance issue just trial and error at different settings?
not just settings. sometimes people add mass or dampers to the leadscrews etc.
but for you, the step mode will be the simplest change and also have the biggest effect.
some fancy drives have electronic damping
well, i guess i need to play a bit
what ICs are on that little probotix driver board?
btw, chris, when I bought that estate sale, I got thousands of tiny little bits that are either for drilling pcbs, or routing them. dunno for sure.
well, maybe a thousand
more that a hundred anyway
how much does an estate cost?
the ICs are new. probotix had a prob with the code and they sent me new chips
sounds very useful
interesting - what are the chip markings?
haha, this is sure a nice idea: http://www.geekologie.com/2008/04/exhaust_jack_takes_the_work_ou.php
i dropped $1500 on two buildings of tech stuff.
photos of some of the stuff are here: www.bussert.com/forsale/index.html
they should run LCARS on that new optimus keyboard
cant read the markings at the mo. bad eyes!
use the electron microscope :)
hmm, if these aren't trusted drivers yet, you may be seeing driver bugs
I assume the control chip is a microcontroller with probotix's barely-tested code in it...
(oh did I say that aloud?)
cradek: which lathe did you think was good for a CNC mod?
a little cheap HF thing
errr... so, perhaps probotix isn't well liked or respected in here?
I think so
or the really tiny C0 clone?
Jessica501: no! just unknown, and it sounds like you are their beta tester
I didn't mean to imply that they are bad. I don't know anything but what you've told me.
ok. actually, I've found Len, the owner, to be quite nice and helpful so far
btw, qtr stepping -sounds- nicer so far. no big tests yet.
Wow, steppers and the drive just arrived!!! Tooo Cool!
good night all
8.5 hrs of LEAN-6 Sigma brain washing... im baked..