skunkworks711: Then... DONT DO THAT!
I figured out my problem last night... Defective reader on the linear scale. I have taken reader from the Z and put it in the X. What would you do for the Z scale. Buy heidenhain or go with something else?
do i need some kind on interface board for drivers? opto isolation?
when iconnect seperate drivers to LPT
i don't think so
jimbo655: do either of the quadrature outputs change?
If not maybe its a bad reader light bulb, its apparently tricky
but some people have been successful replacing the bulbs
any encoder experts out there?
it's a trap!
(just ask your real question - I bet someone can answer it)
what is the purpose of reading not A and not B?
you don't gain any additional position info right?
if you don't need to reverse, you don't need both channels
you will *lose* position information
just task the machine to count a higher frequency
because you lose half your resolution
yes this can be an advantage, if you are reading the encoder with something slow
my encoders have 20,000 counts per rev
was the question about reading only one channel, or about using A and NOT A plus B and NOT B wires?
is that reasonable to try and count that on 3 axis machine through parport?
imagine a spindle encoder with a spindle that doesn't reverse. if you are reading it in software, you can turn the spindle twice as fast before reading fails, if you read only A
after all that, I misread the question
ok, the only reason you would need the /A or /B wires is if you use differential receivers
there's an unexpected not in there :)
differential signals are more immune to noise
you don't read them separately -- you hook them to a differential receiver
hmmm. there's another reason, and that is if you have true differential transmitters, which I think would require use of differential receivers
thats what I thought. if you count all four signals. losing one count is less severe
it's not four signals -- it's two
a and not a are a pair of wires, with one signal on it
they are each a special noise-immune kind of signal
think of not A as ground for A only
do you know what differential signaling is?
basically, instead of having ground (always at 0) and a signal line which is either 0 or 1, differential changes both wires
when the output is a zero, A is 0 and /A is 1 (probably 5V)
wikipedia is good
when the output is 1, A is 1 and /A is 0
the only thing that matters is the difference in signal
so if the wire picks up noise, the differencing cancels it
think of it like this: the signal comes in on two wires; to evaluate it, you subtract: A - /A = signal
special receivers do this for you
because it's (A + noise) - (/A + noise). notice the noise cancels.
you can ignore /A and only consider A, but you lose those advantages.
so you don't get any additional pos'n information, just a more reliable signal. by reading /A, /B
but only if you have a differential receiver?
and sometimes a faster top speed, since you don't have to do noise cancellation which necessarily slows down the reading.
all real encoder reading hardware will take differential inputs
labview UMI ?
flannel shirt ?
National Instruments off the shelf motion control hardware
* SWPadnos throws up
is good for science stuff but not real men stuff
heh. you would really blow chunks if you saw what my company paid for that stuff
I'm well aware of how expensive it is
which is part of the sickening feeling
I'm trying to move away from it. but the encoders we are using are 20,000 counts/rev. I don't think the parallel port can handle that at the feeds we want.
SWPadnos: morning sickness?
PCW: Yes but thaey are dirty ( IE spikes where there should be none and erratic (output is not consistant)
skunkworks711: I finally got around to putting the eagle scripts up again, but of course under git now. http://git.unpy.net/view?p=eagle.git;a=summary
Ok here is another question... How does one automate the sensing of tool length when you are changing tools?
jepler: Thanks - now I have to find the thread that I wanted to add it to ;)
there are two methods: use tool holders with repeatable lengths (and the tool table), or probe
Where does one come by a probe and how does this connect to the system?
jimbo655: you buy or make it; you can hook it to any compatible digital input you have. EMC doesn't care where the signal comes from - you hook it up in HAL like anything else.
So I am assuming it is just a limit switch or is it also an encoder or are there both types?
EMC's probing expects just a digital input, so it's more like a switch than an encoder.
it can be as simple as this, depending on your accuracy requirements: http://emergent.unpy.net/01216264526
(I touch off with the tool that requires very fine depth control; all subsequent tools have pretty loose depth requirements -- they just have to drill all the way through the circuit board I'm making)
(but as the blog entry mentions the short-term repeatability is pretty good)
contrary to what that photo shows, I probe at the base of the lever instead of the end
Check if you have continuity between your spindle and work holding. If your spindle has ceramic bearings it will be isolated. Then you can detect tool height using continuity
*should be isolated
you have to move VERY slowly to do that - any overshoot, and there always is some, is bad
(so I definitely wouldn't recommend that method)
the switch will continue to have some "give" after it closes..
[02:51:25] <MikeGG> http://www.theopticaledge.net/sites/default/files/MS-4-D.pdf
for your reading pleasure
jepler: you should try a long lever one and see what numbers you get
I would think with the optical and the switch It would take two passes for more accuracy. Fast to get close and a slow pass for for the final number.
molehill -> mountain?
That's a big ass 40 foot tall mole!
Cradek: looks simple enough. 1 mil ait bad either.
after year soaking and mutating in Round Up (tm), he bursts from the depths!
anyway I have some machines with really ghetto tool probes
they're just metal button switches on an arm
and they get better than tenth repeatability
with zero effort or retakes on measurement
i'm not sure this is the brain surgery that is being discussed, but I could have missed part of the convo
I agree - make the simplest setup and test it first
tazer proximity sensor?
i suggest a switch with a flat metal button, lap it or something
if you jog slow, all your tools will trigger it the same way
I have a 1" flat round carbide insert I intend to use ... someday
yeah but it's about the flat - I'd braze something to the back of it
it is simple and it works very well.
I like the "I'm not touching you" proximity sensor... When you get close, you get socked in the arm!
we sent parts out the other day to get passivated, stainless steel
platers sent back parts that had like, carbon suet on them
they're ruined, but they want me to machine them anyway so they can reject shiny parts
toastydeath: job security?
i guess, i've got tons of that - the list of things I need to do this week is long, and this is going to take at least two more days
jimbo655: tried cleaning the reader? or swapping 11uA to TTL converter channels, maybe one is bad...
there's a +.0005/-.0000 slot on the part, and this carbon-ish stuff has corroded large pits in the material - 1"-2" wide and .010"-.015" deep
i'm not sure on what planet a +.015 error on a +.0005 slot is acceptable
but we're going to find out, goddamnit!
Here is what my work room looks like someday it may grow up to be a real shop.... http://i559.photobucket.com/albums/ss35/jimbo-colleen/IMG_0088.jpg
well on the way
not much need for a lathe?
they say if you only have room for one, get a lathe - I don't think I agree
I think I use the mill more, and for a bigger variety of stuff.
I have have a small 9x20 lathe have to find a hole for it. During my time as a machinist 25 years ago I worked with mills mostly. Lathes are not my favorite.
Maybe I will put the lathe in the wood shop.
cradek: i agree, it's really hard to say "this is what everyone does"
i really like lathes, though
I definitely use both in most nontrivial projects
but a boring head on the mill is more useful than a terrible lathe milling attachment
a boring head is a proper tool
a milling slide on a lathe....
not so much.
Now, get yourself a horizontal boring mill
I must not need it
if I wanted to use up another chunk of floor space, I'd get a surface grinder first
i just like the boring mill asthetic
I tink it's funny that you have to choose your toys by the ability of floor space
funnier than by aesthetics?
All I have for floor space is a 20 X 20 area under the garage. I have limits of what I can pile on My structure. But I will make do.
limited space is a fact of life
cradek: No, that that funny I guess....
I have a lot more of it than some - a lot less than others
anybody know anything about the -g option on pyvcp?
I'd take a boring mill over a horizontal, i guess
and have that as my sole milling machine
Not my fault you guys dont have 8ft wall that can support 50,000 lbs
hey, don't forget the 14' garage door required.
The joys of living on a cliff
toastydeath: No need, just hinge the roof like a hatchback
I had to machine a part on an angle plate saturday - it was a pain. I'd hate to have to do that all the time - vertical is nice.
man can you imagine the hinge
i dunno, i work horizontal all the time
I like it better than vertical mills for most stuff
it's true I've never used one
it's got some quirks, for sure
cradek: When I said wall mount, I meant with the tool configuration rotated 90 degrees
I've been a packrat for so long that I can pack things in to 2" of the ceiling (thermal expansion), and 8" if there are sprinklers =)
And dont ask how I know 8" clearnace is required
a romantic date with a fire extinguisher?
Does anyone have a Bakers Square in theri area?
there is one in the bay area unless that closed down
They filed for BK in Calif
guess I don't go up to Newark often enough to notice it
Closest I've found is Chicago
micges1 is now known as micges_plasma
how hard is it to set up hal for a stg card, would it differ from machine to machine?
this machie is working under emc1, could info from its emc.ini help in setting up hal?
hnu: machine is working under emc1 and you want to set up emc2 configuration for it?
what is IDC connector?
[12:10:27] <kakeman> http://en.wikipedia.org/wiki/Insulation-displacement_connector
When you connect a differential encoder to a 5i20 the A-, B-, and Z- just go to the ground pins (even pins)?
BJT: if you are connecting directly to a 5I20 (which only has single ended inputs),
the A-,B- and Z- remain unconnected
(they are outputs so you dont want to short them to ground)
ok thanks Peter
If the outputs were truly differential (floating)
grounding the - outputs would make sense
but the plus and minus outputs are just the same signal
inverted but both referenced to ground
pcw, do you have cards for 4-20 ma analog in out?
pcw /me quoting for a job
No. not much analog I/O yet
hmm ok I just hate the NI and AB ptices
thanks pcw, that kinda makes sense to me :)
wow 50 BMG on sale for $3.99 each
skunkworks, SWPadnos, ever have any USB problems with your goal3+ board?
geo01005: why - what is it doing?
I'm wondering if I got a junk power supply, or if the motherboard is bad.
Any USB device I have plugged in turns on for a few seconds, flickers and then stays off.
I have only tried USB powered devices though.
I was going to try to find another power supply to try.
I wasn't very wise and just got a barebones kit, junk power supply and case.
yeah, I'll say.
I have used some pretty crappy power supplys with success - like <$10 :)
geo01005: what are you trying to hook in?
(I could test it here)
LawrenceG: How is it going?
skunkworks_, right now I would be happy if the stupid keyboard and mouse would work. Bet later I'm going to be using a USB touch screen.
wow - I am sure that is working correctly on my systems. :)
uhoh - now jmkasunich_ is having connectivity issues? It is spreading ;)
wasn't usb pretty critical on swp's systems too?
that was for the atom boards..
I really don't know what he was using the goal boards for.
I would have got an atom, but I needed two pci slots.
the goal has much better latency results than the atom
I don't really need the supper high latency, I'm running hm2 stepgen.
The atom is consistanly just under 20k while the goal is usually well under 10k
low latency rather...
yah - not as critical.
Has anybody had USB problems like this on any board?
Am I in my right mind to think it may be the power supply?
can't say that I have. you say the keyboard also just powers up then powers down?
yeah, powers on, works for a few second, then flickers and dies.
I have been stuck using ps2 keyboard and mouse for now.
stupid question - do you have both power connectors plugged into the motherboard (normal one and the 4 pin?)
yeah, both connectors connected.
hmm - internet just went out at home...
skunkworks_, good morning, going great here new servo design is doing well... built a test stand to torture it
nice! any pictures?
[15:47:09] <LawrenceG> http://imagebin.ca/view/tydai2Y.html
skunkworks_, those 135w scooter motors make quite a good servo motor...
not bad for $15
heh - that is awesome - love the 'jog' wheel (that is exactly how I hooked the mouse in to do these tests http://www.electronicsam.com/images/KandT/servostart/Fastermouse.png
what kind of reduction are you thinking for your machine?
yea.. easy encoder for testing
actually, the motor has enough torque for direct drive, but because of critical speeds, it doesnt make sense to spin the leadscrew much faster than 1000rpm.. so 3-1 will fit very nicely
of 1 to 3 motor to leadscrew
that encoder in the picture is 1000 lines/rev (4000counts/rev).. its kind of large, but I have a bunch that were the right price (dumpster special)
Nice industrial package
crap - I missed jeplers post to the list. Oh well - redundancy is good - redundancy is good
about the freezeup?
a and thread
> I can see why 99% of computers LINUX free.
that guy is just sooooo ....
I can't figure out what word to end that sentence with
I just cant look sometimes
he seems to have trouble with virtually everything he tries. if only we could figure out what the common element is.
* jepler bites his tongue
I shouldn't have said anything
but that remark tweaked me
me too me too
[18:34:21] <skunkworks_> http://skycraftsurplus.com/index.asp?PageAction=VIEWPROD&ProdID=1877
there where 20 this morning. - I ordered 12. The second I ordered them they switched to 'out of stock'(6 for my self and the rest for friends) so I don't know if I am getting them yet.
oh well - just waited too long. :)
have you called?
no - just waiting for a tracking number - guess I could call. Or email
cradek: how was the runout on the pullys you bored out?
I don't think we measured after the reaming
I have only done one - the hole ended up not quite parallel to the pulley teeth, but the runout looks very small (looks like wobble, not runout)
ah - cool
I ran a DTI up the pulley hole to the middle of the toothed region, and used that reading to center it
so the belt tension doesn't vary, even though the hole is imperfect
cradek: I think the common element is "trying"
I hope to do better next time, even though it was plenty good enough
I was trying to decide if I wanted to get 1/4 inch hole pullys and make an adaptor. (turning the outside and boring the hole all in one setup.
it seems like that would be trouble for the setscrew
I would run the setscrew through the adaptor.
so it was tightening on the flat of the servo shaft.
if I had a cnc lathe, I'd make thoose conical couplings
dont need cnc to make taper lock
ofcourse, but it helps :)
what behaviour is expected when I'm settings huge (1.0 mm) backlash? huge ferror?
I'm asking becouse I had 10 mm ferror..
increase acceleration headroom
backlash uses "more acceleration" to take up the backlash in a controlled fashion
that sounds like the backslash on my big mill
It's either an additional acceleration equal to the inifile acceleration, or 1/2 of inifile acceleration, I forget which
it started compensating it smoother when I turned up the acceleration
I see, thanks
before it got lagging behing and gain grew trying to take up backslash..
and it made the table jerk on reversal
(when running a handwheel)
are there any common computer screens with a wider ratio than 16:9? or is that the limit?
1.85:1 and 2.39:1 are somehow common
but not so much for PC screens
2.39:1 is for 35mm film ;)
there are some 17:9 displays
[19:21:00] <alex_joni> http://en.wikipedia.org/wiki/File:Vector_Video_Standards2.svg
I emailed the company and they think they can fill the order. :) they found a descrepency in their inventory and took it down for a bit until they can get them counted.
They think the have more
the power supply dosen't seem to be cause of my USB problem.
jmkasunich_ is now known as jmkasunich
I wouldn't call one dropout "connectivity issues"
especially since we've had thunderstorms here
regarding boring/reaming of timing belt pulleys (I read back):
I've done a couple different sizes. I stuck a scrap of fat aluminum rod in the lathe, bored about 3/8" deep to fit over the pulley, turned the OD just enough to get it concentric, then parted (or sawed) off the ring
OD has to be bigger than the pulley flanges
then split it, so you can put the two halves together over the flanges, and chuck (or collet) the outside of the ring
good night all
Eeeesh.... Bombed the garage last night. Even with the garage door open and three fans going (one of them can usually air out the house in 20 minutes) it took 3 hours to air out the garage!!!
And that's just *most* of it - enough to breath that is =)
I told you to stop eating beans
oh look. dinner
jmkasunich: Neat idea
has anyone looked at or started on a port of EMC to ARM ?
Wifey is on the move OUT... and I'm keeping the kids and house... attrition WORKS...
I thought I had heard rumors in the past
L84Supper_ is now known as L84Supper