success! finally managed to wedge that new mill into the garage, using only a cheap shop crane
i'll be digging metal splinters out of my hands for days
* archivist hopes for the cnc conversion by monday
it does look like it will be pretty "easy" to convert
for x and y
not sure about the Z yet
i had to take the knee off to crane it in, and it wasn't immediately apparent how the best way to fit a screw in there is
i think step one will be getting it leveled on the garage floor, which is apparently not level at all
moving heavy lumps can be fun
it has a slight rock to it when you lean up against it
i guess you can use some of those vibration mounts to level it??
some cast cement under the base, some use adjustable screw, some both, some use packing
[00:50:01] <dareposte> http://www.use-enco.com/CGI/INSRIT?PMAKA=325-6615&PMPXNO=5832301&PARTPG=INLMK32
i was thinking of getting four of those and putting one through each hole
that would help with transmitted noise through to the house and next door
that would be a good thing too I guess
mostly I just want it leveled though
and I guess a phase converter too
I would get a vfd that has 0-10v in spead control and phase for the spindle motor
yeah that's what I was thinking
i have a 2hp one, but it is a 208v 3 hp motor
motors can be reconfigured star to delta
yeah but what would that accomplish
changes the voltage rating as well
still be 3 phase, 3hp right
see label if its designed for both
I will probably just put one of these on it: http://www.driveswarehouse.com/Drives/AC+Drives/Phase+Converter+VFD/X200-022NFU1.html
it has a nice 0-10v interface on it
the only down side is it requires 240v, but oh well
for a 3hp motor i'd rather be able to plug it into a 20A 120v outlet and let it run off that
dareposte: What kind of mill did you get?
an "exacto" brand bridgeport copy
I think I determined it is a series 1 copy, with a J head
the place I went to pick it up is like machine tool heaven
did you go to HGR?
no, I went to Mohawk Machinery in cincinnati
similar to HGR
they had bridgeport clones stacked up about 5 rows deep by 4 columns wide
like soldiers in formation
several different warehouses for manual / stamping / edm / cnc / etdc
i would have gotten a small flywheel press too if I had any way to get it home
I think it was a 40 ton press, and it totally would have fit in my garage
one of my friends is interested in making stampings for re-enactment armor, and wanted it for that
tiny little scale type things, maybe the size of a golf ball or slightly larger
know anything about emc? :]
haha, actually, no
I'm sure someone else does though
like that guy right there
(might not be me ;) )
that guy knows a lot about emc.
ah ok. you don't use emc then?
nope, but swpadnos does
you could ask the real question, and see what answers you get ...
well, I plan to, but I don't use it yeu
I just help write parts of it :)
I finally finished building my machine, hooked it up and got everything working!!
our work is done
the only thing is, when I test my axis, it only goes about 2~3 inches when it's supposed to go 5
how do you mean "test"?
using EMC or stepconf or something else?
using the stepconfig wizard
I'm not sure, but I think the stepconf test may allow something like blending
so as the axis moves toward one end of travel, the position command changes to the other end. so it never quite gets to the full excursion
but like I said, I'm not positive that's the way it works
you could try doing a move in EMC, and see if the distance is correct
if not, change the scale to make it correct
hm.. ok. I think I'll try some gcode and see how far it moves
also, when I test at 2 in/s, it always brings it back down to 1.5. any idea about that?
it just may not have enough accel to get up to speed
actually, your machine may not be able to run it as fast as you want
you mean the computer speed test result thing?
if the latency test numbers were too high, or you have very very high resolution stepping, the max speed the PC can go may not be as high as you want
I set that on whatever default value they had, would that be a bottleneck?
well, the first thing you need to do is get real numbers for your computer
but yes, that can be a bottleneck
what's the steo resolution?
ok, thanks I'll try that
1.8 degree per step
so 200 steps/turn
no, I mean how many steps per inch (or cm)
um.. 10 tpi x 200 steps. think that's 2000
ok, direct drive, no gearing?
wait.. 20 000
I'm actually not sure.. it's a gecko 251
do I have to set that in stepconf?
if you look at the bottom of the axis configuration page, it will show you the scale value it calculated for you
I recall the default being 2 or something
from the steps/rev, microstepping, TPI stuff you enter
default is 2, but I'm pretty sure the G251 is 10
oh. last question :] how do I use a series home switch configuration? the stepconf wizard seems to expect 3 home switches on 3 pins
toastydeath: I didn't realize you don't use emc!
hmmm. I don't know if there's a shared home option in stepconf
I know there's shared home and limit (per axis)
dareposte: YOU REALIZE NOW, I'M SURE
one thing you can do is add to the custom.hal file
toastydeath: so.. how did you wind up finding this place??
stepconf will generate a line like "net Xhome axis.0.home-sw-in"
it's the only cnc related irc i know of that isn't dead
that is what i was looking for, and stayed around (much to the chargin of some)
you can add lines to custom.hal that also connect that signal (Xhome) to the axis.1 and axis.2 home inputs
hah, well i think you have been pretty helpful
like "net Xhome axis.1.home-sw-in" (or however it's spelled - check the .hal file that stepconf generates for you)
would that work? how would it recognize which switch has been triggered?
I thought you said there's only one switch input??
well, 3 switches in series
they'd have to be in parallel
but there's no way for EMC to tell which switch closes, which means you have to home in sequence
and there's an option that says that home is shared between multiple axes (HOME_IS_SHARED or similar) - you'll have to put that in the ini
once you edit the ini, you'll lose the ability to use stepconf without it overwriting your changes
sounds like it'll be easier to wire it in parallel :]
well, it makes no difference if you only use one pin ;)
check the manual, I think homing is pretty well explained in there
sure - have fun with it :)
what machine do you have? I'm just starting out with a simple mdf build
I have a Bridgeport milling machine and a Hardinge lathe
which I have yet to retrofit :)
the lathe or the mill
collecting round tuits
no, I seem to be all out at the moment
I did finally finish my accounting work though, taxes are in the hands of the accountant now
(at least for the business - I get to do personal taxes next month)
I dont like taxes
no, me either
I wish I had some cool gear. Then I might be able to mill some metal. with my machine I think I'll be barely able to route mdf
especially because I get to do them twice
jack000, slow but sure will - uh - not break as many bits
he might have a 3kw servo on it, you never know :)
might burn them though :)
slow but sure...
I find that mdf flexes quite a bit. I can move it like 1/2 cm just with my hands
oh. thicker MDF might be better
until the humid season starts
hm.. yeah, still need to coat it with poly
i have been taking pictures of stuff at work in progress as a new hobby, but somehow i lost three or four pictures
so are you guys doing cnc professionally?
i occasionally attempt, but usually fail
hindsight i should have said "i'm sparticus!" instead, and seen if a bunch of people picked up on it
what are the chances of my doing some signage, etc to get back some of my capital? :D
depends on how serious you are about it
I'm pretty serious about eating..
DanielFalck: are you using emc commercially?
[02:53:46] <toastydeath> http://twitpic.com/img/2acqj-210075ca7f457af62bae6f32009c87fb.49c45732.jpg
dareposte: not at the moment- I have in the past though
pictures like that makes me want to start on a steel machine
grab metal start making
if only I had more money :]
that is a 15" chuck at 800 rpm
cheap metal at scrap yard
what spindle nose does that mount to toasty
like an A2-12 or something
the spindle is almost flush with the chuck.
I've never been to a scrap yard before.. are there quality steel to be had?
(i don't know)
some yards save good looking bits
I'm sure you could weld car doors together or something
make a bridge machine
could have bought a lathe from the local one for £25 this week
I've never actually done metalwork before either, so that's another problem :]
you'll break a few endmills, and pick it up
come to think of it, I've never actually done woodwork before this machine
some parts will come loose and put a hole in the wall
learning is part (or a lot) of the fun
but that's the fun isn't it ;]
thats just the MDF machine
depends on how heavy the part is when it goes flying
(and where you're standing)
co-worker had a 150 lb block thrown across the room
start with small pieces of balsa wood then
anyone have experience with use_index?
my machine homes back to where it came from
how about building a plexiglass "safety booth"
a plexi saftey booth is a great idea from a dust/chip/coolant containment perspective
regardless of safety
also wear plexiglass eye shields. mine caught a piece of 9/16" stainless hex recently
I got a full-face shield :]
jonpry, have you read the manual section(s) on homing setup?
not plexiglass - polycarbonate
whatever they are they don't breka
yeah, that's polycarbonate, good stuff
can you mill aluminum with a 24000 rmp woodrouter?
not likely, unless you have a 0.01" end mill
it will melt on you and weld to the end mill
and a very very very very low TIR (like 0)
and no backlash on any axis
plain carbide is good to a couple thousand SFM
and a very rigid machine
and some coolant
hm.. ok. how about a variable speed router at 8000 rpm?
which isn't good for mdf
wood routers are for routing wood
pure ally needs lube
no wood router is going to cut metal adequately
Tap Magic Aluminum
excellent cuts and it smells like cinnamon :)
what can I use besides a wood router? is a spindle the only way to go then?
or a can of wd-40
it's like asking if you could cut down a tree with a dremel tool - technically the answer is yes, but it's asking the wrong question
what do you need cut out of aluminum?
I get through dremels
jack000: milling machine, spindle speed between 80-3k rpm
is usually a good range for all purpose metal duty
you could always use your wood router to make a wood pattern, and cast it
backyard casting is a bit of an adventure]
from what I've seen of diy casting you need to mill it a bit aftwards anyways
anyway a slower spindle, if one can be had, will do you fine
you can cast, file flat, and hand fit parts
can I just get a cheap chinese spindle from ebay and cut wood/al/steel?
what will you mount it on?
aluminum machine with 8020 probably
you can't cut steel on that, and probably not aluminum either
mills are made of tons of cast iron for a reason
really? I figured an aluminum machine would be able to mill aluminum
you can take light cuts.
it's not going to be anything anyone would mistake as a brisk pace
.050" depth passes with like a 1/2" 2fl endmill
you can get a bench mill and cnc it
you can use speed and inertia and get away with a looser machine
starting with a bench mill is a much smarter approach
anyone ever tried grinding some granite? :D
my cousin does granite work, and he had this crazy idea of a cnc granite machine
countertop guys do that all the time - just takes lots of water
i've seen a video of a homemade granite cnc
what kind of endmill would that take? some kind of grinding rock lump I'd imagine
there is a website of pics of an epoxy granite machine
they'd retrofitted a hand grinder to a lathe
and added a C axis
i just made a batch of stainless inserts for some guy trying to build a granite cnc mill
i told him he was crazy but made them anyway
brittle stuff does not mill well =(
alright, I'm going to give it another try. thanks for the tips!
is anyone around?
a couple folks, yes
posted a question earlier about threading issues thought I might see if anyone here had any ideas
must've missed it
what was the question?
for some reason I get rapids in the middle of some threads
oh i had that problem
wow, that is unfortunate
wound up being noise on the encoder line
are you using single index pulse?
yes single index
try using shielded cable for your encoder
ground one end of the shield and leave the other end unshielded
threaded tons of M22x1.5 with no issues switched to M20x2.5 and every other was junk
or add a bigger current sinking resistor
well that wouldn't make sense then
I have shielded cable run in a steel conduit
Running Jon elson's boards, I belive they have a built in pull-up or pull-down resistor
well there goes my theory
does halscope show any problems?
I have not checked. What should I be looking for?
Guest869: I answered your message on the list. did you see it?
Guest869: also i wanted to ask: are you 100% sure you are using 2.2.6 and not 2.1.6? 2.1.6 had this behavior.
Guest869: look for a missing or extra index pulse whenever it screws up a thread, try to crank up halscope's sampling rate by using only a single channel on the spindle_index line
he is using ppmc which is a hardware encoder counter board. he will not have direct access to the index signal because it is too fast.
it's the job of the hardware (and driver) to handle the index pulse properly, and this behavior is a sign that it's not
you can observe the index-enable signal which should go low when the count resets
if you get an index-enable going low without the count reset, or a count reset without index-enable going low, you have a driver or hardware bug
i am running 2.2.6 upgraded a few months back when I was having a similar issue
have you done the troubleshooting with halscope I suggested in the email to the list?
cradek for some reason I have not yet gotten your email
I have not looked at this issue with halscope, honestly had no idea what to look for.
didn't Jon make a change to the FPGA code in the last couple of years?
to deal with index issues
[03:41:22] <cradek> http://article.gmane.org/gmane.linux.distributions.emc.user/13168
SWPadnos: yes I think so.
thanks! you were right. g251 does use 10. works great now
Guest869: have you talked to Jon E? He should be intimately familiar with this problem - he and I and others spent a LOT of time debugging it
Cradek: I have not yet contacted Jon E, will send him an email. thanks
I will give you $1 000 000 when I become rich from my cnc ventures muahahaha!
ok maybe 1 000 000 japanese yen..
in 60 years..
maybe stop now, you're starting to insult them
i am reading the emc.user list, some guy named kir wallace asked about a mori seiki SL4
i wonder if he knows that machine is like 40-50 hp and draws full current when the spindle lights up or stops
how do i reply to this guy
does emc usually work well with preexisting spindle and servo drives?
kirk seems pretty clueful
I think he has a big shop. maybe he has 3 phase and lots of it
i'd love an sl4, if he can power it i hope he gets it
and so big
[04:29:57] <jmkasunich> http://www.youtube.com/watch?v=ifWpe0rm350&feature=related
but for unknown servo and spindle drives, how does emc work with that
do you have to find the specs for them and write a driver or something?
raa butt rock
depends on the drive
many just need +/-10V input
well, that's what we call it
I just got back from the show
he's a local dude
I've seen them about 5 times over the last 25 or so years
he still puts on a good show
its funny being at a concert where grey haired people are standing on bar stools and dancing
[04:33:22] <fenn> http://homepages.nyu.edu/~crm281/butt.html
ok so maybe not
here's another good one: http://www.youtube.com/watch?v=Lfw3hkuFFYI&feature=related
is it more cost effective to build or buy large cnc machines? something like 8' x
depends on what you are going to do with it
signage, guitars.. maybe some aluminum robotic parts
oh, and how do you get sharp inside corners? tiny tiny bits?
depends on how really sharp they need to be
it can be very difficult
concur and a cheap hass mill would work for ya
I don't like hass myself though
you mean like a conversion? how much do ya reckon a used one will cost?
oh nvm they're cnc.
ya and they are fairly inexpensive
hass and inexpensive in the same sentence?
maybe by pro machine shop standards
not by hobbyist standards
commerical machines always give me stickershock
think it's possible to build a quality machine for under 10g?
no more than a new car
jack000: it is a very very wide world out there - for someone trying to put a machine in their garage on a hobby budget, building has a lot going for it
yup did it for under 1g
for a shop, buying makes sense
jack000: you have to define "quality machine" better
I just finished my first mdf machine. cost me about 1300 canadian
you said guitars and maybe aluminum
and just now MDF
8' x 4' y, rigid enough to cut aluminum
I'm pondering about my second machine :]
how much Z?
um.. 1' or so?
ok, large and flat
that is "router", not "mill" by most peoples standards
a "mill" with an 8' x 4' working envelope is gonna way many tons
because it can cut steel
think a router can cut aluminum?
the bigger it is, the less likely it will be able to cut metal
is there a softer metal that's better for machining? gold maybe :D
if you make the gantry twice as long, it gets four times more flexible
I see, so a smaller metal router might be able to cut al
to get it back where it was, you need to at least double the thickness, so you wind up with at least 4 times as much metal in the frame (and quite possibly 8 times as much) to make the machine twice as big
would a mill conversion be more cost effective? second hand mills shouldn't cost too much right
the difference is really between "cut" and "cut well"
8' x 4' is a freaking huge size for a mill
yup don't have anything that big at work .... that is large
I have never seen an 8' ballscrew
regarding cut vs cut well - the rigidity needed to run a 1/8" end mill 1/16" deep, and the rigidity needed to run a 1/2" end mill 1/4" deep, are two totally different things
I'll try to think about what I really need in a machine
jack check out mechmate.com - it relies too much on laser cut parts but the basic design is good
just for reference: http://www.hgrindustrialsurplus.com/sub/product_detail.aspx?id=30-689-003&searchtable=1&sortExpression=&SortASC=&pageSize=50¤tPageIndex=0&searchNAP=
that mill has a 2.5' x 4' table
and I bet it weighs 4 tons
there are different alloys of aluminum, and most of them machine like crap
make sure that you get one that isn't too gummy
avoid 5052 like the plague
it's quite possible to machine aluminum with a high quality wood router
6061 and 6063 are so-so, but cheap
mic-6 is very nice to machine, and not too expensive
2024 and 7075 machine well and can be very strong, but are expensive
mechmate looks interesting. do they just buy their own steel/components then?
you'll have trouble getting the speed low enough and/or feed high enough to take a decent thickness chip
fenn: when you say router, do you mean "motor and spindle assy", or do you mean "cnc machine with rails and such"
i mean motor and spindle
I agree that a router motor/spindle assy can cut aluminum
I think most variable speed wood routers go down to 8000 rpm
is that slow enough?
but many CNC routers aren't rigid enough
uh, cnc machine mounted on rails.. well, it depends
jack000: there is some simple math there....
you like to keep the chip thick enough that you are actually cutting, not rubbing
there's no particular reason why not, but a lot of people who build woodworking CNC machines don't understand the principles of vibration dampening and rigidity
say 0.0005 as a minimum (0.001 to 0.002 is better)
dampening? or is it damping?
at 8000 RPM with a two flute cutter, you are taking 16000 chips/,minute
with a 0.0005 chip, you need to move at 8 inches/min, with a 0.002 chip you need to move 32 inches/minute
a lot of "variable speed" controls just change the voltage, which means the motor will bog down and heat up when you give it something to chew on
(and snap off the bit in short order)
ok. thanks for the advice. I'm a bit new to metalworking.
at the very least make sure it's a current regulated variable speed, but even better would be velocity control
move too slow, and you will start rubbing instead of cutting, heat will build up, chips will start sticking to the tool, then the tool will break
jack000: make sure you understand the difference between "feed" and "surface speed"
heck, I'm new to woodworking. I build my first machine in my bathroom because I don't have a proper shop :D
what is the difference between feed and surface speed..
a lot of people chicken out/make excuses because they live in an apartment
i want to make kits that people can use regardless where they live and how much they desire to procrastinate
feed = the xyz velocity
surface speed = the velocity of the cutter's edge
I've never really liked kits. I think they kind of subvert the diy spirit
hmm i guess i'm not really thinking kits, more like products
anyway they would be partially disassembled when shipped
yeah, sometimes those things make practical sense, if you need to run a business and whatnot
it's a tool to make projects with, not a project in itself
i'd probably publish the plans for building your own from scratch as well, because of my unreasonably high expectations of morality and fairness
I just realized that when I was talking about speed and chips above, I completely glossed over surface speed
surface speed for carbide on aluminum is so ridiculously high it shouldn't be an issue with tiny router bits
oh it's ok, fenn filled me in :]
fenn: I want to show the math that defines "tiny"
let's say 1/4" dia as upper limit
for high speed steel cutters, 200 surface feet per minute (SFPM) is a good number
'8000rpm*(pi*inch/4)/rev' = 523.598 feet/min
200 sfpm * 12 = 2400 sipm, divided by 8000 RPM = 0.3 inches/rev, divided by pi (since the surface speed depends on the circumfirence of the tool) means 0.1"
carbide can go to several hundred SFPM, _but_ you must make sure the feed is right - at the higher speeds, avoiding rubbing is extremely critical
even a few seconds of feeding too slow could start melting chips onto the tool
actually, carbide can probably go over 1000 SFPM, with the right tool, coatings, coolant, etc
jack000: do you have an ordinary router (handheld)?
really old one I bought at a garage sale for $25
i think it would be fun to put a low res encoder on a wood router and do constant feed per rev with emc :)
get a 1/8" (preferred) or 1/4" end mill - two flute - and stick it in the router
set depth of cut quite shallow - 1/16" or less to start
I have a 1/4" 4 flute one
put on your safety glasses
get some 1/8" or thicker aluminum sheet
don't use a 4 flute endmill when slotting
do NOT use 4-flute for aluminum in a router
ok. I figured as much
it will clog instantly
and then break
anyway, clamp the aluminum sheet down, and clamp a straightedge to it
then route by hand, trying various feeds and depths of cut
that will do more than anything you can read (here or elsewhere) to give you a feel for speeds, feeds, and depth of cut
I already feel scared, but I'll try it :]
don't be afraid to jam the router into the work hard enough to get a good feed rate
can you use a light dimmer to slow down the router? I heard that was a bad idea but don't remember why..
also i'd like to recommend Boelube to keep the alumunum from sticking to the bit
or wd-40 if you like making messes
I use WD-40
I think I'll stick to mdf for now, I don't want to break my router on the first run :D
jack000: for this "manual router testing", you should use depth of cut as your main variable
you can't reduce router speed much beyond what the router is designed for
you can't reduce the feed rate much below 0.002 per tooth if you want to avoid heat
jack000: don't forget that it's possible to make your own milling spindle with speed reduction pulleys and big beefy bearings etc
but you can make very shallow cuts
i hear tapered roller bearings for trailers works well and is inexpensive ($10 ea or so)
fenn: true, but - the slower you go, the more rigidity you need
something like that
I heard you can get a cheap chinese spindle with vfd for like $500
at high speeds, the mass of the motor and other head parts tends to "filter out" the fluctuations in cutting force as the cutter enters and leaves the work
at low speed, the machine frame has to resist those fluctuations
can't you just use a flywheel?
or are you talking about lateral x/y/z movement/flex of the head
inertial confinement fission :P
oooh, big words
think about wood routing - you can control a router by hand
put that same cutter in an electric drill and run it at a few hundred RPM - it would be totally unusable
so how's the market for cottage-industry signage? I'd sure like to get some of my money back...
depends where you live
I have clue
in US you need to be a certified master electrician in order to get a permit for a sign installation
usually, people figure out the market, then make a machine to suit the product they are gonna make
starting with a machine and looking for a market seems backwards
fenn: I assume that is for an electric sign?
(becoming a master electrician takes 20 years or so)
yes, but in practice almost all signs are electrical
I'm an engineering student, needed to make robotic parts and stuff for school projects
but money's tight!
jack000: find something you would have spent money on but you can make instead, then sell them
[06:01:53] <jmkasunich> http://images.google.com/images?gbv=2&hl=en&safe=off&q=engraved+sign&btnG=Search+Images
most of those are not electric
most of those don't require a 4x8 router either
novelty plates? could say I hand made them, which is sort of true :D
btw, some of those hits are sign making businesses - their pricing may give you a clue about what is competitive
and now I really am going to bed
here's something that could fall under specialty signage with no electricity
[06:04:51] <skinnypup> http://images.google.com/imgres?imgurl=http://www.libertymirrors.com/Quickstart/ImageLib/sh_palm_2_200.jpg&imgrefurl=http://www.libertymirrors.com/page17.html&usg=__fswvZoez1ngJEGdORE0GPFnlcOI=&h=514&w=1097&sz=207&hl=en&start=3&um=1&tbnid=TW021IdId2uKmM:&tbnh=70&tbnw=150&prev=/images%3Fq%3Dsandblasted%2Bmirror%2Bsign%26hl%3Den%26sa%3DN%26um%3D1
re: speeds and feeds, with the right carbide tools, you are essentially unlimited in rpm
is that sand blasted glass?
yeah sandblasted , looks nice on mirror signs too
muahahaha, with my newly acquired cnc skills my plans for world domination is complete!
I'm just excited because I finally finished my router tonight.. took me like 6 months
man that stuff is cheesy
is it running... cause if it ain't your not maken money... that is the trick.... lights out machining
clip-art != art
haven't actually routed anything yet, still need to read the emc docs and learn the software
xyz moves though! yay
what type of non-mdf wood is best for signage? ie. won't splinter under a router bit
i don't want to be a total poopyhead
preparing to be pooped...
but what's your competative advantage versus a shop that's been open for 10 years, has several 50k+ routers, and the very expensive software and EXPERIENCE to program them quickly, with complicated graphics?
my time is virtually worthless :[
so, lower prices..
and your signs will reflect that.
at least in machining job shops, people try to do home businesses by undercutting the big guys all the time.
yeah, you get what you pay for I suppose :D
they always fail, because undercutting is not a business strategy.
it's an effect of your business strategy.
but you can always try, i suppose
the way I figure it, I'd get maybe one job a week, and that's ok because I mostly built it for myself
is it portable?
I built a modular controller so I can just unplug it
how about starting by going to flea markets and little craft shows
and offer to make signs for the middle aged ladies who sell things they make from craft shows?
cool, I might try that :]
it's a safer bet than taking on work from a business
the main motive was because my school didn't have a cnc machine, which I thought was incredible given the amount of tuition they charge..
my school has a cnc, and nobody uses it
because it's not as easy as it looks to actually get things made
is it an engineering school?
it's an engineering program in a small school
the shop takes up most of the engineering wing, if that matters
yeah, me too. my school (SFU) does mostly computer science/electronics and not much mechanical
it's got like a drillpress and a lathe, and that's it
a semester isn't enough to teach someone how to run a cnc, much less become a programmer
I figure I can start a club around a cnc machine, so people with projects who need it can join and use it
we've got 9 lathes, 6 bridgeports, some drillpresses, shear, surface grinder, a vertical machining center, and a turning center
hm.. I thought it was pretty simple. just model the part, conver to tool path, then to gcode and run it
no, it is not that simple.
how are you holding the part, do you need to fixture?
I have a custom clamping system
cutting certain features before others will affect accuracy and rigidity
basically a grid of threaded inserts
process is important
that's why even though it "sounds" simple, most shops don't let anyone but a few senior machinists do programming
and at my shop the programmers don't get to program my machines cause they suck using surfcam
hm.. what subtleties are there? I thought the cam program would do most of the work..
the cam program does what you tell it to.
just like writing code by hand.
they are programmers not machinist and have no clue on anything except from the shop floor feed back
I'm a software programmer by trade :]
that is why quality help is important not just wheel spinners
jack000, you need to actually cut some metal, a lot of metal, before you are going to realize exactly how much you don't know about machining
time is your only teacher
i am only two years into machining, in general, and oftentimes the only thing i learn on any given day is that i don't know much
yeah, I guess I'll find out when I break a few bits :]
what size bit is good for routing 2d shapes? would a 1/8 bit dull faster than a 1/4?
probably in passes though
it depends on what, exactly, you're trying to cut out
a rectangle mostly
smallest feature, biggest feature, is this some crazy contour, is it mostly squares and circles
how big of a rectangle?
a pocket, a frame?
mdf or plexiglass
is this a pocket, or are you tracing the outer contour
how tall is it
1/4 thick, outer contour I guess
on your machine with how fast a minimum spindle speed?
24000 rpm fixed
i'd try the 1/4 bit, possibly a 3/8ths
and take it in two or three passes
one flute, by the way
if you can find it
i know they make one flute router bits somewhere
seems like 4 flutes are pretty useless then?
you don't have a big enough machine to use four flutes
shame.. I already have two 4 flutes..
it won't even work for mdf?
i calculate you have to run at a minimum, 96 inches a minute
four flute endmills are pretty much for steel
tracing outer profiles in steel, not full slotting
i have not yet heard of someone running EMC at over 50 inches a minute in a cut.
guess I'll have to get some spiral bits tomorrow then..
for a contour, anyway
straight facing sure
MDF will dull any bit rapidly
it's full of silica
if you use a one flute bit, you're going to hopefully get some wiggle room on speed, but you'll still be moving 24 ipm
even wood spiral bits? what would be a better material then?
to do what?
you still havent told us what you want to make
you have a 24000 rpm fixed spindle, there are LOTS of better materials to make it out of
the most urgent thing is a remote controlled robot for my engineering class
UHMW or acetal are great materials for machining random crap
but between that spindle speed and the rigidity of the machine, they are not really avaolable
but your router will probably be too fast and melt them :\
yeah I heard acrylics gum up the bits
acrylic is especially bad
but with a wood machine
it's just a pain in the ass overall
fragile, cracks if you look at it wrong
yeah, aluminum or steel next time..
it's used because it's easy to thermoform, it's cheap, and optically clear
UHMW would be the best bet
yeah UHMW is pretty cheap
witha 1/8th bit you could get through it at ~1500 sfm
and it won't dull the cutter
toastydeath: ever machined polypropylene?
just use carbide, and keep the whole thing wet with wd40
not personally, no
we were able to zip along in uhmw at about that sfm without difficulty
jack if you are on a tight budget and want to do lots of fancy alumium shapes, check out lost foam casting
yeah I looked into it, I heard za-12 was better for casting?
"i have not yet heard of someone running EMC at over 50 inches a minute in a cut" iirc les watts was doing something like 125ipm (but maybe that's my faulty memory)
contouring wood thingamabobs
but yeah, i could route out the foam and cast the part. but molten metal is scary as hell!
there've been several people through here cutting at 120-150 ipm getting path deviations
[06:42:27] <fenn> http://lmwatts.com/cnc.html
that nobody has been able to help
yeah he was getting path deviations
because the servo cycle was too slow
ah, okay then
someone (pete_v?) got the servo cycle up to 10kHz with some tricks but i dont remember if it mattered for their application (some vertical mill)
using ppmc and a pci parport card
well that it works period proves it's not emc
and is hardware-related
alright, battlestar time. I'll be back :]
like, the last time i was looking on, one of the devs was talking about maybe it being related to lack of look ahead
and that's that last time i heard anything about it
the new TP is very primitive compared to the old one
but we understand how it works so we can fix gross bugs
so far nobody has cared enough to make anything more sophisticated
just you wait until someone picks up an integrex with a busted control
usually the easiest solution is just to reduce the number of segments of the toolpath
or something along those lines
i'm not a big fan of realtime lookahead
in what way?
i think the trajectory should be calculated before running the program
instead of trying to do everything on the fly
but nobody else seems to agree
there IS a command to run a pre-compiled set of servo pulses
no no, i meant on like, fanuc
so someone agrees with you, at least, out there
anyway the reason it isn't implemented is because i'm too lazy to dig through piles of C++
is there an implementation in c++ out there somewhere?
offline trajectory generation? probably
reading lots of papers is just a way to procrastinate
"it's work, i swear"
jeebus that's a clean install: http://www.cnccookbook.com/CCLatheCNCEnclosures.html
woah, points for the labeler
these "look at my control box" pages are much more interesting now that I'm building one
unfortunately i have to work with crap tools and no materials
next time i get a job like this i'm taking all the electronics/electrical stuff back to the lab to put it together
more tools there, eh
and less black grit/metal shavings everywhere
* fenn uploads some pics..
[06:58:34] <toastydeath> http://twitpic.com/img/2acqj-11cb6e2964ffe800e8b2d6b82abbf00f.49c49090.jpg
* fenn drools
somebody bought like, 5" stock for a 3" job
most of that gets turned off =/
where are the pics, good sir.
looks like they bought 10" stock for a 3" job
it was pretty unncecessary, yeah
the finished thing is just a bit bigger than the hole in the center
I guess it depends on how much of a rush job
it's some grinding fixture for a big air bearing
then again, why go to the bother of ordering something when you have something you can cut down?
i really hope that's what happened, but we've been ordering way overstock size for some reason lately
it's been happening a lot
well so much for that idea
I need an mpc
building a pendant?
[07:06:59] <fenn> http://imagebin.org/42173
cookie for whoever can spot the error
(not the detached power supply connector tab either)
relay only has one bolt
the cable is too open about its sexuality
and is making the other, more bland cables uncomfortable
[07:08:59] <fenn> http://imagebin.org/42174
toastydeath: getting close
toastydeath: the rainbow cable goes the wrong way :\
those IDC connectors don't have tabs on them
so you can plug them in backwards
haha what a lucky smartass comment on my part
*also that's a nice table you have there
what is the bob?
i mean router frame table
you should have made it a couple feet longer so you could route out car bodies
300 hp planing spindle
they have those giant routers for airplanes and boats
this table is cooler i think http://imagebin.org/42175
who's the dude on the phone
the rails on the second one cost about the same as my car
nah they are just v-rails
unless you have a really cheap car
like the bishop-wiescarver v rails?
i think that white one has about $6k in it so far
it's funny how people get to about the same point and poop out
I was going to buy some v rail for an experiment, and I figured out it was going to cost me $3000
My boss would notice if I did that
speaking of things your boss notices
i broke a tool changer arm today
sometimes I wish I could just go on ebay
i didn't know you could do that, but you totally can
I bet a lot of people noticed that
like this https://www.motioncontrol.com/products/index.cfm/BishopWisecarver-Corporation-Offers-NEW-Integral-Bushing-and-Stud-Shaft-DualVee-Wheels
yeah man, "crack, tink" as the claw snapped in two and fell on the table
followed by "pshhh, KAWHAM" as the 35 lb facemill fell out of the spindle and also hit the table.
i think i'd blame whoever built the machine
was that your fault?
nah, it wasn't my fault, nor the machine's fault, i just happen to be pressing the green button
fenn: that's what I thought you meant
earlier, they had a problem with the toolchanger "pot down" switch, and somebody made a little cap for it, but they made it like, a mile longer than it should have been
so the pot got stuck at an angle because the switch was now an interference mechanism, but it still triggered as "down"
so the tool arm crashed into that with a shocking amount of force
that's probably what did it
and it's just been holding on by virtue of how it's put together since
the guy who did the repair is an old toolmaker who doesn't understand how the cnc's are put together, and never listens to what our boss asks for
i thought poor boss was going to drive his truck into the building and kill everyone after that
just leave a copy of this near it
[07:26:04] <skinnypup> http://imagebin.org/42176
haha we used to have some guys who lived that philosophy
are they happy cows?
you'll have to check for yourself
it could vary by machine :)
no thanks, I saw Mike Rowe do that before...
Hey guys. I'd like to change the pwmgen.0.scale-value from the G-code. Is this possible? I'm under the impression that it's not since the scale-value is a parameter.
you can't change parameters from g-code
and you can only very indirectly change pins from g-code
my gut feeling is that changing the scale (param or pin) from g-code is a very peculiar thing to do
either you have a very peculiar task that you are trying to accomplish that needs a weird approach, or you are doing it wrong ;-)
Then I will go on your guts here since I'm feeling pretty confident that they're much more experienced then mine here.=)
what are you trying to accomplish (that requires changing pwmgen scale on the fly)?
what kind of currents can i expect in the diodes that protect the L298 ?
MrSunshine: same as the motor current, but probably only for short periods each PWM cycle
I'm not familiar enough with the L298 to know the actual duty cycle off the top of my head
L298 is ust a h-bridge
so it depends on the control mode
ok so i will have to have diodes that can take atleast 2A then :)
wonder how many amps a stepper from a printer takes
need something to develop with until i get myself better diodes, got some 1N4148 at home .. but they take 450mA peak current
then limit the motor current to 450mA
ahh true :)
I got my speedcompensating-module for my laser working yesterday. I can now burn a 'field' and get a nice, even shading over the entire area. My next step in developing it is to be able to create diffrent shades. I figured I'll just put the commanded spindle speed value in the pwm-scale unil I realized it was a parameter. =( Do you have better idea?
Tottish: use a 'scale' or 'mult2' block to change the input to pwmgen, rather than changing the scale.
what he said
mult2.. is that a multiplyer with two inputs??
refer to man pages or manual
man 9 mult2; man 9 scale
OK, and then I could for instance use one input on it from the XY-velocity and the other from the spindle speed? Is it possible for the spindle speed to be set lower than 1 RPM?
commanded spindle speed, that is
I don't know - but you can certainly scale it
spindle-speed-out -> scale block -> scaled-spindle-speed -> mult block
set the scale block to 0.1 or 0.01 or 0.001, etc
OK, I'll check it out, thanks alot!
if you set it to 0.001, then 1 to 1000 RPM from the g-code will give you 0.001 to 1.000 to the multiplier
Yeah, I see.
good evening.In the lib directory of emc is presente some shared library .so , but i don't see the documentation for the declaretion the parameter void.this the documentation for shared library use . thanks
i just received an Owon digital oscope in the mail, at first glance it doesn't seem too bad
the screen is adequate but slow
motioncontrol: "the parameter void" ?
void is a C keyword meaning "there is no parameter"
I am overhearing my wife trying to help her mother hook up her printer :0
how's that going?
the tenor of the conversation is becoming more strained over time
do you feel inclined to assist?
ah, ... no
more likely inclined to suddenly remember an errand that requires his presence elsewhere
not exact void. the declare the single argument the fuction i search.
rather run an errand than hook up a printer?
sounds like a bad situation over there
said printer is 3 1/2 hours away by speeding car
rather run an errand then be around arguing females
example int hal_param_bit_set(const char *name, int value)
motioncontrol: I see no void there
eric: I get what you mean now. I tried to help a friend set up a wireless router, and I was thinking I could just remote in and fix it up, but trying to get them to set up the remote in capability was probably harder than just having them fix the router
yes not is void , but only declare the fuction .there are the documentation for this shared library?
or look in hal.h
if you have an installed EMC2, the man command should work
if you are using run-in-place, do ". scripts/emc-environment" first, so man can find the EMC2 man pages
ok i prove in this moment the fuction hal_param_bit_set, this fuction set un pin value whit in input have the name pin and the value pin is correct ?
looks like hal_param_bit_set doesn't have a manpage, but that's because its only legitimate use is in halcmd anyway
int hal_param_bit_set(const char *name, int value)
return hal_param_set(name, HAL_BIT, &value);
what jepler said
also, read hal.h, it documents all the public functions in the hal API, even if they don't have man pagesx
i have pass char in argument 1(name) :halui.mode.auto , and pass at argument2(value) a integer value =1 , but the halui.mode.auto not change and the return the fuctionc is -3 because?
is halui.mode.auto a pin or a parameter?
is a pin
what does the documentation (man halui) say?
headline of the day "pub closed by holy hand grenade"
then "hal_param_bit_set" would not be a function that changes it
because pins are not parameters ("param" is short for "parameter")
the return value of -3 is: #define HAL_INVAL -3/* invalid argument */
ok jepler yes i understand you
because the name you are passing is not the name of a pin
jmkasunich: you mean, is not the name of a parameter
[19:14:02] <dareposte> http://www.youtube.com/watch?v=xOrgLj9lOwk
eric_unterhausen: that holy hand grenade?
[19:14:56] <eric_unterhausen> http://www.telegraph.co.uk/news/newstopics/howaboutthat/5018294/Pub-evacuated-after-Monty-Python-prop-mistaken-for-grenade.html
the way you set the value of an input pin is by hooking it to an output pin with a signal. then when the output pin sets its value, the input pin gets its value.
not with a function call which takes the name of the pin
i don.t see the fuction in hal.h for set the pin because only fuction for create a new pin because ?
because that is not how you use pins
consider a standard stepper system: a signal such as "Xpos-cmd" connects output pin "axis.0.motor-pos-cmd" to "stepgen.0.position-cmd"
exist a fuction for read ad write in a pin ?
at any rate, that's not how you generally want to affect pin values
if you are asking this question, you do NOT understand HAL well enough to write a program that uses it
you want to affect an input pin's value by having an output pin which is connected to the input pin by a signal
then you change your output pin's value, and it simultaneously changes the signal's value and the input pin's value
because they are all stored at the same memory location
one moment jepler.i want set the pin whit exsternal c program whith use the shared library , you confirm is no possible?
I am telling you that is the wrong way to think about your task
almost nothing is impossible, but there are many wrong ways to do a possible task
you can hel me ?
help me ?
read and understand the HAL introduction and tutorial sections in the manual
halui.mode.auto is an *input* *pin*. The way to change the value of an input pin from a different component is indirect: you do it by giving that component an *output* *pin* which you assign the desired value at the right times
in your hal file, you use a "net" command to connect the two pins together with a signal
[19:23:14] <BigJohnT> http://www.linuxcnc.org/docview/devel/html//hal_intro.html
[19:23:38] <BigJohnT> http://www.linuxcnc.org/docview/devel/html//hal_tutorial.html
our documentation bot, BigJohnT, has helpfully provided you with several links to the documentation
ok i study the manual , but at some day please hel me for use the shared library for read and write hal pin . thanks for all
you do not modify hal pins by calling the library
imagine that the realtime motion controller worked in the way you suggest
you'd have to hardcode the string "stepgen.0.motor-pos-cmd" inside it
but then you could only run one kind of machine, a stepper machine
you'd have to edit the source code of the motion controller to change to something else, like a servo machine that uses pid.0.command instead
and it would be inefficient, because each time you set a pin you would have to do a search for a matching pin by name
your component declares a pin, and then it's code modifies that pin using "*(comp->the_pin) = 100",
the way hal is designed is very elegant and you would do better to understand it and stop asking for it to work in some way other than it does
then you connect your pin(s) to halui's pins
ok i understand .more thanks for help
is there a pin/signal in hal that lets you tell if a job is currently running?
[21:18:46] <BigJohnT> http://www.linuxcnc.org/docview/devel/html//gui_halui.html#r1_2_14
thanks, so halui.program.is-running ?
awesome, thank you
One wrong way to get a knee mill off a trailer: http://www.youtube.com/watch?v=8BNWPQIKmdg
but proof it eventually works
[21:30:11] <dareposte> http://www.nerdulator.net/mill1_.jpg
need to borrow my cable ratchet thingy
would've been handy
wound up removing the head and the knee, and then using the truck to drag the casting to the end of the trailer to get it with the shop crane
that works too... divide and conquer
kind of abused the snot out of my shop crane, but it didn't break yet
what ever you do don't spill your beer
i try not to abuse my alcohol
by spilling it that is
always had it to your buddy so he can back way off and film
its only a 1 ton shop crane, and fully extended is rated for 1/4 ton
but it picked the knee, the head, and the casting
and actually the whole assembly for a minute while we got the wood pallet out from under it
so the safety factor is at least 4x
what does your mill weigh
according to the shipping paper
you were ok then so long as your buddy didn't lower it down on your foot
yeah i guess so
but at the fully extended crane arm it's only supposed to lift 500 lbs
and it was flexing quite a bit
and naturally the dog kept walking under the load
trying to lay in the shade of the dangling mill
we used to have a dog like that in the neighborhood
he removed himself from the gene pool
so often it happens that way
if i had somewhere to park it i would just get a small fork lift and this would all be so much easier
but then i would want a bigger machine
its a never ending cycle
you can rent forklifts...
yeah i got a quote
it was like $150 a day which isn't too bad, but they charge a $90 dropoff and $90 pickup fee
here they just let you use a low rider trailer to haul it
that would be nice
the trailer is part of the rental fee...
i only got a quote from two places, but they were so close i assumed ti was standard
a bumper pull?
electric trailer brakes?
on the tounge
ah a surge brake
i guess that's enough
yep and you don't use a S-10 to pull it either :)
I found it quite hard to reverse up a hill with the surge break!
these have a lock out for that
yup... too late for me :}
you put a pin in it when you back up
my boat has a surge brake on it, it has an extra wire that you have to have wired in and it releases
like an extra pin on the normal 4-pin connector
every job is a learning experience
no it is a pin you use to stop the surge brake from moving
like a 1/4" pin
yep, just don't leave it in when you take off
the boat trailer has a little weird looking horseshoe shaped pin hanging on a wire, i guess that's what its for
good night all
* BigJohnT watches the blinky lights on the 5i20 led board
i've been looking for a power drawbar kit, but they all seem to cost nearly what the mill did :)
I just use a hammer thingy with a socket in the other end for my manual mill
sounds like it might be the best plan
have you seen one?
i know what you mean at least
works well for me anyhow
it would be easy enough to get an air ratchet and rig it up with a 3-way valve I think
I've seen some made around here
from air ratchets?
i didn't think you would need that much torque
maybe a small one wouuld be fine
they are real small ones
fit in your hand with a fwd rev lever
maybe worthwhile then
i saw something called a quick-change tool holder
but haven't figured out how thats different from a drawbar yet
maybe a special type of collet
unless your doing production you don't need it
I have a quick change on my bridgeport it is quite different than a r-8
I can mount all my tools in the holders then set the Z offset for each one and change them out during a run with a known Z location for each tool
you can get a r8 adapter but the holders are pricey
the tool holders?
this is a collet holder http://www.tools-n-gizmos.com/store/agora.cgi?user2=yes&cart_id=2485939.24877*KL3wN2&p_id=10093&xm=on&ppinc=1a
the "ears" locate the holder in the master holder
so the spindle is not even an r8 taper spindle then, its something special
or you use an adapter
mine is a kwik switch spindle
i saw some conversion where it was a big spring washer which kept an r8 1/2" collet closed until an air cylinder opened it, and the tools were set in something similar to what you showed, but just a 1/2" with a shoulder on it
so all the mills and drills were basically adapted to a 1/2" shank
[22:33:36] <BigJohnT> http://cgi.ebay.com/Kwik-Switch-200-Bridgeport-Quill-model-J1-and-2J-heads_W0QQitemZ290304537557QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item290304537557&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50
wouldn't work so well with big fly cutters, but it was on a smallish machine
it would be nice to not have to set tool heights all the time
I set them for each job
then remove the tools usually from the holders
but unless your doing production work it don't pay to have them but the cool factor is up there
if you were running batches it would probably be worthwhile
how do you set the tool height otherwise, with a fixture or something?
I easily have $1500 worth of holders and $1000 worth of collets for my one cnc mill
no, I use a piece of paper :)
I put the part in the vise and slam the tool holder up into the quill then Z down with my MPG until I just touch the paper then hit my offset button
if I had EMC on the mill then I would use the Stuart method
whats the stuart method?
* dareposte man stuart_method
use a dowel pin to find the tool height above the part
lower the tool to below the height of the dowel then slowly raise the tool until the dowel just rolls under and set the offset
that's basically how i do it on my lathe... i used to use a piece of paper but found it wasn't repeatable enough
he told cradek and then cradek told me :)
on my lathe I take a cut then measure and set my dial
i use a 5/16" hss tool bit blank and then touch off to the tool table and add 5/16"
that's probably the best way
same method on the mill
BigJohn: that halui pin was the right thing. Our system now turns off the laser when you pause or stop a job :)
I'm the doc bot :)
* BigJohnT needs to go fling pizza dough into the air and make the wife laugh
i have a tgp piece of tool steel i chuck in the 3-jaw, jog out to be pretty close, then inch up to where the is a very very slight drag on the 5/16" tool bit when i pass it between the tgp and the tool, then touch off to tool table and set the value
talk to you guys later
have a good night
Heh, I use a flashlight to sett height
I find it far more accurate than a piece of paper
At least for me that is
that works too, i guess for a mill?
I guess for anything you can shine I light on
so you set tool height at every tool change?
i'm trying to figure out a method for my mill
i'm leaning towards r8 end mill holders
Well, I do, because I dont have tool holders (router)
hows that work with emc, it won't let you jog during tool change will it
i guess use a bunch of separate programs
Usually I just separate the g-code into seperate files
that works pretty well i guess
for some reason i always want to automate everything
I would too, but $$$
it must be my error
yeah stuff gets pricy pretty quick
i need to set up a toolpost grinder on my lathe and figure out how to make some of those fancy tapers
it might be moderately effective to turn it to rough size out of oil hardening tool steel, harden it, then finish by grinding the taper
or it might be a miserable failure
hard to say