i have to quit - can't hold it anymore pain like hell
what did you do? fall off the bike?
exreme hard off
any will work in large enough doses
all three can be taken at the same time
hehe i was in the hospital lots of xrays making
just keep em stacked 2 hours apart do you are never in pain
and wash them down with beer :)
robin_sz: final solution to pain.
roel01: collar bone?
but they said nothing is broken my ass it cant only bruces that hurts this way
actualy half of the upper site is bruced
tinkeling and coolder arm cant be right
usual racers pains :)
i was fast thats right :)
second overall that day
cu in a short wile hey'
anyone is looking Montreal 2005 on TV ?
swimming show :D
* anonimasu aywns
Synchronized swimming, very nice..
* fenn is reading about celestial mechanics
thank $deity the universe isn't run by emc
oh sorry, the trajectory palnner is a bit rough
* Jymmm sighs
well the universe is only accurate down to the heisenberg uncertainty principle.. that's when you reach the resolution limit :)
fenn too much resolution for you! go away!
what's the data rate of C * hv ?
it's a rhetorical question
you mean 1/0
ach .. time for bed
it might be a finite number, but i'm too dumb to figure out where to start
Start here ---> .
the emc handbook pdf ...
why is it so broken ?
never got finished
gv and xpdf refuse to display it
works for me
i've been having lots of problems with .pdf files though
john.. is it safe to use a small capacitor and schmitt trigger to introduce a delay in an electronic circuit.. like if i need a setup or hold time
is that the standard way to do it, or is there a better way?
sorry fenn, I was away
RC time constant and schmidt can work, as long as the delay is significantly shorter than the high and low times of the signal
example: you can delay a direction transition by a few or even tens of microsecond that way, but you can't delay a 10uS long step pulse for more than 1-2uS
i only need a couple hundred ns at most
what logic family?
well.. i'm looking at a couple different chips
should be OK then... outputs swing rail-to-rail
the input threshold is ideally at 1/2 the rail, like HC... HCT has the thresholds offset, which means you'll have different delays on rising and falling edges
i want to use a binary up/down counter to keep track of position
counting step and dir?
so i need to apply a setup time to the step signal
how do you say that?
so you're sending dir to the up/down input, and step to the clock input?
i'm decoding quadrature output from an optical encoder, that's step/dir right?
no, that isn't step/dir
yes but decoded
run it through a logic circuit to get step/dir
they say "oh its such a simple circuit"
the logic ckt can be very simple if you only need one count per cycle, but if you want 4 counts per cycle it is non-trivial
oh.. actually i was going to divide the step signal anyway
if you only need one count per cycle, do this:
phase A becomes your clock, it clocks the counter, and a 74HCT74 D-latch
B goes to the D input of the latch
Q of the latch is your direction signal
(if B is hi on the rising edge of A, that is up, if B is lo on the rising edge of A, that is down)
in fact, you may be able to just send B to the counter up/down input, if that input is only sampled when the counter is clocked
that is confusing
maybe it will make sense if i draw a state diagram
and i need to look up how a d-latch works
I can't talk without a pencil
d latch sets its output to whatever state it's D input has on the rising edge of its clock input
what chip are you looking at as a counter?
ummm.. at this point pretty much any binary up/down counter
they only make them in 4-bit versions it seems
how fast do you need to count?
but that will probably be ok
well... 500 cycles/rev encoder = 2000 pulse/rev
2700 max rpm
so either roughly 20 khz or 90 khz
and only a 4 bit counter, it will overflow pretty fast ;-)
i will be sampling with emc at like 40 khz right?
er, maybe not
what exactly are you trying to do?
control 6 servos via parallel port :)
spending under $100 total
you can cut the data rate down to suit
what are you using for DACs?
that's why i was going to divide the encoder output, to match the data rate
DACs... well, probably something simple like a transistor.. one-bit DAC :)
PWM or something?
i dont know.. it depends how many bits i have free on the parallel port
well unless you treat it like a bus, you simply aren't gonna have enough bits
i am going to treat it like a bus
which cuts my sampling rate by n, where n is the number of devices on the bus
so no 40 khz sampling rate
do yoy already have servo amps and just need +/-10V, or are you trying to make amps too (under $100)?
making amps too
11 watts i think
you got your work cut out for you then
power stage: H bridge
power stage drivers
22 watts actually
PWM generator (both number of channels and speed rule out software PWM)
DAC to feed PWM generator
a latch does both directions right?
no (if I understand the question)
like, if the comparator senses that the address is for that device, and it sends enable to the latch,
you talking about something like a 74HC374 latch?
i dont know yet
my pdf viewer is busted so it takes forever to look up datasheets
hint: you don't want address comparators
driving me nuts
lots of hardware to do something that can be done simpler
i'm thinking, something that looks at 4 bits, and says "is this equal to 0110"?
if so, it sends a signal to the latch
the latch gets the signal, and connects the data lines to the DAC inputs (or whatever is on the other side of the latch)
you can use a 138 to decode 8 ports (3 lines)
fenn: You want a BCD>Octal/Decimal decoder
three address lines in, two active lo and one active hi enable in, 8 active low outputs
when all enables are in their active state, one output (selected by the address lines) goes lo
if any enable is inactive, all output are high
hold on.. gotta snort some coke to keep my brain running
I hope you're only kidding
never had any electronics education
74HC374: octal tristate D-latch:
8 data inputs, 8 outputs, one clock, one enable
ok after reading that three or four times i got it
on the rising (IIRC) edge of clock, the 8 internal latches capture the state of the 8 inputs
if the enable input is active (lo), the 8 outputs show the state of the 8 internal latches
if enable is hi, the outputs are tri-stated (high impedance)
so one 138 and 6 374's can give you 6 output ports, 8 bits each
yeah, basically open-circuit, they don't drive hi or low, they just sit there
just floating voltage
usefull for input ports, you can connect multiple chips to one bus, and enable only the one you are interested in
ah.. otherwise they would interfere with each other
momentary change of subject: what do you know about "Wno-strict-aliasing"?
nothing at all
* fenn googles
our mystery coder (Yabo Sukz) added it to the make files and now make is failing on three of the four compile farm slots
The documentation states that the option -fstrict-aliasing is not
> invoked for any optimization levels because it is new and relatively
sounds like a good reason to not use it
what is aliasing?
I suspect the failures are because we often use older compilers for kernel related stuff
aliasing relates to some forms of optimization
suppose you have a pointer to some variable, call the pointer foo
just read the wikipedia article
[03:00:33] <fenn> http://en.wikipedia.org/wiki/Aliasing_(computing)
there are 2 kinds of aliasing
the strict-aliasing relates to the amount of optimization gcc can do
so you dont access memory out of bounds on accident?
* fenn wonders which version of "aliasing" its referring to
if it is forced to assume that nay pointer accessed variable can be aliased, then it can't store temporary results internally and just write to ram after a series of calculations, because for all it knows, the intermediate result might be accessed in the middle of the calculatoin thru an alias
gawd I can't spell
kinda similar to atomicity then
any way, Yabo (I wish I know who that person is...) added it and it broke stuff
yeah he tends to add a lot of commits at once
there's like 20 files that have empty lines added
with less than detailed descriptions
it was broken before he did anything actually
at least on my machine it was
well, i ahvent updated yet, i can tell you what the error was
I had a clean compile last night, but now it's failing with:
cc1: Invalid option `-Wno-strict-aliasing'
oh.. maybe that flag isnt supported in your old gcc
that's my theory
this is the error i get from an update a couple nights ago: http://pastebin.com/318935
i have an older version also that compiles fine
emcmot_comm_timeout_count++; is the first error
hmmm... you made the last changes in that file ;-)
maybe i did
i forget now
commented out "spammy debug messages"
how does commenting out printf "blah blah" mess it up
i was messing around with adding include files to see if i could get EMC_DEBUG to work
but i think that's only available in kernel space
i might have deleted an include file on accident when i removed the ones i put in?
doesn't look like it
(well, you didn't commit it with deleted include files anyway)
do a cvs diff, see if your local copy is messed up compared to cvs
i will probably get a lot of spam from yabo sukz
i can comment out #includes and the compiler will skip over them, right?
if you are trying to fix those spammy messages, wait a minute
I put them in there, and I didn't use the normal DEBUG mechanism
well right now i'm trying to figure out what i broke
so you can include until you are blue in the face, and they will never go away
cvs diff, see if your stuff differs from CVS
i put in the code for the DEBUG mechanism in iocontrol.cc
CVS can tell me exactly what you changed
but it was undefined in usrmotintf.cc
[03:25:57] <fenn> http://pastebin.com/318941
line 22 is the problem
you started the comment at line 20, ended it on 21, the } is outside the comment, and fscked up the nesting further down
the line numbers I was just quoting are the pastebin line nums, not the file lines
what's this part all about? printf("axis acc: ?\t");
pastebin line 28 and 30
I tend to use #if 0 and #endif to comment stuff now, instead of actual comments - got bit once too often by nesting of /* */
I think I was printing out some info on a per-axis basis
why'd it change on its own? i never touched that line
let me take a look at the cvs version
i wonder if cvs diff hiccuped on a funny hidden character
dont know... that entire block is inside an #if 0 anyway
there's two spaces in earlier cvs versions, one space in HEAD
i'm only editing files with kate
I deleted the space and the \t, put them back in, and did a diff, nothing came up
I have one suggestion...
delete usrmotintf.cc, do cvs up
IOW start over with a fresh one
i checkout a new one and apply the changes i made to that one, then cvs commit
just to make sure it works
check out new, apply changes, _cpmile_, _test_, then commit ;-)
thats what i mean
glad it was something simple in the end
you know the one that talks about five messages can probably just be deleted
btw how do i know if something is in kernel space or user space?
since apparently the whole EMC_DEBUG mechanism is in kernel space
anything .cc is user space
beyond that it gets complicated
iotaskintf.cc has EMC_DEBUG in it
you can look in the makefiles, there are variables SRCS and RTSRCS (I think, the makefiles got changed a lot because of kbuild)
EMC_DEBUG isn't kernel space only
how come i get not defined errors when i try to use it?
it's defined in emcglb.h
if i #include emcglb.h it says its not defined
the five printfs in usrmotWriteEmcmotCommand() should just be removed anyway
seems useful to have a debug message system
note that they aren't indented... that's what I do when I'm sticking in temporary printfs during debugging
I had no intention of committing with them in there
i didnt want to just delete something i didnt know what it was there for
well now you know... I'm the guilty one
jmk, you're fired.
I can delete them if you want...
time flies when you're having fun, eh
03jmkasunich * 10emc2/src/emc/motion/usrmotintf.cc: removed some debug printfs that I added months ago and forgot about
there, my great accomplishment for today
i ate a whole canteloupe.. that's my accomplishment for today
that's a lot of mellon
its a muskmelon actually.. about twice the size of a canteloupe
one down, three to go
there's a watermelon too.. i dont know what i'm going to do
on the subject of massive eating, I stumbled across this a couple days ago: http://katestelnick.com/
wow.. eleven pounds
talk about bloat
03jmkasunich * 10emc2/src/hal/classicladder/Makefile: removed -fstrict_aliasing and -Wno-strict-aliasing... the latter caused compile errors on 3 of 4 BDI systems in the compile farm, and the former may not be safe for kernel modules and related code
03jmkasunich * 10emc2/src/rtapi/examples/shmem/Makefile: removed -fstrict_aliasing and -Wno-strict-aliasing... the latter caused compile errors on 3 of 4 BDI systems in the compile farm, and the former may not be safe for kernel modules and related code
03jmkasunich * 10emc2/src/hal/components/blocks.c:
added AND, OR, GAIN, and LOWPASS components to HAL, as originally coded by Knud
Dombrowsky. I changed AND and OR to AND2 and OR2 to indicate that they are
two-input and allow for wider gates in the future. Also added a NOT function.
Jymmm is now known as Red70sShow
Red70sShow is now known as Jymmm
just us here ghosts
stupid friend was in the states too long, she's now saying "y'all"
That's not States, that's hick
But no worse than visiting Canada and saying 'eh', Eh!
any idea what thomson rails and bearings cost?
got any plans for bb guns?
thomson rails, not that expensive... www.mcmaster.com
if you're going for unsupported, just get precision ground shafting.
if supported, good luck
the breadloaf looking rails
oh, those kind... no clue.
I was talking about cylinders/bars.
if using unsupported rails, you'll have a big advantage over your competitors
especially if you are milling curved surfaces
or have warped materials to begin with
* robin_sz nods
could be a bit of a problem doing flat surfaces though
Nah, you just use bowed endmills
I still think Igus rail (low precision) and Hiwin rail (high precision) offer the best value
hiwin == cheapest?
of linear rails
a 15mm linear rail, 750mm long is �40
carriages are �20
Igus rail is half that price
Ok, heres the deal.... I got the replacement parts they made for me and fucked up. They would like to offer to change out the rail and skate bearings for 20mm THK style linear rails (on X and Y only) for an additional $285 USD
and they fucked up
well, no they didn't really
No the replacement parts they sent me were fucked up.... too short by 1"
you gave them full engineering drawings of each part?
No, this is their design
The router I bought from K2CNC, remember?
I dont remember
but if they are offering to swap out unsupported rail for linear rail ... take it
the rail snow are supported
find out whose rail though ;)
I'm suspecting hiwin
as they are the cheapest
20mm is plenty big enough for a router .. 15mm is fine, so they havent goen too cheap
[09:01:18] <Jymmm> http://www.k2cnc.com/Picture/KS-2525gallery/pages/Pic%20cnc%20router%2025x25%20(4).htm
that is what it has now.... uses ABEC7 skate bearings
[09:02:26] <Jymmm> http://www.k2cnc.com/Picture/KS-2525gallery/pages/Pic%20cnc%20router%2025x25%20(2).htm
lil better image of the existing rails
so they cut it 1" too short?
so what are you lacking? Are you sure you're missing 1" of travel?
fuck, that looks expensive
They made the replacement ballscrew too short
robin_sz what does?
that carriage with the skate bearings .. what a bunch of idiots
I really don't like their slide design.
with the skate bearings.
that must cost twice what proper linear rail costs
I'm inclinde to agreew ith robin_sz, about just getting premade slides.
the skate bearings actually isn't bad...
robin_sz, unless there's no precision in it.
useless for a router too
I only get .000.5 deflection for the whole travel
well. Jymmm. have fun. :) heh.
what are the new slides like? Are you sure they are short some 1"?
Are you getting the same about of travel?
I said the ballscrew is too short
the ballscrew? for the coupling? or travel?
fine. bye jymmm.
robin_sz... still playing with the gecko g2002?
I found this company that's modifying Proxxon shapers and puts stepper motors on it. I was wondering if anyone already used it with emc
oh. sick. http://geckodrive.com/ycom/documents/C163R22_spiral.wmv
I want a g2002 now.
Poincare, don't know. you'll probalby have to ask on the email list.
What do use emc for?
What do _you_ use emc for?
I use it for milling. on my retrofitted mill.
and it's 4:38am... time to sleep
it's 10:38 here :-)
have a nice sleep
milling wood, just starting, its 10:38 here too ;-)
as a hobby or for professional use?
booth, trying to do some investigations into high tech self-providing
Well, I'm looking for something to drill holes and cutouts in aluminium
for the electronic equipment I make
for small series etc...
something or someone ?
are you planning to buy a milling machine or to build one yourself ?
I do get this ideas at weird times and want to make/try it at weird times :-)
I saw someone on a tradeshow in Friedrichshaven last month who modifies Proxxon milling machines
Price looks fine for me, but it comes with DOS software, brrrr
I've got a old ISEL-mill without electronics. Actually I try to get it working.
It's completely dead?
It is running already. Now I start to get fammiliiar with emc
toka: familiar on a pda ?
dont understand: what do you mean with pda (personal digital assistant ) ?
not realy, why ?
I was thinking you was talking of Linux Familiar
just googled, seemst to be interesting ... what is the connection to emc ?
should be fun run emc on Linux Familiar
but not possible I suppose
you get a full powered pc for the price of a pda, what would be the benefit ?
I've an Ipaq 3970 with Gpe Familiar installed
so, I was asking ..
sorry, leaving for breakfast, if someone is interested in sharing experience about emc and self build milling machines: http://coforum.de/?ThomasKalka
toka: do you have a cnc machine ?
off to work... see you later
I build from myself a prototype some mounth ago
I'm looking for a good 3D laser scanner project now
laser + webcam
to retrive 3D models
[10:04:22] <toka> http://www.muellerr.ch/engineering/laserscanner/tutorial/the_tutorial.html
yeah, already seen ;)
anyone know hot to run a program (gcode-file) from an arbitrary line ?
03yabosukz * 10emc2/src/ (Makefile.inc.in configure configure.in emc/log/Makefile): need flag to fix bug wit c-3+
They sent me the replacemnt parts, they were screwed up. Now they are offering to convert from the skate bearing to THK rails for $285
So, now I'm trying to find street pricing on 20mm THK style rails
I think Hiwin, but not sure.
anonimasu : Well, with leadscrew made too short, why are they offering rails ?!
what you mean 'no clue'
I have no clue why they would do something like that.
Me neither, but I'm just wondering if $285 is worht it.
well, you still need new leadscrews..
it might be to compensate for the trouble..
it's a good deal on rails for sure..
if they are good
but well rails > skate bearings..
interesting to read about Jymms router woes
seems those guys selling the routers aitn very clueful huh?
I saw some bad points in the design too
bleh I need a cnc lathe :/
I need to turn a screw with 2 different threads on it..
that gantry driven off a single screw in the middle, its going to be bad for loads applied at one side
going in Thread1<>thread2
for a gripper..
for my toolchanger
yeah the changer fork..
mmmm . pneumatics?
I might machine the fork solid..
maybe a block with 2 precision holes & pisons..
need to grip the tool, other then the fork..
[18:55:57] <anonimasu> http://images.google.se/imgres?imgurl=http://www.whitneysystems.com/Data/Images/Image104-tn1.jpg&imgrefurl=http://www.whitneysystems.com/Custom%2520CNC%2520Tool%2520Changers.htm&h=200&w=290&sz=8&tbnid=I68tWOfxmaQJ:&tbnh=75&tbnw=110&hl=sv&start=6&prev=/images%3Fq%3Dcnc%2Btool%2Bchangers%26svnum%3D10%26hl%3Dsv%26lr%3D
* anonimasu wishes he could fit retainer knobs easily
one word ...
do not even consider makign your own
bleh.. they are like $25
well, your funeral
I was just kidding ;)
the trouble is the drawbar, really
and the taper..
I'll use the drawbar I have now to push the tool out..
but I am working on the fork to hold the tool and to grip it..
[19:05:31] <anonimasu> http://www.laserspec.net/cnc-equipment/lsi800.html
who is kidding ? :P
anyone know a good CD collection of 3d Clipart ?
anonimasu: neat looking router .. wonder how much
$2000 USD sound snice =)
I am looking for ideas for servo amps to use with the mesa 5i20 card... I need something that accepts pwm and a dir bit... any ideas?
I would like to build something if I cant find an ebay special
who on the list plays with that stuff... Jon does... anyone else come to mind?
nobody in particular... I'd just post the question to the list
will try tomorrow when the list is active....
The guys in Germany seem to be using the mesa cards... I will try and find out what they are using
Imperator and swpadnos were waiting for cards ... havent heard a peep from them
set your hair on fire from across the room yet?
been away a while....got a tractor and am prepping property etc
dig pond, take out trees, and stuff
oh and my two hole par 4 golf course...
been away...playing with new summer toy
[21:27:07] <les> http://www.tractorbynet.com/forumfiles/692005-tractorlr.jpg
nice day in the north west... just getting ready to go out to a ham radio club bbq
oh yea... nice toy... had a kabota 4wd about that same size.... very handy machine around the farm
My dad is a ham but I was always an audio type...a little lower frequency
yes very handy
not bad in the shop for a portable crane either
well I am getting forks for it....it can pick up 1500 lb to 7 feet
not quite a forklift...
the pto is great for running pumps, welders light plants etc
easier than straining the back!
yeah this is 30 hp on the pto
540 or 1000 rpm
lots of beef... mine had 20hp on the pto and 27 overall engine hp... nice 3cylinder diesel
this is too
It will help me a lot
not cheap but it will outlast me i'll bet
its amazing how much work they can do on 5 gal of diesel.... a full day..... do you have a backhoe attachment?
no....just a loader and bushhog....disc plows coming this week
and log splitter
stupid log splitter conversation in the 7x10minilathe group. wow is that group bloated with pompus windbags.
I used my hoe a lot... put in building footings and waterlines etc.... a few outhouse pits as well!
the one I am getting uses the tractor hydraulics...no engine needed
a tractor driven splitter will be awesum.... fast and nothing will stop it.
Lots of things you can put on those....heh had to draw the line somewhere though...it cost more than a lot of new cars!
2 cars in some cases!
have been away a bit
I also used a landscape rack a lot.... kind of a curved spring rake that when on the 3pt hitch... cleaned up 22 acres after the excavator pulled the stumps.
les: yeah we've missed you a bit..
les: how are things going?
I hear those are good to have
ok anon. Have been doing outside stuff and also an acoustics research project
yeah, the one with the power generation..
how does it go?
lots of impedance matching with stubs
kinda tough...with stub matching I need a q of several thousand
Am trying low impedance piezopolymer now
High all... : )====~~~~
Anyone know the cost of 20mm THK style rails and slides?
LawrenceG: have my card now
If you would like to have a amp, try the ones with +-10V Input
Jymmm: don't know the price of THK but BoschRexroth ones (Star) are about 80 EUR per slide and the Rails are 80 EUR per Meter in normal quality
are those the cheapies? I thought hiwin were the cheapest
jymmm just get some drawer slides already :)
fenn only to beat you over the head with!
anyone here from finland?
i know picnet is.. but he never says anything
The Bosch ones are not the cheapest, they are like THK I think
Hiwin are the cheapest I know
got some Bosch rails and slides from ebay :-) new ones of cause
Finnland !! There are the moskitos alive at the moment, right ???
i'm from indiana, usa, not finland
and why are you searching for somebody from Finnland ?
fenn : Indiana, Well that explains EVERYTHING!
Imperator_ what was the damage on the rails you got?
i want to ask them if all finns are nutcase mountain-men at heart
damage ?? they are ok. Sometimes you get usefull stuff on ebay
Imperator: I think he is asking the price (USA slang, refers to damage to your wallet)
jmk: ah ok
fins are all nutcase mountain-men at heart
I am one, and I want to dig a hold 10000 ft deep with a cavern at the end to live in it
that's pretty deep
with cnc, I'll get there! lol
Jymmm: about 250 $ for two rails (700mm long) with four slides
you get your racks'n pinions yet?
still cant find the ones i want
Yuga: you are from south africa ??
cool, which city
I'm from germany
was in capetown and bloomfontain last year
and in Durban
durbs = shithole... far to hot there
in summer ?
even in winter
it was ok
but yet... the summers are killer
far to humid
what where u there 4?
was at rapdasa conference in bleom
dont have a clue y some one would wanna come to sa if it wasnt for buisseness
that was about rapid- prototyping
know some people how like to spend there holidays in sa
not my idea of fun
would like also to go there again
Imperator_... sooo what u goto do with emc?
got a cnc machine?
and collecting stuff on ebay
router mill lathe?
high speed mill
nice... servo's i am guessing?
polymer concrete frame
jep, Simens Simodrive Servos
got a addy for them?
like to c what ppl are up to
i am also in the process of planning a cnc machine
sa people realy like to shorten everything
no point in typin it all
got a addy for them?
what meany the C and the ppl ?
see and people...
you mean where to get the servos ?
yep.. where to get them...
puh, somewhere on ebay
John is the english english translator today
* Yuga is going to be using stepper motors
the problem with ebay is that this stuff is now very expensive, because the people who are repairing the older CNC machines are buying them all the time
a smal Siemes Servo is about 1000 EUR, on ebay you get a new one for about 200 EUR, but that is even to much for hobby users
got mine for about 50-100 EUR
shit... not bad
the steppers i am wanting are like 200 each
200 what ?
very expensive for steppers
they are realy big :)
[23:15:11] <Yuga> http://www.campbelldesigns.com/stepper-motors.php
the bottom ones
depends on what you want to do, but normaly a servo is better in that aerea
yep... but they are far more expencive... doubt i could afford it
you will get nice resonance effects
a stepper don't turn, it makes stepps
what u mean
expecting it to vibrate the machine more than the router?
* Yuga is making a cnc router
you need a coupeling element that is not to stiff
going to be using a rack and pinion aproach.... the pinion's going to be linked to the stepper via a timing belt
that should unstiffen it enough :)
what do you want to do with that machine
just hope that it doesnt get too unacurate
you could use a timing pulley with a damping layer.. they make them for auto engines
fenn... cool. something i did know :)
I think a normal timing belt is damping enough
that is why nobody is using that for machine tools
ya... alittle worried about all the play i will get with the timing belt's and rack and pinnion
or better it is not damping it is elastic
belts are good for pick and place machines but not for machine tools
you can adjust for backlash in software.. i dont know if there are issues with that strategy or not
the biggest problem i have with using a screw is getting one long enough... and shiped to sa
what size are you thinking about
that's what size i need... it's not even debatable
--> 40mm or 50mm spindel
for doing what ?
that's how big the sheet's of wood are
what about chain drive? like a garage door opener
think that is probibly less acurate?
it is less accurate than a ballscrew, for sure
when you're sticking several racks together, it might be about as accurate
you want to mill in wood or to engrave ?
even less acurate than the rack
mill mainly... would like to engrave... but not sure if it will be good enough
ask Hiwin, they are about 1500$ I think
take one on each side
we are building a machine with 1.7m in Y direction
what about spindles?
we want to buy a 2m spindel with 32mm or 40mm diameter. It is about 800 EUR ->1000$
you mean ballscrew?
spindle means the part that holds the cutting bit
aaahhh... was alittle confused
in Germany we say Spindel
in german I mean
ooohhhh... found some nice cheap ballscrews :)
523.2$ for a 3 meter one 1 1/2" dia
you better make a webpage, once you get it to work, for all your whining :)
i wanna see pictures of this
hey... i refuse to start untill i know what i want
and i still dont have a clue.. so get use to the whining :)
i like this chain idea.. i may end up using it myself
seems much more efficient than screw drive
regular screws that is
what kinda chain??? cause chains i have worked with have a shitload of play
well, if you apply preload to them it takes up all the play
then any error is in the difference in distance between roller pins
i'm talking about 3m sized machines
not expecting <.001" accuracy
i'm thinking either motorcycle chain or bicycle chain
more likely bicycle chain.. i wont be applying more than a hundred kg of force
the chain on my mountain bike is after 1000km about 3 elements longer !!! Don't think that is something for a machine tool
your mountain bike is submerged in an abrasive slurry
I throw away two of them each year
well, nothing's perfect
wonder if a 25mm ballscrew is thick enough
look up how to calculate the critical frequency of a ballscrew, and find out if that is below your maximum rpm
any input for the whiner?
this is for acme screws, but it should apply to ballscrews: http://www.nookindustries.com/acme/AcmeGlossary.cfm
the main parameters are the stiffness of the material and geometry of the part
eh, it's about 3/4 of the way down
big machines are expensive !!! If you try to build them with cheap or to small stuf, you wil have something that dont run.
i'll show you! *shakes his fist*
Imperator_... fenn is a cheap chap
but you have to do it with ingenuity, not by using wimpy versions of what the big guys use
but a chain isn't the solutian
we are buying two screws, one for each side
one linear scale one each side also
those acme screw's are quite cool
and a granit table
Imperator_: you are milling metal, right?
i think yuga mostly will be doing plywood and mdf