[00:13:34] <dmess> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230272792893&ssPageName=ADME:B:EOIBSA:US:1123
what are you scraping??
ways on his newly acquired benchtop surface grinder.
grinder Y ways
scraping? scraping what? hardened emulsion?
uh, what are you scraping away?
the X axis is steel balls on hardened steel rails, little or no wear
the Y is cast iron dovetails, and they are worn in spots
I'm scraping away the high spots to make them flat again
how do you do that?
err, how do you remove the material and keep it level and true?
thin film of prussian blue on surface plate, put part on plate to mark high spots, then turn it over and scrape where it is marked
repeat till done
oh, hmm, fun.
its an art
I've done 13 cycles so far, an it looks a lot better than it did
with some carbide scraper?
I assume it's enough to scrape the large flat section of the way
as you can adjust the dovetail tightness to keep it tight enough
the flats are more critical than the dovetail on a grinder
ok. any idea of how much material you're removing?
which is fortunate, because scraping the dovetail is a pain in the rear
I can imagine that...
well under 0.001" per pass
oh, that much?
[00:20:26] <dmess> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330254039921&ssPageName=ADME:B:EOIBSA:US:1123
scraping IS an art... congrats .. there arent many of us left who CAN
I'm taking pictures of the blue pattern every 5 passes, I'll post them later
"well under 0.001"
do you get some crud/dust/chaff after each pass?
I wouldn;t be surprised if it is actually 0.0001
.0003-/0005 per GOOD strock
yeah, a bit of dust
if the way is that flat, and you could only get a part flatness of something like 10 times that, what's the point of scraping it?
dmess: I'm not particularly good at it
the way is not that flat
I bet I started with 0.002" or so of sag in the middle where it is worn
thats what make a good scraper/artist
the finished surface is flat, but not smooth
so now smooth it..
the individual scrape marks hold oil, it actually runs better than a ground way
oh. so you get a flatness by just using lots of elbow grease and multiple passes :(
lerneaen_hydra: right, lots and lots and lots of elbow grease
and wrist action too..
I would guess that a scraping a grinder is easier than doing a mill.
I wish I could actually see somebody who knows scraping do it
could some one have a look at the last link i posted and let me know what they think??? Has any one seen/tried these before
I learned from a book, and like welding, you can't really learn the strokes from a book
The x and y axis don't have to be perpendicular.
I have a video by a guy named Morgan (I think that's his name).
i learned from a Japanese Toshiba Engineer
the guy who collected money for books about 5 years back, and then disappeared without delivering, after some sob story
(he has some of my money)
I was pleasantly surprised to see that this machine was scraped when new
I'll look for the video. If I find it, I can lend it to you. (Or anyone who would like to borrow it.)
* jmkasunich starts on round 14....
Let's build a cnc scraping machine. First you grind the part then the machine goes over the part and puts scrape marks on it. :-)
good luck jmk
Lagun used to do that
Am I correct that the XY plane doesn't even have to be square to the Z? That seems right because the wheel will get dressed so the edge is square.
are you planning on doing any sidwheeling??
naw still wont matter..
cradek: I moved the switch so that I can probe closer to the actual switch and not at the end of the lever .. it's much more repeatable now
will EMC2 handle a VFD controller??
jepler: for my home switches, I removed the lever and push on the switch "button"
dmess: will EMC2 handle a VFD controller?? - sure
skull you know hardware??
some - most VFD use a +/- 10V control signal
[01:00:27] <dmess> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330254039921&ssPageName=ADME:B:EOIBSA:US:1123
is this gonna run my hardinge lathe??
not unless Hardinge makes micro-lathes now
ouch - there was a thread on cnczone about those.
that is sherline territory
the VFD i have on hunt is an allen bradley... we'll see if it materializes before i waste brain power
but it is a micro lathe... hls 59
can you pick it up with one hand?
they were not putting out rated power even for smaller motors.
dmess: yes, your lathe
weighs 750 pounds without the base
then its not a micro lathe ;-)
seriously - NEMA23 motors are NOT for full sized machines
but the slides are just little hardinge slides
i have 2 axes on the cross slide...
the cross slide doesnt move
on the bed
you clamp it on
go measure the handwheel diameter, figure out what weight will give you 90 oz-in (for example, a 4" dia wheel = 2" radius, so 45 oz * 2 in = 90 oz-in
pick a weight about 1/4 that amount - say 12 oz
hang that on a string, wrap the string around the handwheel
does the weight move the wheel?
if no, the motor is too small
45 oz will spin these handles NO PROBLEM
if yes, the motor _might_ be big enough
I said 1/4 of the rating
holding torque is the absolute max that the motor will do - at speed is is lower
at high speed it is _lots_ lower
anyway, regardless of the specifics, you've just proven why asking that question here is not very usefull
wit 6-8 oz i move the z and about 2x that for the x for some reason.. but i believe someone has played with the gibbs
we don't know how much torque it takes to turn the wheels on a Hardinge 59
my son ( the one whos been gone for a monthe and has a new lathe in his bedroom asked why the x was tight??? asked
within the 1st hour of being home.... ; ) thats my boy....
dmess: The relay board might be useful.
but Instead of paying $30 plus shipping from Mexico I'd likely buy this http://www.lococnc.com/Relay_Board.htm
what's the relay board going to be used for?
i have 2 of them coming... oh well i'll test drive this one for the team i guess.. for 200 bucks its not the end of the world... ive had good piss ups that cost more than that
Get a Widgetmaster router for it.
i 'was' thinkin' 110v motor + brake for 1 board and maybe coolant for 1 of the next
a Micro router that is beautiful.
hmm let me find a pic
im more of a full sized mill kinda guy..
this lathe is a super precision manual 2nd op lathe... i have 2 cross slides they clamp to the dovetail bed
was up in a 5s auction... i couldnt pass it up...
lemme find 1 on e bay
[01:40:44] <SkullWorks_PGAB> http://imagebin.ca/view/bjQyKkz.html
[01:40:46] <dmess> http://cgi.ebay.ca/Hardinge-Model-HSL-59-Precision-Speed-Lathe-1990_W0QQitemZ280246143027QQihZ018QQcategoryZ104241QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
dmess: ok, thats a lot smaller than I thought - maybe NEMA23 is OK
as long as they are strong NEMA23 with good drives
that is a true SPEED lathe slide.. i have 2 dial handles but the same lathe
it has slide handles
the 115V single phase, 1/2HP spindle is what tells me its a small lathe
mine was 575v 3 phase... im gonna switch the motor down to 208v and run it off the dryer plug
you know how to do syuff like that??
hopefully a VFD will show up next week and the parts will all almost be in the same place at the same time...
When doing bar work on the HNC, A "Loop Tape" is used. ... Following these last blocks of data there must be at least 8 inches of leader before the beginning of the first operation. ...
To make the loop, the two ends of the tape must be glued or spliced together.
I guess we need to add M2.1 "tape ends of program together"
you just use M2 [program stop] instead of M30 [program stop and rewind tape]
hm good point
this has no decimals. you always program all the following zeroes. you can change the 'resolution' (least significant digit) from .0001 to .00002 using an M code
cradek: don't tell me you are going to have TWO CNC machines, both of which are not using EMC
well, 20 rounds of scraping done, and I toasted
5 or 10 more tomorrow and it should be good
for endless loops most controls use M99
Its the end of sub - return command.
Atleast that is the code used by Haas, Fanuc, and Mazak - does not work on Okuma.
jmkasunich: I really sort of doubt this control is working well. it came with a lot of disclaimers.
the only thing I need to avoid is fixing it
Hi cradek. What control are you dealing with?
it came with a GE 550 monster
not sure if that's the actual model name :-)
Ah. that control.
Is there a U-Stor hanging off the front?
it's not off the trailer yet. maybe if I'm lucky I'll tip it over.
yes U-Stor sounds familiar
I recall seeing a 'mu' - micro symbol
I think it's a tape reader replacement? or maybe there is still a reader behind it.
he was using rs232 somehow.
I had one with a bad memory location near the start. By loading a dummy program I was able to run other later] programs
Drip feed I suspect.
The 550 itself ran directly from tape.
is tooling around for these? I don't have much of anything.
I have 3 little clamps that slide in and have a setscrew on top, that clamp a 3/8 (?) lathe tool to the top of the turret.
Yes. The tool holders that fit to the turret are available but I've not gotten any lately.
That sounds like them.
there's another shape that seems like it would be used for most turning operations
it would have to stick out I think
I've seen quite a few bars that had carbine hanging on the side and a flat where the setscrew fastened them into the holder.
oh like the boring bars that came with my boring head maybe?
The 550 and the box under the spindle end both have some pretty primitive boards.
You might talk with MattS about the approach we took to one of these.
yeah it's great that you guys have worked on them
vfds for the spindle and coolant motors.
I have two Hardinge HNCs with GE 550 controls I hope to convert to EMC. The micro-stores have weak batteries and only keep a program for a short period of time.
kirk recently did his too...
And JonE's drives and PPMC cards.
I hope to keep the amps - but I don't have any info on them yet. I have schematics for everything (?) else.
Not real certain how to approach the spindle drive encoder yet.
right JohnJ. I put a new power supply in the one I used.
On all the time.
I've got several spare amps for these if you need.
slick, thanks for that offer!
The problem with those drives is that they and their power supply are in the bottom of the BIG 550 control.
Why reuse the old ones? I'm going to scrap mine or put them on ebay.
Yeah not to mention a heavy supply too.
because I assume they're velocity mode amps with tach feedback, well matched to the motors
They do tune really well to the Electro-craft motors.
that seems hard to beat, if they work
also, they are 'free'
The only real problem I had with them was brush dust shorting the motors.
They probably are, but if I recall right they use resolvers with the GE 550 controls. I think I remember they do have a tach.
That would take out quite a few of the drive transistors and resistors.
If you pull the covers over the motor end of the ball screws you'll see the feedback package.
Most of those covers I've seen were black.
Some had what looked like cooling fins.
On the feedback package there are both tachs and resolvers sticking out toward you.
Between them is a gear that drives them from the end of the ballscrew.
I have to run - thanks for your expertise rayh - I will read back tomorrow. goodnight!
see you later.
Does EMC support resolver feedback?
There are some converters that change a resolver into 1024 pulse quadrature.
I thought natively it only supports encoder feedback.
Oh, I didn't know any converters exist.
JonE is making one. You might check with him.
for price and all.
I very well might do that. The Hardinge already has the tach, resolver, and motor assembly similar to what you were mentioning. It might be a bit of a pain to try replacing the resolver with an encoder in the limited space.
Awesome, for the first time in 5 years, irssi closed on me
did any1 get my quit message?
* fragalot has quit (Remote closed the connection)
fragalot has left freenode (Remote closed the connection)
apparently i ran out of memory
12:48 -!- fragalot [n=thomas@gentoo/user/FamousToaster] has quit [Remote closed
12:00 -!- Irssi: error gmem.c:135: failed to allocate 16392 bytesAborted
thats what I got at my end :p
I think joining this channel overflowed my memory limit i've set on my server for all users lol
(it was worth it!)
now to finally fix,wire and test the lats axis
its tyop monday
mmph, trying to figure out how i would run 3 steppers from 1 PIC taking the input from the parallel port
guess i'll just put another entry in the registry to see if the previous step input was already high or not
* archivist mills his first helix 4 axis
* skunkworks_ will be expecting a video
* fragalot 2
was just a practice, need to make a worm and wheel for an antique machine
* archivist drinks coffee to celebrate
we wanted a video anyhow
fun part was it machined parts for its own Z
I might have my future pet project mill out it's own controller PCB :/
who needs reprap we can do it with metal and EMC
well.. you can.. EMC apparently doesn't support USB parallel ports, so all of my computers are out of the question :p
it's easy to make a mill with a mill, but the problem is they keep getting smaller each time...
cradek: you can make a big mill with a smaller one
you just need to make them bigger in steps
hang off the table "a bit"
yeah, thats why they have windows on the sides
they have sides?
the ones at work do..
to keep you dry
(altho the top is open, so everything just splashes over from there)
mm,.. for my PIC based stepper controller.. would i add an X-tal or have it run on its internal 4Mhz clock
fragalot; are you the same person from yesterday?
building a stepper driver for a small benchtop mill?
yeah, just finishing up on the schematic
I don't see why you would need a crystal
just figuring out if i need some power resistors for the stepper or not
:) decided that too ;)
it's not like there's any serial data comms
nope, just bitbanging
oh, right. lowered supply voltage to the steppers maybe?
mm, steppers are rated for 12V, and the PSU is 12V..
so,.. I don't need them?
hmm, I don't think so, if it's 12V constant and not when running
uh, if the steppers are rated for 12V constantly, compared to 12V while running, as when they're running the inductance will lower the dissapated power
[15:37:13] <fragalot> http://omploader.org/vbWRw/Interface_Controller_1.pdf
-- as i said i'm ALMOST done, just imagine that there are freewheel diodes present for the FET's :p
page 2 of this PDF shows why voltages higher than the motor's "rated voltage" are desirable (generally with a current-limiting drive, which is the same as a torque-limiting drive)--it gives more torque when the motor is moving at a particular speed. http://www.geckodrive.com/photos/Step_motor_basics.pdf
your performance will suffer.. (if they are 12v rated steppers and running them on 12v) normally for the best performance you want to current limit the voltage to the steppers at 10-15X rated stepper voltage.
*current limit the voltage? Sort of makes sense.. ;)
but if you only have 12V motors and 12V power supply available, there's nothing you can do
I think he said yesterday that this was supposed to be a super-simple setup, so no chopper driver
super-simplest is 4 transistors driven by 4 parallel port bits
yes, but then i loose pretty much all outputs :p
been there - done that.... have the mental scars.. ;)
yes it takes all 12
fortunately you can add some more parallel ports if you need more
i just mocked up a PIC-based thing that uses 6 inputs
fragalot: use 74ls inverters :)
fragalot; are the mosfets any good with only 5V VGS?
OoBIGeye: yeah, couldn't find those in multisims database,a ll i care about is the symbol and the footprint ;)
lerneaen_hydra: logic-level FET's, so yes
cradek: any idea if you still have that program for atmega that converts step pulses to winding activations?
found out about those about an hour ago
probably. let me look.
I don't recall whether it's all "C" or whether it's got asm parts for speed -- it might be useful if fragalot is going to do something similar.
jepler: i've already got a rough idea of how i'll code it, I just need to figure out if i could do microstepping or not, and how that works
[15:42:25] <cradek> http://timeguy.com/cradek-files/emc/maxnc.c
microstepping seems a bit over the top for a non-chopper drive
half stepping might be good though (IMO)
you definitely want half stepping
half it is
oh well, looks like it's fairly specialized to the avr
there, before I start making the print, any last-minute changes i should make to the schematic?
if you're feeling wussy then zeners on the gates of the mosfets are good, though it's probably easier to replace them when/if they break
fuses on incoming power?
replace pic with avr? :-)
lerneaen_hydra: those are external to the PCB
provision for separate (higher) power supply for the motors
cradek: cradek that would just mean hooking up a higher voltage, no real need for a seperate one
this circuit should run just fine for anywhere from 8V to 30V
fragalot: until your 7805 overheats
at 30volts or so it'd be dissipating ~6Watts :/
owell, thats why god invented the heatsink
might be nice to be able to do 7-10 in for logic supply, and separately 30-40 for the motors
it could be a simple matter of cutting traces later though.
yeah, but that would require getting yet another supply, etc..
cradek: seems unlikely to have a non-chopper, no-ballast-resistor drive that will use 40V supply, though
right now i plan on getting a cheap lil' intel board with parallel port, etc... and hook this up to the same PSU, if that would work.. :p
yes you would have to add ballasts
adding ballasts isn't exactly the hardest thing to add later on
yes I suggest thinking about how you will do that (because I'm almost certain you will end up wanting to)
simple. connect ballast in series with the 2 respective lines
I don't understand the purpose of the diodes on the PIC inputs e.g., to pin 2
to keep me from sendi.... good point
after the capacitor C7 is charged by current from U4A through R12 and D5, C7 will stay at a "logic high" voltage for a long time; not much current will be drawn when PIC pin 2 is being used as an input
it also looks like you've got 'Vdd's going to the PIC on pins 11 and 32
naming mistake, it's 5V
(look at the lil' ICD2 part near the top)
In "power section", I see VDD on the input side of the regulator and VCC on the output side..
I just throw naming conventions overboard
so, removed the diodes going to PIC, what else?
the grounding of the dsub connector looks fishy -- are the other items you grounded unused inputs to the PC?
those pins are all GND
parallel port has GND from pin 18 to 25
in that case, you need to double-check all the pin numbering
1-13 run on one row of the connector, and 14-25 on the other row.
thx for reminding me of that "small" mistake
here's the symbol from the circuit board program I usually use: http://emergent.unpy.net/files/sandbox/db25.png
and what was that about the capacitor for pin 2 on the PIC?
and what about the resistor (I just basically copied that from an existing DIY circuit by somebody else)
fixed the parallel port
if it's supposed to be an RC network to filter the step and direction signals, I think it's more typical to put that before the inverter/buffer. that's how this other board with step+direction inputs does it: http://www.pminmo.com/l297-8/L297_8HVschematic.pdf
lol too late again to fetch parts
cradek: are verlocity mode amps better then normal ones?
cradek: ones without feedback
anonimasu_: for low speeds yes I think they are much better. think of shallow taper turning on a lathe. a position loop will have to step at the encoder resolution.
but they are also 30 years old. you have to take that reliability into account I guess.
I've got tachos for my mill motors..
also beware that I'm no expert.
and im pondering if I should buy amps off jone to use the tach..
ofcourse mount a encoder too(they have the motor shaft sticking out)
on any retrofit I guess it's hard to decide how much of the old setup to use. this is another one of those decisions where there's no 100% right answer
well, I have new motors..
do I use them?
(no amps yet)
IMO I would use the tach feedback.
anonimasu_: motor-tach + encoder is the way to go
hm.. can you explain why?
unless you have motor-resolver combos
Makes tuning EMC to them much easier.
for a desktop sized mill, with ~170mm travel, using an M6 lead screw, what would the minimal torque be (basically just PCB's and simple engraving, no heavy parts)
anonimasu_: you need the encoder for position control
i think that will depend on what type of ways you have
and tach will give you much better tuning especially at low speeds and during accel phases
alex_joni: yeah, I know that already, but the tach?
alex_joni: hmm.. where it matters
during regular feeds you can do without the tach
but at slow speeds it's much more stable with
I've always found it odd that most comercial machines use tach feedback
at least they used to
nowadays you can use a resolver for both things
nowdays the controls themselves are digital :)
but if you look at jon elson's drives with tach feedback?
what if I don't?
I dont quite get what you mean with use one at low speed.. do you wire them up to emc both.. or do you just use velocity mode amps?
just use velocity mode amps
anonimasu_: you mean this? http://pico-systems.com/servo.html
"This amplifier takes in a +/- 10 Volt analog velocity command from the CNC control" -- analog.. over the parallel port? or am i confusing things here
uh.. no you use a analog output card like a motenc
err motenc lite or the mesa cards
or the stg :)
having run x whole revs on my A axis how can I reset to 0 without rotating A
[17:11:26] <fragalot> http://omploader.org/vbWVi/Interface_Controller_1.pdf
revised design on my controller, are there any mistakes remaining
archivist: you can use touch-off
last.fm just went sideways :<
[17:35:04] <fragalot> http://omploader.org/vbWVl/Interface_Controller_1.pdf
hopefully the last update?
fragalot; do the inverters go to vcc?
it may be a good idea to have a series resistance before the capacitor to give a simple low-pass filtering
if you haven't considered it
oh from the 7805?
lerneaen_hydra: 74HC14 is the inverter that i'll use, not the one listed on the CCT
and i found another mistake,.. a missing line from one of the caps to GND,.. w ell.. my dad did
lerneaen_hydra: and, which capacitor
Has anyone tried to send UDP-networkpackages from a realtime comp file?
fragalot; the buffer capacitors before the inverters
they won't do much good as the switches usually have very low impedance
though I'm not sure if you need a lowpass function
well that part is for the limit switches
i cant include <sys/socket.h> and get errors with <linux/sock.h>
well then, guess i'll put a 1k in series there
uh, depending on how much you like math you can find the rise time for a given pole position (if you
've done basic filter design and linear systems and transforms yet)
well, basically let me put it like this
the furthest i've gotten to in school sofar are basic resistors, BJT's, and diodes
hmm, done bode plots?
the rest is just out of curiosity and interrest that i know
"bode plots?" (you may assume not :p)
gefink: you can't use networking APIs from HAL realtime components. You might be able to find a way that does not give compile or link errors, but if you do you are losing guarantees of real-time execution.
the behavior of a linear system's response to different frequencies, a lowpass filter for example will let through low frequencies and block higher
gefink: there is RT-NET which in principle you can use while keeping real-time execution but I don't know of anyone who has provided instructions on how to use that successfully in a HAL realtime component.
jepler: yes. that i thought
lerneaen_hydra: in that case, not in detail,.. only that a speedup-capacitor helps switching at higher freqs for BJT's, but not how to figure out what values, or when its needed, without trial&error
basically pretty much all the values in my CCT are wild guesses
or suggestions from others =/
jepler: if so i can try things like halsampler...
RT-NET is to hard to implement it with my small AVR rhernetdevive
fragalot; the rise time will in any case be approx. 0.35/(1/(resistor*capacitor)/(2*pi))
that's in seconds
with 1k and 100n that's about 200µS
to go from 0 to 1V
I think... :p
too high values? :p
maybe a little
maybe 100µs for 0-5 volts would be good?
proabably just a matter of trail and error so there
's no noticable bounce
thats the answer to everything
so, the PCB itself is approved?
you might have to adjust some values
how fast do you plan on running?
mosfet drivers may be worth looking into
doubt it 'l be speedy, :p
lerneaen_hydra: these are logic-level ones, they have built-in drivers
(which is why i'm not sure that i was told to add resistor values there, but meh, can just bridge them on the pcb afterwards)
why the 100 ohm resistor?
usually you only use those if there's no driver
nfc, was told to have it there, lol
so there's an integrated npn/pnp driver?
thats what most of the forum messages i've come upon when googling said
hmm not according to the datasheet
[18:18:12] <lerneaen_hydra> http://www.irf.com/product-info/datasheets/data/irlz44npbf.pdf
[18:20:09] <fragalot> http://ohmark.co.nz/3step/hardware/3Step%20schematic%20-%20full.pdf
<-- approx the same connections as mine (used this as a base design :p) and,.. well for him it worked
do you know how fast you want to drive it?
hey all.... what signal or pin initiates an axis to home?
no idea how fast i CAN drive it
then again as this isn't a chopper driver you won't be able to go all that fast
are you etching this at home?
or ordering it?
hmm, I'd probably add pads for a mosfet driver and bridge them to begin with
if i could i'd make this on a breadboard, and have it mill out it's own PCB :p
Roguish_: an NML message is sent to home an axis. This message is only obeyed when the machine is in manual mode. You can send this NML message from halui based on the rising edge of a signal -- refer to the halui manpage for the pin name.
lerneaen_hydra: k, i'll add the drivers
[18:24:45] <lerneaen_hydra> http://export.farnell.com/1549140/semiconductors-integrated-circuits/product.us0?sku=zetex-zxgd3003e6ta&_requestid=394240
<-- I like this one, it's pretty good (read: cheap)
you'll need one per mosfet
Jepler, thanks. so it homing by joint? halui.joint.0.home ?
and ideally an npn with a pullup
awesome. that gave me a page where I have to select a country?
do drive it in turn :p
oh, go to farnell and search for ZXGD3003E6TA
it's surface mount though fwiw
Roguish_: if that's what the manual says I bet it's right
fancy, 5A peak
yeah, damn good
ideally you'd drive it with an npn bjt and a pullup
lerneaen_hydra: could I have it drive a normal 12V, and trigger its input with 5?
though that's adding quite a lot of components
it's output voltage is = input
but it's got near to no input capacitance
there is Vdd input, and the trigger?
uh, it's got vdd, gnd, output and input, the output voltage is kept to the input voltage
yeah but they're cheap :p
how fast do you reckon i could step with this thingy
hmm, the mosfets will turn on in under 50ns
so it's all up to the stepper
the stepper motor turns 0.9° per halfstep, lol
it's going to be one *SLOW* machine.. (1 step would be approx.. .0025mm)
you should probably be able to do 1-2 rps at least though (though I'm pulling this number out of my ass)
so thats ~2mm per second
with an M6 leadscrew and no transmission that's 60-120mm/min
rofl i could probably just mill stuff out using only G00
most likely ;)
.me finds a less 'accurate' stepper
1.8 degrees per step is fairly standard
5° per step is common for unipolars though
y'know, i'll likely spend quite a bit on this making my PCB myself,.. which controller do you guys recommend thats affordable, lol
I dont know about anything affordable with mid band resonance compensation
one you can just buy?
lerneaen_hydra: lol, yeah
anonimasu_; as his current one isn't even a chopper i doublt midband resonance is an issue :p
to the best of my knowledge, a chopper is a bike, ... care to clarify that part? :p
haha, a chopper driver
[18:37:20] <fragalot> http://www.magnetron.ch/products/Chopper_Driver_e.html
it applied a large voltage, maybe 50V in your case, which ramps up the current quickly, then it switches the power on and off and keeps a constant current
though that's bipolar
well I don't have the steppers yet,.. hell i still need to get my rails & plumbing to make the machine itself :p
(yes, i'll make the frame out of plumbing pipes)
sounds nice and true
[18:39:39] <fragalot> http://www.hobbycnc.com/products/hobbycnc-pro-chopper-driver-board-kits/
how many wires are actually on the motors you have?
jepler: I don't have any yet, but i'm assuming 6
you're aware that if it's 6, you can use them with either unipolar or bipolar, right?
the end goal of this project is to a) have fun with it afterwards b) learn more about steppers & other stuff
jepler; oh, nice, that's pretty slick actually, never thought of that before
6 or 8
4, 6, 8 wires work with bipolar. 5, 6, 8 work with unipolar. 6, 8 work with both.
4 taps per winding?
yes center tap split
(lets you put the coils parallel)
page 8 of this pdf shows how to connect 6-wire steppers to a bipolar driver (2 wires, the "center taps", are left unconnected): http://www.xylotex.com/XS3525V202.pdf
*reads & bookmarks*
anyways, reckon that that hobbycnc thing would work?
(incidentally the xylotex.com board works nicely on my machine with a 24V supply, but my motors' ratings are very different from yours: 3.5V, 1.5A)
* chr0n1c needs to finish his hobby cnc board, it's only been about a year
jepler: I don't have motors yet, I just assumed i'd get a certain set i found on the web
[18:47:01] <alex_joni> http://www.hobbycnc.com/products/hobbycnc-ez-driver-board-packages/
Spring Sale $410.00 CLICK for details
^above my intended price range ;)
alex_joni: yer i was just looking at that one :)
tahts approx 150 euro.. and its a lot better than what I tried to pull off
incidentally I bet this is the stepper motor that is on my machine: http://www.alltronics.com/cgi-bin/item/28M034/55/Lin-Engineering-4218L-01-11-bipolar-stepper-motor
-- NEMA 17 is physically smaller than the most common motor size you see on small milling machines like sherlines
well tomorrow i'll figure out how much the construction itself will cost, and see if i have that
the machine is fairly light (plastic construction), the screws are 1/20 inch/rev (1.27mm per turn), and I get 72in/min rapids (1800 mm/min) http://axis.unpy.net/01188441458
yeah thats about the size of machine i wanted to make
but for me it'd be the table that moves X-Y wise and not the tool holder
good night all
wow -- http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190238620400
-- it seems the guy's newer model does 800in/min (20000 mm/min) rapids
scary for that lil' bugger
jepler: a guy is asking if stippler still runs on hardy
I haven't used it in years
well.. you still have a userbase to support out there
800 inch/min would be .6 seconds from the front of the table to the back.
it is probably the color that does it..
jepler; is the zenbot made from HDPE?
I bet you can't even hit 800 in/min in 4 inches. (then slow down to a stop in the remaining 4 inches)
lerneaen_hydra: I'm not sure which plastic it is
* chr0n1c needs a 1 3/8" x 5/8" motor coupler for .187" to .250" with 2 set screws on each end (Brass, SS, CRS...)
jepler: do you see that the motors are now mounted at right angles somehow?
anyone with a decent lathe in the us?
cradek: yeah, the text talks about some kind of belt .. I assume he's increasing the RPM at the screw
(which seems backwards from the usual, decreasing RPM to get more torque)
but right angle + belt I don't quite get
it's this thing i'm planning on building
might use plastic for the frame aswell, not sure yet
i'll see what I can find
how can they seriously call that thing a milling machine
jepler: sounds like a plasma table design
at least be honest and say 'etching'
motor at 90 degrees
belt is over the motor shaft
belt moves the carriage
not a leadscrew, but a belt?
fenn: it might not be the most accurate ever, but it can do what others can!... just... a lot.. slower..
no more leadscrew..
that's crazy talk
lots faster, but lots less accurate
drive system is all new as well, featuring kevlar-reinforced urethane timing belts on all 3 axes
hey it's there in the text
fragalot: wrong, it can't do the same because it's not rigid enough to take the minimum sized cut
rigidity is everything when it comes down to how well a machine works
well, very very much of it.
well.. I was off to bed :)
alex_joni: this is used on plasma machines?
jepler: you can't do screws in sizes up to 3-4m long
fenn: well then, find me something else thats as easy as this one to build (or a full system for under 350 euro :p)
or actually you can .. but they tend to get really big
alex_joni: oh sure you can
or they will warp
cradek: what's the name of stuart's crazy big machine?
it's a G&L horizontal boring mill
8" diameter, 100" length leadscrew or something
jepler: the biggest screw driven thing was a robot table I saw once
fragalot: if you're just doing PCB's and nothing else, then it should be fine
it was about 20m long
maybe 10" diameter
fragalot: but i think the stepper motor as thrust bearing will give you hell with backlash
fenn: might make some small 3D decorations on wood
it was used to tilt a table for 4.5t parts
fenn: some motors have a spring to them and it actually works ok.
the table was maybe 30-40m long (so 100 feet .. if my math is right)
fragalot: at least step up to ball bearing drawer slides
depends a lot on the motor I'm sure.
* alex_joni is gone
fenn: could do that
"As shown in Figure 3 on Page 2, the belt 60° tooth profile limits the backlash factor to a maximum of approximately 0.003" per tooth engaged, and substantially reduces the backlash accumulation factor." http://www.chemiflex.com/technical_data/tb3000_1.htm
(they're hawking special pulleys that reduce backlash from .007"/engaged tooth)
.003 inch * (half the teeth around the pulley) is a huge amount of backlash
er I guess it's their belt which is different, not the pulley
but either way that's a lot of backlash
the proper way to do it is to use round tooth belts/pulleys
using the wrong angle will just cause a lot of belt wear
first place I found it is under six bucks a 20" belt so it's not expensive .. but it does cost a fair bit more than cheap threaded rod which is what's on his older machines
re that belt backlash that site concludes that
In addition, the installation and operating tension of the belt tends to deform the belt tooth down into the pulley tooth. This additional benefit essentially eliminates backlash completely (degree of backlash will change in proportion to tension).
I admit it, I stopped reading as soon as I saw ".003 per tooth engaged" :-P
hm.. spring loaded tensioner..
np. I just couldn't believe that I might have .07 backlash
on my grizzly
0.070 isn't completely horrible for a manual machine
just never climb cut ;)
yeah it would be fine if you were careful.
This was my first cnc conversion.
it's not even a full turn of the wheel :-)
[19:38:57] <fragalot> http://www.youtube.com/watch?v=RctndyASLzY&NR=1
is it me, or would this machine break down fairly quickly with those lines dangling along across the table the minute you hook up a piece that pokes up fairly high & jog away from it
* ds2 scrolls back to find out if it is a lathe or a mill
even with my worn out ballscrew machine I can place things within .001-002. we're all spoiled.
I remember the old manual lathes at my highschool...
one tossed its clutch over my shoulder, and the others had a ~3mm play on the handles
I'm thinking that what they are talking about is slip between the belt and the pulley that drives it.
So to see what the real lash is you have to figure diameter of the pulley and then angle of lash.
pretty much comes down to the same in the end. it's got too much play
Not at all. I know of many commercial machine tools that use belts.
ofcourse, I just mean, whatever transmission you use, you end up having too much play for modern standards
they just electronically make up for it more & more lately
if it were up to the clients pieces had to be accurate within 0.001mm, which is just plain silly
*continues on sketching out his own model for the mill*
im stuck on cnc videos :/
owell, atleast i got a basic sketch of how i'll make it..
y'know, the type without measurements or thought behind it
* anonimasu_ sighs
I might be stuck until tomorrow watching nice machining
like,.. if it were in scale, my Y axis would be approx 2cm away from the X+ limit
lol, 22 bearings in this lil' package.. sofar
is there any perticular reason that on everybodies DIY design, the tool moves if you move the Y-axis, instead of the table?
hmm.. my z axis only moves up and down
** like a bridgeport
[20:02:24] <fragalot> http://www.youtube.com/watch?v=qvOFhNmsZSU&feature=related
stuff like this one
somehow lots of the DIY designs are like that
yeah.. y is usually less weight, and less trave i assume...
takes up less space
somebody make me one and send it over, lol
my x/y are move as one unit and z is on a post above
yeah thats how my lil' sketch works
problem is.. lots of wasted space
also, where the f*ck does everybody get those plexi plates
uh.. white plastic?
or they order it..
I can't find that anywhere here :p
acetal is not cheap.
uhh, i mean the dollar store
cutting boards are probably cheaper..
don't have a "dollar store" here, and cut which boards
i've seen the nylon cutting boards on ebay
i mean eb*y
you can find uhmw reasonably on fleebay
[20:11:34] <fragalot> http://cgi.ebay.com/DAEWOO-CNC-LATHE-ONLY-21-HRS_W0QQitemZ280246374881QQcmdZViewItem?hash=item280246374881&_trksid=p3286.m14.l1318
-- .. we have this thing at work,... it's a NIGHTMARE to work on if something breaks down
damn ebay grabbing my attention to things that i don't want
now if only shipping werent so damn expensive.
yeah, last time I paid ~650 euro on a free server I got from a friend
* fragalot curses customs
fragalot: where are you from
ah I see
* fragalot scraps his current design and starts on another, probably better one
I have code that loads DXF files and generate gcode from it
It is free and I want to emc have it
LINE ARC POLYLINE CIRCLE LWPOLYLINE supported
I think that DXF is already supported by emc2.. isn't it? (correct me if i'm wrong)
ah,.. it's on the request page, nvm :p
no it's not
i put that request there... :|
that code sounds sexy
lol yeah :p
now give me iges :p
I wrote that code
y'know, it sucks how most DIY CNC machines actually... require CNC machines to get build (or the manual equiv)µ
find a better way ^_^
all I have is the trusty arsenal of hand tools :p
you only need a 12" scale and a drill press, maybe a hacksaw and a small lathe to build your first cnc
point is that I don't have time to develop filters or sth that fits to emc
and the machines at my summer job, but can't use those for personal things :p
or a cordless drill & hacksaw combo
chr0n1c: note the "lathe"
also, quit using inches, it's evil
"maybe" a lathe
inches are the win
but a lathe makes lots of things a lot easier & better
is considering a small lathe chuck for my 5c indexer/spin fixture
does any1 here have plans for a lil' tabletop CNC mill that will actually /work/ ? :)
mine might work for about... well,... untill it starts moving, then it 'l likely fall apart
fragalot, use a mini drill press frame and bolt 3 slides to it
quick and (can be) cheap
the slides are my main concern.. with hand tools only, htf do i get it to lign up straight
slots and dial calipers would be a close start
scribe lines right on the parts with dial calipers... center punch holes... let the drill do the work and holes should be almost right on
bolt one rail and mark it as "master"
then align the other one after it..
*sketches something out*
micges is the code available online somewhere?
anonimasu_: i see you have been reading on the 5bears site :)
no I havent since he stopped updating it
I *started* reading on there, but it looked a lil' out of my league when i saw his "pet projects" like the turbine, etc...
if you look at the dates it'st not as amazing..
if you think about the time involved
nevertheless really great stuff
it's not because somebody starts in 2000 and finishes it in 2006 (example) that a lot of work has been put into it
could be like an hour a week or so
I doubt it :)
that would still be 300 hours.. :)
but an hour is barely enough to get started on a machining operation
fenn: one moment
Daewoo puma 240's lathes take approx 5 minutes just to start up
heh.. one hour is about the time to set stuff up in a mill..
then the parts are like 2 minutes each :p
anonimasu_: hehe, or less
i want your mills
i had 30min setup time and 4.5 hours machining time today for a really simple part :(
I'm still trying to learn feeds/speeds :/
would have been 6 hours easily with turbocnc though, i'm really glad i changed to emc2
anonimasu_: fun part is one of the older mills at work... it somehow decided after making 200 or so pieces, that it should take a depth gauge (or whatever its called) to drill a hole instead of the drill it's been using the entire time
so,.. you hit the STOP button
how the hell did that happen
then the toolchanger blocks, and doesn't go back to it's home position
the thing is that you doze off when the machine does nothing but finish parts..
between changes :)
i have no idea how that happened
i still don't
or in my case drill/change tool
endmill then change tool
then center drill then change tool
(I hate changing tools)
hehe, more fun if the machine does it for you
then you can REALLY doze off
until it slams into a clamp :p
(untill you hear something crashing, because an air hose snapped and the tool falls out)
that wakes you right up
or if a piece flies loose
Seems like air pressure should release parts or tools rather than hold them in place.
* anonimasu_ nods
rayh: it is like that, but not in the middle of the process (eg. the clamp holding them as it switches)
[21:02:10] <micges> http://emc-files.webpark.pl/dxf.py
[21:02:16] <micges> http://emc-files.webpark.pl/generator.py
not too much slower than C code
you MIGHT want to translate those printf things, or atleast put a commend what it means
print "Czas przetwarzania pliku: %d ms" % ((time.time() - t)*1000)
good point :P
well, i'm off to bed.. cya
I dont know how to put it together int some filter program
to many options...
micges, is there a readme for the scripts or a wiki blurb?
anyone have any docs about dxf r14 SPLINE command ?
i don't know enough python to read and understand what would be happening in the scripts
here is readme : :)
like what version of .dxf files do they read?
and are all 3 scripts required for conversion?
up to r12
this is the wroking code
filter program can be build but I dont know how
ok... i was going to see if i could get some output, but didn't really know where to start after looking at the files
* chr0n1c didn't run them though
so that might explain a few things?
give me few minutes
I think I just found my biggest issue with making a CNC mill
micges: what is imported from machine_global?
hmm probably dxf.DXF.source
fenn: I have working version
and download this: http://emc-files.webpark.pl/conv.py
all files and dxf file in one dir
and then: python conv.py dxffile.dxf
should work :)
hey it works :)
DXF is really a worthy feature...
dxf files should have header to load
options are in source
fenn: It's quite fast code :)
retype: anyone have any info about dxf r14 SPLINE command ??
[21:40:58] <chr0n1c> http://www.autodesk.com/techpubs/autocad/acadr14/dxf/
micges: is all the .append stuff to make it faster?
instead of using functions
have you tried psyco?
its supposed to reduce the cost of a function call
cost of cpu power?
I have this code builded to axis
and when I use psyco I have to huge memory cost (about 1GB after 2h work)
ah i see
to this small code psyco do well its job
chr0n1c: yes, time cost of function calls
I don't know well python library ,maybe it has libs to speed it up better
fenn: have you tested this few times ?
i'm trying to get it to print out the list of gcodes
i'm sorta confused why you use None here: conv = Conv(None)
quick n dirty
my god alibre is annoying to make 2D schematics with
param was pointer to axis main window
thats it, i'm going to bed
* chr0n1c just had a salad from his own garden... so yummy
any one have any idea how i could use my 3rd axis driver as an input for a VFD to control my spindle??
figuring out how to program an fpga image to flash via jtag the first time is less than obvious
in fact, I think it took an hour
what are you doing with the fpga?
[22:52:51] <jepler> http://www.sump.org/projects/analyzer/
still not sure whether it works yet; next I have to get the f***ing java GUI to start
goog luck.. it looks like a cool and worthwhile project
if you really can get a device that does all that page promises for a hundred bucks or so, it's like a miracle
as i said... looks to be a VERY worthwhile piece of work.. ;)
im still waiting for my drives and driver board to show up... then we'll hack it into the boy's PC
OK, I've finally communicated with it .. in python
yay, the lathe is safely on the ground and in the garage
how big a lathe cradek?
right on... i have an hsl-59 we just lugged into the basement
i have 2 clamp on cross slides so i am putting EMC on 1 of them
cradek: pictures??? :)
too hot outside to even think about going back out to take a picture
mind if i ask what it cost ya??
1.5 billion dollars
(I don't want to say and make everyone jealous)
1200 miles worth of gas money was a big part of it!!
so you stole it... COOL... me to
WOW... mine was in the HOUSE
shipping and moveing cost me nothing more than MA alone at 1 end and ME and my son and a good friend of his to get it in the house... shipping would have been a mint on this its small.. but massively heave
finally after 3 yrs i may start to take baby EMC step... ;)