just a fun link, an old timey carbide lamp for a bicycle http://www.jkdey.com/cycle.htm.
Adding an encoder to my lathe for threading what count resolution should I look for, running a 3k spindle and elson's servo board?
if you are counting pulses in hardware, you can use just about anything
if in software, you need to watch out for the high frequency limit
speed in RPM / 60 = speed in revs/sec * counts/rev = frequency in counts per sec
software can't count much over 20,000 counts/sec
hardware can count at least 10x that
is there a sweat spot on rev count?
not sure what you mean
for threading, "a few hundred" counts/rev should be fine
encoders are available from "a few dozen" counts per rev, to "a few thousand"
the highest end of the scale usually costs more
but up to about 1000 cpr is pretty much the same
we rigid tap on the mazak with a 360 line encoder
if you are buying new, look at usdigital for what is availalbe
for that it is plenty. and threading is much more forgiving than rigid tapping
if you are buying ebay or scrounging, just see what is available, then do the math to make sure the frequency isn;t too high
do I need an index pulse for threading?
hey, there's an echo in here
only on the easy questions
this half of the echo is going to sleep
any ideas on where to source a dual gang 33k potentiometer?
i've been googling..
cradek_ is now known as cradek
wow... just wow.. http://www.cnc.info.pl/topics60/frezarka-cnc-x1500-y500-z500-vt1706.htm
hmm pics are good and I like the gears
cant understand da werds
I also like making bits bigger than the machines are designed for
what is the gearbox for?
ratio will vary with angle, sort of trick shapers use (they use cams)
must be interesting making the internal gear, can only easily be made by generation or some evil wire erosion
we have a planer almost that big..
granted - it isn't together right now.
that machine is made similar to our kerney and trecker.. all weldments. (1 inch thick weldments though)
I don't understand why people like to use 'love-joy
style couplers for connecting servos/stepper to leadscres.
and the missing 'w' shows up in jeeze
sweet. they forgot to show the step where you fill it all with epoxy-granite
or its hollow and sings
also notice the foundry flasks in the background
i wonder if they annealed the whole thing once it was welded
the two wooden packing cases?
I think it should be filled with a non-newton liquid... Like silly pudy.
[15:34:39] <skunkworks_> http://www.cnczone.com/forums/showthread.php?p=477086#post477086
in front of the brown garage doors.. i suppose they might be shipping crates but they have little nubs sticking off the side like you'd use for alignment
skunkworks_: the magic technobabble words you're looking for are "viscoelastic shear damping"
fenn: thanks.. I didn't know the technical term :)
yes - there is actually an drive enable... :)
maybe that should be "drive enable" as this is not tested yet.
and "current limit" ;)
current limit is more fun to test :P
heh - jmkasunich says I should use a real comparator instead of an op-amp.. So there are a few changes yet.
but the logic works out that I can put 2 amps on 1 board and use up all the extra gates.
why bother.. comparator is like fifty cents
having a separate board for each axis is worth way more in terms of troubleshooting time
I feel bad for the unused gates..
poor poor gates, he must be so bored now that he has no job
there's some video of that welded mill.. it does screech: http://pl.youtube.com/watch?v=JyHQG7bvp68
looks like it has through-tool coolant too
yes - he has a picture of coolant spraying out of the end of a drill
ok that's enough polish tv for now.. :)~
Is anybody can help to build embedded-like version of emc2 ? Ubuntu is bad decision
hey all, who's sells an inexpensive (and reliable) parallel port breakout w/ opto-isolator? and how much $$ ??
Roguish, I made this ... http://members.shaw.ca/swstuff/bob.html
it is buffered, but only has a couple of inputs opto'd, I use it to drive Parker stepper drives which jave there own optos on step/dir
BigJohnT: good answer. :)
LOL your fast or at lunch :)
just got back from a lunch walk :)
Hi John... just out of bed here....
lewin1 is now known as lewing
hi skunkworks ... off to raid the coffee pot
wow AB push buttons LawrenceG
LawrenceG: thanks. i'm looking to add some i/o to an M5i20 system. kinda using up the 32 i/o pretty fast interfacing to an existing panel.
Guest739: if you are looking to build an embedded version of Linux to run EMC, you probably want to check out Gentoo or t2, might take you a month or two though
bahh didn't notice he had left :P
tomp: are you around?
BigJohnT, only the best!
only takes about 5 of them to cost more than a 6" touch screen!
no kidding.... I raided the junkbox.... I had been hoarding these for the last 20 years from an industrial panel I took apart
we bought a couple of panels from a junk guy that had about 40 on each one. We paid $10 each... We don't use them for customers but for shop projects they are great
LawrenceG: I wish you had a CNC plasma cutter
then you could design a THC and I could copy it :)
back from kernel update
LawrenceG: if you had a plasma cutter you could design a THC and I could test it for us :)
I am looking for a unipolar stepper motor driver for a Sherline mill (4 axis). Any good pointers? The Sherline box is way too expensive (700$) and I can solder. thanks
The EMC FAQ suggests Linistepper, but no one has tried it
Is there a pluto based stepper driver?
what you need is the drive.. (what runs the stepper) the pluto can be setup to output step and direction.. but you still need the drive.
have you looked at cnczone? I think there are a lot of people using the linistepper.. I have no experience with them.
skunkworks: sorry I am not sure I understand. I need something between my parallel port and the motors... pluto is not the way?
No - in that respect - printer port -> pluto -> drives -> stepping motors.
you dont want a unipolar stepper driver
skunkworks: I will check cnczone as well. So what is it that the pluto does?
i suggest waiting until the new cheap-o gecko drives come out
depending on how fast you need. - you could probably just do - printer port -> Break out board -> drives -> stepping motors.
linistepper is mainly for telescope mounts
fenn: thanks for the info
it really depends on the stepping motors you have... You might be able to run them bi-polar..
you can connect drives to the parport directly but this is potentially a bad idea due to electrical shorts and noise. a board that goes between the parport and drives and other stuff is called a breakout board
i can't recommend any as i haven't really studied the market
fenn, skunkworks: Its for a friend's old Sherline Mill. I already put din5 connectors so I can use it with my Sherline box, so I think my motors are unipolar
Thanks for the info guys...
Hugomatic: this is a good primer.. http://www.geckodrive.com/photos/Step_motor_basics.pdf
Those gecko boxes are not very expensive.... :)
Hugomatic: you can also check http://www.xylotex.com/
Dallur: nice link, thanks...
Dallur: I think my motors are unipolar, so a xylotex board might not work
Hugomatic: There are also several others plus it's quite doable to build one if you have way to much time on your hands :)
are you sure they are Unipolar?
I got some steppers from sherline, and they were bipolar
good night all
just cropped a COOL guitar..... cant wait till it gets here.. Martin Backpacker ... ;)
still lookin for servo/stepper drivers
buy something simple to start...
then if you need it add a bigger driver someday
jepler: I'm not using that spindle and probably won't for a while. it takes a few weeks to get one from the guy. if you order a replacement for me, you can just have it.