* cradek is playing mr. fixit tonight
don't you hate those crappy old appliances that need to be repaired every 25 years?
some nice changes in emc - kruft removal and improvements in ini clarity
yeah, the commit list has been busy
I'm doing fixit too
digging into the lathe to acces the motor (with the blown run cap)
I hate wires
I hate the smell of the hardener part of epoxy.
I bought some 500v 45a mosfets - dont tell jmk though
going to use pwm for your huge machine?
pretty fragmented conversations tonight
I don't know what he's planning, I was hoping he'd elaborate4
what are you fixing?
tonight I fixed the old washing machine at the rental, and my car's washer pump
25 years on a washer is pretty good
don't make em like that anymore
I just cleaned the contacts on all the switches - its timer wasn't running
good for another 5 years now
and sprayed them with deoxit
yeah, maybe 10 or more, it doesn't show any signs of wear
I guess it's had the belt replaced once too
yeah even the racks aren't rusty, the rubber coating is all intact
our dishwasher is about 14 years old, and I've had to repair it twice
unlike my newer one at home which is rusting to pieces
once the float switch that turns off the water during fill was corroded, the other time a door spring broke
it's fun to fix stuff that was made to be fixed
sorry. Depends on how some medium sized servos work.
dc brush servos?
In the back of my mind I think I am going to add some simple current limit to the circuit.
thats a good idea
prevents popping fets in the event of a short or something
I have 45 of them. :) lots of oopses. I will need them.
(please don't lump me in with bo^dick)
that scheme sure works on my small machine
it'll be interesting to see what you can do
I have dreams of doing an AC drive using computer controlled PWM (not software, more like Jon's UPC, or a m5i20, or something like that
with pwm it's hard to both keep the frequency up AND get a lot of different levels
I have a _large_ AC servomotor that I'd like to use as a spindle drive for my lathe
unfortunately I'll have to hack up a drive for it
before I get into that I need to figure out how I'm going to deal with wires
packaging CNC stuff (drives, etc) is a pain
whats up with the wires?
well right now its just the tip of the iceberg - I need to replace a blown run cap on the lathe motor
to get at the motor I need to remove a chunk of housing, but the power switches are mounted on that
and wired to the motors
so its all unbolted, but still tied down by wires
which are terminated in tiny, unlabeled, crappy, chinese terminal blocks
I don't want my CNC project to end up like that
I want to be able to remove any part (electronics box, motor, etc) without fscking around with wires
bluetooth :) with electro-magnetic coupling for power.
are you thinking lots of plugs?
trying to remember how the mazak handled that kind of thing
not all the well IIRC
liquidtite flexible conduit with discrete wires in it mostly
and little conduit boxes on things like limit switches
I remember seeing a lot of blue wires run externally ;)
I found it hard to believe how complex that machine was
heh, its a lot simpler than it _was_
we simply ignored a lot of I/O
things like "fuse F23 just blew" inputs to the control
skunkworks: I don't think there were any external blue wires
lots of wires in wiring troughs and such, with the covers removed
there was lots of blue wire that had been pulled from it I think
but if the machine was buttoned back up I think everything was inside either metal or conduit
yes, lots and lots of that
pull out a one end of a bundle of 50 wires, then buzz it out and connect the 20 wires we cared about
the other 30 were probably still hanging there, but in the long run they'd be removed
[02:18:46] <skunkworks> http://www.electronicsam.com/images/KandT/cncworkshop/mazake2.JPG
:) notice the wires on the left
I just remembered something I saw on the web - clever way to deal with oil and chips, but not with disconnecting for service
hose barbs and clear vinyl hose, as a substiture for small diameter liquidtite conduit
yeah, thats a bundle thats not buzzed out yet
thats ok - makes me feel beter about my projects :)
[02:20:39] <jmkasunich> http://www.electronicsam.com/images/KandT/cncworkshop/mazake1.JPG
the bundle in the lower right (next to somebody's shoulder in a purple shirt) is the one you saw in the other pic
that end is coming from a conduit and entering the compartment, the free end is draped over the open door in the other pic
the upper right is another bundle, the free end of that one is draped the other direction
I like the sherline approach to stepper wiring
I don't like plugs.
Unless they are mondo expensive cannon plugs - I have had bad luck.
(plus all I work on is old machines :))
I'd scrounge around for good plugs
a _good_ terminal block (with ring lugs on the wires, and everything labeled) is OK too
but its got to be sealed up to keep chips and crap out
so then the drill is
1) remove lid from terminal box
2) disconnect wires
3) disconnect liquidtite or whatever from conduit box
all that just to separate one part from another
the other thing I need to figure out is exactly where I want to put my electronics box
theres no free space on/under the bench that holds the machine
I could maybe mount the box on the back of the bench, but access would be horrible
and it would have chips landing on it all the time
cradek: did you ever wire up your machine to use that cannon connector you bought at the fest?
no, maybe next time it's apart
I often under-engineer things and then don't mess with them as long as they work
that stepper drive setup is a prime example... ugly but sure makes the mill go
the lathe needs attention first - the wiring and drivers are all exposed so a chip in the wrong place is bad news
so you have the same issues I'm tangling with, only on a smaller scale
you remember the motors with exposed encoders on the ends
I haven't figured out how to cover all that
I don't recall exactly how exposed
completely exposed circuit board
and you can see the encoder disk if you look just right
did you post pics of your setup once?
[02:42:52] <cradek> http://timeguy.com/cradek/emc
it has to be here but I'm not spotting it
[02:43:21] <cradek> http://timeguy.com/cradek-files/emc/DSCN6290.JPG
I'm tempted to get a heavy latex balloon and stretch it over the end of the motor and call it good
you can rotate the motor by 90 degree increments, right?
there might be two orientations that are acceptable on this axis
you'll have a hard time stretching the mouth of the balloon big enough to pass the PC board
the other one can't be rotated
yeah, couldn't use exactly a balloon, but something like that
plastic bag and cable-tie?
yeah maybe so
I assume you replaced the flat cable with something else?
doesn't have to be pretty, just has to work
yes wiring is all replaced
ideally the belts would be protected too but that's much less critical
the motor mount plate is 1/4" thick?
I think each piece is 3/16
kinda thin then
I was thinking of drilling and tapping the edge
maybe it is 1/4
the big cap screw is 10-xx
then taking a sheet of thin aluminum (like flashing - maybe 0.010 or so) and forming it into a oddly shaped tube
the plate would be one end-cap of the tube
the other end would be out by the encoder
if you're really lucky, the encoder board footprint fits inside the mounting plate footprint
I see what you mean
another complexity is the pulley sticks above the top of the table/mount
the pulley flange does
that can be fixed ;-)
yeah maybe it's just the flange and not the belt
I think I'll get a plastic bag and wire tie :-)
it's fitting with the rest of the lathe setup
or janky, depending on your point of view
well, I need to be a little better
because I scatter a lot more chips over a lot wider area
and some of them are hot enough to melt the plastic bag
yeah that sounds a little different
I've made hot chips with the mill but not many
I'm pretty conservative with it, don't want to break anything
I was looking for our digicam, wanted to post a pic of my machine with the cover off
time for bed. you guys have fun.
found the camera
the images in this directory tell so many stories about emc and other things
they go back quite a while, I never clean them up
pic from our trip: http://home.att.net/~jmkasunich/Pics/mattie_rail.JPG
a visitor or your traveling companion?
belongs to the director of the nature preserve, who lives in the other half of the house
[03:09:37] <jmkasunich> http://home.att.net/~jmkasunich/Pics/fern.JPG
on a rock wall
oh was this your anniversary thing? how was that?
[03:12:36] <jmkasunich> http://home.att.net/~jmkasunich/Pics/porch.JPG
its very green there ;-)
that porch and coffee in the morning would be pretty darn nice.
I'll skip the coffee, but yes
the pic doesn't convey the sounds
birds, bugs, and running water
what does your wife do for fun? not a machinist too I assume
she is a bench jeweler
neat, a different way of building stuff
does she do casting etc?
[03:16:30] <jmkasunich> http://home.att.net/~jmkasunich/Pics/purple.JPG
not at home
cradek: hah, nobody ever "improved" on fuglui
I can't say I blame them
I've always wanted to try that but have no idea what I'd do with any jewelry
jepler: late, but as promised, I'm posting pics of our trip
jepler: it was done, wasn't it?
"purple" came out pretty nice, given a point-n-shoot digicam
looks done to me, totally configurable
yeah, and I don't recognize that flower
[03:19:09] <jmkasunich> http://home.att.net/~jmkasunich/Pics/greenrock.JPG
the biggest darn millipede I've ever seen - 2-1/2" long (maybe 3")
[03:20:23] <jmkasunich> http://home.att.net/~jmkasunich/Pics/millipede.JPG
those things are cool
from another planet, but cool
[03:25:35] <jmkasunich> http://home.att.net/~jmkasunich/Pics/goat.JPG
we were walking along the road back to the house, and we heard a "clunk"
"what was that?" start looking around, then look thru the bushes and see a face staring at us between the fence rails - the clunk was his horns hitting the fence when he tried to look thru
darn horns always getting in the way
the other day I saw goats standing up on their hind legs to eat tree leaves - is that usual? (I'm a city kid)
I think so
it seemed like an unlikely sight at the time
trying to decide what other pics to post
got more of mattie
couple of the interior of the hose
grasshopper on a tree ;-)
[03:30:56] <jmkasunich> http://home.att.net/~jmkasunich/Pics/grasshopper1.JPG
< jmkasunic> I was looking for our digicam, wanted to post a pic of my machine with the cover off
more millipedes there on the left
ok, this is the last trip pic
[03:31:58] <jmkasunich> http://home.att.net/~jmkasunich/Pics/bedroomdoor.JPG
you are joking I assume
oops, you're not
oh you must not have noticed them
I didn't see the millipede, thought you were referring to the vines and their rootlets
them? I see one
oh maybe it is one long one
jeez, I'm not so much of a city kid that I can't tell a vine from a millipede
reminds me of the 'guess the animal' game
"and what is a question that would distinguish a millipede from a vine?"
"and the answer for millipede would be what?"
is it moving?
[03:37:20] <jmkasunich> http://home.att.net/~jmkasunich/Pics/lathemotor.JPG
[03:38:31] <jmkasunich> http://home.att.net/~jmkasunich/Pics/lathebeltbox.JPG
theres a few chips on the motor
I see that
the clean spot is where the box used to be
I'd like to replace the box
yeah you're going to have to protect everything pretty well
put a 3/8" or so aluminum plate against the end of the machine (where the 1/16" box back used to be)
can't you stick a computer to the left? looks like a nicely sized empty spot
and mount the new motor to the plate
it would have to be movable, because there is a cabinet there
you can just see the door handle in the top left of the beltbox pic
oh I see it, I mistook that for a wall
the paint job tricked me
the colors are terrible
I've seen worse
the former owners of the house really liked yellow
I've seen worse indoors
I've repainted part of the basement walls to a light gray, but not behind the machine
I like yellow, it's the brown-purple that's a bit wild for my taste
too much work to move it (700 lbs, not counting the bench and all the crap in it)
the floor is the same color as the lower part of the wall :-(
paint is not important.
colors are all arbitrary
lighter colors do make the room brighter
handy in a basement
true, light is good
in the long run I want to completley redo the lathe drivetrain
crap it got late again
get rid of the v-belts, and have 2 or three speeds, each about a 3:1 step
use variable motor speed between the ranges, only change the belt when very low speed and high torque are needed
damn, I forgot - I'm gonna have to move the machine anyway to CNC it
the Y motor will stick out the back of that box that is on the rear of the table
(the box that ends up 1/4" from the wall when Y is all the way back right now)
this is why I've been doing my conversion for 3 years and made almost no progress
I hope when you finally get started it will go fast because you have spent a lot of time planning
I hope so
but things like moving the machine will take time regardless
I dunno if I should move it straight away from the wall by 6", or turn it 90 degrees and put the tailstock end to the wall
another possibility is to drop the crank handle on Y and put the motor on the front
can you move it with a floor jack or pallet jack and ingenuity, or does it take more?
but that would wind up obstructing the tee-slots, making it hard to insert t-nuts or remove chips
the bench is wood
strongly constructed wood, but still wood
oh I see that now
so I'm hesitant to move it from underneath
the original install went like this:
1) remove mill head
2) set machine under final location
3) install 4 eyebolts in joists, and block them up
raise main part of machine
5) slide bench underneat
6) lower machine onto bench and bolt down
7) replace millhead
if I moved the whole bench out 6", it would be tempting to stick the electronics box in back
do you use this much as a mill? it sure looks like it has a small table
6-1/2" x 19"
I don't use it as a mill much right now because its not rigid enough to take heavy cuts
but once CNCed, I'll use it for lighter precision work
the Van Norman handles my heavy work
the travels are something like 11" x 11" (depending on where the tailstock is and if the chuck is in place)
"not rigid enough" is relative - compared to a sherline or maxNC or Grizzely mini-mill its pretty rigid
it definitely looks like a nice machine to have around if you only have one
I better get to bed!
and I better get the info on the toasted cap
jmkasunich: thanks for sharing the photos
alex_jon1 is now known as alex_joni