jmkasunich_ is now known as jmkasunich
cradek: a little off the top, eh?
the mill is reassembled and is working!
well, as well as it ever did, I think
something seems fragile - I keep getting error 4000 (?) and if I try to MDI it sometimes crashes (junk on the screen) but maybe that's when I forgot to enter a decimal point or something
(no manuals yet, so I'm kind of flying blind)
but this is a great accomplishment - the gearbox is back together, the phase converter works, etc etc
Congrats! I will look up the error code. They are a bit mapped.
I had the Z belt off, so I probably moved its index - wonder if it's hitting a limit sometimes
code 4000 maps to "drive fault", stand by while I list the bits MSB to LSB
8000 electronics fault
4000 drive fault
2000 internal comm error
1000 front panel not sneding valid key codes
0800 part program check sum error in stored program
0400 tool table check sum error in stored table
0200 ram failure
0100 rom failure
0080 system fatal error, whatever that is....
0040 communications error
0020 EAF board communications error
0010 commanded move would exceed machine limits
0008 spindle not running for a non-G0 move
0004 cutter comp error #2, indeterminate intersection
0002 cutter comp error #1 no intersection found
0001 program error dound by parser
thank you! that is surely the most important data in the book!
that and the debug monitor stuff, minimal as it is
I haven't hooked up a terminal yet
(but there is a DB9 cable on it)
debug monitor talks to a connector directly off the MC68000 board, no external connector
debug monitor only knows world of motion control as seen by MC68000
the Z8000 parser offers no such support
I wonder if "drive fault" means my power is inadequate
strange that it rapids fine, but faults when homing or when it's just sitting there
Did you say that Z axis belt was not installed? Drive fault usually means that motion was commanded and not detected by encoders.
basically following error
no, it's all back together
seems to move smoothly
I need to collect more data before we try to debug it :-)
maybe I can figure out the pattern
re-reading your earlier comments, getting "junk" on the display is NOT good
that did happen once
after I did an MDI command
I think it executed the command and then went to the junk
well a drive fault should relate to a single axis
miss-alignment of the Z axis microswitches if a possibility since that stuff got futzed with
they looked pretty solid, I checked them out when I had that apart
it hits all 3 nicely
there is a timing/gearing relationship between the microswitches and the index pulse from the Z axis encoder
I surely screwed that up
I should have marked it somehow but I didn't...
I did think about it as I was taking the belt off though - that counts doesn't it?
repeat after me... "my bad, my bad"
but you don't know how minor that seems after all I had apart and after 1000 successful applications of prybar/hammer
somewhere in the manual are re-timing instructions that cover X and Y for sure, and for Z one would hope
what you resorted to the the bigger hammer approach.... 8-)
none of the pulleys have holes for a gear puller - what a huge pain
in fact most of it was a huge pain - that mill will be in that garage until the end of time
FYI, the axis drive pulleys are a possible source of backlash on this machine, it seems the taper lock can become loose
and hard to figure out....
it has quite a bit in X - about .005
I haven't tried to debug that at all yet
oops, not good on backlash if it is in the ballscrew
there an option, present on everyexample I have seen, for backlash compensation
it is a pair of pots connected to an A/D on the MC68000 board
both of his machines had about the same, .003-.005 on X and Y both
I figured it was normal
the debug monitor can be used to read the value, and set it if the pots are not fitted
hmm, maybe those are wrong and making it worse?
no, I pulled the table, duh
so it's real
I did see two mystery pots in the bottom section
not good news on backlash, the one I mentioned doing a successful bearing bore has less than 0.001"
I should measure it near the end of travel too
ball screws tend to wear the balls and the nut more than the screw, so the backlash is more evenly distributed than is typical for an Acme screw
bad in that it is everywhere, good in that correction applies more evenly
of course EMC can map it
BOSS assumes constant backlash correction
.... so now that the deed is done, how did you get it through the door?
I took the whole gearbox/transmission apart and removed those three castings, then set the spindle motor on its side
then pulled it up a 1/4" steel ramp using rollers and a comealong anchored to a very conveniently placed huge tree
then, "simply" reassembled it
all in a good days work
I started at sun-up. I'm not used to that kind of a day's work
now you know how to replace the vari-speed belt when the time comes
yep, no problem
I also see how to mount the spindle encoder (easy)
cradek: does the machine have a quick change spindle?
it's regular 30 taper
and you have toolholders to match?
yes quite a few, and a very nice collet set
1/4 to 7/8
and a tap head (that I don't yet know how to use)
keep an eye out for 1/8" and 3/16", you may find them usufull
yes 1/8 would be nice
tap heads are nice
and easy to use, if its what I'm thinkning of
makes rigid tapping a breeze
well, not rigid, but thats the point
makes tapping a breeze
internally reversing, or just compression/extension
I need a jacobs chuck and whatever crazy tapered things necessary to hook it up
steves_logging: I don't even know that, I just threw it in the box
hold out for a keyless chuck
self reversing tapper will have a "reaction arm" or at least a place to install it
this one seems to have no arm
you need to take some photos
machine, tooling, etc
I have a couple
I should have photoed the big move, it was a sight to see, but I was busy moving
life goes on...
without photos, that is...
[03:03:08] <cradek> http://timeguy.com/cradek/emc/bridgeport
cradek: does it have a name yet?
if so, it would be "R2 unit"
so... you did manage to "split" the head, great
yeah I kept splitting until it was short enough
each piece could be lifted by two people, which was nice
seems like that airmotor wants to be replaced by a stepper ;-)
FYI, in case you don't alreay realize, that air duct on the top of the rear cabinet is not stock 8-)
yep I noticed that. There are two of them.
jmkasunich: as far as I can tell so far, that and the brake are the only air operated parts
I think it's electric
OK, could not remember
I should be sure (and make sure it's working)
I think the air motor spins fast - it's reduced by two worms - a stepper might kind of suck
yes and check for clogged metering widgets on all feed lines
right, check the metering widgets (??)
the lube pump pressurizes the oil lines, but there is a little orifice at each lube point that actually meters out the oil
lube pump has small metering orifices so that lube feeds equally to all points
I can't get to the upper ones (that you can see in the disassembled photo) - I'll have to look for evidence of them working and hope for the best
trash clogging the metering units is the main cause of ballscrew failure
X axis nut spins and tends to sling off the oil
* jmkasunich is easily amused
(watching my computer play the game "color lines" by itself)
woo hoo! 1344 points... not bad for something I coded up in a couple of evenings
what is color lines?
so JMK, what is it that you are trying to avoid having to do?
I'm avoiding working on 5i20 stuff
cradek: if you have an ubuntu system up, its in the games menu called "five or more"
I've wanted to code an AI to play it since I first saw it (but that was on a doze box)
I hacked the gnome version to allow call an AI function to calculate the next move
and have been messing with it a bit
(open source is cool ;-)
at this point, I'd say the AI is at least 90% as good as I am
oh ... you don't have to move in a straight line.
jepler_ is now known as jepler
cradek: does the bridgeport have split ball nuts to get rid of backlash?
mine doesn't, but I put the ballscrews in myself
I have no experience with bridgeport equipment
work here bought import knee mills. At home we have a large manual brown and sharp mill.
the brown and sharp is a 50 taper head
"wait for external digital input (#) to (rise / fall / be high / be low) (with timeout)" -> stores 1 in #5678 if timeout reached, 0 otherwise
"read external digital input (#)" -> finishes all motion, then stores current value of digital input in #5678
"read external analog input (#)" -> finishes all motion, then stores current value of analog input in #5678
I wonder if these are good primitives to add to gcode
everything would happen through new canon calls, so that sai or the axis preview can return whatever values seem like good ones
hmm.. I don't quite understand the first one
it simply pauses the g-code and waits / timeouts?
the prototype for the canon call might be 'int WAIT(int input_number, int wait_type /* rising, falling, etc */, double timeout);'
so it's the job
of the canon implementor to do the timeout
(in axis, for preview, the "timeout" would take no time)
and the input number would be one of the ones synced to motion?
sounds good to me..
WAIT() would finish all motion, then wait for the level or edge trigger specified
what if the condition is true after the motion stops? (ie, looking for high on a logic input, what if it's already high)
I imagine 4 wait types, so that you have the choice of edge or level trigger
steves_logging is now known as steve_stallings
skunkworks - the Bridgeport and most other commercial machines have anti-backlash ball nuts that rely on two slightly offset tracks in the nut fitted with selected balls to preload properly on the precision ground screw
the "cheap" rebuilds are just polish the screw and fit new balls
steve_stallings: interesting. I think our big K&T has 2 nuts that are shimmed for backlash.
but for the fact that I have enough trouble putting the balls back into a non-preloaded nut, I might try a "cheap" rebuild myself
as the machines get larger it is more likely that there will be two independent nuts
I would think that for as popular as the bridgeports are - rebuilt ones would be inexpensive.
depends on whether that's BP CNC or BP manual machines, I Think
relative to other machines, maybe, but still a few hundred dollars I would guess
the $700 kits for X and Y to fit manual conversions are a lower grade screw than the factory ones and do not involve the spinning X axis nut
yay for not involving the spinning X axis nut :)
well, it does limit X axis speed due to screw whipping
I like the Bridgeport mechanicals on the Boss machines
true, though I'm not sure the manual machines could really handle really high speeds anyway
if you keep near the center of travel, you actually have 3 points of contact for the screw, so the unsupported length is ~18 inches, which isn't bad for a 1.25 or 1.375 diameter screw
(well, you have 3 supports anyway, but you get what I mean ...)
but are the screws in the $700 kits that large, I thought they were 1" at the most
the ones I got are that large, and precision ground as well
at ~$600 or thereabouts (new old stock, chinese screws)
ah, from the guy that sells on eBay?
yeah - Machine Tools Direct, I think
those are supposed to be nice
yes, that is the guy
mine are definitely good
steve_stallings is now known as steves_logging
cradek_ is now known as cradek
steves_logging is now known as steve_stallings