steves_logging is now known as steve_stallings
rayh: I could use some advice about my Z axis. It still oscillates. when I null the vel input it still does it, so it's not the position loop oscillating - it's in the vel loop/amp
the tach output looks nice and clean.
I can damp the oscillation with an allen wrench on the end of the screw and it easily stops. but when I move, it starts up again.
turning the gain control up and down doesn't make it better or worse.
I replaced two nasty looking electrolytics on the amp and that didn't change anything.
steve_stallings is now known as steves_logging
EMC: 03cmorley 07TRUNK * 10emc2/src/hal/classicladder/module_hal.c: How did I miss hal_exit(compId) in exit code?
morning rayh and cradek
huh my simple enco order is coming in four separate shipments. it's good I found the 'free shipping' code.
EMC: 03bigjohnt 07TRUNK * 10emc2/docs/src/Master_Developer.lyx: Added more NML messages 40 down 112 to go...
EMC: 03bigjohnt 07TRUNK * 10emc2/docs/src/code/NML_Messages.lyx: Added more NML messages 40 down 112 to go...
what are you getting
oh just various supplies. It started with me needing a gallon of way oil, and ended up costing $150, you know how it is
one roughing end mill is coming in its own box, so is one box of shop towels
I've been getting my end mills from Lakeshore carbide and like them
Keep up the good work on those NML messages. I need em.
wish there was an easy way to get them from the spreadsheet to lyx
cradek, I've known those little pots on that drive board to not make good contact.
I still have not needed a solid carbide over 1/4". they are expensive.
does the format look ok on the NML messages
I've had to turn them back and forth a few times to get them to settle down. Seems the coolant makes a film on the wiper.
I use solid carbide for all even aluminum
rayh: ok I'll meter it -- but I have turned them a lot.
Then that may not be it.
the offset one definitely works
and the one at the bottom of the amp [unmarked] also does something (makes the oscillation change but not get better)
Good. That is a step in the right direction.
It's good that tach feedback is clean.
I use this one with aluminum dry and it seems to last forever. http://www.lakeshorecarbide.com/index.asp?PageAction=VIEWPROD&ProdID=59
I unhooked the vel command signal and nulled the offset so it didn't move, then moved it with a 1.5v battery both directions
moving with the battery had the same grumbling oscillation
I looked but couldn't find any of the manuals for that drive.
darn, thanks for trying
The tach v command comparator is right close to those pots.
A single transistor if I remember.
there are carbon comp resistors nearby too that I should check
also I have not done an obvious thing - swap the amps - just because it's a lot of screws and stuff. I should do that.
BigJohnT: do you use that with cold air? or just nothing?
holy cow, they recommend 1800 sfm
no way can I do that on my mill except with a VERY big end mill
haha I would need 1.75"
cradek: just compressed air
I rigged up a small regulator to some loc-line with a nozzle and it works real well
the cool thing about that series of endmill is is handles deep pocket corners without chatter and you can run it as fast as you dare...
and with a corner radius it lasts 10 times longer than other carbides
cradek: checked the brushes?
* skunkworks bets the servo is full of carbon
no I have not done anything at all to the motor
do they look like this? http://www.electronicsam.com/images/KandT/servostart/smallservo.JPG
I think they where hardinge..
yes I think so
they where packed full of carbon. I was impressed ;)
and thanks for the photo, which tells me where the brushes are hidden :-)
any hints for opening and cleaning it?
Those motors were made by ElectraCraft in Minnesota. Bought out by
Don't just pull them apart.
You'll weaken the magnets.
I think we just pulled the endcap off
We used a hunk of hollow steel tubing about the same size as the armature.
although ithas been a while.
If the carbon gets real bad it will short out the brush holder and then blow some transistors and resistors under the heat sink on the drive.
Oh they are pretty easy to replace.
I had some trouble with the caps - with the magic disintegrating 70s circuit board traces
Looks like I did replace 4 transistors on the board I've got in my hands here.
this one has a bunch of rework on the back. it may have blown up once before.
SK3260 is the replacement I used.
logger_dev: hear that? remember for me please.
I'm logging. I don't understand 'hear that? remember for me please.', cradek. Try /msg logger_dev help
rayh: want to stop over for coffee and have a look? :-)
You bet. Be right there in 14 hours.
I'll fire up my transporter
(it's loud so I don't let it run all the time)
Okay. "Now would be a good time, Scotty"
cradek, Does the growl persist at all speeds?
if I stop the oscillation with the wrench I can sometimes jog at very slow speeds and it won't start oscillating. but once it starts it seems to persist at all speeds, even stopped
Do the repairs to the board traces seem like they are recent or are they covered with crud?
they are pretty old
So it seems like it worked a while after those repairs.
I think so
he said he was using it 3 months ago. I have a hard time believing that but he seemed honest.
I suppose he may have been using it with the oscillation.
Want me to send you one?
let me make sure it is the amp first. I will troubleshoot some more including swapping the two amps.
if it is the amp and I can't seem to fix it, I'd appreciate that a whole lot.
Sure. Don't expect good behavior without retune after the swap
No two the same sort of thing.
do you know what the third pot near the bottom is?
mine aren't marked
the one I'm calling gain is marked "max speed" and the offset one is easy to identify by its behavior. the third at the bottom is a mystery
I used to know but...
Let me look brb
not a clue
I will mark it first if I get the urge to turn it on the working one
Might be a motor current feedback adjustment.
Although a lot of that scaling was done with the resisitors and caps on those solder posts
On this board, that bottom pot was glued to a specific setting.
one of those is 2.2Mohm carbon comp - I should desolder one end and check it.
oh hmm, mine isn't glued, and I've turned it all different ways.
You might pull the heat sink and look at the current sense resistors.
ok good idea. I could scope them and maybe see a motor brush problem too
If it was blown up and they replaced some with less accurate it might cause something like what you are seeing.
They are 0.1 ohm precision
thanks again ray, I'll let you know what I come up with. I better get going - lots to do this weekend!
cradek P3, the pot at the bottom is current loop balance. I found a set of the papers for that. Also found a description of the tool holders that Hardinge used. Send me an email with your addy and I'll get them out to you.
I might be on to a problem. the tach isn't as clean as I thought. when I ground the vel and tach inputs, and move the motor by changing the input offset, it moves smoothly
so I think it's a tach problem. I'm trying to figure out whether I should/can open up the tach
* skunkworks_ hates tachs
shhhhhh it will hear you!
heh - the old k&t had tachs for the velosity loop. They caused a few problems.
Ah. I've rebuilt them. When your reassemble them you'll need to chuck them up in your mill and adjust the back brush holder so you get the same voltage both ways.
ok so I should take these two screws out? :-)
a lot of them also have holes to place pins so the brushes are retracted for easy assembly.
(if you can get to them from the outside)
cool, the brushes face forward
can I safely pull the armature out?
Yes I believe so
I've got several of these as well. They may be for a bit later version of the feedback but you could swap brushes or the front end.
so - the commutator is like a disk?
I'd make a scratch mark between the end and the sides.
don't know if I have seen that.
EMC: 03bigjohnt 07TRUNK * 10emc2/docs/src/code/NML_Messages.lyx: WOW they are all done! NML messages galore
when do you guys plan on putting 2.2.6 out?
EMC: 03bigjohnt 07TRUNK * 10emc2/debian/extras-Ubuntu-5.10/usr/share/applications/emc2-integratormanual.desktop: changed comment for integrator manual
EMC: 03bigjohnt 07TRUNK * 10emc2/debian/extras-Ubuntu-6.06/usr/share/applications/emc2-integratormanual.desktop: changed comment for integrator manual
EMC: 03bigjohnt 07TRUNK * 10emc2/debian/extras-Ubuntu-7.10/usr/share/applications/emc2-integratormanual.desktop: changed comment for integrator manual
EMC: 03bigjohnt 07TRUNK * 10emc2/debian/extras-Ubuntu-8.04/usr/share/applications/emc2-integratormanual.desktop: changed comment for integrator manual
EMC: 03bigjohnt 07TRUNK * 10emc2/debian/extras-sim-Ubuntu-5.10/usr/share/applications/emc2-integratormanual.desktop: changed comment for integrator manual
EMC: 03bigjohnt 07TRUNK * 10emc2/debian/extras-sim-Ubuntu-6.06/usr/share/applications/emc2-integratormanual.desktop: changed comment for integrator manual
time to chill