#emc-devel | Logs for 2008-07-30

[01:54:13] <jmkasunich> cradek: around?
[01:54:29] <jmkasunich> looking for recommendations to clean gummy jewels
[01:55:04] <jmkasunich> Starrett Last Word indicator, 0.0001 graduations, main problem seems to be goop
[01:55:41] <cradek> I'd throw it in the ultrasonic watch cleaning machine with watch cleaner. I think the main ingredient in the cleaner is ammonia.
[01:56:03] <jmkasunich> hmm
[01:56:24] <cradek> if you don't have ultrasonic, you can sharpen a piece of soft wood with a knife and use that
[01:56:24] <jmkasunich> I don't have a sonic, or watch cleaner - but I do have window cleaner - I think that is similar
[01:56:55] <jmkasunich> toothpick, sharpened?
[01:57:01] <cradek> sure I bet that would work
[01:57:20] <cradek> you can press the joint into the center of the jewel and spin it. then check with the microscope to make sure it's clean and you get the wood out.
[01:57:42] <jmkasunich> joint = point? or am I missing some watch lingo?
[01:57:46] <cradek> I have gummy stuff that can be good for finishing off - think something like silly putty
[01:57:52] <cradek> err right, point
[01:58:24] <jmkasunich> I was thinking of some solvent - dip the toothpick point in starting fluid or something
[01:58:47] <cradek> window cleaner will have water in it, so follow up with alcohol
[01:58:53] <jmkasunich> I have starrett's fancy instrument oil for putting it back together - supposed to be non-gumming
[01:59:20] <cradek> good. use 1/4 the amount that seems right :-)
[01:59:37] <jmkasunich> I'm thinking a drop on the bench, then use the toothpick
[02:00:11] <cradek> maybe a clean piece of wire instead? the toothpick might contaminate it.
[02:01:16] <jmkasunich> I could do that
[02:01:40] <jmkasunich> turns out I actually have some alcohol
[02:02:24] <jmkasunich> the trickiest one is gonna be the "preload wheel" (no idea what its actually called
[02:02:50] <jmkasunich> it has a hairspring that is staked into the housing, so I can't remove the wheel, just push it to the side to access the lower bearing
[02:02:57] <jmkasunich> s/bearing/jewel
[02:03:49] <cradek> ah I had that in my Gem indicator. I think it had a hairspring that could be unpinned.
[02:04:11] <jmkasunich> I could probalby pull the pin (brass, in a steel post), but I'm afraid to
[02:04:37] <cradek> oh it is pinned - glad to hear it is at least as good as a Gem.
[02:04:49] <jmkasunich> its a starrett
[02:04:56] <jmkasunich> (an older one)
[02:05:03] <cradek> bending the hairspring would be worse than dropping/losing the pin.
[02:05:42] <jmkasunich> no idea how I'd get the pin out, or put it back in
[02:06:16] <cradek> it just takes tweezers
[02:06:52] <cradek> you don't pull on the pin, you squeeze the small end toward the post. to replace, squeeze the big end back the other way toward the post.
[02:07:17] <jmkasunich> hmm, my arrangement doesn't sound like what you are describing
[02:07:40] <jmkasunich> I have a round steel post, with a crosswise slot in it (all the way across, from the top end)
[02:07:46] <cradek> I've cleaned one indicator in my life so I'm assuming it's like a watch :-)
[02:08:12] <jmkasunich> the spring is in the slot, and a small round brass pin is pushed down right in the center of the slot, pushing the spring to the side of the slot
[02:08:22] <jmkasunich> pin and post are concentric
[02:08:31] <cradek> oh the pin is perpendicular to the spring?
[02:08:36] <jmkasunich> yes
[02:08:48] <jmkasunich> top of brass pin looks like it was cut of with dikes
[02:08:54] <cradek> ah then it does sound like you'd have to pull it
[02:09:05] <cradek> hmm.
[02:09:45] <jmkasunich> I think I'll stick with plan A - clean around that wheel
[02:10:32] <jmkasunich> there are 6 bearings - bottom and top of main wheel, bottom and top of needle shaft/pinion assy, bottom and top of preload wheel
[02:10:45] <jmkasunich> I can easily to all three tops (I have the top plate off)
[02:11:01] <jmkasunich> I can do the bottom of the main wheel (that is in the body, not the round part with the gears)
[02:11:17] <jmkasunich> I can do the needle shaft bottom - that is in the center of the round part, not hidden
[02:11:44] <jmkasunich> and I can do the preload bottom bearing from the outside (bottom) of the round part (it is removed from the body)
[02:12:11] <jmkasunich> just have to make sure I don't tip it too much, don't want the preload gear hanging by the spring
[02:13:34] <cradek> in a watch, the hairspring can almost always support the balance wheel without distortion. I would be surprised if the indicator is different
[02:14:13] <jmkasunich> I'm going to try not to test that
[02:14:18] <cradek> yes, trust your eyes more than me
[02:17:54] <jmkasunich> heh, toothpick looks like a 4x4
[02:43:45] <jmkasunich> found out how to remove the spring
[02:44:02] <jmkasunich> the post is drilled all the way thru, you push the pin out from the bottom
[02:44:06] <jmkasunich> it is tapered
[02:58:21] <cradek> get it cleaned?
[03:02:42] <cradek> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230185123205
[03:02:54] <cradek> expensive, but an interesting type for mounting on a mill table
[03:04:06] <cradek> the motor is around the spindle?
[03:11:46] <jmkasunich> or is it underneath, with belts going up?
[03:12:06] <jmkasunich> no, I guess one of the pics shows air underneath
[03:12:28] <jmkasunich> regarding hairsprings - I don't know how much preload - gonna guess
[03:12:49] <jmkasunich> should I be turning it in the direction that tightens the spring, or loosens it?
[03:15:16] <jmkasunich> * jmkasunich guesses tightening
[03:33:52] <cradek> all I can guess is you should put it back however it started
[03:52:23] <jmkasunich> heh
[03:52:37] <jmkasunich> well, it is back together
[03:52:42] <jmkasunich> and even works, sort of
[03:53:10] <jmkasunich> the part I disassembled (the dial/gear assy) works, but the lever inside the body still seems "weak"
[03:54:01] <jmkasunich> there is a spring on that lever that is reversed by a small manual lever outside - that spring should be much stronger than the needle preload, so the lever will go the desired direction
[03:54:37] <jmkasunich> but its not - either the spring is weak, or something is binding or gummy in there
[05:39:42] <CIA-35> EMC: 03seb 07TRUNK * 10emc2/debian/emc2.files.in: install the hostmot2 sample configs as part of the debian package
[05:41:39] <CIA-35> EMC: 03seb 07TRUNK * 10emc2/debian/emc2.files.in: install the new gcode files as part of the debian package
[14:44:35] <cradek_> cradek_ is now known as cradek