#linuxcnc | Logs for 2013-01-25

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[17:59:24] <rob_h> cheap machine for someone ... http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=121056526142&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en
[18:01:09] <andypugh> Won't fit under my door either.
[18:02:04] <L84Supper2> stone/furlong/fortnight^2
[18:02:09] <rob_h> here is floor space shortage
[18:03:43] <L84Supper2> we need a device that just temporarily reduces the mass of an object just during shipment
[18:03:46] <andypugh> 5.7 tons in Guildford isn't great either
[18:07:40] <L84Supper2> How do you teach an entire culture about quality? How long does it take to train someone about QC if the concept is completely new to them?
[18:08:47] <PCW> wow, look at all the toggle switches and lights!
[18:10:26] <L84Supper2> looks like a Heathkit stereo system form 1976 :)
[18:32:13] <skunkworks> Feels really nice.
[18:32:20] <skunkworks> heh
[18:37:15] <AR__> has anyone purchased from A2Z before?
[18:38:22] <AR__> i went through their checkout and paid with paypal but did not receive a confirmation or anything
[18:38:44] <AR__> other than a paypal receipt
[18:41:38] <ReadError> yea AR__
[18:41:42] <ReadError> you should be good
[18:41:50] <ReadError> if not call they are pretty nice
[18:42:38] <AR__> are they pretty quick?
[18:42:42] <ReadError> yea
[18:42:45] <AR__> cool
[18:42:47] <alex4nder> they're legit.
[18:42:49] <ReadError> when did you order?
[18:42:56] <AR__> just earlier today
[18:43:00] <ReadError> oh
[18:43:10] <ReadError> might go out monday then
[18:43:12] <AR__> yeah probably
[18:43:13] <ReadError> depending how early you ordered
[18:43:15] <ReadError> actually
[18:43:18] <ReadError> they are still open i think
[18:43:22] <ReadError> give em a call
[18:43:42] <AR__> yeah they are out west i think
[18:44:00] <AR__> i'll just wait till next week to see
[18:44:21] <AR__> i ordered a taig spindle and pulleys :)
[18:44:37] <AR__> got this old treadmill motor running
[18:45:05] <AR__> i think i'm done purchasing the major parts for the machine now
[18:45:07] <AR__> finally
[18:45:15] <ReadError> i was thinkin about using a taig Z axis on my router
[18:53:39] <andypugh> I am thnking about a scratch-built lathe.
[18:53:56] <andypugh> I have a hankering after a big through-hole.
[18:55:24] <AR__> get taig spindle and lathe chuck
[18:55:34] <AR__> mount it on a piece of iron
[18:55:35] <AR__> ???????
[18:55:42] <AR__> you have a lathe
[18:56:05] <AR__> add a little slide for your tool
[18:56:05] <andypugh> I want something like 3" through the spindle.
[18:56:12] <AR__> oh
[18:56:46] <AR__> build headstock yourself?
[18:56:52] <AR__> lol
[18:57:01] <andypugh> I have a 2.2kW washing machine motor that looks ideal for direct-drive
[18:57:32] <andypugh> And yes, I am thinking about making patterns and having a casting made for the headstock
[18:58:44] <AR__> you mean belt drive
[18:58:51] <andypugh> No, direst.
[18:59:00] <andypugh> Direct even
[18:59:47] <AR__> who the hell direct drives a lathe?
[18:59:59] <andypugh> Nobody.
[19:00:22] <andypugh> But perhaps they are all wrong and I am right?
[19:00:29] <andypugh> This is the motor: https://picasaweb.google.com/lh/photo/IyoF5obSvIRdd9xn6yIL1NMTjNZETYmyPJy0liipFm0?feat=directlink
[19:01:30] <PCW> Torque rating?
[19:02:06] <AR__> lol
[19:02:06] <andypugh> I don't know, bit if it can throw a drum of wet washing around, it can't be pitiful.
[19:02:25] <AR__> well, true i guess
[19:03:11] <PCW> I guess the spindle bearing is all you need
[19:03:36] <andypugh> I am not going to build a lathe and hope. I am not _that_ daft. I will jury-rig it to my current lathe first and see how it goes.
[19:04:11] <PCW> if its not enough torque, stack 'em
[19:04:12] <AR__> you can find decent headstocks on ebay for a good price
[19:04:13] <AR__> http://www.ebay.com/itm/Enco-Headstock-Assembly-for-7-x-10-Variable-Speed-Mini-Bench-Lathe-110-0803-/190781632573?pt=LH_DefaultDomain_0&hash=item2c6b78b03d
[19:04:22] <andypugh> I imagine that it will index well though, and be great for the sillly hexagon turning game.
[19:05:02] <andypugh> a) Not Decent. b) Very expensive :-)
[19:05:18] <PCW> may only be 300 RPM or so
[19:06:07] <andypugh> My washing machine spins to 1400, and I think the direct ones are faster, that's part of the point.
[19:07:22] <andypugh> The DSG Headstock i got (from DSG) for a test rig, now that was a decent headstock. :-)
[19:08:41] <andypugh> I wanted a very wide speed range, so got the head from one of these: http://www.lathes.co.uk/dsg/index.html
[19:09:02] <andypugh> Not the way I would do it now. I would be using an AC servo.
[19:09:37] <andypugh> At the time it was a big motor, star-delta contactor and gears.
[19:11:51] <andypugh> At max speed (3000rpm) it was terrifying. There was a 100kg flywheel, and this thing would spool up like a jet engine, getting louder and louder, and just when you thought it was there, it would switch to delta and get even faster. Then I had to click a mouse to engage the pneumatic clutch to drive the cam, so smash the platten and sample into the load cell. 0 to 50mph in 3/8".
[19:12:28] <AR__> lol
[19:12:50] <andypugh> I recall not having the nerve to click the mouse.
[19:13:53] <PCW> Does the washing machine motor have any winding options?
[19:14:32] <andypugh> Looks like straight 3-phase
[19:14:52] <andypugh> 3 pins for the windings, 5 pins for the Halls.
[19:16:20] <andypugh> I will probably hook it up to a 7i39 first
[19:16:20] <andypugh> (as I have a handy generic 7i39 port on the side of my controller, as can be seen in my latest dull youtube video.)
[19:16:20] <PCW> maybe you need another 8I20 (if it works)
[19:17:34] <andypugh> Yes, I am pretty sure I will. Brace yourself for an order :-)
[19:17:39] <PCW> Do you have the peak current specs?
[19:18:07] <andypugh> I can't imagine LG run the motor at less than mains voltage, and I know it is 2,2kW
[19:18:56] <PCW> looks like ceramic magnets, and you would not want to degauss them
[19:20:59] <PCW> although maybe the iron would saturate first
[19:22:37] <andypugh> The whole thing was £27, so it's just a plaything
[19:24:24] <PCW> thats a deal if it works (even if you have to stack 2 or 3)
[19:34:32] <archivist> andypugh, I have plenty files, cannot afford those
[19:36:45] <andypugh> I am not sure how big my favourite file is, I keep meaning to measure it as I want more the same size.
[19:39:25] <andypugh> Hmm, probably 16" but I have a feeling it might be 18"
[19:42:04] <archivist> I went out on an ebay collection of a strange item about 5 yrars ago and came back with extras on of which was a box of about 20 files
[19:43:12] <archivist> also get plenty of needle files and rifflers for the small work, also obtained while working as a clockmaker
[19:48:30] <andypugh> For someone with a set of CNC tools I do seem to spend a lot of time filing.
[19:49:51] <andypugh> It's often much easier to just make something than to design it, especialy when you don't know what yu want until you see it in the metal.
[19:50:54] <archivist> we used files a lot in clock work, nothing is as accurate as it first seems
[19:53:59] <AR__> lmao
[19:57:37] <andypugh> I spent a fair bit of Christmas adjusting the chime parts of my dad's clock
[19:58:36] <archivist> the ultimate file a clockmaker uses is a pivot file, you can get a burnished polish on a surface
[19:58:56] <andypugh> The basic problem had been that the gap had fallen out between 2 and 3. I had a hard time persuading my dad that 1 and 2 are the same hole, with no gap.
[19:59:39] <archivist> you can use a bit of hss if you grain it with fine wet & dry the right way
[20:00:15] <archivist> yes the wide slot :)
[20:00:28] <andypugh> They basically have no teeth at all?
[20:01:45] <archivist> no teeth just the right grained finish, a touch of oil and press against the surface of the pivot as it is spinning
[20:02:17] <andypugh> Hmm, do I need a sapphire burnisher? I suspect not yet :-)
[20:03:16] <cradek> archivist: a watchmaker with a file can be quite a curse. sometimes he doesn't know that metal doesn't SWELL with age
[20:03:35] <archivist> a bought pivot file does have some teeth one end to go from rough turned to better finish before you use the shiny(user adds his own grain) to burnish end
[20:03:56] <cradek> archivist: usually it's ok unless you give him a repeater or chronograph or something else he's not used to :-)
[20:04:34] <archivist> cradek, its called "take out the wear" :) but we know how to add metal to the hole in the plate and hide the fill
[20:05:23] <archivist> and one re pivots if a shaft needs it
[20:05:55] <archivist> another art, using small bits of blued steel rod
[20:07:16] <archivist> some that were rather bad http://www.collection.archivist.info/searchv13.php?searchstr=pivot
[20:07:50] <archivist> the lower one I straightened
[20:09:29] <cradek> wow, those are bad
[20:09:50] <archivist> it is amazing how bad some get
[20:10:01] <cradek> it's amazing it runs long enough for them to get that bad
[20:10:12] <cradek> I guess if you keep adding weight it'll run until one breaks
[20:10:52] <archivist> then you get a smashed clock with some teeth missing and a spring barrel to repair
[20:12:15] <archivist> inserting a tooth or few is where a set of tiny files are required
[20:13:21] <andypugh> Though it would be better to add a dovetail then re-cut to the original cycloidal/involute/octoid form :-)
[20:14:35] <andypugh> Right, sleep time.
[20:15:41] <archivist> original form there's a novelty ! some form is only approximate
[21:14:17] <tjtr33> L84Supper: is 1stime in China? #1 stay cool! Always smile, always calm, Never accuse. Damn hard... find an old expat whos been there a long time to explain.
[21:35:33] <tjtr33> andypugh maybe the 5pin cnxr uses 4 like in this washer repair manual page 33 http://ww2.justanswer.com/uploads/thehomesmithy/2012-02-19_165402_wpgt9350_sm.pdf
[21:35:37] <tjtr33> very neat motor
[22:04:17] <dgarr> tjtr33: [06:41:16] <tjtr33> when you have multiple .hal files, and a component of same type in each... well the 1st .hal has to loadrt it (like loadrt or2 count =3), this is kinda ugly, and hides
[22:04:27] <dgarr> see http://linuxcnc.org/docs/html/common/starting-emc.html#_twopass
[22:06:02] <dgarr> there are example sim files in configs/sim/simtcl/twopass_demo.ini
[22:10:56] <tjtr33> dgarr thx!
[22:12:18] <dgarr> using the names= method is highly recommended for readability and maintenance
[22:13:25] <tjtr33> hx again, that is super info. yes i wanted to use named comps, ended up doing all loadrts in 1st hal and used numbers. this TWOPASS feature fixes that :)
[22:29:42] <tjtr33> "using the names= method is highly recommended for readability and maintenance" ... and allows adding features by adding a hal file :)
[23:42:13] <mikegg> evening gents