#robotics Logs
Jan 28 2018
#robotics Calendar
12:00 AM rue_shop3: huh
12:06 AM rue_shop3: so, the old program needs to convert it to a profile?
12:06 AM Tom_L: no i was able to do it
12:06 AM Tom_L: just forgot how for a while
12:06 AM Tom_L: converts surface to polylines
12:06 AM Tom_L: there's some broken lines though
12:06 AM rue_shop3: ?
12:06 AM rue_shop3: I have a suspicion that there is some rounding error on endpoints
12:12 AM Tom_L: it's still missing a little on translation
12:25 AM Tom_L: i still think the old ver would do a better job translating it
12:25 AM Tom_L: the new one brings it in but overlaps segments and requires quite a bit of editing to fix it
12:52 AM rue_bed: huh
12:52 AM rue_bed: they must be within .0001" of each other
12:52 AM rue_bed: (endpoints)
12:52 AM rue_bed: arg
01:01 AM rue_: reflow oven, looksl ike 300c is a good upper limit
01:01 AM rue_: so
01:01 AM rue_: its defieitly enough for my food controller
01:01 AM rue_: so, should I use 16 bits
01:01 AM rue_: well
01:01 AM rue_: I'm not planning on using 0c
01:01 AM rue_: a 10c offset would be just fine
01:01 AM rue_: 256
01:01 AM rue_: 300
01:01 AM rue_: 255
01:01 AM rue_: 45c diff
01:01 AM rue_: hmm
01:02 AM rue_: to 8 bit, or not to
01:02 AM rue_: if I use a scale factor of 1.18
01:02 AM rue_: gives me 0-301c range
01:03 AM rue_: I need a rtc, and a storage area for profles
01:04 AM rue_: should I use an external rtc
01:04 AM rue_: how much would it help
01:04 AM rue_: aside from being accurate, it wouldn't just count linear seconds for me
01:04 AM rue_: which is something you want
01:05 AM rue_: so it might be better to use a 32k crystal
01:05 AM rue_: will the mega88 handle it
01:06 AM rue_: yup, timer/counter 2
01:06 AM rue_: which pins
01:06 AM rue_: PB6 and PB7
01:06 AM rue_: ok
01:06 AM rue_: 32.000 or 32.768
01:07 AM rue_: dividors are 8, 32, 64, 128, 256, and 1024
01:07 AM rue_: and its an 8 bit counter
01:08 AM rue_: 32768/256 is 128
01:08 AM rue_: so, I could give you a 1 sec, 1/2sec or 1/4 sec tick
01:08 AM rue_: 1 sounds good
01:09 AM rue_: ok, so, 32.768Khz on PB6 PB7, with a divider of 128, and an interrupt on rollover
01:16 AM rue_: the encoder can have its bounce dealt with via the RC filter and the 74hc14
01:16 AM rue_: which saves me painfull software junk
01:16 AM rue_: the temp sensor it a matter of the adc
01:16 AM rue_: not really a big deal
01:17 AM rue_: unless I try to linearize it
01:17 AM rue_: how about slow pwm for the elements?
01:17 AM rue_: limbo eh?
01:18 AM rue_: tc0 is 8 bit
01:19 AM rue_: ok, heat
01:19 AM rue_: lets say 1 sec pwm
01:19 AM rue_: and how fast are we running? 8? 16?
01:21 AM rue_: you didn't put a crystal on it
01:21 AM rue_: { page 109 }
01:22 AM rue_: so lets assume 8Mhz
01:23 AM rue_: no, lets assume 8.192Mhz
01:23 AM rue_: 8Mhz / 256 = 32Khz
01:25 AM rue_: your largest scaler is 1024, results in 31Hz
01:25 AM rue_: but idea...
01:26 AM rue_: if you use phase correct pwm, it slows it down by another factor of 2
01:26 AM rue_: ...kinda
01:26 AM rue_: I have an idea
01:27 AM rue_: why not use software pwm
01:27 AM rue_: ok, play that
01:27 AM rue_: take the rtc, divide it by 256 less
01:28 AM rue_: what if I prescale by 256, and rollover at 32
01:29 AM rue_: no, you want the interrupts 256x faster
01:29 AM rue_: do we need 8 bit pwm for heating?
01:29 AM rue_: what if you use a clock 256x faster than 32.768Khz?
01:30 AM rue_: 8.4Mhz?
01:30 AM rue_: I have an idea
01:30 AM rue_: why not use timer0, but divide the system 8Mhz by 256
01:31 AM rue_: 8.192Mhz / 256(rollover) = 32Khz / 1024 (prescaler) is 31Hz, call it a 5 bit pwm
01:32 AM rue_: or prescale by less
01:33 AM rue_: so, what we need is a divider of 128, and we dont ahve it
01:33 AM rue_: but we can get 7 bit
01:33 AM rue_: use a divider of 256
01:34 AM rue_: so, 8Mhz / 256 = 32Khz / 256 = 128 counts/sec
01:34 AM rue_: aka 7 bit pwm,
01:34 AM rue_: OR a 0.5Hz pwm rate
01:34 AM rue_: is 2 seconds too long?
01:35 AM rue_: at 7 bits, 1Hz
01:35 AM rue_: your about 8ms per tick
01:35 AM rue_: AC cycle is 16Mhz
01:35 AM rue_: or not
01:35 AM rue_: 16ms?
01:36 AM rue_: 8.3ms per half cycle
01:36 AM rue_: so you can trigger a half cycle
01:36 AM rue_: so there is no point in 8 bit
01:36 AM rue_: not really
01:41 AM rue_: regulator, ideas?
01:41 AM rue_: proportionate?
01:42 AM rue_: and how do we deal wit 2 elements
01:43 AM rue_: obviously as a gain adjust
01:43 AM rue_: so, error > k = use both elements?
01:43 AM rue_: now, thats project specific, we dont need it for the supper machine
02:20 AM rue_: how long is 65536 seconds
02:21 AM rue_: 18 hours
02:21 AM rue_: ah, that'll do then
02:24 AM rue_: I want to go try that schmitt on the encoder
02:24 AM rue_: and I want to go to bed
02:24 AM rue_: hmm
02:24 AM rue_: erm
02:24 AM rue_: uh
02:24 AM rue_: hmm
04:02 AM Sol is now known as Guest73113
07:20 AM Guest73113 is now known as Solgriffin
11:36 AM rue_: you wanted to try that schmitt trigger
11:36 AM rue_: yea
11:36 AM rue_: ok
11:36 AM rue_: waking up is a good start
12:19 PM Tom_L: too much trouble with the cad file
02:48 PM rue_shop3: huh
02:49 PM rue_shop3: so you have to turn the job into 3d to make an nc file?
02:49 PM rue_shop3: so, what if there is something like an overhanging edge that the machine cant do?
02:50 PM rue_shop3: so I got some laquer paint to try that pcb transfer process
02:50 PM rue_shop3: hard stuff to find
02:50 PM rue_shop3: nobody has white
02:55 PM Tom_L: you flip it and do a 2nd op on it
02:56 PM Tom_L: that cad file was just being too stubborn for my patience today
02:56 PM rue_shop3: it didn't think the ends met?
02:57 PM Tom_L: it comes in as surfaces which i convert to poly lines
02:57 PM rue_shop3: all the software I have uses a tolerance to make sure infinitly close points meet
02:57 PM Tom_L: then they just don't want to cooperate like they should
02:57 PM rue_shop3: huh
02:57 PM Tom_L: probably lost in translation some
02:57 PM rue_shop3: all in all, its a pretty simple file
02:57 PM Tom_L: i know it is
02:58 PM rue_shop3: see, there just isn't software that can do 2.5 properly, I have to write my own cam program
02:58 PM Tom_L: most of those probably started out as arcs anyway
02:58 PM Tom_L: my first smartcam package was 2.5d
02:58 PM Tom_L: i still have it too but i don't have it loaded because i always use the 3d one
02:59 PM Tom_L: oh, and the file you sent me has at least 3 layers in it
03:01 PM rue_shop3: we had to take a scanned image of it, and outline it by hand
03:01 PM rue_shop3: ?
03:01 PM rue_shop3: that second file only had layer "0"
03:02 PM Tom_L: it came in with at least 3
03:02 PM Tom_L: i brought it in solidworks first as a flat file
03:02 PM Tom_L: because the cam converter i have doesn't like that file for some reason
03:07 PM rue_shop3: ? the 3inch4tom.dxf ??
03:07 PM rue_shop3: I deleted all but layer "0"
03:07 PM Tom_L: i'll have to check on that later
03:07 PM rue_shop3: which is a default layer it wont let me do anything with
03:07 PM Tom_L: i know
03:07 PM Tom_L: i think it may be solidworks doing it
03:08 PM Tom_L: because i have to give it 'mass' to use as a solid which then i can save as an iges or other 3d format
03:10 PM Tom_L: we should figure this out so i can help you make parts
03:31 PM Tom_L: ok
03:32 PM Tom_L: i tried to bring it into autocad and it says invalid or incomplete DXF file
03:32 PM Tom_L: on the last one you posted
03:32 PM Tom_L: if it's gonna work anywhere it should be acad i'd think
03:36 PM rue_shop3: hahahahhaahahahahaha I been working all morning
03:36 PM rue_shop3: to make this circuit board with a debouncer on it
03:36 PM rue_shop3: dosn't fit in the project
03:37 PM Tom_L: woops
03:39 PM rue_shop3: so, you cant just take a 2d profile and have a cnc machine cut it out....
03:39 PM Tom_L: the problem is getting it in the cad not using the 2d profile
03:40 PM Tom_L: see, the old versions used .sh2 and .sh3 file formats which were 2.5d
03:40 PM Tom_L: and i can still read those
03:40 PM Tom_L: so i try to convert to those first then use the file and save it in the .sh4 format
03:40 PM Tom_L: which 99% of the time works fine
03:41 PM Tom_L: solidworks will read the file but i can't save it to anything useful unless i make a solid from it
03:41 PM Tom_L: let me try something..
03:43 PM Tom_L: yeah i read it in sw but it won't let me save it back as a dxf
03:44 PM Tom_L: i was gonna see if it fixed anything missing in the file
03:49 PM Tom_L: kinda frustrating
04:02 PM Tom_L: trying catia now
04:03 PM rue_shop3: id astounds me because dxf is such a prevalent formar
04:03 PM rue_shop3: t
04:04 PM Tom_L: catia completely screwed it up on export to iges
04:04 PM Tom_L: but it brought it right in
04:04 PM Tom_L: yeah maybe 100 years ago
04:04 PM rue_shop3: I'm not 100% surprised that autocad would reject it, its probably not 100% compliant,
04:05 PM rue_shop3: then again, if any program should be able to fix, it should be autocad
04:05 PM Tom_L: these other programs can read it in fine
04:05 PM Tom_L: sw and catia can read it in fine and i can make a solid from it
04:05 PM rue_shop3: do you think it would be easier from an SVG?
04:05 PM Tom_L: no
04:05 PM rue_shop3: huh
04:05 PM rue_shop3: I dont know how the world takes a 2d idea and makes it into a thing
04:06 PM rue_shop3: even sheet metal shapes are done as 3d?
04:06 PM rue_shop3: so, how would you make a punch?
04:06 PM rue_shop3: I dont get it
04:06 PM rue_shop3: what about laser cutters, their just 2d, it must be impossable on modern software
04:07 PM rue_shop3: or water jet cutters...
04:07 PM * rue_shop3 baffles...
04:07 PM rue_shop3: ok I have to make a new debounce board
04:07 PM rue_shop3: it took me 4 hours just to find 2 0.02uf smt caps...
04:07 PM rue_shop3: *sigh*
04:25 PM rue_shop3: I wish I started working on it back in 1999 when I first had the thought
04:30 PM Tom_L: ok well i've screwed with this long enough...
07:32 PM rue_: and if you cant do it, nobody can, I need to write my own software
07:32 PM rue_: REALLY kicking myself for not having started in 1999
07:54 PM rue_: ok, that should work for the rtc code
08:42 PM Tom_L: i probably can, just don't have the time to spend on it atm if it's gonna bed difficult with me
08:43 PM Tom_L: -d
09:09 PM rue_: yay, the new oven code works so far
09:09 PM rue_: yea, no I get it, its just that your pretty damn good and you have really expensive software
09:10 PM rue_: and its given you a run for your money
09:10 PM rue_: but it only takes me about 10 mins to set everything up with what I have
09:10 PM rue_: (which is only good for 2.5D)
09:17 PM rue_: need to get to programmable profiles this time, 60/40, RHOS, mac & cheese, BLT, Strip Board, pizza reheat...
09:21 PM rue_: "reflow xbox360"
09:40 PM Tom_L: it's like asking a greek to translate german to english
09:41 PM rue_: yea
09:41 PM Tom_L: but i wanted to get a little done on the mill too so i set it aside
09:42 PM rue_: its just an eye opener to every time people said I was wasting my time.....
09:42 PM Tom_L: we used to have to do that sort of thing alot on parts
09:43 PM rue_: I can whip stuff out really fast
09:43 PM Tom_L: and alot of times we'd have to patch up the models where the ends didn't meet etc
09:43 PM Tom_L: i know
09:43 PM Tom_L: doing 2.5 d is easy stuff
09:44 PM rue_: and the most expensive software in the world cant do it anymore
09:44 PM Tom_L: but when you're translating stuff from cadam, catia, solidworks, autocad, mastercam, smartcam etc it looses a bit in translation sometimes
09:44 PM rue_: nobody handles th mnumbers properly and the decimal places drift
09:45 PM rue_: all that 64 bit software
09:45 PM Tom_L: and i've got 3 generations of that program and it's hard to remember what i did with each one
09:45 PM Tom_L: no
09:45 PM rue_: 1.00000000000000000000000000000000000000000000000000000056 is not equal to 1.00000000000000000000000000000000000000000000000000000057
09:45 PM Tom_L: that's another slowdown, switching os from 64 to 32 and back
09:45 PM rue_: so, endpoints dont meet and shapes are not solid
09:46 PM Tom_L: then you get some free software that tries to emulate a standard and doesn't quite make it doesn't help either
09:47 PM rue_: indeed
09:47 PM rue_: esp when the makers of the format itself cant do basic corrections on it
09:47 PM rue_: For Fox Sake, what is the world comming to?
09:47 PM rue_: :)
09:48 PM Tom_L: sometimes we'd have to send stuff back to the mfg and tell them to send us something better
09:48 PM Tom_L: i've gotten whole wing sections to process before
09:49 PM Tom_L: because they were too lazy to pull the parts we were making
09:49 PM rue_: working on the reflow oven again
09:49 PM Tom_L: i thought you had it
09:49 PM rue_: trying to work out how to manage 2 elements
09:50 PM rue_: I'm thinking that if there is more than a particular amount of error, to bump the gain with the second element
09:50 PM Tom_L: that's not hard
09:50 PM Tom_L: i ran 2 io parallel
09:50 PM rue_: but I'd like to not just cut them in and out at the same time
09:50 PM rue_: trying to think how to phase the pwm or something
09:50 PM Tom_L: mine was pretty even
09:50 PM Tom_L: it has 2 top and 2 bottom iirc
09:50 PM * rue_ nods
09:51 PM Tom_L: you may as well come get it too, i'm probably done with it
09:51 PM rue_: AT THE SAME TIME, I want to make a controller for a food machine thats almost exactly the same gig, so I'd like this not to be tooo specific to the oven
09:51 PM rue_: I'm sure youll reflow again one day
09:51 PM Tom_L: i kinda doubt it
09:52 PM rue_: I'm gonna play with that heatless toner transfer thing
09:52 PM rue_: part of me is worried about the amount of fr4 I have left
09:52 PM Tom_L: someone in linuxcnc was telling me how they did it with inkjet
09:52 PM rue_: (about 75lbs)
09:52 PM Tom_L: sounded ok and easy
09:52 PM Tom_L: but it's not one i've ever tried
09:53 PM rue_: yea, if you put out a lot of money for special die and junk
09:53 PM Tom_L: i don't think they did
09:53 PM rue_: prolly
09:53 PM Tom_L: wipe the board with oil
09:53 PM Tom_L: and apply
09:53 PM Tom_L: and watch the magic happen i guess
09:53 PM rue_: ... they did it using ... whats that called...
09:53 PM rue_: e...
09:54 PM Tom_L: it's in their logs
09:54 PM Tom_L: from today i think
09:54 PM rue_: lithography with an inkjet printer?
09:54 PM Tom_L: could be
09:56 PM Tom_L: my program has an acad r13 specific translator, a dxf one and an iges one besides the stuff solidworks does
09:57 PM Tom_L: catia kinda sucks when it comes to that
09:58 PM Tom_L: and it's supposed to import .sat .sab and iges files
09:58 PM Tom_L: i've never used the first two
09:58 PM rue_: none of those are open standards are they?
09:58 PM Tom_L: ACIS text .sat, ACIS binary .sab
09:59 PM Tom_L: iges should be fairly open
09:59 PM Tom_L: it's the most common
09:59 PM Tom_L: but all of those deal with 3d
09:59 PM Tom_L: not 2.5
09:59 PM Tom_L: that's why i keep going back to my dos version
10:00 PM Tom_L: because once it gets into it, they made their newer stuff able to import those old files
10:00 PM Tom_L: the .sh2 .sh3 to .sh4 ( shape file )
10:02 PM rue_: my cad program ONLY does dxf
10:03 PM rue_: how do you make a gear?>
10:03 PM Tom_L: i have a program for that
10:03 PM rue_: and it outputs?
10:03 PM Tom_L: i modified it to make sprockets
10:03 PM Tom_L: a file
10:03 PM rue_: sh3?
10:04 PM Tom_L: i could export it to something else
10:04 PM rue_: but what does it output, what kinda file?
10:04 PM Tom_L: shx, iges, maybe dxf
10:04 PM Tom_L: probably wireframe
10:04 PM Tom_L: but i can usually pull what i need from it
10:05 PM Tom_L: i'm fixing this catia export right now
10:06 PM rue_: so, that dxf would be more usefull to you if it was a 1:1 pdf and you just traced it out to make a new part?
10:06 PM rue_: how long would a part like that usually take you to design?
10:07 PM Tom_L: if i hadn't thrown out my digitizer it would
10:07 PM Tom_L: if i had dimensions not very long
10:07 PM rue_: its mostly arbitrary curves tho
10:07 PM Tom_L: unless it's got ^^ yeah
10:07 PM rue_: huh
10:07 PM Tom_L: polylines
10:07 PM Tom_L: then you're guessing
10:07 PM Tom_L: unless you have a point file
10:08 PM rue_: :) I can use my dxf library to make one
10:08 PM Tom_L: actually this catia file may be coming together
10:09 PM Tom_L: i'll take a snapshot of it and you can see if it looks the same
10:09 PM Tom_L: it threw the surfaces kinda all over the place but it looks like a jigsaw puzzle i'm pieceing together
10:09 PM rue_: I'm still like "wow"
10:13 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/rue_part.jpg
10:13 PM Tom_L: kinda hard to see
10:14 PM rue_: by eye, that looks right
10:14 PM Tom_L: but they're all surfaces still
10:14 PM rue_: whats a surface?
10:14 PM Tom_L: it's about 4.2" wide
10:14 PM Tom_L: i'll show you
10:14 PM rue_: smartcam shouldn't have any issues with a dxf
10:15 PM rue_: oooh wait, i'm thinking of masteram
10:15 PM rue_: mastercam
10:16 PM Tom_L: look at that same part again now
10:16 PM rue_: I almost broke out laughing when the cam processor I'm using couldn't drill a hole from a point
10:16 PM Tom_L: all those are surfaces
10:16 PM rue_: ok
10:17 PM Tom_L: that's the wireframe of it
10:17 PM rue_: 1/4" thick, thats fine
10:17 PM Tom_L: that's probably 1/8"
10:17 PM rue_: looks pretty close to 1/4
10:17 PM rue_: based on scale
10:17 PM Tom_L: yeah it's .125"
10:18 PM rue_: huh
10:18 PM Tom_L: it's deceiving
10:18 PM rue_: fair enough
10:18 PM rue_: thats that part tho
10:19 PM rue_: we save time by not drilling the hole all the way thru, I just shallow pocket it, we use the drillpress
10:19 PM rue_: tho, I THINK I can push the 1/8" bit over 47mm/min
10:19 PM Tom_L: then you do a surface edit on it and change all those to polylines
10:19 PM rue_: but its a 3d thing...
10:20 PM rue_: you seem so close
10:21 PM Tom_L: now i just pulled the top outline off it
10:21 PM Tom_L: and hopefully i can use that as a 2d profile
10:21 PM Tom_L: it's just a little more complicated than 2.5d
10:22 PM Tom_L: but here's where the trouble begins because not all the polylines will meet
10:22 PM Tom_L: oy
10:22 PM Tom_L: it seems to have done better with this file
10:25 PM rue_: it takes the sherline 2 hours to make one
10:25 PM Tom_L: yay i got it to all join finally
10:25 PM rue_: hah
10:26 PM Tom_L: and i used the catia export
10:26 PM Tom_L: so that will do ok
10:26 PM Tom_L: i had to patch 2 endpoints
10:26 PM rue_: which ones?
10:26 PM Tom_L: but it's all one entity now in 2d
10:26 PM rue_: two of the arcs?
10:26 PM Tom_L: the lower inside curver on the right end
10:27 PM rue_: huh
10:27 PM Tom_L: where it heads off to the surface below the hole
10:27 PM Tom_L: that's a 1/4" hole right?
10:29 PM Tom_L: now look at the same part
10:30 PM Tom_L: ready to cut
10:30 PM Tom_L: with a 3/8" cutter
10:30 PM Tom_L: which i'll go smaller but i wanted to see
10:30 PM Tom_L: but there's still one little gap at the lower right end i gotta fix
10:30 PM Tom_L: endpoints didn't join
10:31 PM Tom_L: so what you do it find the smallest radius and use that size cutter or smaller
10:31 PM Tom_L: or use a larger cutter and come back and clean out those corners with the smaller tool
10:32 PM Tom_L: i just had too much going on earlier to think about it
10:33 PM Tom_L: yeah that fixed it
10:34 PM Tom_L: what size cutter do you have?
10:35 PM Tom_L: ahh you said 1/8"
10:37 PM rue_: yup[ hole is 1/4"
10:37 PM Tom_L: i got some code for you
10:38 PM rue_: heh
10:38 PM Tom_L: do you do a leadin move to the part?
10:38 PM rue_: no
10:38 PM rue_: I dont think the cam processor I ahve does leadin
10:38 PM rue_: I'm doing it in .25mm passes
10:38 PM rue_: or .20mm.... cant remember
10:38 PM Tom_L: hmm
10:39 PM Tom_L: i wasn gonna cut it all at once :D
10:39 PM rue_: that would be a stability test
10:39 PM rue_: I'd be really curious on the speed/feed you would use
10:40 PM rue_: one of the axies broke once on my new machine, it ploughed thru about 1/8" in one pass, didn't stall or anything
10:40 PM rue_: I'm still creeping up the feed rates
10:40 PM rue_: like I said, 47mm/min
10:41 PM rue_: 1.85ipm
10:41 PM rue_: at less than 8krpm
10:41 PM Tom_L: how many passed for 1/8" thick material?
10:41 PM Tom_L: 2?
10:41 PM rue_: say I'm going 9.8 thou/pass
10:42 PM Tom_L: holy crap that would take forever
10:42 PM rue_: that part you have there takes 2 hours
10:42 PM Tom_L: naw, that part takes 15 min
10:42 PM rue_: actaully, it was 16, I upped the feed to 47mm/min
10:42 PM rue_: with what size motor tho?
10:42 PM rue_: (spindle)
10:42 PM Tom_L: sherline
10:42 PM rue_: hmm
10:42 PM rue_: I dont know if I can push the bits I have that much
10:43 PM rue_: I think I can dial up to 2.8ipm
10:44 PM rue_: I'm also not running coolant
10:44 PM rue_: just the air puffer
10:44 PM rue_: to clear chips
10:50 PM Tom_L: you can't do 1/16" cuts?
10:50 PM Tom_L: half
10:50 PM Tom_L: 2 passes with a cleanup cut .010
10:50 PM Tom_L: at full depth
10:50 PM rue_: hmm
10:50 PM rue_: feed rate!?
10:51 PM rue_: 0.5ipm?
10:52 PM rue_: I was really surprised when I tried my milling machine for the first time and broke off a 1/2 HSS bit before I even felt any resistance from it
10:52 PM rue_: *clank* !?!@#
10:52 PM Tom_L: now look at that pic
10:52 PM rue_: they were used bits, maybe it was ready to go
10:53 PM rue_: paths?
10:53 PM Tom_L: 2 passes at 1/16" each with a cleanup pass at .010" in
10:53 PM Tom_L: yes
10:53 PM rue_: ok, you forgot holding tabs
10:53 PM Tom_L: i was gonna use the bolt to hold it
10:53 PM Tom_L: and somewhere outside the part
10:54 PM Tom_L: in the rectangular stock
10:54 PM Tom_L: it will hold itself until it breaks thru the bottom
10:54 PM rue_: 2 operation job?
10:54 PM Tom_L: one
10:54 PM rue_: then the peice will tip, pinch and bread the cutter off
10:54 PM Tom_L: or alternatively leave a skin cut on the bottom and punch the part out of it
10:54 PM rue_: marring itself hopelessly in the process
10:55 PM rue_: I just use 3 or 4 holding tabs
10:55 PM Tom_L: hah
10:55 PM rue_: easy enough to sand off
10:55 PM Tom_L: maybe i'll make you one and see, if i get a slab of aluminum on the mill sometime
10:55 PM Tom_L: i'm not gonna mill right on the mill table
10:56 PM rue_: your method also relies on the material thickness being what its supposed to be.... I'm seeing a surprising amount of varriation in the plate were getting
10:56 PM rue_: yea
10:56 PM rue_: you want that sacraficial stuff
10:56 PM Tom_L: we left .003 to .005" alot of times on thin parts and just snapped them out
10:56 PM rue_: (I use a milled flat wood block cause I can just sink woodscrews into it)
10:56 PM Tom_L: the bottom is still the bottom
10:57 PM rue_: ...
10:59 PM Tom_L: so that wasn't so bad once i got it to cooperate
11:00 PM Tom_L: see the first 2 passes are offset from the part by .010"
11:00 PM * rue_ offers tom a box of bandaids for the battle scars...
11:00 PM Tom_L: then a cleanup cut is at full depth against the part
11:00 PM rue_: http://ruemohr.org/~ircjunk/images/p1090623.jpg
11:00 PM rue_: bzzzzzzzzzzzzz
11:00 PM Tom_L: meh, it's just another part...
11:01 PM Tom_L: i'm gettin real close to using the mill
11:01 PM rue_: so what can we make thats interesting?
11:01 PM Tom_L: need a hole pattern and a piece of aluminum on it to mill on
11:01 PM rue_: Tom_L, its farther than it looks
11:02 PM rue_: note the brass screws :)
11:02 PM rue_: we've killed about 4 of them sofar
11:02 PM rue_: that puffer works good
11:03 PM rue_: I need to get a new peice of 1/4" tube and make something a little tighter
11:03 PM rue_: I was looking at some of the skelatonized small struts on a project and getting giddy at the idea of making someting like that
11:04 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/PART1.txt
11:04 PM Tom_L: there's the file
11:04 PM rue_: where is the F
11:05 PM rue_: oh 4
11:05 PM rue_: ah, its imperial isn't it?
11:05 PM rue_: 4 ipm!?
11:05 PM rue_: 3 ipm...
11:05 PM rue_: 6!
11:05 PM Tom_L: is that slow for you or fast?
11:05 PM rue_: geez, I dont know if that machine can even go that fast
11:05 PM Tom_L: ok
11:05 PM rue_: seriously, I dont know
11:05 PM Tom_L: heh you can edit those
11:06 PM Tom_L: that's about what my sherline _would_ do
11:06 PM Tom_L: i expect this one to do alot more than that
11:06 PM rue_: the jog speed is set to the abs max it can do reliably, and I dont remember what it was
11:06 PM rue_: I wanna see it making something ;)
11:06 PM Tom_L: i might have an mm cam file i can use on your stuff if you prefer
11:07 PM Tom_L: i think i made one up
11:07 PM Tom_L: but i never use it so i'd have to hunt for it
11:07 PM rue_: I think I wrote something for importing gcode
11:08 PM Tom_L: it's long because of all the polylines
11:08 PM Tom_L: converts them to lines and arcs
11:08 PM rue_: sure
11:08 PM Tom_L: short ones
11:08 PM rue_: its not an engine cam, so all is good
11:08 PM Tom_L: the big machines would eat that up so fast you couldn't read the screen
11:09 PM rue_: I'll gradually bump the feed rate of what I'm using, see what the bit can take
11:09 PM Tom_L: i'll probably kick the rpm up a bit on that too
11:10 PM rue_: iirc, if you put too much power into an aluminum cut, the material starts to melt and smear on the bit, causing @#$^%$#^&@
11:10 PM Tom_L: i've always had so much slop in the sherline i wasn't sure where to set it
11:10 PM Tom_L: wobble breaks bits
11:10 PM rue_: I'm at about 6000 now, at the 1.85ipm
11:10 PM Tom_L: stay within your chip load and you'll always be ok
11:11 PM rue_: with slightly less than 10 thou deep
11:11 PM Tom_L: so you could run at 15000 rpm and kick that part out in a min or so
11:11 PM rue_: chip load dosn't say anything about long bits and how much force they can take for how long...
11:11 PM rue_: the new cnc can do 16k
11:11 PM Tom_L: it does to an extent
11:11 PM rue_: but I dont have provisions for cooling, just chip clearing
11:12 PM rue_: when I new pack of bits arrives, I'll be more daring
11:13 PM rue_: nomatter where I put that file, i'm gonna lose it...
11:13 PM rue_: can I just leave it with you for now?
11:14 PM Tom_L: i need the rest of the assembly to make
11:14 PM rue_: ?
11:15 PM Tom_L: this isn't the whole thing is it?
11:15 PM rue_: no, its just an activation lever
11:15 PM rue_: there are ...
11:15 PM Tom_L: are the other parts the same thickness?
11:16 PM Tom_L: so we lay them out and slap a nice size piece of aluminum on there and let it cut a few at a time out
11:16 PM rue_: 3 peices that are cnc cut, then hand processed, there are 3 3d printed parts, there are 3 parts made on lathe (one of them is a spring) and one pipe thats jabbed into 2 bits of a router 3 times before being killed by hand with a few files....
11:17 PM rue_: that is the 1/4" part, the others are 5/16 and 1/8"
11:17 PM rue_: there are something like 22 parts to the whole thing
11:18 PM rue_: when we finished making the first one we just sat in awe staring at it.
11:18 PM rue_: and most of the design was copied from another guy (who died)
11:18 PM rue_: we think he had a pentagraph router
11:18 PM rue_: and was a seasoned woodworker
11:19 PM rue_: and jigs, lots of jigs
11:19 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/rue_part.jpg
11:19 PM Tom_L: like that
11:19 PM rue_: yea, we use a 20mm offset of the machine
11:19 PM rue_: the paths just cross into each other
11:19 PM rue_: but the sherline is shallow, so there is a lot of muffing
11:20 PM rue_: the new machine I made is nice that way, you can kinda feed-thru with it
11:20 PM Tom_L: anyway, i stretched my cad muscles today so i'm gonna go sleep now
11:21 PM rue_: I did a part the wrong way in the sherline and literally cleared the upright by 1mm fromt eh material
11:21 PM rue_: I was sweating as it came close to the edge
11:21 PM rue_: Tom_L, awesome work, victory is yours
11:21 PM Tom_L: yeah the last one i did, i had to lower the plate a bit
11:21 PM Tom_L: the standoff for the sherline spindle mount
11:21 PM rue_: I'm excited to see a video of your machine tearing into some material
11:22 PM Tom_L: we'll see
11:22 PM rue_: (better not be the bed either)
11:22 PM Tom_L: i need to take cutter inventory soon
11:22 PM rue_: hah
11:22 PM * rue_ thinks of his
11:22 PM rue_: 1x broken 1.8 bit
11:22 PM rue_: 4x broken 1mm carbide..
11:22 PM Tom_L: i snapped a nice carbide cutter the other day
11:23 PM rue_: 3x borken 1.5mm carbide....
11:23 PM rue_: 1x bent drillbit modified into a milling bit...
11:23 PM rue_: 6x carbide drills modified into V bits...
11:23 PM Tom_L: later..
11:23 PM rue_: gnight...
11:24 PM Tom_L: did you notice the leadin move i added to the file?
11:24 PM Tom_L: lower right
11:25 PM rue_: is that what that was
11:25 PM Tom_L: it's probably not long enough to reach the material edge
11:25 PM rue_: I need to write my cam processor
11:25 PM Tom_L: usually i define the material on a layer first
11:25 PM Tom_L: then you know the box you have to cut from
11:30 PM orlock: cam processor?
11:30 PM orlock: for determining cam profiles?
11:31 PM rue_: no
11:32 PM rue_: for taking a dxf and making an NC file from it
11:32 PM rue_: I dont care what anyone says anymore, its not out there
11:32 PM rue_: and the most expensive software you can get your hands on cant do it
11:33 PM rue_: so, whatever, I should have done it in 1999 and if I had I'd be the author of the leading diy-home software cam in the world
11:55 PM rue_: and i'd ahve the only one that ran on linux
11:59 PM rue_: well, I dont think the avr is running at the speed its supposed to be