#robotics Logs

Feb 12 2018

01:01 AM Jak_o_Shadows: Surely it's listed
01:05 AM Jak_o_Shadows: also, plane lights are cooler.
01:05 AM Jak_o_Shadows: Through boat parts may be easier to get
01:09 AM Jak_o_Shadows: But like, the FAA list EVERYTHING
01:17 AM rue_shop3: I'm printing lenses
01:18 AM rue_shop3: https://www.thingiverse.com/thing:2790590
01:18 AM rue_shop3: https://www.thingiverse.com/thing:2790609
01:19 AM Jak_o_Shadows: ah, these parts have some aesthetic need to them
01:20 AM rue_shop3: :)
01:20 AM rue_shop3: I need to design a retainer ring for the cnc
03:03 AM rue_shop3: ok 0.3mm passes at 90mm/min need cooling and good chip clearing
03:09 AM Jak_o_Shadows: Is 90mm/min slow or fast for you?
03:19 AM rue_shop3: fast
03:19 AM rue_shop3: well, 47mm/min was fast
03:19 AM rue_shop3: today we set a new record
03:20 AM rue_shop3: :)
03:20 AM rue_shop3: how do I make a chocolate extruder?
03:20 AM rue_shop3: I suppose if I use PTFE pipe I can heat it
03:25 AM Jak_o_Shadows: Continuous extrusion? Or melt all, and keep it heated?
03:27 AM Triffid_Hunter: rue_shop3: you'll want cold wind under the head to rapidly cool the chocolate
03:29 AM Triffid_Hunter: rue_shop3: seen a few around already, I think they had a syringe and heated water jacket down to the nozzle and cold air under, peltier element for both maybe
03:30 AM rue_shop3: oh, I was just gonna go REALLY SLOW
03:30 AM rue_shop3: ooo, jacket the bowden with hot water
03:30 AM rue_shop3: thatd give good thermal control
03:31 AM rue_shop3: I was thinking run the head cooler than the transfer
03:31 AM rue_shop3: I want to print wax too
03:32 AM rue_shop3: I was thinking same thing, media is transfered hotter than its printed
03:57 AM rue_shop3: so, I need to work out what I do, so I can build a capable macro machine
04:49 AM rue_shop3: ok I finally designed a piece for a z belt drive
09:11 AM SpeedEvil: https://en.wikipedia.org/wiki/OpenWorm
10:22 AM Miyu is now known as hackkitten
01:31 PM rue_bed: im slowly drifting to 100% sleep
01:33 PM Tom_L: WAKE UP!!!!!
01:33 PM Tom_L: you can't get anything done if you're asleep
01:39 PM rue_bed: yea I know
01:39 PM Tom_L: i fixed the program some too
01:40 PM Tom_L: gonna try it later today
01:40 PM rue_bed: ?
01:40 PM rue_bed: some?
01:40 PM rue_bed: path improvements?
01:40 PM Tom_L: shortened the ballnose cut so it doesn't hit the unmachined material stock
01:40 PM Tom_L: on the left end
01:40 PM rue_bed: I'm starting to get the idea you need to hand code them
01:40 PM Tom_L: no
01:40 PM rue_bed: k
01:40 PM Tom_L: you can't do that with surfaces easily
01:41 PM rue_bed: yea I know
01:41 PM Tom_L: flat parts you can
01:42 PM Tom_L: fix the damn offsets so that doesn't happen again...
01:42 PM rue_bed: maybe if I crawl out to the shop for a bit, maybe it'll help keep me up
01:42 PM rue_bed: so, this laptop is a 3 cpu 800Mhz intel
01:43 PM rue_bed: its slower than the 2 cpu 800mHz amd in the shop
01:43 PM rue_bed: waaait, this is a 2.5Ghz?
01:43 PM rue_bed: running at 800
01:44 PM rue_bed: :/ its still slower
02:59 PM durrf: https://www.youtube.com/watch?v=fUyU3lKzoio new boston dynamics video
02:59 PM durrf: terrifying
03:11 PM -!- #robotics mode set to +o by card.freenode.net
03:39 PM MoziM: durrf: i'll be terrified once i see it run for 10 hours +
06:54 PM rue_: ok it was a long weekend, what did I do
06:54 PM rue_: .....
06:54 PM * veverak made state exam and is a bachelor
06:54 PM veverak: gg wp
06:59 PM rue_shop3: congrads
07:00 PM rue_shop3: you should find a partner and fix that
10:03 PM AchiestDragon: apparantly mg996r servos run at 4.2 to 7.2v , have a stall toque of 3a each and 12 of the 18 did not like beeing run directly from the lipo supply at 7.4v
10:05 PM AchiestDragon: going to stick a 20a bridge inline on the power input that should give a 1.2 to 1.5v drop
10:19 PM rue_shop3: bipolar bridge!?
10:19 PM rue_shop3: who uses bipolar!
10:19 PM rue_shop3: :)
11:05 PM rue_: Tom_L, so I was cutting some acrylic today with the cnc
11:05 PM rue_: my rule of thumb is to have the feedrate too fast and the rpm too slow
11:05 PM rue_: I still had to give it a spritz of water, but I was thinking
11:05 PM rue_: about aluminum basically being the same game
11:06 PM rue_: your comment not to use mroe than a 2 flu cutter
11:06 PM rue_: the 1mm cutter I been using on alum is a 1 flue
11:06 PM Tom_L: huh
11:07 PM Tom_L: you're loosing half your time them
11:07 PM rue_: heh
11:08 PM Tom_L: does A12 look more efficient than what you're doing?
11:09 PM rue_: it looks easier
11:10 PM rue_: the basic outline might be hard to improve, I'm gonna take the job and apply the numebrs I worked out today
11:10 PM Tom_L: slap a slab of 5/16 on the table and cut a dozen profiles at once
11:10 PM Tom_L: then switch to P2 and do the slot
11:10 PM rue_: we edit in an offset at the end of the program
11:10 PM rue_: have it run one at a time, incase something goes wrong
11:10 PM rue_: I might upgrade my old machine to take gcode
11:10 PM Tom_L: what could possibly go wrong???
11:11 PM rue_: so we can eat up 2 machines while making them
11:11 PM rue_: things do, stuff comes loose or a bit breaks
11:11 PM rue_: or a power outage, motor slip (not yet!)
11:12 PM Tom_L: look over that flange where A9 goes into the tube and see if the ballnose gouge is ok there when you get them
11:12 PM Tom_L: i can back that off a little if i need to
11:13 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/Extra/A9_error.jpg
11:13 PM Tom_L: zoom in there and you can see it
11:13 PM rue_: I see it
11:14 PM rue_: I have some aluminum solder,
11:14 PM rue_: I was supposed to use it on the head I made yesterday, didn't get to it
11:14 PM Tom_L: it's only like .005 or so maybe a little more
11:14 PM rue_: hu?
11:14 PM rue_: the cut off top ear?
11:15 PM Tom_L: where the ballnose cuts into the L
11:15 PM rue_: ooh
11:15 PM rue_: thats prolly ok, we set that shoulder 5mm into the pipe
11:15 PM Tom_L: you're not getting the part i scrapped
11:15 PM Tom_L: it's still on the plate
11:15 PM rue_: :) np
11:16 PM Tom_L: it ran like a champ once i fixed the tool table
11:16 PM rue_: sweet
11:16 PM Tom_L: i didn't even dry run it, just fired it up and watched
11:16 PM rue_: feeling th bonus of the extra rigidity then?
11:16 PM Tom_L: very much so
11:16 PM rue_: cool
11:17 PM rue_: so, new spindle motor is soon on the list?
11:17 PM Tom_L: everybody said i should fill the tubes with something but i get no ringing at all
11:17 PM rue_: maybe get it to generate some finances first
11:17 PM Tom_L: i've got all these collets i hate to no use them
11:17 PM Tom_L: not*
11:18 PM Tom_L: and tool changing is easy
11:18 PM rue_: what size motor were you gonna target?
11:18 PM Tom_L: i just put them on hand tight
11:18 PM rue_: 1HP?
11:18 PM Tom_L: i dunno
11:18 PM Tom_L: if i can find a small one
11:18 PM rue_: I was going to do a motor change on the sherline I have here for 20krpm, but... mmmm
11:18 PM Tom_L: i'd like to be able to run a 3/8 cutter without worrying about it
11:18 PM rue_: those brushless look nifty
11:19 PM rue_: fro aluminum, the calc said ~6mm is ideal size
11:19 PM rue_: units 6mm inch
11:19 PM rue_: * 0.23622047
11:19 PM rue_: so 1/4"
11:19 PM Tom_L: 1/4"
11:20 PM Tom_L: i got 2 new carbide 1/4" cutters
11:20 PM rue_: iirc it was like 240mm/min for that bit at 3300 rpm
11:20 PM Tom_L: maybe
11:21 PM Tom_L: i'm running the ballnose at 3000rpm at 7 ipm
11:21 PM Tom_L: the flat one could probably do that or a little more
11:21 PM rue_: units 7inch/min mm/min
11:21 PM rue_: * 177.8
11:21 PM Tom_L: err, the ballnose is at 4000 rpm
11:21 PM rue_: we need an auto translation bot :)
11:22 PM rue_: I'm glad I'm not using radians/sec
11:22 PM rue_: :)
11:22 PM Tom_L: have you ever tried cutting 2024?
11:22 PM Tom_L: i hear it's crap to cut
11:23 PM Tom_L: but that's all the 5/16 stock i could find here
11:23 PM rue_: no
11:23 PM rue_: I'v never even heard of that one
11:23 PM Tom_L: they've got alot of 7075 too
11:23 PM rue_: what happens if you take a hacksaw to it?
11:23 PM rue_: gummy?
11:24 PM Tom_L: it's pretty nice to machine
11:24 PM Tom_L: i dunno
11:24 PM Tom_L: i'm not sure i have any
11:24 PM Tom_L: that 1/8" piece i'm sending might be
11:24 PM Tom_L: you can't always find marks on the scrap i get
11:24 PM Tom_L: i try to
11:25 PM rue_: tell me what the shipping is too, !
11:25 PM rue_: me and the fellow making them want to run the numbers
11:26 PM Tom_L: did you show him any of this?
11:27 PM rue_: yup
11:27 PM Tom_L: what'd he think?
11:27 PM rue_: he kinda said "hmmm" stared down and ground hsi foot intot he floor
11:27 PM Tom_L: uh oh
11:29 PM rue_: no he's just like that
11:29 PM rue_: https://www.aliexpress.com/item/1pc-3-175-4-mm-SHK-Sprial-Bits-Wood-Cutting-1-Flute-Tools-Carbide-Engraving-Cutters/32624794388.html
11:29 PM rue_: hmmm
11:29 PM rue_: too pricey
11:30 PM rue_: its funny Tom_L. I think the guy who used to make these was using a pentagraph router and jigs
11:31 PM rue_: and a plane to take the plastic he was using down to 15mm...
11:31 PM rue_: and a table saw
11:31 PM rue_: we were having a hard time guessing how much labour he was putting into them
11:32 PM rue_: it was all hand tho, that was for sure
11:32 PM rue_: https://www.aliexpress.com/item/10x-Parallel-Carbide-1mm-CNC-PCB-Milling-Cutter-Bits-for-Color-Plates-Acrylic/2049631807.html
11:32 PM rue_: thats the 1mm bit I'm using
11:33 PM rue_: I can get 11mm/min out of it (0.4 ipm)
11:33 PM rue_: the calculator said to use 1.5mm, full speed, at 200mm/min
11:34 PM rue_: it looks like my max speed is 500mm/min
11:34 PM Tom_L: i can get 1/8 carbide for around 6-8 bucks here i think
11:34 PM rue_: (19ipm)
11:34 PM Tom_L: on that mist nozzle, it really doesn't take that much air once you get the coolant to the nozzle
11:35 PM Tom_L: i turn it way back once it starts flowin
11:35 PM Tom_L: and it keeps going
11:35 PM rue_: oh
11:35 PM Tom_L: you can also raise the bucket up
11:35 PM rue_: I'v not found a good home brew mix for coolant
11:35 PM Tom_L: just keep the tube low
11:36 PM rue_: but, for perspective, the compressor I'm using has a 1/4HP motor
11:36 PM Tom_L: heh
11:36 PM Tom_L: mine's 5hp
11:37 PM rue_: http://ruemohr.org/~ircjunk/images/compressor.jpg
11:37 PM rue_: devilibis!
11:37 PM rue_: putputputputput
11:37 PM rue_: :) I put an unloading valve on it
11:38 PM rue_: the middle thing is a moisture trap
11:38 PM rue_: works good
11:39 PM Tom_L: http://itwprofessionalbrands.com/litart/tech_647.pdf
11:39 PM Tom_L: that's the coolant i use
11:40 PM Tom_L: it makes a big difference
11:42 PM Tom_L: We have something called Dawn dish soap. Mixed into water..it works
11:42 PM Tom_L: pretty damned well for rough duty coolant. I mix a pint of Dawn and 5
11:42 PM Tom_L: gallons of water.
11:42 PM Tom_L: https://groups.google.com/forum/#!topic/rec.crafts.metalworking/oo-QabQCa74
11:43 PM rue_shop3: .. just soap and water?
11:43 PM Tom_L: somebody did
11:43 PM Tom_L: not me
11:44 PM Tom_L: i went this far, i'm not gonna let coolant screw it up
11:45 PM Tom_L: or lack of
11:46 PM Tom_L: single stage compressor ehh
11:47 PM Tom_L: i've got an old motor like that sitting on the shelf
11:49 PM rue_shop3: I got another compressor late last year, but its motor is 240V and its under a tarp that got burried by firewood (gently)
11:49 PM Tom_L: mine's 220v
11:49 PM rue_shop3: I have a bigger one under the house, but its not plumbed over to the shop
11:49 PM Tom_L: with a big start relay on it i got used somewhere
11:50 PM AchiestDragon: putting a bridge with bat + - wired to the ~ and ~ inputs and of the bridge with the - as gnd out and + as the v supply out besides giving a prox 1.5v drop would also have the bonus of "protecting " against the battery beeing connected reverse polaraty in that it wont mater
11:51 PM rue_shop3: ah
11:51 PM rue_shop3: the "oh let me show you this quick! ARG!! I just hooked the battery up backwards, I JUST FRIED IT!!!"
11:52 PM rue_shop3: ok, these machines will be at it for the next 9 hours, going to bed...
11:52 PM AchiestDragon: not that revers polaraty was the issue as you cant plug deans connectors in the wrong way arround
11:52 PM Tom_L: ditto
11:52 PM Tom_L: gnite
11:53 PM AchiestDragon: no it was over voltage the batterist actulay can give about 7.9 to 8.2v when fully charged way over the 7.2v servo rating
11:54 PM AchiestDragon: but was a thought that that could happen also that made me decide to use a bridge
11:57 PM AchiestDragon: and 20 a bridges are easyer to get hold of than 20a diodes