#robotics Logs

Dec 03 2013

00:10 rue_shop2 damn
00:15 MrCurious indeed
00:18 notorand1 after further research, it seems they can make to order with up to 16 valves.
00:19 notorand1 my application is a boxing robot... humanoid.
00:20 notorand1 time for bed, for me 2.. tired.. must work in morning.
00:23 GargantuaSauce someone has his work cut out for him
00:24 MrCurious yeah, dont start with something simple like a turtle...
00:24 MrCurious go strait for t\e darpa combat biped challenge...
01:31 ablegreen i have a Firgelli L16 actuator: http://www.firgelli.com/Uploads/L16_datasheet.pdf according to the datasheet it is "0-15VDC, rated at 12V". what does that mean? what's the max voltage it can take?
01:44 rue_bed can you wait 8 hours for an answer?
01:44 rue_bed sleeeep!
09:32 GuShH yey.. got the 11.5mm bit, they didn't have 11.25 nor 11.75 though, and only up to 12mm... the hell, I needed a 16mm!
11:52 KongfuPanda GuShH, have you got a funny gif for today?
15:32 GuShH KongfuPanda: no, have you?
15:33 GuShH MrCurious: alright got the missing bits from my drill index... clerk gave me a 11.25 instead of 11.75 I almost didn't notice, assholes.
15:33 GuShH from or for... I'd say they're for the index.
15:33 GuShH and upon close inspection with the caliper, they are not very accurate either even though I paid for mid range
15:33 ShH scratches
15:33 GuShH stupid metric system
15:34 KongfuPanda GuShH, do you want to see cool animations that I generated? they are not funny, but cool nevertherless
15:37 GuShH god dammit these are not 1" washers either
15:37 GuShH they're .975, what the fuck is wrong with people, can't they measure things?
15:37 KongfuPanda GuShH, a e/m dipole intensity isosurfaces: https://dl.dropboxusercontent.com/u/26776513/new_cross.gif , https://dl.dropboxusercontent.com/u/26776513/near_dipole.gif , https://dl.dropboxusercontent.com/u/26776513/medium.gif, https://dl.dropboxusercontent.com/u/26776513/normalized_int.gif
15:38 GuShH DO I HAVE TO WALK WITH CALIPERS IN MY PANTS
15:38 KongfuPanda wait until gifs load, dropbox is slowish
15:38 GuShH KongfuPanda: neat
15:38 MrCurious are those calipurs in your pants, or are you just happy to see me
15:40 GuShH MrCurious: stab stab stab
15:40 GuShH I didn't know you were a HAMBOY, KongfuPanda
15:40 GuShH ham boi
15:41 KongfuPanda the woot?
15:41 KongfuPanda I like ham, yes
15:41 GuShH lol
15:41 KongfuPanda I was actually about to go to the fridge now to get some Italian bresaola ham
15:41 MrCurious have to remake part of cnc. seems i am seeing some flex where i wasnt expecting it
15:45 GuShH KongfuPanda: HAM not ham
15:46 GuShH ie ham radio
15:48 MrCurious -. -. --.-
15:50 KongfuPanda GuShH, what does it mean?
15:55 MrCurious CQ
16:05 KongfuPanda MrCurious, what is hamboy?
16:05 KongfuPanda I'm not a native speaker
16:06 MrCurious amateur radio operator, for transmitting on licensed frequencies, typically requiring understanding of theory and a test
16:06 KongfuPanda oh, I see
16:07 KongfuPanda well, I understand the physics behind antenna and stuff, even very deep one, such as relativity and stuff, but I have very little knowledge how to build a radio :D
16:07 MrCurious thats back to GuShH, i was only here to explainHAM
16:14 ace4016 you understand antennas but don't understand radios?
16:14 ace4016 :P
16:14 ace4016 means you might not understand antennas
16:21 KongfuPanda_ ace4016, I don't like electronics that much :) the physics formulas I understand
16:22 KongfuPanda_ because I'm a physicist
16:23 ace4016 KongfuPanda, look up heterodyne receivers
16:25 ace4016 though, the general concept of radios is:
16:26 ace4016 take signal and multiply it by carrier signal, send combined singal via antenna. receive signal via another antenna that is hooked up to something that brings the signal back to the original frequency range (getting rid of the carrier signal)
16:27 ace4016 there's some amplification along the way though
16:27 ace4016 like before you send to get the right power level
16:28 ace4016 and right when you receive the signal on the other end (because it's easier to filter out noise when your signal is strong and the noise is hopefully weak)
16:28 KongfuPanda well, I'm not gonna build a radio :D
16:28 KongfuPanda ace4016, have you seen my robot?
16:29 ace4016 nope
16:29 ace4016 did you link it a little while ago?
16:30 KongfuPanda ace4016, yeah, the dodgy homemade hexapod :D
16:30 ace4016 ah, don't think i've seen it
16:31 KongfuPanda ace4016, http://www.youtube.com/watch?v=4FxWpbLiw5g
16:32 ace4016 cool
17:09 KongfuPanda -Peggy? - Yes Mr Griffin? - That fart I have at 3, can you push that up to now? - Very good sir. - Prrrrrrrrrrrppppppppppprrrrrrttttt
17:19 Tom_itx kids.
17:32 KongfuPanda Tom_itx, it's funny :D
18:16 MrCurious the flex in the 20mm hardened steel rods is proving to be a huge problem on this cnc
18:34 Tom_itx uh huh
18:34 Tom_itx should have those mounted on those rails made for them
18:42 MrCurious yeah thinking i need to do that
18:42 MrCurious BUT
18:42 MrCurious not sure open bearings dont bring their own slop...
18:47 MrCurious and i am relly not keen on re-buying bearings
18:56 MrCurious maybe this deflection i see is to be expected, and i should just cope with it for now, and once working make a better machine
18:57 MrCurious but i can spread the bearing blocks, and move the shafts further appart to minimize deflection
18:57 MrCurious suppose i could also add a 3rd or 4th shaft
19:01 MrCurious wonder if aluminum ccnc's can mill soft steel
19:04 GuShH MrCurious: sure, just very fine passes
19:05 GuShH with the right spindle speed and feeds, no biggie
19:05 MrCurious if i apply 10 lbs of lift to the quill, it will deflect 2 or 3mm
19:05 armyofevilrobots That sounds.... excessive.
19:05 MrCurious its a heavy router motor
19:06 MrCurious maybe i do need to switch to supported rods and open bearings
19:06 MrCurious or make a smaller one, as 13" rods dont notably distory, but 30" do
19:06 armyofevilrobots 20mm rods? Oh. Not supported.
19:06 armyofevilrobots Yeah, that'll be problematic.
19:07 MrCurious thought chrome plated hardened steel from VXB would have been fine
19:07 armyofevilrobots it's surprising how much deflection you can get.
19:07 MrCurious yeah
19:07 MrCurious thinking if i seperate the Y rods further appart to match teh z axis length
19:08 MrCurious i could minimize some of the deflection
19:08 Jak_o_Shadows The calculations for that sort of stuff arn't too bad.
19:08 MrCurious as well as spreading the y bearing blocks an extra 4" appart
19:09 MrCurious i suppose once its working, i can mill lighter parts and replace much of the bulk
19:09 MrCurious perhaps add pillows at half way marks of z and y to make it better while i mill lighter bits
19:13 MrCurious maybe i will do a shallow pass milling test tonight driving the axis by hand and see how it performs
19:39 MrCurious tried light passes and got a nice flat trench
19:39 MrCurious seems 23k rpm is better than 10k rpm
19:42 MrCurious too heavy a cut, and it bogs and dives
19:43 MrCurious got horrible results at first, with 2 axis's free wheeling
19:43 MrCurious locking all but 1 gave better results
19:46 MrCurious should be good enough to cut a Z pattern resulting in 2 L's from a aluminum plank
19:47 armyofevilrobots OTOH, SBR20 or 25 mounted to aluminum extrusion are crazy stiff.
19:48 MrCurious even in side to side and top to bottom?
19:48 MrCurious i think once done that willl be the upgrade path
19:48 armyofevilrobots If you get the supported ones, they have worked pretty good afaict.
19:49 armyofevilrobots My current router is steel plates, which are stiffer again, but they aren't perfectly straight.
19:51 MrCurious its also far quieter than i expected
19:51 MrCurious the router that i
19:51 MrCurious s
19:51 armyofevilrobots heheh, I have never ever thought that :D
19:52 MrCurious i could hear bearings sliding over the router at 23k + cutting light passes
19:52 armyofevilrobots Wow. That's quiet. Mine sounds like a jet engine taking off.
19:52 armyofevilrobots what kind of router?
19:53 MrCurious i think it a porter cable 690
19:53 MrCurious annoyed i have to re-buy rails and bearings
19:54 armyofevilrobots Huh. I have a Hitachi KM12VC and they're supposed to be quiet, but LOUD in my opinion.
19:54 armyofevilrobots Yours is rated a little lower power, but imho porters are usually a bit better than rated, so they're probably really close.
19:56 armyofevilrobots anyhow, quiet router == awesome.
20:01 MrCurious :)
20:02 MrCurious wonder if this debgging accuracy, bearing slop, sag, deflection is something every cnc maker has to cope with, or if i am just lucky and special
20:05 armyofevilrobots sorry. not special.
20:05 armyofevilrobots :D
20:06 MrCurious HURRAY! i am plain!
20:06 armyofevilrobots Just assembled mine 3 weeks ago, still don't have it totally square and ready.
20:06 armyofevilrobots and it was built up and running for two years before that.
20:06 MrCurious ok, not feeling special
20:06 armyofevilrobots the debugging and tweaking never ends.
20:07 MrCurious so on yours....
20:08 MrCurious you acn mill steel?
20:15 MrCurious oh yeah, it mills oak ilke butter taking 1 - 2 mm passes
20:24 MrCurious ugh. $300 to replacec the weak rails
20:26 MrCurious suppose 3 of the 4 rods would be recycleable into a delta bot
20:26 armyofevilrobots Mine has never been used on steel.
20:27 armyofevilrobots I have done tons of brass though. Very shallow cuts but at high head speed, low rpm.
20:27 MrCurious have you done a + shape cut spanning max width/length to test for square, and depth
20:27 armyofevilrobots cooling is a problem though. I usually have a vacuum sucking up the mess and spraying coolant from a hand pump.
20:27 armyofevilrobots I don't actually cut to test square. I have a really big accurate cabinetmaker's square that I put on the bed and calibrate to.
20:27 MrCurious i used wd40 to cool the aluminum testing the wood ddidnt seem to be a problem
20:28 armyofevilrobots WOod is fine, just metals have cooling issues.
20:28 armyofevilrobots I have an air nozzle that supplies extra cooling and chip clearance for really hard woods.
20:28 MrCurious wonder if compressed air is enough to cool for alluminum
20:28 armyofevilrobots Never tried it, might be.
20:28 MrCurious or if i need mist and a mess removal system
20:29 armyofevilrobots anyhow, I am square to within 5-10 thou over 4 feet, although that changes with temperature and time.
20:29 MrCurious impressive
20:29 armyofevilrobots vertical repeatability is pretty shitty though. It's out 1/32" in the center. I have to mill my bed cupped to keep sheet goods cutting flat.
20:29 armyofevilrobots that's the guides I have; the steel plate is bent slightly from the factory.
20:31 armyofevilrobots the bed can go out just from sitting in the sunshine though, so I have to keep the room heated. It'll easily go out to 2mm or worse over time too, if I don't keep re-calibrating.
20:31 MrCurious hmmm
20:39 armyofevilrobots It's not a lot of change, under a mm, but it adds up.
20:39 armyofevilrobots thermal I mean.
22:56 Fiesta afaik there's no single-stage-to-orbit in existence.
22:57 MrCurious1 thought i read something about using the ocean to launch into space
22:57 Fiesta so compared to things that actually exist, spaceshipone is pretty good
22:57 MrCurious1 didnt read it, wonder if it was like holding a ball underwater and letting it shoot up
22:57 Fiesta sounds like a bit of a.... pipedream *badum-pssh*
22:57 MrCurious1 i would agree with that
22:59 Fiesta was that Canfield joint video of an RCS thruster?
22:59 MrCurious1 woohoo supported linear bearings set ordered
22:59 Fiesta pretty crazy
23:02 Fiesta i think that underwater launch pipe thing is like a light-gas cannon, they have to be very long, so you'd probably drill it down into teh ground. But having it in water allows it to be re-positioned.
23:02 Fiesta with a long enough pipe you might even survive launch :)
23:02 Triffid_Hunter Fiesta: the requirements for hydrodynamics would make the ships look very sci-fi too :D
23:03 Fiesta they'd be bullets
23:03 Fiesta or knives. you know, standard fast airplane stuff
23:05 Fiesta firing scramjet powered craft outof them would help, the cannon can just get it upto speed then the scramjet continue to accelerate once otuof the tube. Will allow shorter tubes
23:06 Fiesta but then it's technically not a single stage to orbit, the cannon would count as stage 1, scramjet would be stage 2.
23:06 Fiesta but who cares. i can count to 2, im' ok with it.