#robotics Logs

Sep 04 2014

00:52 rue_house I think sandpaper comes in 9x11 sheets, so 9" is a good size
05:21 Solarlux What's name of surface mapping technologies?
05:21 Solarlux In industral robotics/
05:21 Solarlux ?
05:33 ace4016 3d scanning?
05:35 trshfx hi
06:23 Solarlux Like position scanning
06:23 Solarlux when system camera take pic
06:23 Solarlux of chip
06:23 Solarlux anddetermine what position it is
06:23 Solarlux placed there on camera
06:23 Solarlux and pickerpicks it
06:46 GargantuaSauce that falls under the umbrealla of computer vision
06:46 GargantuaSauce pick and place systems use fiducial marks to facilitate the process
08:01 robotust1a morning people
09:13 robotust1a MrCurious: next time leave a message, I was worry where did you dissapear
10:31 armyofevilrobot1 rue_shop3: I might be able to drop by tomorrow.
14:48 Loshki Solarlux: talking about SLAM? http://en.wikipedia.org/wiki/Simultaneous_localization_and_mapping
15:57 adam789654123 cool
22:51 rue_more outa time, I think my tig adveture will have to wait till rommorw
22:53 fluffywolf I want a tig welder.
22:53 rue_more make one
22:53 rue_more 40A 20V
22:54 rue_more some argon gas
22:54 fluffywolf the HF bit is hard.
22:54 rue_more be adventuresome make a tig tent
22:54 rue_more you dont need hf
22:54 rue_more make an argon tent, that the sheilding gas goes in, like a sand blasting booth
22:54 fluffywolf let's see you tig aluminum with no hf
22:55 rue_more easy, you start it on a peice of steel and walk it onto the aluminum
22:55 rue_more :P
22:55 fluffywolf the arc goes out
22:55 rue_more are you sure!?
22:55 fluffywolf the hf is to keep the arc going during polarity changes
22:55 fluffywolf yes
22:56 fluffywolf you can scratch start tig with any stick welder and a cheapo gun... but not on aluminum.
22:56 rue_more why is aluminum othe only metal you use?
22:57 rue_more have you seen the induction smelter/heaters people are making with IGBTs?
22:57 uffywolf googles to c
22:57 fluffywolf Top 10 mistakes - tig welding aluminum
22:57 fluffywolf 1. On transformer tig welders, forgetting to set high frequency to continuous when tig welding aluminum ….. this will result in the machine stuttering at low amperage because the alternating current will loose some of its half cycles when the direction of the current changes. Its pretty obvious and hard to miss. If the machine sounds like a Volkswagen with one spark plug wire missing, this is probably what it is.
22:58 fluffywolf because I like mig for everything else.
22:58 rue_more I'd really like to write some software right no
22:58 rue_more w
22:58 rue_more maybe I should take another look at adding fucnction uspport to my equation solver
22:59 fluffywolf you can also do aluminum with a square-wave output instead of sine wave... so you could take a dc welder output, filter it with some big caps, then invert it with a bit igbt hbridge...
22:59 rue_more or porting the ir remote code to mega 32
22:59 fluffywolf of course, a square wave happens to have lots of high frequency components, so it's kinda the same thing, just accomplished differently.
22:59 rue_more why not just modulate it with the IGBTs
22:59 rue_more I got a set, just to play with
22:59 rue_more rated for something stupid like 300A 1200V
23:00 rue_more I have 1 hour left, then I cease to exist
23:00 rue_more what would you do?
23:00 fluffywolf I have some 600V 400A darlingtons... 12 of them... one of these days they'll find a project. :P
23:00 rue_more I'm gonna start by turning off the shop lights so I dont run up a bill
23:00 fluffywolf ... huh?
23:00 rue_more I have some really big SCR's in that kinda range too
23:01 rue_more big paddies :)
23:01 fluffywolf these are small bricks
23:01 rue_more no idea what to do with them
23:01 fluffywolf http://fw.bushytails.net/transistor.jpg looks like that. :P
23:03 rue_more nice
23:03 fluffywolf I got 12 of them from a very large UPS.
23:03 rue_more even being a 3 layer, the drive current must be pretty significant
23:03 rue_more true sine or modified?
23:04 fluffywolf dunno
23:04 fluffywolf I'd imagine true.
23:04 fluffywolf the transistors are designed for very high speed on/off switching, for a pwm driver.
23:05 rue_more huh
23:05 rue_more I'd expect it to be a bit slow
23:05 fluffywolf they're impressively fast... a few uS from off to saturated and back.
23:05 rue_more cooool
23:06 fluffywolf they actually have pretty poor heat dissipation limits, designed to be only on/off.
23:06 rue_more you should make..... a ups... ?....
23:06 fluffywolf "pretty poor" is 1000W, which sounds large, but consider it's only 2.5V at rated current...
23:06 rue_more yep
23:06 fluffywolf or maybe it was 1500W. come to think of it, 1500 sounds more right.
23:07 fluffywolf so 4v. :P
23:08 fluffywolf yeah, 1500. googled a datasheet again.
23:09 fluffywolf 3.0us rise, 3.5us fall, switching 400A at 300V, with 0.8A base current.
23:10 fluffywolf I find that pretty impressive for a BJT.
23:11 fluffywolf 2.5V collector-emitter voltage at 400A with 0.5A base drive
23:29 rue_more sometimes they get it right
23:30 rue_more you dint' keep the power bridge? what blew up?
23:31 fluffywolf dunno. there was some evidence of arcing on top of the big bank of metal-canned capacitors.
23:31 rue_more driven by pulse transformers?
23:31 fluffywolf I heard they just remodeled the building and out it went.
23:31 fluffywolf government
23:31 rue_more huh
23:31 fluffywolf it's other people's money.
23:32 fluffywolf it was at the local scrapyard
23:32 rue_more say that next time the tax rate goes up
23:32 fluffywolf it had a very large battery bank to go with it... one of the scrapyard employees claimed it for his solar system.
23:33 fluffywolf the power unit was two boxes the size of walk-in closets
23:33 rue_more 2V?
23:33 rue_more huh
23:33 fluffywolf dunno, I never saw it, just the empty racks, and being told what happened to the batteries when I asked.
23:34 rue_more my 8kw true sine died
23:34 rue_more "no output votage" error
23:34 fluffywolf I recently upgraded to a 3.5kW true sine... outback gvfx3524.
23:34 rue_more from what I can tell its not turning on the damn inverter
23:34 fluffywolf and/or it tries to turn it on, but all the fets are blown so nothing happens. :P
23:34 rue_more er, sorry 5kw
23:34 fluffywolf I got one on ebay like that...
23:35 rue_more the 8kw takes 96V of batteries
23:35 fluffywolf mine is 24v, for my solar system.
23:35 rue_more backup genny?
23:35 fluffywolf I have a honda eu3000is
23:36 rue_more inverting?
23:36 fluffywolf yes
23:36 rue_more nice
23:36 rue_more take much load to break an idle?
23:37 fluffywolf I haven't used it extensively... it seems to work well.
23:37 fluffywolf I like free power, not $4+/gallon power. :P
23:37 rue_more propane/natural gas/gasoline/diesel?
23:38 rue_more or E) not applicable
23:39 fluffywolf gas
23:39 fluffywolf (gasoline)
23:40 rue_more I have a 4kw thats prettymuch just a pain in the ass
23:40 rue_more I just accepted at some point every time I need to run it I have to rebuild and retune the carb
23:40 fluffywolf heh
23:41 fluffywolf I have a propane string trimmer like that. I've about given up on it. it's buried under crap in storage.
23:41 rue_more and reprime the fuel line
23:41 fluffywolf I even put a BRAND NEW carb on it... it worked for five minutes.
23:41 rue_more I didn't know they made propane 2 strokes
23:41 fluffywolf they sent me the new carb for free, because they all fail.
23:41 rue_more is it 4?
23:41 fluffywolf turns out the new ones fail too.
23:41 fluffywolf four
23:41 rue_more oh
23:42 rue_more valves?
23:42 fluffywolf actually, 2
23:42 fluffywolf I'm thinking of the honda one in my head...
23:42 rue_more so its a 2 stroke propane...
23:42 rue_more how do they oil it?
23:42 fluffywolf separate oil... so maybe it is four.
23:43 rue_more oh
23:43 rue_more hmmm
23:43 fluffywolf have I mentioned I haven't touched it in years, and it's under so much crap I can't see it? :P
23:43 rue_more I want 2 stoke propane for the mecha
23:43 rue_more I dont know if boat engines use seperate oil, I dont think so
23:43 fluffywolf you don't want these trimmers. they're crap.
23:44 fluffywolf http://golehr.com/
23:44 rue_more mines a gasoline 2 stroke, if you prime it up right it starts first pull (starting pull, not priming pull)
23:44 fluffywolf http://www.amazon.com/LEHR-ST025DC-Curved-Shaft-Discontinued-Manufacturer/dp/B001H1LS98
23:45 fluffywolf I did some research when I got it... the carbs ALL fail, and CAN NOT BE MADE TO WORK. defective by design.
23:45 rue_more the propane carb?
23:45 rue_more odd
23:45 rue_more why not?
23:46 fluffywolf every part of it is crap. bad lines, bad high pressure regulator, bad carb, bad crankcase vent system, etc, etc...
23:46 rue_more oh
23:47 rue_more when I'm trying to test an engine, I use the welding torch to push propane right into the intake,
23:47 fluffywolf their official advice is to run it only half full of oil, to reduce the amount of oil that gets into the carb and clogs it... but then the bearings fail.
23:47 rue_more proves out the ignition and timing
23:47 rue_more then I know I just have to make the carb work
23:48 rue_more I'm amazed they managed to get it to production
23:48 fluffywolf I just use starting fluid/carb cleaner/brake cleaner/anything I have handy that's reasonably volatile and contains neither pigments nor adhesives...
23:48 rue_more I can turn the gas right off or leave it out
23:49 rue_more with it running on propane I can get the carb working,
23:49 rue_more dial down the propane as the carb kicks in
23:49 fluffywolf I just tune carbs by feel, no propane needed.
23:50 rue_more nothing like a flooded cold engine thats carb dosn't work
23:50 fluffywolf eh, I've never not been able to find a setting that'll start anything with compression and ignition after a couple tries.
23:51 e_more dials it all the way up and repeats the intro to 'closing time' a few t
23:52 fluffywolf ?
23:53 fluffywolf bbl, wolfy bedtime
23:53 rue_more gnight