#robotics Logs

Feb 18 2017

06:39 AM pokmo: just curious, anyone know how these small rubber pads are made? http://i.ebayimg.com/00/s/MzAwWDMwMA==/z/LLsAAOSwd4tUB6bd/$_35.JPG?set_id=2
06:42 AM pokmo: water jet? but they're pretty small
06:49 AM Snert: they look like tiny rubber feet
06:50 AM Snert: if you want tiny rubber bands then dental industry. braces.
06:52 AM Snert: prolly just mold them.
08:29 AM veverak: hmm
08:29 AM veverak: after I wrote serialization (from/to json, to string) for my structures
08:29 AM veverak: and proper doc in doxygen for them
08:30 AM veverak: I think I will think twice before modifing them in future
08:30 AM veverak: hmm
08:30 AM veverak: :)
08:59 AM ace4016: lol
12:00 PM z64555: the feet are probably molded on a sheet
12:00 PM z64555: and then cut off
12:01 PM rue_house: those are project box feet
12:01 PM rue_house: yes, rubber, usually
12:09 PM z64555: 3 dudes agree, it's tiny rubber feet
02:12 PM deshipu: here's a stupid idea: put two leds of different color, with resistors, of course, across the motor inside those transparent servos
02:12 PM deshipu: then you can see their load
02:18 PM z64555: could put them in series with the motor and gnd
02:19 PM z64555: have one led in opposite polarity
02:20 PM z64555: ---|<|---
02:20 PM z64555: -/\/\---| |--
02:20 PM z64555: ---|>|---
02:21 PM z64555: like that
03:17 PM deshipu: the motor is not connected to gnd
03:40 PM z64555: the circuit could be on either leg of the motor, then
03:41 PM z64555: If the impedance of the motor is high enough, the resistor might be omitted
03:41 PM z64555: ...wait
03:42 PM z64555: yeah, I think that's right
09:43 PM Jak_o_Shadows: 3/4 of the way through building something on a protoboard.
09:43 PM Jak_o_Shadows: Starting to think I should've gotten a PCB made
09:43 PM z64555: nahhh
09:44 PM synja: you should get some PCB protoboards then
09:45 PM Jak_o_Shadows: ? synja?
09:53 PM synja: did you mean breadboard by protoboard, or the PCBs which don't have etched pathways?
09:58 PM Jak_o_Shadows: One of these, basically: http://www.elecfreaks.com/store/images/PDBM_12.jpg
09:59 PM synja: ah, yep. those work pretty good
09:59 PM synja: not as good as a machine etched one, but meh
09:59 PM synja: cheaper :)
10:01 PM synja: there has been some work in the 3d printing community for printing custom boards, but i think they're about 5 yrs. from commercial quality
10:19 PM Snert: actually printing the metal traces?
10:23 PM anniepoo: question about those boards like Jak linked
10:23 PM anniepoo: I've used them, but was never sure what was best practice for wiring them up
10:32 PM rue_shop3: OK
10:32 PM rue_shop3: so
10:32 PM rue_shop3: I redid the old compressor, its now got a cooling tube and an unloading valve
10:33 PM rue_shop3: and the line to the shop is back up
10:33 PM rue_shop3: and there is a line thru the wall to the inside of the shop
10:33 PM rue_shop3: and there is a regulator in the shop
10:33 PM rue_shop3: that dosnt leak anymore
10:33 PM rue_shop3: and the compressor has a new air filter
10:37 PM Snert: I didn't think 3d printing of metal was "pure" enuff to be used for circuit traces.
10:37 PM Tom_itx: is the compressor not in the shop?
10:38 PM Tom_itx: Snert 3d printing metal is quite expensive
10:38 PM Snert: but is the metal pure enuff for metal traces on circuit boards.
10:38 PM synja: yeah snert. the imperfections were enough for it to not be stable
10:38 PM Snert: ok
10:38 PM synja: i wish i had a metal printer
10:39 PM synja: but yeah, hella expensive
10:39 PM synja: anniepoo, idk either. i just use some simple jumpers
10:39 PM Snert: I've seen sintering 3d processes used to compose metal gun parts and such.
10:40 PM synja: yeah i printed a lightweight plastic gun for my pentacopter
10:40 PM synja: never had the nerve to test it out though ;)
10:40 PM Tom_itx: http://tom-itx.no-ip.biz:81/~webpage/cnc/temp/prints/Ti_print2.jpg
10:40 PM Tom_itx: printed as one piece with Ti
10:40 PM anniepoo: you put the jumper and ocmponent wire in same hole?
10:41 PM anniepoo: or adjacent holes and bridge with one of the wires bent over?
10:41 PM synja: i do both in the same
10:41 PM Snert: Tom_itx: nice. It'll get better with time I guess.
10:42 PM synja: there are some PCBs with etched jumpers on the sides though which makes it a little nicer
10:42 PM Tom_itx: that was done at the uni with a $$$$ printer
10:42 PM Tom_itx: http://tom-itx.no-ip.biz:81/~webpage/cnc/temp/prints/Ti_print1.jpg
10:42 PM synja: i hate looking at metal printers Tom_itx. it just depresses me
10:43 PM Snert: Tom_itx: that looks like an artificial hip joint
10:43 PM Tom_itx: which?
10:43 PM Snert: lower left of the 2nd pic
10:44 PM Tom_itx: left side was just some dagger thing somebody wanted
10:44 PM synja: i'd give my left arm for one of those printers
10:44 PM Tom_itx: the golf club head is Ti and the composites department made the handle
10:44 PM synja: ...then i'd print one and hook it up to an emg
10:45 PM Tom_itx: takes about 30K per run
10:46 PM Snert: thirtythousanddollars?
10:46 PM Tom_itx: uses a tremendous amount of inert gas
10:46 PM Tom_itx: yes
10:46 PM Snert: h o l y wow.
10:46 PM Tom_itx: they've got about 15 large bottles hooked to it
10:47 PM rue_shop3: no, compressor is not in the shop
10:47 PM rue_shop3: I'm not using the big one, its just for the chip blower on the cnc
10:47 PM rue_shop3: the little one i had was drawing too much power and burping the arduinos that run the cnc and 3d printers
10:47 PM Tom_itx: if i put mine outside, somebody would steal it
10:47 PM rue_shop3: yea
10:48 PM Tom_itx: 5hp 80gal
10:48 PM rue_shop3: and I live here
10:48 PM Tom_itx: dual stage
10:48 PM rue_shop3: this one is single stage, single cylinder, 1/3Hp, prolly about 20 gal
10:48 PM rue_shop3: devilibis
10:48 PM Tom_itx: i had one similar
10:48 PM Tom_itx: wore it out
10:48 PM rue_shop3: this one is OLD
10:48 PM rue_shop3: and its ok
10:49 PM Tom_itx: started putting sheetmetal screws in all the rust holes
10:49 PM rue_shop3: I gave it the tank its got
10:49 PM rue_shop3: it didn't come with a tank
10:50 PM Tom_itx: the only thing it won't keep up with is the HVLP sprayer
10:50 PM Tom_itx: i don't use that much anymore anyway
10:52 PM Tom_itx: why would your compressor be upsetting your arduinos?
10:52 PM Tom_itx: aren't their supplies regulated?
10:53 PM ace4016: Tom_itx, printing replacement hip joints and micro radial compressors for fun?
10:54 PM Tom_itx: http://tom-itx.no-ip.biz:81/~webpage/cnc/temp/prints/plastic_prints.jpg
10:54 PM Tom_itx: some of the plastic stuff they've done
10:55 PM Tom_itx: they have a large version of that vase in the lower right that is one layer thick
10:55 PM Snert: I'm jealous
10:56 PM Tom_itx: the red belt in the center was actually printed as a replacement timing belt for something
10:56 PM Tom_itx: flexible and strong
10:56 PM Tom_itx: dunno what plastic it was
10:56 PM rue_shop3: its a little obnoxious one, its inrush causes too much power bump between computer and arduino with usb and locks up the arduinos usb
10:57 PM rue_shop3: being that usb isn't isolated at all
10:57 PM Tom_itx: oh
10:57 PM Tom_itx: load balance your circuits
10:57 PM rue_shop3: I may also derp the arduinos built in usb to serial and put my own on that are opto-isolated
10:58 PM rue_shop3: even with the compressor on the house panel I can see the lights pulse when its running
10:58 PM Tom_itx: put led lights in and you will see them pulse alot more
11:00 PM rue_shop3: .. yea I know, damn are those things sensitive
11:00 PM Tom_itx: they should add caps to the innards
11:00 PM Tom_itx: or bigger ones
11:00 PM rue_shop3: I put a short strip on my new printer, and all the filtering I could throw at it wont stop them from strobing with the nozzel heater
11:01 PM synja: Tom_itx> started putting sheetmetal screws in all the rust holes
11:01 PM synja: lol
11:08 PM Jak_o_Shadows: anniepoo, not like me is my advice
11:14 PM rue_shop3: ok I need supper