#robotics Logs

Aug 20 2015

01:07 deshipu I like to use this flat plastic brush for it
01:07 deshipu its handle
01:07 deshipu plastic makes it less likely to scratch or short stuff
01:12 Hyratel there's a limit to how much torque you can get with plastic
01:12 Hyratel especially at an edge
01:37 deshipu some plastics are harder than metal
01:39 Hyratel tougher than steel? by volume and geometry?
01:42 deshipu sure
13:55 Snert_ I have 2ea. NEMA 17 size stepper motors.
13:55 Snert_ I want to put encoder wheels on them.
13:55 Snert_ and do optical position encoding.
13:56 Snert_ Anyone know of a good source for encoder wheels and optical modules for encoding?
14:00 deshipu they are not very hard to make
14:01 deshipu just print tgem on paper and glue to a wheel
14:01 deshipu optical modules you will get at any electronics parts shop
14:02 deshipu its's basically a led and a phototransistor in a single package
14:02 Snert_ I know.
14:02 Snert_ I need a source.
14:02 Snert_ of encoder wheels and optical modules.
14:03 Snert_ printed on paper will not be very durable.
14:03 Snert_ I was thinking of metal.
14:04 deshipu then laser etch them on metal
14:04 veverak hi folks
14:04 deshipu whatever
14:04 veverak any tips for power distribution inside a box?
14:04 Snert_ but good ideas I'm more into buying than making from scratch.
14:04 veverak http://hobbyking.com/hobbyking/store/__17138__Hobbyking_PowerStrip_Fuse_Protected_Power_Distribution_Board.html
14:04 deshipu hi squirrel
14:04 veverak looks cool, but I suppose I should be able to make it
14:05 deshipu I have a nice SPG board
14:05 Snert_ I must look like a person that has access to a laser etcher lol
14:06 deshipu well, lots of online lasercutting services
14:06 Snert_ interesting idea.
14:09 deshipu you could also use transparent acrylic
14:10 deshipu and led/photo sensor on opposite sides of it
14:10 deshipu of course also lasercut and etched
14:10 deshipu maybe with some black paint applied to the etched parts
14:14 Snert_ I can see this is going to take some research
14:14 Snert_ with maybe cardboard wheels at 1st for proof of concept.
14:14 Snert_ then move on to metal wheels with holes in them.
14:16 Snert_ so thanks for the ideas.
14:23 veverak hmm
14:23 verak can't decide how far he shoul
14:23 veverak I mean, do I just want to split wireS?
14:23 veverak or make led indicator and fuse for each?
14:28 Snert_ how many fuses...what level of detail do you want?
14:28 veverak I am not sure
14:28 veverak to sum it up, now I need to give two power lines to "megatronics" (controls reprap)
14:29 veverak one for fan that cools the box
14:29 veverak one for external drier for one motor
14:30 veverak megatronics got fuses on it's own
16:10 veverak well
16:10 veverak another question!
16:10 veverak I know that most people have electronics of reprap laying on the bed
16:10 veverak buuuut, what is better?
16:10 veverak plastic or metal box?
16:11 SpeedEvil cardboard
17:08 veverak ok
17:08 veverak fu this
17:08 veverak I even forgot how to wire basic switch for 230v !!!
17:10 Snert_ be sure to use a left handed voltmeter to verify stuff
17:16 veverak I mean, I have three wires for 230v
17:16 veverak line, protect, neutral
17:16 veverak protect goes to the body of the thing
17:16 veverak so, I should switch both "line" and "neutral" on my switch?
17:16 veverak or jsut one of it?
17:17 rue_school the power, the switch and the load to in parallel, when you flip the siwtch, the light goes out ;)
17:18 Snert_ hire an electrician.
17:18 verak should know
17:18 Snert_ 230V ain't nuthin to play around with if you don't know.
17:19 veverak I mean, I should know how to connect switch in front of PSU
17:20 robopal how many poles your switch has
17:20 veverak 2x2
17:21 veverak it's ON-OFF
17:27 veverak so, I've got fuses, properly picked their values, proper fuses holder, indicator leds...
17:28 veverak just not sure abou that goddam button
17:31 robopal got a link or picture for it?
17:31 robopal it is a power button for a psu?
17:32 veverak it will be
17:32 robopal is it double pole single throw or double pole double throw?
17:32 veverak for this
17:32 veverak http://cncshop.cz/upload/products/preview/396-S350s.jpg
17:32 veverak http://www.gme.cz/img/cache/800x600/624/241/p-sw201a-red-obrazek-1.jpg I want this
17:33 veverak robopal: double pole, single throw?
17:33 robopal check the continuity on the poles, make sure
17:34 veverak I udnerstand that :D
17:34 veverak anyway, given that it's double pole, single throw
17:35 veverak should I 'disconnect' only one of the 'netural' or 'line' ? or both of them?
17:35 veverak 230V AC
17:35 veverak and just know I googlet terms for 'netura', and 'line' so I can have them wrong :D
17:35 Snert_ myself, I'd use a bigass bat toggle switch.
17:35 Snert_ running 220 through that little flimsy switch I wouldn't do.
17:35 robopal center two poles come N and L, choose two side ones to connect your psu, the opposite side poles should be NC
17:36 robopal not connection
17:36 veverak so both N and L? ok
17:37 robopal Snert_, those are proper rated switches we use them everywhere here
17:37 robopal its ok
17:37 Snert_ I've had those things fall apart.
17:38 Snert_ and when the subject is 220 I get the willies
17:38 Snert_ but to each their own I guess.
17:38 robopal you must had a really abused switch!
17:38 veverak :)
17:38 veverak also
17:38 Snert_ I'd prefer bakelite or heavy plastic.
17:38 veverak I know output of that PSU
17:39 veverak which is 12V, 29A
17:39 veverak if I want to pick proper fuse that should go in front of it, given that I don't know input values
17:39 veverak I can 'pick' it just by making: 12*29+0.83(effeciency)
17:39 veverak no
17:39 veverak 12*29/0.83
17:39 veverak which gives me watts
17:39 robopal where "in front"?
17:40 veverak whic than I divide by 230v and got the in current?
17:40 robopal the psu doesn't already have input protection?
17:40 veverak robopal: between the main button and the PSU
17:40 robopal yep so input protection
17:40 robopal there is no fuse under the metal cage? :-/
17:41 veverak not one I know of
17:41 veverak :D
17:41 robopal check
17:41 veverak I mean, they wrote that it got overload protection (for 105%-135% power), automatic restoration
17:42 veverak and over-voltage protection
17:42 veverak but I don't see anything about shortcut
17:42 veverak nor any fuse on the PSU itself
17:42 veverak P.S: it is industrial psu
17:43 Snert_ fuse it. that PSU is about as cheap as they come.
17:43 Snert_ I have 2 of them. They're cheap.
17:43 veverak anyway, my calc (12*29/0.83)230 should be ok to design the input protection?
17:43 veverak 12V 29A output, with 0.83 effeciency
17:44 veverak results in 1.826... so I picked 2A fuse
17:46 robopal there is no datasheet for it?
17:46 robopal i see a sticker on the photo
17:46 robopal ac input
17:47 robopal 230vac 4A it says, no?
17:47 veverak I see!
17:47 veverak yeah
17:47 veverak it's there
17:47 veverak :D
17:50 robopal well, if you short that switch whats the worst it can happen?
17:50 veverak it's just that when the device would be ON
17:51 veverak and something would fail with the PSU
17:51 veverak it will stop before leavin the device itself..
17:51 robopal hm?
17:52 robopal no I was going to ask about a device like a circuit braker
17:53 veverak fuse?
17:53 robopal if you short the switch when you flip it due to a misconfiguration the braker will flip
17:53 veverak I wanted to install it after the switch at first :D
17:53 veverak but I suppose before switch is better idea...
17:54 robopal http://www.civicsolar.com/sites/default/files/DIN%20Rail%20Breaker.JPG
17:54 veverak yeeeeah, but I have another devices in the room which I would liek to keep ON
17:54 veverak :)
17:54 veverak and I don't have separated circuit breaker for it
17:56 robopal how many you should have depends on how many amps per breaker
17:56 veverak wow, they even make panel type circuit breaker?
17:56 veverak ehmm
17:56 veverak there are several circuit breakers in our flat, but I am pretty sure there is only one for this room
17:56 veverak and it works now...
17:57 veverak so I suppose it's strong enough
17:57 veverak but I would prefer to warry about this thingy, so...
17:57 robopal how many devices are you running in your room?
17:57 veverak 3d printer (which we are talking about now)
17:58 robopal do you draw more that 10-16 amps from all the devices?
17:58 veverak two monitors, laptop, reproductors, homeserver,...
17:58 veverak I suppose not :D
17:58 veverak but we got 20A+ for entire flat
17:58 robopal well we will find out, aren't we
17:58 veverak :D
18:00 veverak https://scontent-vie1-1.xx.fbcdn.net/hphotos-xpf1/v/t34.0-12/11912916_1060582870619764_490747445_n.jpg?oh=f72a3fbb774809d4cb4f1aa7c7582e71&oe=55D7BC80
18:00 veverak this is actual state
18:04 veverak so
18:05 veverak metal box, power button, input power fuse + holder, faston connectors, per-pcb fuse + holder + led
18:05 veverak yeah, that should be enough to make it little bit proper
18:05 veverak :)
18:11 robopal I am trying to find a video thats shows how to wire the switch
18:14 veverak last thing is to finally decide what to use to split wires inside
18:14 veverak I don't really like the big wire-trees
20:42 rue_school veverak, you printed the inferior fan grate, should have used mine
20:42 rue_school what are you making anyhow
20:44 rue_school it could be a motion controller
20:44 rue_school "20A" "flat" australlia?
21:52 NonSecwitter I'm looking to build a machine that throws boxing punches at a rate of 10 RPM to 120 RPM, but I'm not sure where to start. I was thinking motor selection would be first.
22:39 Hyratel so, I'm windowshopping for a SBC to use for a Rugged Field Laptop - anyone have any favorites they want to try and convince me on?