#robotics Logs

Jul 11 2015

05:11 deshipu Hyratel1: didn't get to use them yet
13:30 deshipu https://www.youtube.com/watch?v=_m4RdzTC6yQ
13:30 deshipu pneumatic lego quadruped
14:19 blib deshipu: what kit allows you to build those? :)
14:20 ace4016 LEGO has a pneumatic series iirc
14:21 ace4016 though, looks like there are some custom parts in there
14:56 deshipu blib: I don't think it's a kit
15:01 rue_house good robotics
15:01 rue_house we did plastic stirr welding and basic programming
15:03 blib rue_house: did you guys do that one?
15:03 blib deshipu: the parts look like from some kit - legos?
15:03 deshipu blib: it is LEGO, but it's not from a single kit
15:04 deshipu blib: those guys mix and match the parts they need
15:05 SpeedEvil I tried friction stir welding. Long story short - I'm now banned from the Giraffe enclosure.
15:06 deshipu you have an enclosed giraffe?
15:06 deshipu what did you do to the poor animal?
15:11 rue_house which one?
16:49 deshipu yawn
16:50 e4016 throws spiders into deshipu's m
16:50 deshipu so, the eye test successful: https://www.youtube.com/watch?v=dg8LPhRLjiY
17:35 foul_owl Hi folks, can a servo output be moved by hand, or will that damage it? In my case, 9G servo (HXT900) Thanks!
18:38 rue_shop3 foul_owl,
18:39 rue_shop3 most of the time you can if there is no power to the servo
19:02 foul_owl rue_shop3: What if there is power to the servo, will it damage it?
19:02 foul_owl Or will it damage the electronics?
19:03 Orpheon foul_owl, I'm no expert, but I don't think you stand much of a chance of breaking the electronics
19:03 Orpheon the dangerous things are the mechanical parts
19:03 foul_owl Gotcha
19:03 Orpheon if you work against the motor, something's going to give
19:04 foul_owl Makes sense
19:04 ace4016 if the power is on, you may induce a higher current
19:04 ace4016 higher than what the system was designed to handle
19:04 ace4016 also, gears and such
19:04 rue_shop3 if there is power and signal to the servo, moving the shaft will cause the gears to strip
19:05 foul_owl What if there is power to the servo, but no signal?
19:10 ace4016 foul_owl, for most RC servos, no signal on the line is still a servo command, though a bit more undefined
19:10 foul_owl Ahh ok
19:14 foul_owl Thanks everyone! :)
19:17 foul_owl Ah, one more question. With servo accuracy, are you limited by the servo, the controller (arduino in this case) or the software? My guess would be you are limited by the servo itself. Thanks!
19:18 ace4016 the servo typically
19:20 foul_owl Do servos have a spec associated with regard to accuracy?
19:20 foul_owl ie "accurate to +-0.1 degrees" or similar?
19:24 ace4016 some do
19:24 ace4016 depends on the servo, its quality, and mechanics behind its operation
19:24 ace4016 higher end servos will have more data and typically be more accurate
19:27 foul_owl I see
19:28 Anniepoo slower servos also tend to be more accurate for the same price point
19:28 foul_owl Generally can you swap out a digital servo for an analog servo without no code changes? (arduino)
19:32 ace4016 i don't believe so
19:32 ace4016 different control schemes
19:34 foul_owl Thanks again for all the help
19:34 ace4016 ah, actually, i guess in this case they can be replaced
19:36 ace4016 assuming RC servo
19:37 foul_owl Oo ok!
19:37 foul_owl I realized the current servo I am using is analog anyway, so I'm replacing one analog one with another (metal geared one in the second case)
19:38 foul_owl Basically my project is bed autoleveling on my 3d printer (prusa i3)
19:39 foul_owl And for autoleveling, accuracy is crucial. Speed and torque, not so much.
20:03 wolfmanjm foul_owl: I do not think a hobby ervo will be much good for bed leveling, they tend to jitter
20:03 wolfmanjm unles syou have a way to lock the bed once it is levelled
20:03 wolfmanjm I have seen a design where the servo levels then locks the bed in place.
20:09 wolfmanjm foul_owl: I do not think a hobby servo will be much good for bed leveling, they tend to jitter
20:09 wolfmanjm unless you have a way to lock the bed once it is levelled
20:09 wolfmanjm I have seen a design where the servo levels then locks the bed in place.
20:10 wolfmanjm )Sorry for the repeast but my internet went down briefly
20:31 SpeedEvil foul_owl: 'digital' RC servos are not actually any different to drive
20:31 SpeedEvil they simply have a $.2 microcontroller instead of an $.2 analog circuit
20:37 robotustra hey
20:37 ace4016 ahoy
20:38 robotustra how is robotics going?
20:39 ace4016 for me specifically? not at all; for others, seems well