#robotics | Logs for 2016-11-06

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[00:50:29] <rue_shop3> ANYONE know something better than grblcontrol for spooling files to grbl?
[00:56:37] <rue_shop3> haas is a big cnc maker, who is another
[02:20:52] <rue_shop3> twice now an hour has passed in a few mins of work
[02:25:28] <srilumay> hello everyone
[03:04:48] <rue_shop3> hi
[05:32:43] <jasonsmr> how many of you have ever* come across a spanner head fastener used to secure electronics, (or even to close an electronics case)?
[05:32:49] <jasonsmr> I never see them.
[05:35:06] <robopal> there are some idiot companies that use them
[05:35:19] <robopal> wow
[05:35:41] <robopal> actually I have a power adapter in front of me right now that has 2 such screws
[05:35:44] <robopal> :D
[05:37:05] <robopal> Braun power adapter, I think it is from a hair trimmer
[05:37:07] <rue_house> I'm writing a grbl control program in python... weeeee
[05:39:57] <jasonsmr> yea. that answers that, someone somewhere had to have one,
[06:09:48] <robopal> lol
[06:35:43] <robopal> http://www.popsci.com/watch-flock-german-drone-butterflies-video
[07:57:04] <justanotheruser> hey robopal
[07:57:20] <justanotheruser> why was it that you didn't like the motor I was using last night?
[07:57:39] <justanotheruser> this is the one I'm looking at http://www.ebay.com/itm/NEMA-23-2Nm-283ozf-in-Integrated-Closed-Loop-Stepper-motor-36VDC-JMC-iHSS57/262565317443?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D888007%26algo%3DDISC.MBE%26ao%3D1%26asc%3D39344%26meid%3D319bdc942e0a488a98d9c0487fb01cdd%26pid%3D100009%26rk%3D1%26rkt%3D1%26sd%3D262565328848
[07:58:31] <robopal> because I looked it up and saw it was a CNC motor
[07:58:43] <robopal> very nice for this tast, not so for an arm
[07:58:53] <justanotheruser> why?
[07:58:54] <robopal> task*
[08:00:04] <justanotheruser> The fact that it's a servo? The torque?
[08:05:23] <robopal> not a servo, a stepper
[08:49:02] <justanotheruser> sorry, was thinking of the previous motor I was looking at
[08:49:07] <justanotheruser> oh he's gone
[08:49:10] <justanotheruser> the elusive robopal
[08:52:21] <justanotheruser> 08:20:40 justanotheruser:sorry, was thinking of the previous motor I was looking at
[08:52:28] <justanotheruser> so is your concern that its a stepper motor
[08:52:43] <robopal> yes mainly
[08:52:47] <justanotheruser> why?
[08:54:20] <justanotheruser> I guess the gear ratio reduction + stepper would make it slow
[08:54:43] <justanotheruser> is there a motor or motor+planetary gearbox you would recommend?
[08:54:50] <robopal> have you found a gearbox?
[08:55:19] <justanotheruser> It's nema23, theres quite a few options, but I haven't bought any
[08:57:53] <justanotheruser> of course all of this can be changed
[08:58:02] <justanotheruser> I just want the right tool(s) for the job
[09:01:13] <robopal> have you researched how other people have approached this problem?
[09:01:36] <justanotheruser> yes, but the results I have found are for robots that have significantly less torque
[09:01:50] <justanotheruser> looking for 50-200 lbft of torque
[09:02:33] <robopal> yes, now why is that
[09:03:15] <justanotheruser> looking to lift things 12-50 lbs with a 3ft arm
[09:03:39] <robopal> no, I mean why people havent done this already with heavy loads
[09:04:01] <robopal> I suggest that it can't be done with just a motor and some gears
[09:04:20] <robopal> you need other mechanisms, or really big motors and gears
[09:04:31] <justanotheruser> what is the typical mechanism? A counterbalance?
[09:05:16] <justanotheruser> maybe there could be a horizontal weight that expands and contracts in the opposite direction the arm is facing
[09:05:24] <robopal> see the Asimo robot
[09:06:19] <justanotheruser> can asimo carry a heavy load?
[09:06:32] <robopal> no it has a limit
[09:07:37] <justanotheruser> I'm looking around, but I'm not sure exactly what I'm supposed to be looking for
[09:08:13] <robopal> you should first aim for something realistic and go from there
[09:09:21] <robopal> get a high torque servo, with an arm-1 feet length and see what you can do
[09:09:59] <robopal> perhaps add a second one to help the other, with a belt mechanism and see how much more weight it can lift
[09:10:12] <robopal> how much a longer arm it can support
[09:13:20] <justanotheruser> mhm
[09:13:26] <justanotheruser> I guess I can just double the motors to double the torque
[09:13:30] <justanotheruser> good suggestion
[09:14:02] <robopal> no, I think you will find it doesnt scale that well
[09:15:55] <robopal> it is nice to experiment though
[09:16:36] <justanotheruser> hmm
[09:20:10] <justanotheruser> robopal: think this is overkill? :P http://www.ebay.com/itm/BALDOR-BRUSHLESS-AC-SERVO-MOTOR-BSM90N-4150AA-300V-5000RPM-6-85KW-AUC-1-/262387139592?hash=item3d177e0408:g:xygAAOSw5ZBWIUre
[09:20:45] <justanotheruser> $160 - BSM100N-4150AA 354.0Nm 2000rpm
[09:20:54] <justanotheruser> sorry 354 lb-in
[09:21:50] <justanotheruser> 40Nm
[09:22:29] <justanotheruser> problem is the motor is massive, though that may be my best option
[09:22:54] <justanotheruser> robopal: why do you want me to find a high torque servo instead of a low torque servo plus a planetary gearbox
[09:23:15] <justanotheruser> I don't need the 2000 rpm
[09:25:25] <robopal> perhaps you should look for electric bike motors
[09:25:47] <justanotheruser> and a gearbox?
[09:26:15] <justanotheruser> 60Nm in some tests
[09:26:18] <justanotheruser> that is a good idea though
[11:19:00] <z64555> use an AC motor, or one that has windings for both the rotor and stator
[11:20:50] <z64555> With access to both windings, you'l be able to adjust your torque output
[11:23:00] <z64555> shoot. just salvage one from a power drill
[11:51:10] <SpeedEvil> http://www.hobbyking.com/hobbyking/store/__56935__Turnigy_9014_105kv_Brushless_Multi_Rotor_Motor_BLDC_.html + 10:1 gear
[13:40:13] <z64555> If you use a BLDC, you'll need to use something other than an ESC
[13:55:28] <rue_shop3> yay, I cnc cut something!
[13:56:14] <z64555> yay, finally!
[13:56:38] <rue_shop3> how do I make a flowjet?
[13:56:57] <rue_shop3> start with a saphire nozzel :/
[14:02:32] <ace4016> fancy https://www.youtube.com/watch?v=mVCfqy4vxgI
[14:17:21] <rue_house> is that an 80's! video!?
[14:17:48] <rue_house> wait, I thougth mach3 was a hobbyist machine software
[14:19:53] <rue_house> I wonder what I can do with 8000 psi
[14:29:29] <robopal> !!!
[14:46:58] <rue_house> hmmm
[14:47:07] <rue_house> 8000psi over a 1.5mm stream
[14:48:17] <rue_house> 22lbs
[14:48:47] <rue_house> thats enough to push a peice of sand across a surface and take some material off
[15:41:06] * rue_shop3 stands upon a peice of sheet metal, every limb keeping either the metal flat or the tapemeasure in place... looks for pen.....
[18:09:24] <rue_house> what do you do when you want to scrounge, but the truck and house is full?
[18:10:04] <malcom2073_> rue_house: Build a shed.
[18:10:19] <rue_house> ... have to be another one, current one is full
[18:13:03] <orlock> Self control...
[18:21:33] <malcom2073_> I agree with orlock. You need to have self control, and very carefully build another shed.
[18:21:38] <z64555> is an open loop
[18:22:31] <z64555> I had a cousin who only built one shed
[18:22:59] <z64555> he left the back wall unfinished and just covered with a tarp
[18:23:27] <z64555> if he needed more storage, he'd cuild onto it
[18:23:32] <z64555> *build
[18:23:44] * z64555 is typing with one hand
[22:10:24] <SpeedEvil> z64555: thinking about sheds?
[22:31:29] <z64555> SpeedEvil: yeah, rue was saying he was running out of storage space
[23:48:05] <SpeedEvil> 'z64555 is typing with one hand'
[23:48:12] <SpeedEvil> nvm
[23:53:07] <z64555> SpeedEvil: I had a burrito that I was eating with the other hand
[23:53:25] <SpeedEvil> The comment amused me.