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[01:00:11] <rue_house> who is snowden?
[01:14:13] <rue_house> avr is about 16mips, the 386 running my cnc machine is about 13
[02:39:22] <rue_bed> wtf, an hour just spun me by, it should be 11:15 not 12:10
[02:39:27] <rue_bed> w t f
[02:49:34] <mrdata_> happens to me a lot
[07:16:36] <pokmo> hi
[07:17:51] <pokmo> i'm trying to make a pulley/roller for pulling a string. if the pulley wheel has a radius 3x of the shaft, would the torque be just 1/3?
[07:19:21] <SpeedEvil> yes
[07:19:28] <SpeedEvil> comparing to wrapping it round th ehsaft
[07:19:33] <SpeedEvil> and speed will be 3*
[07:19:42] <SpeedEvil> speed * torque = constant
[07:20:07] <pokmo> yeah, that's what i thought
[07:22:51] <pokmo> thanks
[09:32:17] <pokmo> anyone know if the 28BYJ and the 35BYJ are essentially the same motor but with different gearboxes?
[09:46:07] <rue_house> dunno, all mine are mitsumi
[12:32:33] <z64555> anybody have a reference for a good book on mechanics? My physics book is lacking when it comes to mechanical systems
[12:32:59] <robopal> what book do you have?
[12:34:28] <z64555> University Physics, 12ed, published by Pearson
[12:35:12] <robopal> Young, Freedman and Ford
[12:35:13] <z64555> it covers the basic kinematics, but I didn't see anything about stuff like 3 bar systems, etc
[12:36:05] <z64555> Young and Freedman, Ford must be a newer editor
[12:36:34] <z64555> weighs about 10lbs. :)
[12:40:01] <robopal> what is a 3 bar system?
[12:40:26] <robopal> I am not sure what that means in my language
[12:41:33] <z64555> It is a mechanical structure consisting of 3 beams, affixed to each other at a single point, an example would be a triangle with one side attached to the middle instead of at the its vertex
[12:41:55] <z64555> a 4-bar system is also common, from what I've heard
[12:47:18] <robopal> do you want this book instead? Robot Arms, isbn 9789533071602
[12:49:35] <z64555> That might have the information I need, but it seems rather specific to robot arms. :)
[12:49:56] <z64555> Thank you, I'll see if I can get a preview of it and skim a bit
[12:50:37] <robopal> or I can just give you a link
[12:51:11] <robopal> jacod everist was a fellow robotics scientist that was comming here 10+ years ago, wasn't it?
[12:51:19] <robopal> I just found a paper of his in my library
[12:51:38] <robopal> "A system for in-space assembly"
[13:01:31] <robopal> z64555,
https://www.dropbox.com/s/u4aknfwrpyme1ua/Hardware%20-%20ROBOTICS%20Designing%20the%20Mechanisms.pdf?dl=0
[13:01:46] <robopal> https://www.dropbox.com/s/clyexx1ogulpuhv/Introductory%20Robotics%20-%20Selig.pdf?dl=0
[13:02:02] <robopal> https://www.dropbox.com/s/mtc6ry3yvmgnt8f/9789533071602.pdf?dl=0
[13:02:06] <z64555> Huh, in-space assembly sounds neat
[13:02:17] <robopal> grab those three, I will delete them tomorrow
[13:02:26] <robopal> ok I will upload his paper too :P
[13:02:52] <z64555> It's not copywrited, is it?
[13:03:04] * z64555 says the guy as he downloads the books
[13:03:35] <robopal> no
[13:04:53] <robopal> of course there are but, you wouldn't buy them anyway, if you had the chance you would borrow them from a local library ;p
[13:05:34] <robopal> I have only bought a few books I reference all the time... topic specific robotics books are just for browsing
[13:08:50] <robopal> https://www.dropbox.com/s/x7gid21xo4m1rsd/Everist-IROS2004.pdf?dl=0
[13:15:06] <z64555> Thx much
[17:57:24] <codepython7772> SpeedEvil: any progress?
[19:22:50] <codepython7772> anyone can help with a ESC recommendation?
[19:23:16] <z64555> what motor
[19:23:31] <z64555> do you need speed feedback
[19:26:19] <codepython7772> z64555: yes, I need speed feedback as well
[19:26:47] <z64555> eh, that's gonna be tough, then
[19:27:05] <codepython7772> z64555: Motor: 2x direct drive 3-phase brushless DC electric wheel hub motors, 36V 350W, 700W total
[19:27:18] <codepython7772> the motors come with hal sensor
[19:27:24] <codepython7772> so i just need something to drive them
[19:27:44] <z64555> oh they come with a hal sensor? ok. Then you'll be pulling speed info directly off of it
[19:28:07] <z64555> the ESC's would use back emf
[19:28:27] <codepython7772> z64555: which esc can i buy for this? Seems like 10S ESCs are very expensive?
[19:28:56] <z64555> 10S? holy cow, no wonder
[19:29:12] <codepython7772> z64555: the motor is rated 36V?
[19:29:17] <z64555> for a 350W I would've expected a 3S to 5S
[19:29:31] <z64555> oh
[19:29:36] <codepython7772> 36V rated motors, with 36V battery - can you do it with 3S to 5S?
[19:30:14] <z64555> no, that's definitely a 10S. You can use a battery with a lower voltage on that motor, but you won't get it to top speed
[19:30:43] <codepython7772> z64555: any recommendations for a good ESC for that problem - which does not cost an arm and a leg?
[19:31:26] <z64555> 350W seems light for a 10S motor, though
[19:31:50] <z64555> Do you have a link to it, or a link to its datasheet?
[19:32:28] <codepython7772> They dont have a datasheet - but let me get you something
[19:32:57] <codepython7772> z64555:
http://czjqjd.en.made-in-china.com/product/MvzQfxwJhNVe/China-8-Inch-350W-36V-620-R-Electric-Bicycle-Hub-Motor-Twist-Car-Brushless-DC-Motor.html
[19:33:19] <codepython7772> z64555: the product description has some stuff, but not much
[19:33:35] <z64555> "made in china" well that might be the reason
[19:35:16] <codepython7772> z64555: It seems like it can pull 30A or so? Or was i mistaken
[19:37:44] <z64555> lemme check something real quick, the rated values seem off
[19:40:08] <z64555> as I thought...
[19:40:22] <z64555> codepython7772: They list "0.9A" as the "rated current"
[19:40:44] <codepython7772> k
[19:41:04] <z64555> which disagrees with the 350W and 36V specs
[19:41:34] <codepython7772> how so?
[19:41:45] <z64555> if it was a 36V, 350W motor, it would pull 9.7A
[19:41:49] <z64555> P = V*I
[19:42:08] <orlock> At the very least..
[19:42:18] <orlock> frictionless spheres and perfect worlds, etc
[19:43:06] <z64555> no, that would be at most
[19:43:31] <z64555> I have a motor sitting right here on my desk that's rated for up to 275W, 3S system
[19:43:44] <z64555> which comes out to 27.7A
[19:43:44] <codepython7772> so no load current * voltage = wattage of the motor?
[19:43:58] <orlock> What about loss?
[19:44:05] <orlock> i guess it depends exactly what the 350W refers to
[19:44:09] <z64555> There's another spec on here that states 28A is the max burst current
[19:44:14] <orlock> draw or output
[19:44:20] <z64555> draw
[19:44:27] <orlock> ahhh, yup
[19:44:51] <codepython7772> I've a motor here - which says 12v * 1.8A (Free current ) <= 24W - but the motor is rated at 150W
[19:45:06] <codepython7772> by that math, the chinese specs - ok?
[19:45:30] <codepython7772> 36v * 1A = 36W - but the motor is rated at 350W
[19:46:20] <z64555> it's neglecting "burst" current
[19:46:46] <z64555> which can be much higher than the continous current, but the motor can only do that for a short period of time
[19:46:55] <z64555> For my motor, that's 28A for 15seconds
[19:47:19] <codepython7772> z64555: for this chinese motor - I 've seen people run it with 5S - but i'd rather run it at 36v
[19:48:38] <z64555> What do those balance boards use?
[19:50:15] <z64555> codepython7772: It's more important to figure out the amount of current the motor can handle
[19:50:36] <z64555> Voltage correlates to speed, where current correlates to torque
[19:51:02] <codepython7772> z64555: I'm guessing 50A should be enough for this motor - since I remember seeing somewhere it was drawing 30+ Amps
[19:51:19] <z64555> current also has a tendancy to burn up the coils, too
[19:51:27] <z64555> Yes, but for how long?
[19:51:36] <z64555> continous operation, or limited?
[19:51:47] <codepython7772> z64555: continuously 30A !
[19:51:55] <z64555> ok
[19:52:08] <codepython7772> How is that possible? I thought 350W means it should max draw 10A continuously?
[19:52:17] <z64555> *burst
[19:53:15] <codepython7772> max 90A
[19:53:50] <z64555> ok, if the burst current is 90A, then you need an ESC that can handle 90A
[19:54:09] <codepython7772> z64555:
https://www.amainhobbies.com/castle-creations-mamba-xl-x-1-5-brushless-esc-cse010-0140-00/p451277 - someone used this one!
[19:55:12] <z64555> eh, well maybe not 90A, but something that can supply at most 90A
[19:55:35] <codepython7772> V= 36, C=90A, ESC = Out of my budget?
[19:57:34] <z64555> probably
[19:57:44] <codepython7772> z64555:
https://www.alibaba.com/product-detail/Wholesale-6-5-Inch-Bluetooth-Electric_60480464024.html?s=p - how do these guys do it?
[19:57:46] <eadthem> what are you wanting to do with the motor?
[19:58:04] <codepython7772> $100 bucks has two escs! + a million other things!
[19:58:18] <z64555> ESC's are probably less powerful
[19:58:35] <z64555> andddd maybe even couterfeit
[19:59:12] <z64555> I've heard of these things catching fire, so that's likely part of it
[19:59:30] <z64555> the ESC's would generate too much heat when a fat kid steps on it
[20:00:22] <z64555> You can use a lower-powered ESC for the motor, but that would be your weakest link
[20:00:22] <eadthem> its probably a all in 1 board
[20:00:31] <eadthem> and there probably brushed
[20:00:52] <z64555> mmmnooo... The wheel that he's got is the same one used in those things
[20:01:22] <codepython7772> z64555: did you just drool? :)
[20:01:49] <z64555> no
[20:01:58] <eadthem> the idea is to make a hoverboard right?
[20:02:03] <Snert_> why not buy one for take apart.
[20:02:07] <z64555> nah, he's making a bot
[20:02:21] <codepython7772> Snert_: I looked at the motherboard - i could try - but then its painful
[20:02:36] <eadthem> how fast do you want it to go
[20:02:38] <codepython7772> Snert_: + there is always a chance it burns everything
[20:03:09] <codepython7772> eadthem: as fast as i can make it. The wheels are < 600rpm
[20:03:19] <z64555> gotta go fost
[20:03:35] <z64555> erm, sorry. meme snuck out
[20:03:36] <eadthem> how big of a wheel
[20:03:38] <eadthem> how heavy of a bot
[20:04:01] <codepython7772> eadthem: if i cant control the wheel with the battery i have - never going to build one
[20:04:06] <codepython7772> eadthem: so first the esc
[20:04:19] <eadthem> how big is the wheel?
[20:05:23] <codepython7772> z64555: A friend who tests motors, just says its 250W - does that sound more reasonable?
[20:05:30] <eadthem> If you can estmate the weight you can expect, the diameter of the wheel you expect. i can probably help you find a speed control?
[20:05:34] <eadthem> .
[20:06:04] <z64555> codepython7772: it does
[20:06:20] <codepython7772> eadthem: 50lbs total weight - 6.5" wheel
[20:06:31] <eadthem> max MPH you want?
[20:06:54] <codepython7772> eadthem: at least 300rpm - I'll have to convert that to speed
[20:07:10] <z64555> and he said it was 2 drive motors
[20:07:10] <eadthem> diffrental steering? aka dual drive? Or single drive, with turning wheels?
[20:07:15] <eadthem> k
[20:07:23] <codepython7772> z64555: thanks
[20:11:29] <eadthem> codepython7772 thats about 5.8MPH
[20:12:44] <codepython7772> eadthem: thanks
[20:16:53] <eadthem> heres a theory
http://www.castlecreations.com/en/mamba-micro-x/mamba-micro-x-0808-4100kv-combo-010-0147-01
[20:17:08] <eadthem> You need a high reduction gear box for that of course
[20:17:21] <eadthem> the ESC can do like 25-30 amps i think
[20:17:50] <eadthem> 12V power = 50,000 RPM
[20:18:08] <codepython7772> https://www.alibaba.com/product-detail/high-quality-e-bike-controller_60466075849.html - can i use this?
[20:18:17] <eadthem> so you need about a 83:1 gear box
[20:21:36] <codepython7772> eadthem: if i had a 12V 100W motor - will it carry around 50lbs at 600rpm? 400rpm? same size wheel. What is the math behind that?
[20:22:17] <eadthem> your only talking about 6Mph
[20:22:43] <codepython7772> 600rpm = 12mph - according to your calculation, right?
[20:29:53] <eadthem> my calculation says that if your gearing down for 6mph then you realy arent demanding much power
[20:30:12] <eadthem> https://web.archive.org/web/20160325042417/http://www.castlecreations.com/support/documents/10th-Scale-Gearing-Chart-095-0130-01L.pdf
[20:32:05] <eadthem> so if it drives a 5-6.5 pound car, 50MPH ish, with a gearing reduction of 7.5
[20:32:41] <eadthem> it makes sense it will drive a 50 pound load with a gear ratio more than 75
[20:32:45] <eadthem> about 5mph
[20:33:58] <z64555> Having a balance board going at 50MPH is a rather amusing thought
[20:34:19] <eadthem> 10x gear ratio, 10/ speed, 10x the load
[20:35:15] <eadthem> codepython7772 of course thats a size larger than i sugesed for the ESC and motor
[20:36:44] <eadthem> Call castle if you want more info, they are use to strange stuff
[20:37:15] <eadthem> You could still gut a balance board, but i promise they cut some corners somewhere.
[20:41:34] <codepython7772> eadthem: castle?
[20:41:52] <eadthem> thats the company that made that gearing chart
[20:43:53] <codepython7772> eadthem: I want to use those chinese motors - I've never seen a motor as cheap :) The only problem is that the control is turning out to be an issue
[20:44:09] <eadthem> you alredy have one?
[20:44:12] <orlock> codepython7772: Cordless drill.
[20:45:00] <codepython7772> eadthem: i've two :)
[20:45:12] <eadthem> control as in?
[20:45:17] <codepython7772> eadthem: esc
[20:45:23] <eadthem> not wanting to start and stop?
[20:45:28] <codepython7772> orlock: mine are 18v
[20:45:39] <codepython7772> eadthem: what do you mean?
[20:45:53] <eadthem> what control issue?
[20:46:04] <eadthem> you dont have a ESC, or its not working out well?
[20:46:13] <codepython7772> eadthem: i dont have a esc
[20:46:23] <eadthem> how many wires dose the motor have?
[20:46:29] <z64555> 3, it's a bLDC
[20:46:47] <z64555> hence the need for an ESC
[20:47:07] <codepython7772> 3 ?
[20:47:24] <eadthem> even if its bldc it might have more than 3
[20:47:34] <eadthem> 3 power + 6 sensor
[20:47:51] <codepython7772> z64555: seems like i need to move from 36v to 18v or 24v to get my control circuitry budget on line ?
[20:48:32] <z64555> sounds like it
[20:49:18] <codepython7772> z64555: if one goes from a 100W 36v motor to a 100W 18v motor, the current is higher - torque = 1/2?
[20:50:04] <eadthem> http://www.castlecreations.com/en/phoenix-edge-hv/phoenix-edge-hv-40-esc-010-0107-00
[20:50:07] <z64555> torque would be double, I think
[20:50:11] <eadthem> 48V capable
[20:50:19] <eadthem> of course i dont know what the motors like
[20:50:41] <z64555> but
[20:50:56] <z64555> Yeah, torque would be double, speed would be half
[20:51:10] <codepython7772> eadthem: this will work for my application?
[20:51:16] <eadthem> no idea
[20:51:29] <eadthem> its 40Amp 50V max
[20:51:31] <z64555> so instead of down-gearing, you might up-gear
[20:51:33] <eadthem> you were saying you wanted 48V
[20:52:19] <codepython7772> eadthem: 18v - 600rpm - 6.5" wheel - 50lb load (with 2 wheeled drive) - how much current do i need?
[20:52:33] <eadthem> it depends on so much
[20:54:01] <codepython7772> eadthem: 36v 600rpm 350w - drives 100lb with 6.5" wheels
[20:54:13] <z64555> ok. stop
[20:54:21] <eadthem> i wonder if those bike motors have gears in them
[20:54:26] <codepython7772> eadthem: no
[20:54:34] <z64555> don't go by current, you'll just drive yourself mad
[20:54:34] <eadthem> must be just a very low KV motor
[20:55:53] <z64555> You pick the wattage, then the voltage, and then find the needed current
[20:56:09] <z64555> and find the ESC that'll provide that
[20:56:39] <eadthem> but the slower you go, the less power you need
[20:56:44] <eadthem> gearing wise
[20:56:46] <eadthem> or KV wise
[20:56:54] <eadthem> KV = RPM's Per Volt drive
[20:56:57] <z64555> Power is consumed mostly in the transient
[20:57:10] <eadthem> so 4100KV with a ESC powerd by 12V will go about 50,000 RPM
[20:57:21] <z64555> motors consume less power when in steady state (coasting)
[20:57:30] <eadthem> RC car stuff is made to go 40-70 MPH
[20:57:36] <eadthem> thats acctual speed not scaled
[20:57:39] <z64555> what acceleration.
[20:57:51] <rue_shop4> what speed
[20:58:07] <rue_shop4> what velocity
[20:58:16] <z64555> rue_shop4: target... oh now you're just being cute
[20:58:18] <z64555> :P
[20:58:34] <z64555> target speed is about 6mph
[20:59:24] <codepython7772> z64555: make it 12 please :)
[20:59:46] <z64555> k, 12mph then
[20:59:56] <rue_shop4> haha
[21:01:53] <codepython7772> we also have a 36V 250W motor that we want to use - but the controller is turning out to be priced 2x times the motor :)
[21:02:22] <rue_shop4> oooh right I bought a size 11 chuck that I need to find a motor for, 8mm shaft
[21:04:32] <z64555> codepython7772: 8inch diameter, right?
[21:04:39] <codepython7772> 6.5"
[21:05:02] <z64555> -_- So the motor you linked me before is a different one
[21:08:46] <z64555> codepython7772: which means you'd need the maximum 620RPM if you went direct drive
[21:09:19] <codepython7772> yes
[21:09:28] <codepython7772> My target was 600rpm
[21:09:46] <z64555> ok.
[21:09:58] <codepython7772> I'd still rather use the 36v - because if i change the voltage, i loose the battery - I like that battery. So its just a matter of coughing up the money for ESCs
[21:11:18] <codepython7772> or perhaps there is a better way
[21:13:08] <z64555> I'm not coming up with any gearing scenario where you could keep that voltage and speed
[21:13:52] <z64555> You could go with a lower voltage, but higher current, and use a gear ratio that'll bring it up to 620RPM
[21:14:04] <codepython7772> z64555: if i just rotate that wheel with a ESC - i can do it?
[21:14:14] <codepython7772> that wheel is rated for 600rpm
[21:14:16] <codepython7772> motor
[21:14:39] <z64555> yeah, you can over-voltage a motor for higher speed, but it'll output less torque
[21:15:01] * rue_shop4 looks for a dust buster motor
[21:16:20] <codepython7772> z64555:
http://www.castlecreations.com/en/phoenix-edge-hv/phoenix-edge-hv-40-esc-010-0107-00 - will this work? Seems like they use it more for flying quads?
[21:17:28] <rue_shop4> :/ I think I "rewound" the dust buster motor
[21:17:29] <eadthem> its rated for 40 amps at 50V with 5mph of air flow
[21:18:06] <rue_shop4> how fast is 10000 rpm?
[21:18:32] <eadthem> faster than most HDD's
[21:18:35] <z64555> rue_shop4: how big's your wheel?
[21:18:40] <eadthem> 3x faster than a tablesaw
[21:18:49] <rue_shop4> wheel?
[21:18:52] <eadthem> 2x faster than a skill brand circular saw
[21:19:13] <rue_shop4> oh, its only 166.7Rev/sec
[21:19:52] <z64555> lol
[21:20:08] <rue_shop4> oh its not that much, this one is 11k rpm, at just 6V
[21:20:16] <z64555> codepython7772: yeah, most ESC's you'll see for sale are for flyers. Most RC cars used brushed motors
[21:20:27] <eadthem> not true
[21:20:30] <rue_shop4> at 48V... oh looks that!
[21:20:36] <eadthem> most RC cars use brushless as well
[21:20:36] <rue_shop4> 0rpm and the smoke comes out
[21:20:46] <z64555> oh? when did that chance?
[21:20:56] <z64555> *change
[21:21:00] <eadthem> a while ago
[21:21:08] <z64555> and do they use inrunners or outrunners?
[21:21:13] <eadthem> sidewinder and mamba and monster from castle are for carrs
[21:21:15] <eadthem> cars
[21:21:18] <codepython7772> z64555:
https://hobbyking.com/en_us/turnigy-dlux-80a-hv-brushless-speed-controller-opto.html - so far the cheapest i found?
[21:21:20] <eadthem> normaly innrunners
[21:21:23] <rue_shop4> yea, 22k rpm at 12V
[21:22:17] <codepython7772> this esc is rated 200k RPM! ?
[21:22:28] <codepython7772> will it smoke at 600RPM? :)
[21:22:39] <eadthem> you need a low KV
[21:22:41] <z64555> not likely
[21:22:41] <eadthem> and gearing
[21:22:42] <rue_shop4> this ones 12k at 6V
[21:22:59] <z64555> the RPM thing is more a testiment to its clock
[21:23:00] <eadthem> and a good brushless ESC wont die for slow RPM
[21:23:04] <z64555> It can handle 600RPM just fine
[21:23:05] <eadthem> the motor might get hot
[21:23:26] <codepython7772> eadthem: why would it get hot?
[21:23:41] <eadthem> high current, low airflow
[21:24:12] <rue_shop4> oooh THIS is a dust buster motor
[21:25:15] <codepython7772> how dangerous is 36V DC? :)
[21:25:27] <rue_shop4> yea, 56k rpm at 6V
[21:25:34] <rue_shop4> THATS a dust buster motor
[21:25:34] <eadthem> not that much
[21:25:37] <eadthem> its the battery behind it
[21:25:49] <eadthem> a LiPo at 36V DC can be dangrous
[21:25:59] <z64555> yeah, Voltage isn't what is dangerous, it's the current
[21:26:00] <eadthem> becuase it will do bursts of 1000 Amps
[21:26:06] <eadthem> well not really
[21:26:11] <eadthem> its teh combo in this case
[21:26:17] <eadthem> for shocks yes thats correct
[21:26:17] <rue_shop4> that will be my new spindle motor
[21:26:21] <eadthem> Im talking about explosions
[21:26:26] <eadthem> thats wattage avalable
[21:26:31] <z64555> explosion?
[21:26:47] <eadthem> with a lipo at 36v thats what your talking about
[21:26:55] <z64555> like battery exploding, or something else?
[21:27:02] <codepython7772> I'm using li-ion
[21:27:06] <eadthem> similar
[21:27:09] <codepython7772> 18650 samsung
[21:27:18] <eadthem> its just a be careful thing
[21:28:09] <z64555> codepython7772: check hobby king's listings for car ESC's
[21:28:31] <codepython7772> nothing less than $90 so far
[21:28:38] <rue_shop4> broken dust buster: 6V 56000rpm, 1/8" shaft, FREE
[21:28:41] <z64555> helicopter and airplane ESC's are namely for continous output
[21:28:51] <codepython7772> z64555:
https://hobbyking.com/en_us/turnigy-sentilon-v4-100a-5-12s-hv-bulletproof-speed-controller-w-rpm-sensor.html - tempted to try this one?
[21:29:02] <eadthem> castles car ESC's are good for constant output
[21:29:04] <eadthem> same as air
[21:29:41] <rue_shop4> do you guys know why people get rid of dust busters?
[21:29:52] <eadthem> mm i do wish they had Amp rateings on them however
[21:29:57] <eadthem> http://www.castlecreations.com/en/sidewinder-1/sidewinder-3-esc-010-0115-00
[21:30:17] <Tom_L> rue_shop4, i don't know why people get them to begin with
[21:30:39] <rue_shop4> Tom_L, and tell them the flaw, tell them the flaw!!!!
[21:31:52] <codepython7772> z64555: most car escs are 2-3S!
[21:31:55] <eadthem> rue_shop4 i installed a central vac under my kitchen cabnet
[21:32:18] <rue_shop4> the FLAW is that the BATTERIES die
[21:32:20] <codepython7772> eadthem: that one is 3S? I need 10S, right?
[21:32:27] <rue_shop4> like short lifespan
[21:32:30] <eadthem> 1S = 4v
[21:32:34] <rue_shop4> the MOTORS are fine
[21:32:36] <eadthem> welcome to weard RC nameing shit
[21:32:59] <orlock> rue_shop4: Yup! After less than a year! fuckers!
[21:33:03] <rue_shop4> so free 56k engraver spindle motor to the guy who polls his neighbours for a dead dustbuster
[21:33:04] <orlock> Even a quality "name brand"
[21:33:22] <Tom_L> dyson ones shut down before the motor loses rpm
[21:33:52] <z64555> eadthem: not quite. 1S = 3.3V for lipo
[21:34:03] <eadthem> full lipo is 4V
[21:34:06] <eadthem> empty is 3v
[21:34:07] <eadthem> iirc
[21:34:21] <rue_shop4> need to work out a spindle for this...
[21:34:52] <eadthem> you want 10S your looking at a HV controller
[21:35:47] <z64555> well, true, but if you go with the 3.3V you'll know the minimum voltage it can provide
[21:36:09] <z64555> vs. going with the max voltage, which is only done when the battery is prestine and fully charged
[21:36:38] <codepython7772> z64555: is there a problem if the esc can provide large amount of continuous current? I guess a car does not need it?
[21:36:48] <z64555> codepython7772: no problem at all
[21:36:59] <eadthem> well if you want to make sure you dont fry things with overvoltage
[21:37:00] <z64555> the motor determines how much current is drawn
[21:37:32] <orlock> too much current is never a problem, unless you have bad regulation (as far as i know)
[21:37:32] <codepython7772> z64555:
https://hobbyking.com/en_us/turnigy-dlux-80a-hv-brushless-speed-controller-opto.html - so this will work for my application?
[21:37:46] <orlock> codepython7772: What's this for anyway?
[21:37:51] <orlock> Sumo bot?
[21:38:02] <z64555> codepython7772: what was the wattage on the motor again? 350W or 250W?
[21:38:18] <codepython7772> 250W for real - 350W on specification sheet
[21:38:41] <orlock> codepython7772: how are you measuring real vs spec?
[21:38:45] <codepython7772> orlock: trying to do run around a 50lb 4-wheel platform
[21:38:56] <orlock> Current draw at rated voltage?
[21:38:57] <codepython7772> orlock: two people - giving separate specs :)
[21:39:26] <orlock> Current draw at stall
[21:39:32] <orlock> any idea what that is?
[21:39:42] <codepython7772> oh! That controller wont do reverse it seems :( ?
[21:39:48] <orlock> i have not been able to stall mine, max current draw i measured was 13A
[21:39:58] <codepython7772> Programming Options. : Forward/Reverse - does that mean it will allow me to do reverse?
[21:40:08] <codepython7772> orlock: which motor?
[21:40:26] <orlock> XU1
[21:40:33] <orlock> (cordless drill, XU1 is also a racecar)
[21:40:44] <orlock> so its likely to be a 550 motor with integrated gearbox
[21:40:45] <codepython7772> voltage?
[21:40:53] <orlock> i was feeding it 14.8v
[21:41:16] <orlock> i cant remember factory spec - Migh have been 18v?
[21:41:46] <z64555> uh
[21:42:05] <z64555> this 80A is way over the spec of the motor
[21:42:32] <codepython7772> z64555: agreed ! But : From review, I quote: "Horrible. Lit on fire while on a SK3 6374. Burned my model down." :)
[21:42:59] <orlock> I use one of these, but it won't do the voltage you want:
https://www.pololu.com/product/777
[21:43:04] <z64555> codepython7772: what's your battery voltage/S rating again?
[21:43:17] <codepython7772> z64555: "Braking with this esc will block your wheel."
[21:43:24] <codepython7772> 28 to 42v
[21:43:30] <orlock> codepython7772: You could just go crude to start off with and set up a bang-bang H bridge with relays
[21:43:48] <orlock> clickclickclickclickclickclickclickclick
[21:43:59] <codepython7772> z64555: 4.4Ah Power: 158W . Max discharge 15A
[21:44:13] <z64555> >.>
[21:44:53] <codepython7772> orlock: i could. I would prefer not to, if possible
[21:44:58] <z64555> yeah I don't think you have to worry about anything burning down
[21:45:18] <codepython7772> What is this wheel lock - v brake problem?
[21:46:10] <z64555> I guess it means that particular ESC is too strong for regenerative braking
[21:46:24] <z64555> it'll lock up the wheel instead of smoothly slowing it down
[21:46:37] <codepython7772> z64555:
https://hobbyking.com/en_us/turnigy-sentilon-v4-100a-5-12s-hv-bulletproof-speed-controller-w-rpm-sensor.html - cheaper, looks nicer, and way more overkill
[21:46:44] <z64555> oh lmao.
[21:48:58] <z64555> just go with something like a 20A
[21:49:18] <codepython7772> z64555: there is none!
[21:49:22] <codepython7772> at least on hobbyking
[21:49:37] <z64555> ok, what's the least about 10A
[21:49:40] <z64555> *above
[21:49:55] <codepython7772> z64555: as soon as you go 10S - the one i showed was least :)
[21:50:18] <z64555> go with it then
[21:51:35] <codepython7772> z64555: any other shops i should be looking at?
[21:52:02] <rue_shop4> ok, shopvac motor
[21:52:41] <z64555> codepython7772: There's bp hobbies where I got my motors from, they're a bit generic though
[21:52:48] <z64555> but not as "evil" as hobbyking
[21:53:31] <codepython7772> z64555: do these esc's support reversing?
[21:53:48] <codepython7772> z64555: why is hobbyking evil?
[21:54:02] <z64555> they have some agressive marketing strategies, lol
[21:54:17] <rue_shop4> 10k at 12V
[21:54:41] <z64555> as far as bp hobbies go, the aerial ESC's ones don't reverse, but if they have some for RC cars, they should
[21:54:53] <z64555> rue_shop4: what are you doing?
[21:55:13] <rue_shop4> cnc motors
[21:56:03] <rue_shop4> noise 5k at 12V
[21:56:23] <rue_shop4> rated to 90V
[21:56:28] <rue_shop4> so 10k at 24V
[21:56:34] <rue_shop4> 20k at 48V
[21:57:08] <rue_shop4> so a 24V supply would do it
[21:57:14] <codepython7772> z64555:
https://www.bphobbies.com/view.asp?id=I0800257&pid=D0746135 - but closeout
[21:58:41] <rue_shop4> Tom_L, whats the shaft size on your sherline motor?
[21:59:11] <rue_shop4> @12V, the shop vac motor stall is 1.97kg-cm
[21:59:17] <z64555> oh, it looks like BP hobbies is going/ has gone out of business...
[21:59:30] <z64555> their copywrite info wasn't updated since 2014
[22:03:05] <codepython7772> has anyone here used turnigy ESCs?
[22:03:45] <codepython7772> z64555: i still think this ESC is a big overkill for that motor :)
[22:07:55] <rue_shop4> I got free brushed motors
[22:20:56] <ace4016> if you don't need rotation, this is a neat design
https://www.youtube.com/watch?v=beuY401hfh8
[22:29:25] <rue_shop4> I wonder if 608 bearings are ok with 20k rpm
[23:06:17] <rue_shop4> I might put a vac. motor on the sherline
[23:06:28] <rue_shop4> it looks like I can do a new bracket and all
[23:06:36] <rue_shop4> make the new motor a module
[23:21:35] <rue_shop4> the old cnc motor sounds good at 7.5k
[23:21:59] <rue_shop4> its a weed-eater motor :)